CN110541329A - construction method of ballastless track of heavy haul railway tunnel group - Google Patents

Abstract

The invention relates to a construction technology of a heavy haul railway, in particular to a construction method of ballastless tracks of a tunnel group of a heavy haul railway. According to the characteristics of high requirement on the construction precision of a ballastless track bed and difficulty in control in the construction of the ballastless track, the principle of near laying and convenience in precision control is adopted, the double-block sleeper is hung and placed to a position to be laid near the construction track bed plate, after key processes of steel bar binding, track panel assembly, comprehensive grounding, track coarse adjustment and the like are carried out, the geometric dimension of the track is finely adjusted by using a track inspection trolley measuring system, so that the design precision requirement is met, and finally, the track bed concrete is poured for one-step forming. The process has the characteristics of simple and convenient operation, safety, practicability, accurate track geometric dimension, quick positioning and the like.

Description

Construction method of ballastless track of heavy haul railway tunnel group

Technical Field

The invention relates to a construction technology of a heavy haul railway, in particular to a construction method of ballastless tracks of a tunnel group of a heavy haul railway.

Background

The design driving speed of a railway coal transportation channel in Mengxi to Huazhong areas is as follows: 120km/h, the main line is designed according to a heavy rail, and the structural conditions of the extra-heavy rail are reserved in the heavy-duty direction (namely, a descending left line) of the double-line section. The main track structure mainly adopts a ballast track, a tunnel with the length of 1km or more is paved with a ballastless track in principle, and the ballastless track is considered to be paved in sections. An elastic supporting block type ballastless track is generally paved in the tunnel, and when the ballastless track of the tunnel group section is considered to be paved in sections, a heavy-load long-sleeper embedded ballastless track is paved on a tunnel portal, an out-of-tunnel bridge and a short-circuit foundation. The existing ballastless track construction method is not easy to control in precision and slow in construction progress; particularly, the conventional measurement technology cannot meet the construction requirement of the ballastless track of the high-speed railway, and a high-precision instrument and a modern engineering measurement method are required to ensure the smoothness of the ballastless track line. The high smoothness of the track is the most basic condition for realizing the high-speed running of the train, and the biggest difference between the high-speed railway and the ordinary railway is that a complete, reliable and stable track foundation engineering and a high-smoothness track structure are needed. Therefore, in order to meet the above conditions, a ballastless track construction method for a heavy haul railway tunnel group, which has high construction precision, fast construction progress and reliable construction quality, needs to be provided.

disclosure of Invention

the invention provides a construction method of ballastless tracks of a tunnel group of a heavy haul railway, aiming at solving the technical problem that the conventional ballastless track construction cannot meet the requirements of high precision and high efficiency of heavy haul railway construction.

The invention is realized by adopting the following technical scheme: a construction method of ballastless tracks of a heavy haul railway tunnel group comprises the following steps of constructing ballastless track bed boards in tunnels and constructing ballastless tracks in bridge sections;

Construction of ballastless track bed board in tunnel

(1) Construction method

the track bed slab is constructed by adopting a track panel frame method; the track panel comprises a frame combination device, a tool track, a track gauge adjusting fishplate, an angle adjusting device, a vertical stud and a connecting bolt;

(2) CP III layout

1. The CP III control point is arranged at a position 30-50 cm above the side wall cable trough;

2. After a mounting hole is drilled on the side wall of the CP III embedded part, the CP III embedded part is transversely inserted and embedded by using bar planting glue, and the exposed end of the CP III embedded part is not lower than the embedded end;

(3) Tunnel invert backfill layer treatment

1. Performing chiseling treatment on the tunnel inverted arch backfill layer;

2. Measuring and releasing control points of a track central line on the backfill layer every 10m through CP III control points, applying an obvious color mark to the central line, and recording the accurate mileage and coordinate values of the control points; paying out the side lines of the longitudinal and transverse templates by taking the track central line control point as a reference;

3. The track bed plate is reliably connected with the lower foundation through embedded steel bars, so that limit is provided for the track structure; 5 reinforcing steel bars are planted between every two adjacent pillows or supporting blocks within 50m of the opening; planting a row of 5 steel bars every other sleeper or supporting block within the range of 50-200 m away from the opening of the hole; 5 rows of steel bars are planted below each plate within the range of being more than 200m away from the hole; within the range of 200m from the opening, the diameter of the steel bar is 20mm, within the range of more than 200m from the opening, the diameter of the steel bar is 16 mm. The length of the steel bar is 480mm, wherein the length of the steel bar implanted into the tunnel inverted arch backfill layer or the bottom plate by adopting the bar planting glue is 200 mm;

(4) Road bed board bottom layer steel bar laying

1. The longitudinal structural unit steel bars of the track bed slab are disconnected every 60m units, and the comprehensive grounding is carried out every 100m units by adopting insulation lap joint; during binding, the lap joints of the longitudinal and transverse steel bars are isolated by adopting an insulating clamp, so that the node insulation of the longitudinal and transverse steel bars is ensured; longitudinal steel bars are lapped, lap joints of adjacent steel bars are staggered, the lapping length is not less than 700mm, and the center staggered distance of the adjacent lap joints is not less than 1000 mm; the lapping rate of the steel bars on the same section is not more than 50 percent;

2. According to the measured lofting position and the designed number of the longitudinal steel bars under the sleeper, the longitudinal steel bars are scattered and paved on a tunnel bottom plate in sequence; measuring the interval of bottom layer steel bars on the top surface of the bottom plate by using a steel tape according to a total station lofting point, and marking; arranging prefabricated concrete cushion blocks according to a quincunx shape, wherein each square meter is not less than 4; arranging longitudinal and transverse steel bars, and installing an insulating clamp;

3. arranging insulation clamps at the crossing positions of the longitudinal and transverse reinforcing steel bars and the lap joints of the longitudinal reinforcing steel bars and firmly binding the insulation clamps by using plastic tapes;

4. Longitudinal and transverse steel bars are uniformly distributed, the allowable deviation of the spacing is +/-20 mm, and the allowable deviation of the thickness of the protective layer is +10mm-5 mm;

5. after the steel bars are bound, placing the expansion joint cross template in place;

(5) Track panel assembly

1. The sleeper is hoisted to the assembling platform by adopting a gantry crane, the double-block type sleeper is paved by manual cooperation, the sleeper is stacked neatly and stably according to the marked designated position, and the allowable deviation of the distance between the sleepers is +/-5 mm.

2. picking a plastic cover on an embedded sleeve of a sleeper, putting down an elastic base plate at the center of a rail bearing platform to align a base plate hole with an embedded pipe hole, putting an iron base plate, wherein the iron base plate hole is aligned with the center of the embedded sleeve, and putting a lower rail base plate at the center of the iron base plate;

(6) track panel in position and coarse adjustment

hoisting the assembled track bent frame in place by using a gantry crane, finishing coarse adjustment work of the track bent frame by using a transverse stud (namely an angle adjusting device) and a vertical stud, adjusting the elevation and the level by using stud support legs, and adjusting the center of a track by using a transverse inclined strut; after the rough adjustment is finished, the rail panel frames are connected by using a steel rail clamping plate; the position error of the track after coarse adjustment is controlled to be within-5 to-2 mm of elevation and +/-5 mm of a central line; repeating the measurement and confirming the track panel positioning;

(7) Binding of upper layer steel bars and installation of grounding steel bars

After the track coarse adjustment is finished, the upper layer of the track bed plate is longitudinally and transversely installed with erecting steel bars, grounding steel bars and embedded parts, and grounding terminals are fixed on the grounding steel bars on the two sides of the track bed in a welding mode;

And (3) testing the insulation resistance: after the road bed slab steel bars are erected and before concrete is poured, measuring the insulation performance of each structural steel bar node;

(8) Formwork installation

The track panel frame longitudinal template is designed to be a floating structure, the whole set of template is combined with the track panel into a whole according to the width of the track bed, and when the track panel is adjusted up, down, left and right, the template follows up, so that the straightness and the width of the track bed can be accurately ensured;

(9) track panel fine adjustment

1. A rail inspection trolley is adopted for fine adjustment of the ballastless track;

2. Adjusting a center line: adjusting the left and right rail direction locking devices, and adjusting the center line of the rail;

3. Adjusting elevation: rotating the vertical stud by using a socket wrench to adjust the level and the superelevation of the track; after coarse adjustment, the top surface elevation is slightly lower than the designed top surface elevation;

4. After the track panel is finely adjusted, fixing the track panel frame through a track-oriented locker;

5. The time between the fine adjustment of the track and the pouring of the concrete is controlled within 6h, and the track panel measuring points are arranged at the positions of the track panel supporting frames to ensure the smoothness of the steel rails and the joints thereof;

(10) Pouring of concrete for road bed slab

(11) Vibrating, plastering and forming

1. carrying out vibration operation while pouring concrete;

2. after the surface concrete is vibrated, finishing and leveling the exposed surface of the concrete in time, after the concrete is placed into a mold, finishing rough leveling by using wood, and after 1 hour, leveling by using steel;

3. After finishing plastering, cleaning the track panel, the sleeper and the fastener in time to prevent pollution;

4. after the concrete is initially set, 1/4-1/2 circles of vertical bolts (bolts on the vertical studs) are loosened, and meanwhile, fasteners and the fishplate bolts are loosened, so that damage to the concrete caused by stretching of the steel rail during temperature change is avoided.

(12) Dismantling of track panel and template

When the concrete of the ballast bed plate reaches a certain strength, firstly, sequentially lifting the vertical stud support legs by 1-2 mm; then loosening the rail fasteners, sequentially dismantling the bent frames, disassembling the templates, finally after confirming that the fasteners are completely loosened, hoisting the bent frames by the gantry crane to a rail panel assembly area for cleaning for standby use, and entering the next cycle construction;

second, construction of ballastless track of bridge section

(1) CP III layout

1. CP III control points are embedded in pairs along the line, and the distance between adjacent point pairs is required to be 40-80 m;

2. The CP III control point is arranged on the top surface of the ballast retaining wall above the end of the bridge fixed support;

3. CP III control points are not embedded in the span of the continuous beam with the length within 80 m; a pair of CP III control points are buried in a continuous beam span with the length of 80-120 m; two pairs of CP III control points are embedded in a continuous beam span with the length of 120-180 m;

4. After mounting holes in the vertical direction are dug in pairs along two sides of a line on the top surface of the ballast retaining wall by CP III embedded parts, embedding the embedded parts by using bar-planting glue, wherein the exposed height of the embedded parts is not more than 3 mm;

(2) Base plate construction

1. Preparation for construction

2. structural dimension line of setting-out base plate

after the bridge deck is cleaned, measuring and releasing the center line and two side lines of the base plate by using a CP III control net; e value of line traverse in curve segment; marking the bridge deck with ink lines as a steel bar binding control limit;

3. Bridge floor connecting steel bar construction

Before the base construction, the pre-embedded sleeve protective cover in the beam body is removed, and the base plate is connected with the bridge floor by a straight thread steel bar sleeve;

4. Processing and binding base plate steel bars

After the bed plate steel bars are processed, the bed plate steel bars are conveyed to the position below a bridge by using a flat car, the truck crane is hoisted to the bridge and then is installed and bound, and for a high pier beam, the flat car is directly conveyed to the binding position of the bed plate steel bars of the bridge deck;

the lapping length of longitudinal steel bars in the base is not less than 500mm, the lapping rate in the same section is not more than 50%, and the net protective layer thickness of the base plate is 35 mm;

5. construction of bed plate formwork

firstly, a base plate and a groove template are combined and formed by adopting a shaping steel template and are connected by bolts, and the template installation is ensured to meet the design size requirement of the base plate;

secondly, double faced adhesive tape is clamped between the base plate template plate seams for processing, and slurry leakage in the concrete pouring process is strictly forbidden;

Thirdly, after the base plate template is installed and reinforced, the groove template is installed according to the lofting plane position points, and the periphery of the groove template is additionally provided with embedded ribs for fixing the groove template; after the installation is finished, the total station remeasures the positions of the groove template and the base template;

Fourthly, the template is comprehensively checked before the concrete is poured;

Installing the lateral template according to the mark obtained by measurement lofting, wherein the plane position and elevation of the lateral template must be accurately in place, and ensuring that the template is tightly attached to the bridge floor;

6. Base plate concrete construction

Checking the thickness of the steel bar protective layer again before pouring concrete; the stability of the template installation at least meets the operation requirement of the paving, leveling and vibrating machine;

before concrete pouring, sprinkling water for 2 hours in advance to wet the bridge deck, but no open water is obtained; the slump of the concrete is controlled within 160 mm-200 mm; the concrete is vibrated by a vibrating rod, and the concrete is forbidden to impact the reinforcing steel bars when vibrated; after the concrete is compacted by vibration, leveling the top surface, wherein the flatness needs to reach the requirement of 10mm/3m, the base plate cross slope of the curve section is larger, the concrete slump is controlled to be 180mm +/-5, the concrete in the ultrahigh range needs to be continuously supplemented by manpower in the concrete paving and leveling process, and finally, the concrete is leveled and compacted for two times;

The mold-entering temperature is not lower than 5 ℃ when the concrete is poured; it is also not preferable to exceed 30 ℃;

after the base plate is poured, sundry accumulated water in the limiting groove is cleaned in time;

7. Construction of isolation layer and elastic cushion layer

An intermediate isolation layer is arranged between the base plate and the track bed plate, and the isolation layer is 4mm of polypropylene geotextile with the design width of 2800 mm;

After the base concrete reaches over 75% of the design strength, the installation operation of laying an isolation middle layer and an elastic cushion layer is carried out; the polypropylene geotextile is laid to be smooth, wrinkle-free and damage-free, and the seams are butted and can not be overlapped;

after the geotextile on the top surface of the bed plate is laid, the geotextile on the inner bottom surface of the limiting groove and the elastic backing plates on the periphery are laid;

(3) Construction of road bed slab

1. Clearing and construction lofting of ballast bed working face

Releasing track central line control points at intervals of 10m on the bridge isolation layer through the CP III control points according to the designed ballast bed plate position, accurately positioning by using steel nails, marking marks, and popping out the track central line by using ink lines;

Releasing the sleeper control sideline and the positions of the longitudinal and transverse template sidelines of the track bed plate by taking the track center control point as a reference;

Adopting ink lines to position the position of each longitudinal and transverse steel bar at the bottom layer of the bed plate according to the position of the center line of the popped track;

2. Arrangement of reinforcing steel bars at bottom layer of ballast bed plate

Processing the roadbed slab steel bars in a steel bar processing shed, and binding and assembling on lines;

3、

firstly, hoisting sleepers to be used on a sleeper groove on a track panel assembling platform by using a gantry crane, hoisting 5 sleepers each time, uniformly sleeper-arranging according to a positioning line of sleeper blocks on the assembling platform, and controlling the distance deviation of the sleepers within 5 mm; checking and adjusting the position of a sleeper block, arranging bolt holes on one side into a line by using elastic lines, wherein the deviation is less than 1mm, manually matching a gantry crane, aligning the bolt hole position of a fastener of the track panel frame with the bolt hole position of the sleeper, placing the panel frame on the sleeper, installing the fastener after no error exists, and fastening;

secondly, cleaning a rail bearing table board before assembling the rail panel, and tightening a fastener bolt after the rail panel is qualified;

Checking the distance between sleepers to be controlled within 5mm after the track panel is assembled;

4. track panel frame in place

The installed track panel is transported to the site by using a flat car, the track panel is hoisted to be in place by using a gantry crane, the track panel is sequentially and accurately in place according to the length of a slab section and the central line of the track, and the central line of a track panel frame is aligned to the central line of the track and is slowly positioned below the track; before the track panel falls to a track bed board, a plastic sleeve is sleeved on the vertical bolt supporting leg, and a track gap is adjusted by utilizing the allowable range error of the distance between two adjacent track panel sleepers;

5. Coarse adjustment of track panel

the track panel coarse adjustment adopts a total station, and the track ruler completes the initial adjustment of the track panel; the adjustment principle is that the center line is firstly adjusted to the height;

6. Binding of upper layer steel bars of ballast bed plate

marking the position of longitudinal steel bars on a sleeper steel bar truss according to the designed longitudinal steel bar interval, placing the longitudinal steel bars, installing an insulation clamp at the crossed part of the longitudinal steel bars and the sleeper truss steel bars, and binding the longitudinal steel bars and the sleeper truss steel bars in an inclined manner by adopting a plastic insulation buckle;

Marking the positions of transverse reinforcing steel bars on two reinforcing steel bars on the outermost side of the track bed plate according to the designed transverse reinforcing steel bar interval after the longitudinal reinforcing steel bars are placed, installing the transverse reinforcing steel bars from one end of the track bed plate to the other end one by one, and installing insulating clamps at the intersections of the longitudinal reinforcing steel bars and the transverse reinforcing steel bars; after the transverse reinforcing steel bars are installed, diagonally binding the intersections of the longitudinal and transverse reinforcing steel bars by plastic insulating buckles according to the installation sequence and mode;

7. installation of road bed plate formwork

The main operation content of the process comprises: inspecting and cleaning the template; installing a transverse template; installing a longitudinal template, and connecting a transverse template with the longitudinal template; the concrete construction sequence is as follows:

firstly, checking and cleaning a template;

installing a transverse template: the transverse template is used at a broken joint, the position of the transverse template is overlapped with the transverse position of the base plate, after the rough adjustment of the track panel is finished, the transverse template is installed, the transverse template is hoisted to the middle position of a line at a required position by using a gantry in advance, the positions of two ends of the transverse template refer to the side line of the longitudinal template, and the installation error is 2 mm;

Installing a longitudinal template: the longitudinal template and the track panel frame are installed in a matched mode, the portal crane lifts the template, the bottom surface of the template is positioned on a plane after the template is manually matched in place, the edge of the template is guaranteed to be closely attached to the side surface of the concrete of the base plate, and slurry leakage during concrete pouring is avoided; two adjacent templates are connected by bolts, and the dislocation between the two adjacent templates is ensured when the two adjacent templates are connected by the bolts; after the longitudinal template is installed in place, the longitudinal template is connected with the vertical stud in a reinforcing way, and the top surface line of the road bed plate is marked on the inner side of the template by ink lines; the installation precision width of the longitudinal template is +/-5 mm, the center line position is 2mm, and the top surface elevation is not lower than that of the concrete top surface;

Fourthly, after the longitudinal template is installed, connecting the transverse template with the longitudinal template to ensure that the longitudinal template is closely attached to the transverse template;

8. Comprehensive earth welding

taking 3 longitudinal structural steel bars at the upper layer of each track bed board as longitudinal grounding steel bars, and taking 1 transverse structural steel bar at the middle part of the upper layer of each track bed board as transverse grounding steel bars.

welding the longitudinal and transverse grounding steel bars, and welding the plate end grounding terminal and the longitudinal grounding steel bar; the welding should be: the length of the single-sided welding is not less than 100mm, the length of the double-sided welding is not less than 55mm, and the thickness of the welding seam is not less than 4 mm;

arranging an earthing terminal at each end of each track bed board, wherein the distance between the terminal and the board end is preferably between 100 and 150mm, connecting the track bed board longitudinally by using a stainless steel cable with the length of 0.4m to form an earthing unit with the length not more than 100m, and then carrying out single-point T-shaped connection earthing on the earthing unit and the embedded earthing terminal on the protective wall by using the stainless steel cable with the length of about 3.5 m;

fourthly, the grounding steel cable is made of stainless steel, and the section of the grounding steel cable is not less than 200mm 2;

Insulation detection of steel bar

After the binding of the bed plate steel bars and the welding of the grounding steel bars are finished, an insulation resistance test is carried out, and a high resistance tester is adopted for testing;

9. track panel fine adjustment

the main contents of the process are as follows: setting a total station; measuring orbit data; adjusting the center line of the track; adjusting elevation and locking the track panel.

setting up station for total station

The total station observes 4 continuous CP III points, automatically adjusts and calculates to determine the station setting position; if the deviation is larger than 2mm, resetting the station; after the position of the measuring station is changed, at least 4 CP III points utilized behind must be observed in a cross mode, and at least one group of track panels which are subjected to fine adjustment are retested;

Measuring orbit data

The rail inspection trolley is placed on the rail and is provided with a prism; the total station measures the prism at the top end of the track state measuring instrument, the trolley automatically measures track gauge, superelevation, horizontal position and the like, observation data is received, the data of the plane position, the level, the superelevation and the track gauge of the track are calculated through matched software, and error values are quickly fed back to a computer display screen of the track state measuring instrument to guide track adjustment;

Regulating track central line

adjusting the left and right rail direction locking devices by using an open spanner, adjusting the center line of the rail, and adjusting 2 groups at a time; in the adjusting process, the total station always measures the prism of the track state measuring instrument, receives observation data, and quickly feeds an error value back to a computer display screen of the track state measuring instrument through matched software until the error value meets the requirement and then the adjustment is finished; after the central line is adjusted in place, one side of the elastic buckle is screwed under the monitoring of an instrument, and the adjusted central line cannot be disturbed in the process;

adjusting the height of the track

after coarse adjustment, the elevation of the top surface is slightly lower than the elevation of the designed top surface by 0-minus 2 mm; rotating the vertical stud to adjust the level and the superelevation of the track; after adjustment, whether the screw is closely attached to the concrete or not is manually checked, and the bottom of the screw is guaranteed not to be suspended. Adjusting the stud slowly, rotating 120 degrees to change elevation by 1mm, checking whether the screw is stressed by hands after adjustment, and adjusting the screw nearby if the screw is not stressed;

Fifth, direct connection transition

after the adjustment of the previous station is finished, 8 to 10 sleepers adjusted by the previous station need to be overlapped when the adjustment of the next station is finished; the transition section starts from the first rail bent after the forward connection, and the data decrement value of each sleeper is preferably smaller than 0.2mm until the absolute deviation is close to zero;

after the track adjustment is finished, fixing the track bent through a track locking device; if the track panel is disturbed externally, or the placement time is too long, namely more than 10 hours, or the environmental temperature change exceeds 15 ℃, the track panel must be checked or adjusted again; the qualified report is checked by the supervision engineering report after the retest;

10. Concrete construction of ballast bed plate

preparation work

cleaning sundries on a pouring surface, pouring a required power line, and comprehensively checking various construction equipment pump trucks, transport tank trucks and vibrating rods to ensure that the normal operation can be realized in the pouring process;

checking and confirming the retest result of the track panel

Before concrete is poured, if the track is placed for more than 12 hours or the environmental temperature change exceeds 15 ℃, or the track is influenced by external conditions, the track needs to be checked or adjusted again;

Mixing and conveying concrete

The concrete of the ballast bed plate is intensively mixed by a mixing station, and is poured in a direct unloading or pumping way by a concrete transport vehicle during construction;

fourthly, pouring concrete

in order to ensure that the concrete road bed board is not subjected to over-limit temperature crack pouring, the environmental temperature and the track temperature are monitored all day long during the concrete pouring process, a temperature curve is drawn, the concrete pouring can be carried out in a time period with a small temperature change range, and the concrete mold-entering temperature is controlled to be between 5 and 30 ℃;

One end of the concrete is continuously carried out towards the other end, and when the concrete automatically flows to the next sleeper from the lower part of the sleeper, the concrete can move forwards to the next sleeper to be continuously poured forwards;

When the concrete is directly unloaded and poured, the chute of the concrete transport vehicle is turned to the position above the track panel to be poured, and the valve is opened for discharging;

When concrete is pumped, the pipe orifice of the rubber pump is above the track panel, the blanking direction is basically vertical to the track panel, and the blanking height of the concrete is controlled by moving the blanking pipe;

Fifthly, plastering and cleaning

Maintaining concrete

maintaining the concrete of the ballast bed plate for at least 7 days by adopting moisture preservation and heat preservation;

protection of the final product

11. formwork and track panel frame dismantling and cement mortar filling screw hole

Firstly, the transverse formwork is dismantled

after the concrete compressive strength of the ballast bed plate reaches 5MPa, firstly connecting the longitudinal and transverse formworks and connecting the transverse formworks and loosening the transverse formworks and other connecting pieces, then tapping the formworks, after the formworks are loosened, hoisting the gantry crane out to the space between the formworks, and conveying the formworks to the next cycle by using a special formwork transport vehicle for cleaning;

The transverse formwork can be dismantled in the section where the longitudinal formwork is dismantled, and the transverse formwork is dismantled through the gantry crane and manual cooperation, and then the transverse fixing steel bars of the formwork are dismantled;

② dismantling the track panel frame

And (4) sequentially lifting the vertical stud support legs by 1-2 mm, loosening all fasteners of the unit rails, and taking down the unit rails for cleaning. After the fastener is taken down, the bent is hoisted by a gantry crane to a next operation area for cleaning and standby, and then the next cycle construction is carried out.

Thirdly, the cement mortar fills the screw hole

and (3) cleaning the plastic sleeve in the vertical stud hole, manually plugging the screw hole by using M40 high-strength non-shrinkage cement mortar, and leveling the surface.

The invention has the technical characteristics that:

1, advanced technology and high precision. The ballastless track is of a continuous structure, each plate is provided with an independent data file, the position of the ballastless track is fixed on the track, the track plate is fixed by adopting computer software control, positioning, a mechanical special jack and a track plate pressing device, the laying position is accurate, and the laying precision is high.

2 the bed plate and the roadbed slab reinforcing steel bars are processed by self-made moulds in a unified way, so that the on-site streamlined operation is realized, the process is novel, the efficiency is improved, and the construction cost is reduced.

3, a method of combining line production and parallel operation is adopted, a plurality of working faces are arranged, the construction is performed in a segmented mode, the construction progress is accelerated, and the problem that the construction progress of the ballastless track is slow under the existing conditions is solved.

compared with a ballast track, the ballastless track has better integrity, stability and durability. Although the construction technology is complex, the one-time investment is larger than that of a ballast track, the service life of the ballast track is long, the ballast track is basically free of maintenance in the service life, the maintenance workload in the operation process can be reduced by more than 70%, the contradiction between the railway operation and the maintenance can be effectively relieved, and the total cost is not higher than that of the ballast track.

Application scope of the invention

The method is suitable for construction of heavy-load elastic support block type ballastless tracks and long-sleeper buried ballastless tracks, and comprises tunnels, bridges and roadbed sections.

The process principle of the invention

According to the characteristics of high requirement on the construction precision of a ballastless track bed and difficulty in control in ballastless track construction, the principle of nearby laying and convenience in precision control is adopted, a double-block sleeper is hung and placed to a position to be laid near a construction track bed plate, after key processes such as steel bar binding, track panel assembly, comprehensive grounding, track rough adjustment and the like are carried out, the geometric dimension of a track is finely adjusted by a track inspection trolley measuring system, the track meets the requirement on design precision, and finally, track bed concrete is poured for one-step forming. The process has the characteristics of simple and convenient operation, safety, practicability, accurate track geometric dimension, quick positioning and the like.

Drawings

fig. 1 is a schematic view of the track panel bent structure according to the present invention.

FIG. 2 is a flow chart of a ballastless track bed slab construction process in a tunnel.

FIG. 3 is a flow chart of a ballastless track construction process of a bridge section.

1-frame assembly device, 2-fishplate, 3-tool rail, 4-vertical lifting screw rod and 5-angle adjusting device.

Detailed Description

A construction method of ballastless tracks of tunnel groups of heavy haul railways (construction method of CRTS III type ballastless tracks of high speed railways) comprises the following steps:

Construction of ballastless track bed board in tunnel

1.1 construction method

the track bed slab is constructed by adopting a track panel frame method. The track panel consists of a frame combination device, a tool track, a track gauge adjusting fishplate, an angle adjusting device, a vertical lifting bolt, a connecting bolt and a flat spring pad. The frame assembly device comprises a welding rectangular tube, a trapezoidal plate, an ear plate, a lifting nut and other parts.

1.2 construction process flow chart (see FIG. 2)

1.3CP III layout

1. The CP III control point is arranged at a position 30-50 cm above the side wall cable trough.

2. and (3) cutting mounting holes on the side wall of the CP III embedded part, and then transversely inserting and embedding the CP III embedded part by using bar-planting glue, wherein the exposed end is not lower than the embedded end.

3. When the CP III is arranged, the influence of other facilities in the hole on the CP III control point is fully considered, and shielding and damage are avoided.

1.4 treatment of inverted arch backfill layer of tunnel

1. chiseling the tunnel inverted arch backfill layer, washing concrete fragments, floating ballasts, dust and the like by using a high-pressure water gun and a steel wire brush, and preserving moisture for more than 2 hours without redundant accumulated water.

2. And measuring and releasing a control point of a central line of the track on the backfill layer every 10m by using the CP III control point, applying an obvious color mark to the central line, and recording the accurate mileage and coordinate values of the control point. And (4) taking the track center line control point as a reference to discharge the vertical and horizontal template sidelines (ink line marks).

3. The track bed board is reliably connected with the lower foundation through the embedded steel bars, and limit is provided for the track structure. 5 reinforcing steel bars are planted between every two adjacent pillows or supporting blocks within 50m of the opening; planting a row of 5 steel bars every other sleeper or supporting block within the range of 50-200 m away from the opening of the hole; and 5 rows (3 in each row) of steel bars are planted below each plate within the range of being more than 200m away from the hole. HRB400 twisted steel is adopted for bar planting, the diameter of the steel bar is 20mm within a range of being 200m away from the opening, the diameter of the steel bar is 16mm within a range of being more than 200m away from the opening. The length of the steel bar is 480mm, wherein the length of the steel bar implanted into the tunnel inverted arch backfill layer or the bottom plate by adopting the bar planting glue is 200 mm. No steel bar is planted between the sleepers with the expansion joints. During construction, the embedded steel bars are reasonably arranged according to the actual sleeper interval, are positioned between two adjacent sleepers and are prevented from colliding with the structural bars of the track bed board.

1.5 pavement of bottom layer steel bar of bed slab

1. And (4) processing the roadbed slab steel bars in the steel bar processing shed outside the tunnel, and binding and assembling the roadbed slab steel bars in the tunnel. The longitudinal structural unit steel bars are disconnected every 60m units, and the comprehensive grounding adopts insulation lap joints every 100m units. And during binding, the lap joints of the longitudinal and transverse steel bars are isolated by adopting an insulating clamp, so that the joint insulation of the longitudinal and transverse steel bars is ensured. The longitudinal steel bars are overlapped, the lap joints of the adjacent steel bars are staggered with the overlapping length not less than 700mm, and the staggered distance of the centers of the adjacent lap joints is not less than 1000 mm. The overlapping rate of the steel bars on the same section is not more than 50%.

2. And according to the measured lofting position and the designed number of the longitudinal steel bars below the sleeper, the longitudinal steel bars are scattered and paved on the tunnel bottom plate in sequence. Measuring the interval of bottom layer steel bars on the top surface of the bottom plate by using a steel tape according to a total station lofting point, and marking by using a porcelain pen; arranging prefabricated concrete cushion blocks according to a quincunx shape, wherein each square meter is not less than 4; longitudinal and transverse steel bars are arranged, and an insulating clamp is installed.

3. And arranging insulating clamps at the crossing positions of the longitudinal and transverse reinforcing steel bars and the lap joints of the longitudinal reinforcing steel bars, firmly binding by using plastic tapes, wherein the clamping force of the insulating clamps is not less than 2.5kg, and cutting off redundant plastic tapes after binding. Binding bottom layer steel bars and performing insulation treatment.

4. the longitudinal and transverse reinforcing steel bars are uniformly distributed, the allowable deviation of the spacing is +/-20 mm, and the allowable deviation of the thickness of the protective layer is +10mm-5 mm.

5. and after the steel bars are bound, placing the expansion joint cross template in place.

1.6 track Panel Assembly

1. Before the equipment of double-block sleeper, to its rail supporting groove, bolt hole clean up, whether main inspection truss reinforcing bar is crooked, distortion, adopt portal crane to hang the sleeper to the equipment platform, the double-block sleeper is laid in manual cooperation, and the sleeper stacks neatly, steadily according to the assigned position that the sign is good, and the manual work distributes the sleeper in the design position according to the location line of the sleeper piece on the equipment platform, and sleeper interval tolerance deviation 5 mm.

2. Picking the plastic cover on the embedded sleeve, putting down an elastic base plate at the center of the rail bearing platform to align the base plate hole with the embedded pipe hole, placing an iron base plate, aligning the iron base plate hole with the center of the embedded sleeve, placing a lower rail base plate at the center of the iron base plate, buckling the iron base plate by the flange of the lower rail base plate, installing a gauge baffle, and placing the arc boss of the gauge baffle in the groove of the sleeper or the bottom foot of the rail bearing groove of the rail plate.

1.7 track Panel seating and Rough Conditioning

Hoisting the assembled track bent frame in place by using a gantry crane, finishing coarse adjustment work of the track bent frame by using a transverse and vertical adjusting mechanism of the track bent frame, adjusting the elevation and the level by using stud support legs, and adjusting the center of a track by using a transverse inclined strut; after coarse adjustment is finished, the track panel frames are connected by using steel rail clamping plates, and bolts are screwed down on each joint according to the sequence of 1-3-4-2. The position error of the track after coarse adjustment is controlled to be minus 5 to minus 2mm in elevation and plus or minus 5mm in a central line. And repeating the measurement to confirm the track panel positioning. If necessary, the adjustment is performed again, and the adjustment is generally repeated for 2 to 3 times.

1.8 binding upper layer steel bars and installing grounding steel bars

after the track rough adjustment is completed, the upper layer of the track bed board is longitudinally and transversely installed with erecting reinforcing steel bars, grounding reinforcing steel bars and embedded parts, and the grounding terminals are fixed on the grounding reinforcing steel bars on the two sides of the track bed in a welding mode.

and (5) testing the insulation resistance. After the reinforcing steel bars of the track bed plate are erected and before concrete pouring, whether the insulation cards are installed well or not is checked visually, whether the insulation cards fall off or not is judged, then the insulation performance of each structural reinforcing steel bar node is measured, a megameter not lower than 500V is adopted for measurement, and the measurement result is larger than 2M omega.

1.9 form mounting

The track panel frame longitudinal formwork is designed to be of a floating structure, the whole set of formwork is combined with the track panel into a whole according to the width of the track bed, and when the track panel is adjusted up and down, left and right, the formwork follows up, so that the straightness and the width of the track bed can be accurately guaranteed.

Checking the flatness and cleaning condition of the template, painting release agent, laying longitudinal templates in sequence, connecting with transverse templates, erecting template support rods, adjusting linear shapes and locking.

1.10 track panel Fine tuning

1. the ballastless track fine adjustment adopts a track inspection trolley, the trolley is statically arranged on the adjusted track during fine adjustment, the track position, the design position, the position deviation and the track adjustment direction of the track position and the design position at the corresponding point are displayed in real time through the tracking measurement of a total station on the prism point of the trolley, and the on-site track adjustment operation is directly guided.

2. The midline is adjusted. The special open spanner is adopted to adjust the left and right rail direction locking devices, the center line of the rail is adjusted, 2 groups are adjusted at a time, and the left and the right are respectively matched with 2 persons to operate simultaneously.

3. and adjusting the elevation. And rotating the vertical stud by using a socket wrench to adjust the level and the superelevation of the track. The top surface elevation after coarse adjustment should be slightly lower than the designed top surface elevation. And (3) slowly adjusting the stud, rotating by 120 degrees to change the elevation by 1mm, checking whether the stud is stressed or not by hands after adjustment, and screwing the stud nearby for adjustment if the stud is not stressed.

4. and after the track panel is finely adjusted, fixing the track panel frame through the track-oriented locking device.

5. The time between the track fine adjustment and the concrete pouring is controlled within 6h, and the track panel measuring points are arranged at the positions of the track panel supporting frames, so that the smoothness of the steel rails and joints thereof is ensured.

6. after all fine adjustment operations are completed, any personnel and equipment on the spot cannot collide with the track. The adjustment result is confirmed by related quality control and supervision personnel together, and the detailed record is made.

1.11 pouring of ballast bed plate concrete

1. Preparation for construction

And (4) cleaning sundries on the pouring surface before pouring, and preventing water from being accumulated on the base after the base is sprayed with water and wetted before pouring. In order to ensure good combination of the sleeper and the newly cast concrete, water needs to be sprayed on the surface of the sleeper for 3-4 times within 6 hours before casting. And covering the sleeper, the fastener and the steel rail with a protective cover. And checking whether each adjusting screw on the track panel is suspended. Checking whether the grounding terminal is closely attached to the template.

2. inspecting and validating panel retest results

Before concrete is poured, the geometrical parameters of the track are rechecked, and the track is readjusted when the deviation exceeds the allowable deviation.

3. When the chute of the concrete transport vehicle is directly unloaded for pouring or a hopper is adopted for pouring, the material outlet is not too high from the rail top, and the valve is opened for material discharging. In the blanking process, timely vibration and pollution prevention need to be paid attention to, the blanking is uniform and slow, and the track panel cannot be impacted.

When pumping is adopted, the pipe orifice of the rubber pump is above the track panel, and the blanking direction is basically vertical to the track panel. The elevation of the concrete is controlled by moving the blanking pipe.

1.12 vibrating, plastering and shaping

1. The concrete is poured and vibrated, 4 vibrators are used for manual vibration, the front area and the rear area are tamped at intervals of 2m during operation, the front area is mainly used for tamping the bottom of the lower reinforcing mesh and the bottom of the supporting block, and the rear area is mainly used for tamping the periphery and the bottom of the supporting block. When tamping, the tamping rod is prevented from contacting the bent frame and the supporting block, and the concrete is timely treated when the concrete is redundant or insufficient.

2. and after the surface concrete is vibrated, finishing and leveling the exposed surface of the concrete in time, after the concrete is placed into a mold, finishing rough leveling by using wood, and after 1 hour, leveling by using steel. In order to prevent the surface of the concrete from being dehydrated to generate fine cracks, secondary plastering is carried out before the initial setting of the concrete (about 5 hours after the concrete is put into a mould), watering and moistening the surface are strictly forbidden during plastering, and the quality of the surface concrete is prevented from being influenced by excessive operation. In the process of plastering, attention is paid to strengthening the construction of the lower part of the track, the periphery of the supporting block and the like. The control to the surface drainage slope is strengthened, the slope is ensured to meet the design requirement, the surface drainage is smooth, and water cannot be accumulated.

3. After finishing, the track panel, the sleeper and the fasteners are cleaned in time to prevent pollution.

4. After the concrete is initially set, 1/4-1/2 circles of supporting bolts are loosened, and meanwhile, fasteners and fishplate bolts are loosened, so that damage to the concrete caused by stretching of the steel rail during temperature change is avoided.

1.13 maintenance of ballast bed plate

1. After concrete pouring is finished, a maintenance mode that geotextile covers and sprinkles water and a plastic film covers the geotextile, the sprinkling frequency is determined according to weather conditions, the concrete surface can be ensured to be in a fully wet state, and the maintenance time is not less than 7 d.

2. And strictly prohibiting the vehicle running on the track bed and colliding with the track parts before the track bed concrete reaches 75% of the design strength.

1.14 track panel and form removal

When the concrete of the ballast bed plate reaches a certain strength, firstly, sequentially lifting the stud supporting legs by 1-2 mm in a rotating manner; and then loosening the rail fasteners, sequentially dismantling the bent frames, disassembling the templates, finally, after confirming that the fasteners are completely loosened, hoisting the bent frames by the gantry crane to a rail panel assembly area for cleaning for standby, and entering the next cycle of construction. The arrangement special person is responsible for cleaning the disassembled templates, the bent frames, the accessories and the like by using the brushes, and the accessories are stored in the collecting basket in a centralized mode for the next use.

second, construction of ballastless track of bridge section

2.1 flow chart of construction process (see FIG. 3)

2.2 CP III layout

1. CP III control points are embedded in pairs along the line, and the distance between adjacent points is required to be 60m in principle, and in special cases, the distance is 40m minimum and 80m maximum.

2. And the CP III control point is arranged on the top surface of the ballast retaining wall above the end of the bridge fixed support.

3. CP III control points can not be embedded in the span of the continuous beam with the length within 80 m; a pair of CP III control points are buried in a continuous beam span with the length of 80-120 m; two pairs of CP III control points are embedded in the span of the continuous beam with the length of 120-180 m, and the rest is analogized according to the method.

4. and (3) after mounting holes in the vertical direction are dug in pairs along two sides of a line on the top surface of the ballast retaining wall by the CP III embedded part, embedding the CP III embedded part by using bar-planting glue, wherein the exposed height of the CP III embedded part is not more than 3 mm.

2.3 base plate construction

1. preparation for construction

Firstly, the configuration of constructors and the pre-post training are well done.

And organizing and implementing complete construction equipment of the ballastless track according to the mechanized, refined, standardized and programmed construction requirements of the ballastless track.

and thirdly, pre-embedding of post-station engineering components and constructing a track-crossing pipeline.

And fourthly, checking and accepting the beam surface before construction, and finishing the observation and evaluation of the settlement under the line.

2. Structural dimension line of setting-out base plate

After the bridge deck is cleaned, the CP III control net is adopted to measure and release the center line and two side lines of the bed plate. Line traverse e value in curve segment. And the ink line is used for marking on the bridge surface as a steel bar binding control limit.

3. Bridge floor connecting steel bar construction

The embedded sleeve protective cover in the beam body is detached before base construction, the base plate is connected with the bridge floor through a straight thread steel bar sleeve, the thread length of a thread steel bar after thread rolling is 28mm, and the depth of a thread head of a connecting steel bar screwed into the sleeve is not less than 25 mm. The connecting steel bars adopt HRB400 end socket thread-covered steel bars with the diameter of 16 mm.

For the embedded sleeve with larger deformation or not found out, bar planting treatment is carried out according to the principle of 'lack of one and supplement of two', the bar planting mode is perpendicular to the line direction, holes with the diameter of 20cm and the depth of 250mm are respectively drilled at the positions, away from the center of the connecting sleeve, of the left side and the right side of the embedded connecting sleeve by more than or equal to 35mm, bar planting glue is injected after hole cleaning and dust removal, HRB400 hot-rolled ribbed steel bars with the diameter of 16mm and the length of 452mm are respectively planted in a continuous rotating mode, and the bar planting depth is 250 mm. The steel bar planting material and the steel bar planting process meet the standard requirements, steel bar detection is carried out before steel bar drilling is carried out, no bridge steel bar is in the drilling depth range, and damage to the bridge steel bar is avoided.

4. Processing and binding base plate steel bars

The bed plate reinforcing steel bars are processed in a unified mode in a reinforcing steel bar processing factory, the flat car is conveyed to the position below the bridge, the truck crane is hoisted to the bridge and then is installed and bound, and the flat car is directly conveyed to the bridge floor bed plate reinforcing steel bar binding position through the high bridge pier beams.

the lapping length of the longitudinal steel bars in the base is not less than 500mm, the lapping rate in the same section is not more than 50%, and the net protective layer thickness of the base plate is 35 mm.

5. Construction of bed plate formwork

The base plate and the groove template are formed by combining and connecting shaped steel templates through bolts, and the template installation needs to ensure that the design size requirement of the base plate is met.

And secondly, treating the seam of the template plate of the base plate by clamping double faced adhesive tapes, and strictly preventing slurry leakage in the concrete pouring process. The surface of the steel die must be polished, the release agent is coated, the steel die is uniformly coated at one time, the missing coating is prevented, and the surface cleanness is ensured.

and thirdly, after the base plate template is installed and reinforced, the groove template is installed according to the lofted plane position points, and the periphery of the groove template is additionally provided with embedded ribs for fixing the groove template. After the installation is finished, the positions of the groove template and the base template are retested by the total station, if deviation exists, the positions are timely adjusted, and after the requirement is met, the groove and the base template are fixed into a whole by the transverse channel steel on the top surface, so that the template is prevented from deviating during pouring.

and fourthly, carrying out comprehensive inspection on the template before pouring the concrete. The main contents of the examination are: the axis deviation, the geometric dimension, the elevation, the plate seam dimension, the verticality, the position of the limiting groove template, the supporting condition and the like, and the problem is found and timely treated.

And fifthly, mounting the lateral template according to the mark obtained by measurement lofting, and accurately positioning the plane position and the elevation of the lateral template to ensure that the template is tightly attached to the bridge floor.

after the template is installed, a special person is arranged to check the installation quality of the template, and the measuring person remeasures the top surface elevation and the plane position of the template.

6. base plate concrete construction

checking the thickness of the steel bar protective layer again before pouring concrete; and (4) the horizontal position and the elevation of the template are consistent. The stability of the template installation at least meets the operation requirement of the paving, leveling and vibrating machine; sundries are cleaned in the construction range of the base plate, and meanwhile, dust or other light pollutants in the range of the template are blown off by a powerful blower.

Before concrete pouring, sprinkling water to wet the bridge deck 2 hours in advance, but no open water can be produced, intensively mixing the concrete of the base in a mixing station, transporting the concrete to the site by adopting a concrete tank truck, and pumping the concrete to the bridge and enter the mold by a pump truck. The slump of the concrete is controlled to be about 160 mm-200 mm. The concrete is vibrated by a vibrating rod, and the concrete is forbidden to impact the reinforcing steel bars when vibrated. After the concrete is compacted by vibration, the top surface is leveled, the flatness needs to reach the requirement of 10mm/3m, the base plate cross slope of the curve section is larger, the slump is controlled to be about 180mm, the concrete in the ultrahigh range needs to be continuously supplemented by manpower in the concrete paving and leveling process, and finally, the concrete is leveled and compacted for two times. And (4) leveling the base plate concrete by using an iron trowel before initial setting. Covering and watering for curing in time after concrete pouring is finished, wherein watering times can keep the concrete in a wet state; when the environmental temperature is lower than 5 ℃, the watering maintenance is forbidden, and appropriate heat preservation measures are taken. The curing period is not less than 7 days.

the mold-entering temperature is not lower than 5 ℃ when the concrete is poured; it is also not preferable to exceed 30 ℃. When the highest temperature of the construction site is higher than 30 ℃, summer construction measures should be taken.

After the bed plate is poured, sundry accumulated water in the limiting groove is cleared in time, and waterproof materials are added on the top surface of the limiting groove to prevent accumulated water in the limiting groove. Before the concrete reaches 75% of the designed strength, various vehicles are strictly prohibited to pass on the base plate. And the base plate is inspected and accepted in time after being poured.

7. construction of isolation layer and elastic cushion layer

An intermediate isolation layer is arranged between the base plate and the track bed plate, and the isolation layer is 4mm of polypropylene geotextile with the design width of 2800 mm. And elastic base plates are laid around the limiting grooves.

and after the base concrete reaches over 75% of the design strength, laying and isolating the middle layer and installing the elastic cushion layer. The polypropylene geotextile should be laid smoothly without folds and damages, and the seams are butted and can not be overlapped. And machining and installing a rubber cushion plate and a foam plate according to the size of the groove, and closing all gaps. And carrying the whole roll of geotextile to a construction bridge floor, cutting according to the length of the beam, and aligning one end of the geotextile to the beam end during cutting. According to the position of the limiting groove, a rigid flat ruler with the length of 1m is used to be close to the edge of the groove, marks are made on the geotextile, the geotextile is cut, the geotextile is laid at the bottom of the groove after the cutting is finished, the adhesive tape is used for adhering the periphery of the geotextile, the surface of the geotextile after the geotextile is laid is smooth, and the geotextile has no defects of damage, no tilting at the joint and edge, no hollowing, no wrinkling, no delamination or no tight sealing and the like. When the geotextile is laid, if the length of the geotextile is not enough, the geotextile cannot be lapped, and the geotextile must be butted and bonded by using an adhesive tape. The seam of the geotextile is vertical to the direction of the track, and the folding or overlapping phenomenon can not occur. When the paving direction is on a curve or the paving direction deviates greatly from the line center line, the geotextile can be cut off to adjust the paving direction.

after the geotextile on the top surface of the base plate is laid, the geotextile on the inner bottom surface of the limiting groove and the elastic backing plates around the geotextile are laid, the geotextile cut off in an aligned mode is placed at the bottom of the groove, and it is necessary to ensure that the bottom of the groove is completely covered by the geotextile and is firmly bonded by the adhesive tape. The elastic backing plate is firmly stuck around the groove by using an adhesive tape. The elastic cushion layer is firmly adhered to the side surface of the groove, the top surface is flush with the surface of the base, and the defects of no upwarp, no hollowing, no crease, no delamination or no tight sealing and the like exist at the joint and the periphery.

2.4 track bed plate construction

1. Clearing and construction lofting of ballast bed working face

The scum, dust and sundries on the surfaces of the base plate and the geotextile are removed.

secondly, track central line control points are released every 10m on the bridge isolation layer through the CP III control points according to the designed ballast bed plate position, the steel nails are used for accurate positioning, the red paint marks are carried out, and ink lines are used for popping out the track central line.

And thirdly, taking the central control point of the track as a reference to release the control sideline of the sleeper and the positions (ink line marks) of the sidelines of the longitudinal and transverse formworks of the track bed plate.

And fourthly, positioning the position of each longitudinal and transverse steel bar at the bottom layer of the bed plate by using ink lines according to the position of the center line of the popped track.

Fifthly, the content of the measurement lofting is fed back to a technician in a written form and is delivered to a construction operator.

2. Arrangement of reinforcing steel bars at bottom layer of ballast bed plate

The road bed board steel bars are processed in the steel bar processing shed and are bound and assembled on the line. The specific installation sequence is as follows:

Firstly, longitudinal steel bars are placed according to the positions of the ejected longitudinal steel bars, and the lap joints of the longitudinal steel bars are insulated by adopting insulating clamps.

Secondly, installing transverse reinforcing steel bars one by one from one end of the ballast bed plate to the other end of the ballast bed plate according to the position line of the popped transverse reinforcing steel bars, clamping the insulation clamp on the longitudinal reinforcing steel bars during installation, and then directly placing the transverse reinforcing steel bars on the clamping grooves of the insulation clamp, wherein the distance between the longitudinal reinforcing steel bars and the transverse reinforcing steel bars is allowed to deviate +/-20 mm.

After the transverse steel bars are installed, arranging 3 persons (each person is responsible for the range of about 1m wide) to perform oblique staggered binding on the crossed parts of the longitudinal and transverse steel bars by adopting plastic insulating buckles from one end of the track bed slab to the other end according to the installation sequence and mode of the transverse steel bars.

And fourthly, after the steel bars are bound, installing C40 concrete protective layer cushion blocks with the thickness of 35mm below the longitudinal steel bars of the steel bar mesh, installing 5 cushion blocks (the outermost side is 1 respectively, the middle is 0.6m apart) on each cross section, and ensuring that the longitudinal distance is 0.8m, so that not less than 4 cushion blocks are arranged per square meter.

fifthly, the boss steel bars are epoxy resin coating steel bars with the diameter of 12mm, construction is carried out according to design drawings during construction, and the boss steel bars and the joint positions of the roadbed slab steel bars are fixed by insulating clamps.

3、

firstly, hoisting sleepers to be used on a sleeper groove on a track panel assembling platform by using a gantry crane, hoisting 5 sleepers each time, uniformly sleeper-arranging according to a positioning line of sleeper blocks on the assembling platform, and controlling the distance deviation of the sleepers within 5 mm. The inspection adjustment sleeper piece position to the bullet line becomes a line with the bolt hole cloth of one side, and the deviation is less than 1mm, and manual fit portal crane aligns track section frame fastener bolt hole position and sleeper bolt hole position, and steady, slow places the framed bent on the sleeper, and on-the-spot technician rechecks the sleeper position again and whether satisfies the requirement, and installation fastener is tightened after being errorless.

secondly, cleaning the rail bearing table board before assembling the track panel, and checking whether sundries exist in bolt holes or not and whether sand grains exist on the bolt hole grains or not. The bolt is screwed in by hand to see whether the bolt can be screwed in smoothly, and if the bolt is clamped, the bolt hole is removed until the bolt can be screwed in smoothly. Checking whether the fastener is installed in place or not, and tightening the fastener bolt by using a hydraulic wrench according to the specified torque of 150NM-170 NM. The inspection method is that three points at the front end of the elastic strip are a line and are closely attached to the insulating block to be qualified.

Thirdly, after the track panel is assembled, the distance between the checked sleepers is controlled within 5 mm.

4. track panel frame in place

and (3) transporting the installed track panel to the site by using a flat car, hoisting the track panel in place by using a gantry crane, accurately placing the track panel in place in sequence according to the track central line according to the length of the slab section, and aligning the track central line to the track central line and slowly placing the track panel below the track panel by using the track panel frame central line mark. Before the track panel falls to a track bed board, a plastic sleeve is sleeved on the bolt supporting leg, and the track gap is adjusted by utilizing the allowable range error of the distance between two adjacent track panel sleepers. The rail joint needs to be smooth and has no dislocation.

5. Coarse adjustment of track panel

And the track panel coarse adjustment adopts a total station, and the track ruler completes the initial adjustment of the track panel. The adjustment principle is centerline first and then elevation.

step 1: and (4) adjusting the middle line. The total station and the measuring handbook are equipped, the station is positioned by adopting a free station setting method, at least 4 pairs of CP III points are observed nearby when the station is set, the central reference device on the track panel frame trailing beam is measured, and 4 persons are arranged on two sides of the track panel respectively to adjust the track direction locking device. If the center datum deviates from the left side of the center line of the track, loosening the right side rail locking device (rotating anticlockwise) by using a 46mm open spanner, and simultaneously, screwing the left side rail locking device (rotating clockwise) by using the 46mm open spanner to enable the rail row to move rightwards to the position of the center line of the designed track and then screwing the right side rail locking device; if the center datum is offset to the right of the track centerline, the left side rail lock is loosened (counterclockwise rotation) using a 46mm open wrench, and the left side rail lock is tightened after the track rail is moved to the left to the designed track centerline position (clockwise rotation) using a 46mm open wrench. When the midline is not adjusted in place at one time, the adjustment is carried out circularly until the midline deviation meets the requirement of +/-5 mm.

step 2: and (6) adjusting the elevation. And (3) measuring the elevation (8 points per roof truss) of the steel rail at the position corresponding to the towing beam of each track panel by using a precise electronic level, and comparing the measured elevation with the designed rail surface elevation to calculate the elevation difference. When the actually measured rail surface elevation is lower than the designed rail surface elevation, a 36mm open-end wrench is adopted to rotate the vertical screw rod clockwise to enable the rail panel to rise to the designed rail surface elevation; when the actual measurement rail surface elevation is higher than the designed rail surface elevation, the rail direction locking device is loosened, and meanwhile, the 36mm open spanner is adopted to rotate the vertical screw rod anticlockwise so that the rail panel descends to the designed rail surface elevation. The vertical screw rod can be lifted by 1mm when rotating 120 degrees every time, the elevation of the track panel is adjusted point by point, and the elevation error of the track after coarse adjustment is controlled to be between-5 mm and-2 mm.

and step 3: after coarse adjustment is completed, two adjacent rows of frames are connected by using a clamping plate, and the joint bolts are screwed by using a movable spanner according to the sequence of 1-3-4-2.

6. Binding of upper layer steel bars of ballast bed plate

firstly, marking the position of longitudinal steel bars on a sleeper steel bar truss by using white chalk according to the designed longitudinal steel bar interval, placing the longitudinal steel bars, installing insulating clamps at the crossed parts of the longitudinal steel bars and the sleeper truss steel bars, and adopting plastic insulating buckles to tie the longitudinal steel bars in an inclined manner.

Marking the positions of the transverse reinforcing steel bars on two reinforcing steel bars on the outermost side of the ballast bed plate by using white chalk after the longitudinal reinforcing steel bars are placed, arranging 3 persons to install the transverse reinforcing steel bars one by one from one end of the ballast bed plate to the other end, and installing insulation clamps at the intersections of the longitudinal reinforcing steel bars and the transverse reinforcing steel bars. After the transverse reinforcing steel bars are installed, the crossing points of the longitudinal reinforcing steel bars and the transverse reinforcing steel bars are bound obliquely by adopting plastic insulating buckles according to the installation sequence and the installation mode.

7. installation of road bed plate formwork

The main operation content of the process comprises: inspecting and cleaning the template; installing a transverse template; and (4) installing the longitudinal template, and connecting the transverse template with the longitudinal template. The concrete construction sequence is as follows:

checking and cleaning the template. The following inspection work should be performed before the installation of the template: flatness of the template; template cleaning conditions; the condition of brushing the release agent; replacing the damaged or bent template; in order to not influence the precision of the track panel after coarse adjustment in the installation process of the template, the collision between the template and the track panel after coarse adjustment caused by human factors is avoided as much as possible.

And installing a transverse template. The transverse formwork is used at a broken joint, the position of the transverse formwork is coincident with the transverse position of the base plate, the length of the transverse formwork is 2800mm, after the rough adjustment of the track panel is finished, the transverse formwork is installed, the transverse formwork is hoisted to the middle position of a circuit at a required position by using a gantry in advance, and the transverse formwork is formed by splicing 2 blocks. The steel plate and the longitudinal template are connected and tightly spliced. The positions of two ends of the transverse template refer to the side lines of the longitudinal template, and the installation error is 2 mm.

And mounting a longitudinal template. The longitudinal template and the track panel frame are installed in a matched mode, a gantry crane is used for storing the longitudinal template and the track panel frame at two sides of a side line of a track bed board at one time according to the template installation sequence before installation, the bottom of the template needs to be leveled when the longitudinal template is stored, a panel faces upwards, a specially-assigned person polishes the template, and a release agent is coated. The portal crane lifts the template, after the template is in place through manual matching, the supporting surface at the bottom of the template is cleaned, the bottom surface of the template is on the same plane, the close adhesion of the edge of the template and the concrete side surface of the base plate is ensured, and slurry leakage during concrete pouring is avoided. Two adjacent templates are connected by bolts, dislocation between the two adjacent templates is ensured to be avoided during the bolt connection, and double faced adhesive tapes or adhesive tape strips are adhered to the joint surfaces of the two templates so as to prevent gaps between the templates from leaking slurry. After the longitudinal template is installed in place, the longitudinal template is connected with the supporting system in a reinforcing mode, and the top surface line of the road bed plate is marked on the inner side of the template through ink lines. The installation precision width of the longitudinal template is +/-5 mm, the central line position is 2mm, and the top surface elevation is not lower than that of the concrete top surface.

And fourthly, after the longitudinal template is installed, connecting the transverse template with the longitudinal template to ensure that the longitudinal template and the transverse template are closely attached, and after the track bed board template is installed, checking, accepting and signing.

8. Comprehensive earth welding

Taking 3 longitudinal structural steel bars (1 in the middle and 2 outside) on the upper layer of each track bed board as longitudinal grounding steel bars, and taking 1 transverse structural steel bar on the middle part of the upper layer of the track bed board as transverse grounding steel bars.

And secondly, the longitudinal and transverse grounding steel bars are connected by welding, and the plate end grounding terminal is welded with the longitudinal grounding steel bar by welding. The welding should be: the length of the single-sided welding is not less than 100mm, the length of the double-sided welding is not less than 55mm, and the thickness of the welding seam is not less than 4 mm. The ground terminal locations should be marked.

and thirdly, two ends of each track bed board are respectively provided with a grounding terminal, and the distance between each terminal and the board end is preferably 100-150 mm. Firstly, a stainless steel cable with the length of 0.4m is used for longitudinally connecting the track bed board to form a grounding unit with the length not more than 100m, and then the stainless steel cable with the length of about 3.5m is used for carrying out single-point T-shaped connection grounding on the grounding unit and the pre-embedded grounding terminal on the protective wall.

Fourthly, the grounding steel cable is made of stainless steel, and the section of the grounding steel cable is not less than 200mm 2.

Insulation detection of steel bar

after the binding of the bed plate steel bars and the welding of the grounding steel bars are finished, insulation resistance test is carried out, and a high resistance tester is adopted for testing. The resistance value of any two non-grounded steel bars in each unit plate is larger than 2M omega. And (4) actually measuring the steel bar insulation according to the standard by a specially-assigned person, and filling the actually measured data in an insulation test record table.

9. Track panel fine adjustment

The main contents of the process are as follows: setting a total station; measuring orbit data; adjusting the center line of the track; adjusting elevation and locking the track panel.

setting up station for total station

and (4) observing the continuous CP III points by using the total station, automatically adjusting and calculating to determine the station setting position. If the deviation is larger than 2mm, the station should be reset. After the station position is changed, at least 4 CP III points utilized behind must be observed in a crossed manner, and at least one group of track panels which are precisely adjusted are retested.

Measuring orbit data

The rail inspection trolley is placed on the rail and provided with the prism. The total station measures the prism at the top end of the track state measuring instrument, the trolley automatically measures the track gauge, the height, the horizontal position and the like, receives observation data, calculates the data of the track plane position, the level, the height, the track gauge and the like through matched software, and quickly feeds error values back to a computer display screen of the track state measuring instrument to guide track adjustment.

Regulating track central line

A46 mm open spanner is adopted to adjust the left and right rail direction locking devices, the center line of the rail is adjusted, 2 groups are adjusted at a time, and the left and the right are respectively matched with 2 persons to operate simultaneously. In the adjusting process, the total station always measures the prism of the track state measuring instrument, receives observation data, and quickly feeds an error value back to a computer display screen of the track state measuring instrument through matched software until the error value meets the requirement and then the adjustment is finished; after the central line is adjusted in place, one side of the elastic buckle is screwed under the monitoring of an instrument, and the adjusted central line cannot be disturbed in the process;

Adjusting the height of the track

the elevation of the top surface after coarse adjustment is slightly lower than the elevation of the designed top surface by 0 to-2 mm. And rotating the vertical screw rod by using a 36mm open spanner to adjust the level and the height of the track (loosening the height adjuster and adjusting the inclination angle of the track panel to ensure that the frame of the track panel reaches the designed elevation, and screwing the vertical screw rods on the two sides to ensure that the vertical screw rods are vertical to the ground). After adjustment, whether the screw is closely attached to the concrete or not is manually checked, and the bottom of the screw is guaranteed not to be suspended. And (3) adjusting the stud slowly, rotating by 120 degrees to change the elevation by 1mm, checking whether the screw is stressed by hands after adjustment, and adjusting the screw nearby if the screw is not stressed.

Fifth, direct connection transition

After the adjustment of the previous station is completed, 8 to 10 sleepers adjusted by the previous station are overlapped when the adjustment of the next station is performed. The transition section starts from the first rail bent after the forward connection, and the data decrement value of each sleeper is preferably less than 0.2mm until the absolute deviation is about zero.

And after the track adjustment is finished, fixing the track bent through the track locking device. If the panel is subjected to external disturbances, or if the standing time is too long (more than 10 hours), or if the ambient temperature changes by more than 15 ℃, it must be reexamined or adjusted. And (5) reporting and checking the qualified report after retesting.

Note that: all measuring instruments must be regularly calibrated according to relevant standards; the measuring area reduces other construction operations as much as possible; fine adjustment operation cannot be performed under extreme weather conditions; after the track panel is finely adjusted, protective measures are taken, and treading and impacting are strictly prohibited; concrete should be poured as early as possible after the track panel is finely adjusted.

10. Concrete construction of ballast bed plate

The main contents of the process include: preparing; checking and confirming the retest result of the track panel; mixing and conveying concrete; pouring concrete; smearing and cleaning; and (5) concrete curing.

Preparation work

cleaning sundries on a pouring surface, and spraying water to wet the surface of an inverted arch filling layer and the bottom of a sleeper within 6 hours before pouring, but no accumulated water exists; before pouring, a protective cover is used for covering a sleeper, a fastener and a steel rail; and the power lines and various construction equipment such as a pump truck, a transport tank truck and a vibrating rod required by pouring are comprehensively checked, so that the normal operation of the pouring process is ensured.

Checking and confirming the retest result of the track panel

If the track is left for too long a time (more than 12 hours) or if the ambient temperature changes by more than 15 ℃, or is affected by external conditions, it must be re-inspected or adjusted before the concrete is poured.

Mixing and conveying concrete

The concrete of the ballast bed plate is intensively mixed by a mixing station, and is poured in a direct discharge or pumping mode by a concrete transport vehicle during construction. After the concrete is transported to a construction site by using the concrete transport vehicle, the slump, the air content and the temperature index of the concrete of each vehicle are detected, and the concrete can be unloaded after the slump, the air content and the temperature index are qualified.

fourthly, pouring concrete

In order to ensure that the concrete road bed board is not subjected to over-limit temperature crack pouring, the environmental temperature (thermometer) and the track temperature (infrared thermometer) are monitored all day long during the concrete pouring period, a temperature curve is drawn, the concrete pouring can be carried out in a time period with a small temperature change range, and the concrete mold-entering temperature is controlled to be between 5 ℃ and 30 ℃.

One end of the concrete is continuously carried out towards the other end, and when the concrete automatically flows to the next sleeper from the lower part of the sleeper, the concrete can be moved forwards to the next sleeper to be continuously poured forwards. And when the concrete amount is slightly higher than the designed elevation, the concrete is moved to the next grid for pouring.

When the concrete is directly unloaded and poured, the chute of the concrete truck is turned to the position above the track panel to be poured (the feed opening is 20cm higher than the top of the track, the adjustable range is 80-160 cm by adjusting an adjustable hand-cranking device at the bottom of the feed opening of the concrete truck), and the valve is opened for feeding. In the blanking process, timely vibration is needed, the blanking is uniform and slow, and the track panel cannot be impacted.

when pumping concrete, the rubber pump pipe mouth should be above the section of track and the unloading direction is perpendicular to the section of track basically, through removing the unloading pipe control concrete unloading height.

the concrete must be compact, flat, uniform in color, free from exposed ribs, honeycombs, holes, looseness, pitted surfaces, missing edges and falling corners and the like.

Fifthly, plastering and cleaning

And after the surface concrete is vibrated, finishing and leveling the exposed surface of the concrete in time. After the concrete is placed into the mould, the slope ruler and the wood trowel are used for leveling the ink line which is bounced on the sleeper, the slope ruler is used between two lines of sleepers, and the wood trowel is used under the steel rail, between longitudinal sleepers and on the outer side part of the steel rail. And trowelling and compacting by using steel after 1 h. In order to prevent the surface of the concrete from being dehydrated to generate fine cracks, the surface is plastered for the third time before the initial setting of the concrete, the surface is strictly prevented from being watered and moistened, and the quality of the surface concrete is prevented from being influenced by excessive operation. In the plastering process, the construction of the frame, the lower part of the sleeper, the periphery of the sleeper and the like is strengthened. After finishing plastering, the steel rail, the sleeper and the fastener are cleaned in time to prevent pollution. The control to the surface drainage slope is strengthened, the slope is ensured to meet the design requirement, the surface drainage is smooth, and water cannot be accumulated. The elevation deviation is ± 3 mm.

maintaining concrete

the concrete of the ballast bed plate is maintained in a moisture-keeping and heat-preserving way, a specially-assigned person is assigned to maintain, and the surface of the concrete cannot be polluted and damaged by water for maintenance. The curing time is not less than 7 days. And (4) loosening 1/4-1/2 circles of screws after the concrete is poured, lifting and loosening the transverse template and the construction joint template, completely loosening the fasteners, and releasing stress deformation of the track caused by temperature and creep in the construction process. Care is taken not to disturb the track panel during operation.

Protection of the final product

a. Training field constructors, improving the protection consciousness of finished products and preventing the appearance of the track bed plate from being damaged.

b. The template can prevent workers from carrying hard prying during the template dismounting process.

c. After the templates are removed, collision of construction machines, templates and the like is prevented from damaging a finished product road bed board in the subsequent construction process, and a specially-assigned person is sent to a user to prevent damage.

d. during construction, a template and a machine tool are strictly forbidden to be placed on a poured ballast bed plate, and other operations are forbidden to be carried out on a finished product.

11. Formwork and track panel frame dismantling and cement mortar filling screw hole

the main content of the working procedure comprises: dismantling the longitudinal and transverse formworks and the track panel frame; cleaning and transporting the longitudinal and transverse formworks; unfastening all tool rail fasteners, cleaning the fasteners, and determining whether to dismantle the fasteners according to the field condition; the high-strength shrinkage-free mortar blocks the screw holes.

Firstly, dismantling longitudinal and transverse formworks

after the concrete compressive strength of the ballast bed plate reaches 5MPa, the longitudinal and transverse template connection and the transverse template connection are firstly carried out, and the longitudinal and transverse template connection and the transverse template connection are loosened with other connecting pieces, then the template is tapped, after the template is loosened, the gantry crane is hoisted out to the space between the two lines, and the concrete is transported to the next cycle by using a special template transport vehicle for cleaning. The arrangement special person is responsible for cleaning the disassembled templates, the bent frames, the accessories and the like by using the brushes, and the accessories are stored in the collecting basket in a centralized mode for the next use. And the damage of the concrete of the ballast bed plate caused by human factors is avoided as much as possible during the dismantling.

And the transverse formwork can be dismantled in the section with the longitudinal formwork dismantled, the transverse formwork is dismantled through the gantry crane and manual cooperation, the transverse steel bars fixed on the formwork are dismantled, and after the dismantling, the transverse formwork is immediately cleaned and coated with the isolating agent and is stored in a classified mode.

The template is prevented from being deformed or damaged by rough construction in the processes of dismantling, hoisting, cleaning and storing. The cleaned transverse templates, longitudinal template connecting bolts, longitudinal and transverse template connectors and the like are placed into the material storage basket in a classified mode so as to be convenient to transport and prevent loss.

② dismantling the track panel frame

and (4) sequentially lifting the stud supporting legs by 1-2 mm, loosening all fasteners of the unit rails, and taking down the unit rails for cleaning. After the fastener is taken down, the bent is hoisted by a gantry crane to a next operation area for cleaning and standby, and then the next cycle construction is carried out.

thirdly, the cement mortar fills the screw hole

the plastic sleeve in the screw hole is cleaned, the screw hole is sealed and tightly closed manually by using M40 high-strength non-shrinkage cement mortar, the surface is trowelled, and no accumulated water, sundries and the like are required to be in the hole.

Thirdly, construction of ballastless track of roadbed section

3.1 layout of the roadbed section CP III in the interval

1. The CP III control point should be arranged at the position of the road shoulder.

2. Control points of ballastless track sections are arranged on the basis of contact network rods according to the related requirements of the specification of 2.0.2 of the provisions of the survey and design supplement of the railway track control network of the ballasted track with the newly built passenger-cargo collineation at the speed of 200 kilometers per hour (Total iron construction No. 2013) 88.

3.2 the construction method of the base and the ballast bed plate is similar to that of a bridge section, and the base and the ballast bed plate need to be constructed after the settlement evaluation is qualified.

Materials and apparatus

The adopted machines and equipment are shown in a table 1 (according to the situation of the field operation surface, the quantity of mechanical equipment is correspondingly increased)

TABLE 1 Instrument and tools equipment table

Quality control

1. The template installation must be stable and firm, the seam is tight, must not leak thick liquid. The contact surface of the template and the concrete must be cleaned and coated with a release agent. Before concrete is poured, accumulated water and sundries in the model are cleaned up.

2. the reinforcement cage is bound firmly, and the number of the missing buckles and the loose buckles is not more than 5% of the number of the bound buckles.

3. After the template is removed, the surface of the concrete structure is compact, flat and uniform in color, and the defects of rib leakage, honeycombs, holes, looseness, pitted surfaces, unfilled corners, corner drop and the like are avoided.

4. After the concrete road bed board is constructed, the width of the surface crack of the concrete road bed board meets the design requirement.

Benefit analysis of the invention

1. The method is environment-friendly, energy-saving and pollution-free and reaches the domestic advanced level through the identification of relevant national environment-friendly monitoring departments.

2. by adopting the construction mode of circular operation, the number of times of using the turnover materials is increased, the investment of the turnover materials and machines and tools is reduced compared with the prior art, and the construction cost is reduced.

3. the construction of a plurality of working surfaces is parallel, so that favorable conditions are created for the advance delivery of track laying and the subsequent four-power construction; scientific construction organization and large-scale mechanical operation, shortens the construction period and effectively ensures the construction quality.

4. The track slab fine adjustment utilizes computer software which is independently developed to carry out calculation and control, so that the construction process is standardized, standardized and programmed, and the laying quality of the track slab is effectively ensured.

examples

1. Overview of the engineering

building civil engineering MHTJ-17 standard segment start-stop mileage of railway coal transportation channels in Mengxi to Huazhong areas: DK828+ 253.5-DK 883+289.5, wherein the whole line is 55.036 km in total length, and the up-down link line is 2.2 km. The total length of the tunnel 26 in the standard section is 16804.3 meters, and the total length accounts for 30.5 percent of the total length of the line. Laying ballastless tracks on the tunnel with the length of 1km or more in principle, and generally laying elastic support block type ballastless tracks in the tunnel; when the ballastless tracks of the tunnel group section are considered to be laid in sections, heavy-load long-sleeper embedded ballastless tracks are laid on tunnel portal, tunnel outer bridge and short-circuit foundation. The total length of the ballastless track (single line) is 24.157 km.

2. Application case

The construction method is adopted to construct MHTJ-17 standard sections of civil engineering of railway coal transportation channels in Monte West to Huazhong areas, and through detection, all indexes such as the geometric dimension, the track gauge, the track direction and the like of the track slab meet the requirements of design and standard inspection, and are well received by leaders at all levels.

Claims (2)

1. A construction method of ballastless tracks of a heavy haul railway tunnel group is characterized by comprising ballastless track bed board construction in a tunnel and ballastless track construction in a bridge section;

Construction of ballastless track bed board in tunnel

(1) Construction method

The track bed slab is constructed by adopting a track panel frame method; the track panel comprises a frame combination device, a tool track, a track gauge adjusting fishplate, an angle adjusting device, a vertical stud and a connecting bolt;

(2) CP III layout

1. The CP III control point is arranged at a position 30-50 cm above the side wall cable trough;

2. After a mounting hole is drilled on the side wall of the CP III embedded part, the CP III embedded part is transversely inserted and embedded by using bar planting glue, and the exposed end of the CP III embedded part is not lower than the embedded end;

(3) Tunnel invert backfill layer treatment

1. Performing chiseling treatment on the tunnel inverted arch backfill layer;

2. measuring and releasing control points of a track central line on the backfill layer every 10m through CP III control points, applying an obvious color mark to the central line, and recording the accurate mileage and coordinate values of the control points; paying out the side lines of the longitudinal and transverse templates by taking the track central line control point as a reference;

3. The track bed plate is reliably connected with the lower foundation through embedded steel bars, so that limit is provided for the track structure; 5 reinforcing steel bars are planted between every two adjacent pillows or supporting blocks within 50m of the opening; planting a row of 5 steel bars every other sleeper or supporting block within the range of 50-200 m away from the opening of the hole; 5 rows of steel bars are planted below each plate within the range of being more than 200m away from the hole; the diameter of the steel bar is 20mm within a range of being 200m away from the opening, and the diameter of the steel bar is 16mm within a range of being more than 200m away from the opening; the length of the steel bar is 480mm, wherein the length of the steel bar implanted into the tunnel inverted arch backfill layer or the bottom plate by adopting the bar planting glue is 200 mm;

(4) road bed board bottom layer steel bar laying

1. The longitudinal structural unit steel bars of the track bed slab are disconnected every 60m units, and the comprehensive grounding is carried out every 100m units by adopting insulation lap joint; during binding, the lap joints of the longitudinal and transverse steel bars are isolated by adopting an insulating clamp, so that the node insulation of the longitudinal and transverse steel bars is ensured; longitudinal steel bars are lapped, lap joints of adjacent steel bars are staggered, the lapping length is not less than 700mm, and the center staggered distance of the adjacent lap joints is not less than 1000 mm; the lapping rate of the steel bars on the same section is not more than 50 percent;

2. According to the measured lofting position and the designed number of the longitudinal steel bars under the sleeper, the longitudinal steel bars are scattered and paved on a tunnel bottom plate in sequence; measuring the interval of bottom layer steel bars on the top surface of the bottom plate by using a steel tape according to a total station lofting point, and marking; arranging prefabricated concrete cushion blocks according to a quincunx shape, wherein each square meter is not less than 4; arranging longitudinal and transverse steel bars, and installing an insulating clamp;

3. Arranging insulation clamps at the crossing positions of the longitudinal and transverse reinforcing steel bars and the lap joints of the longitudinal reinforcing steel bars and firmly binding the insulation clamps by using plastic tapes;

4. Longitudinal and transverse steel bars are uniformly distributed, the allowable deviation of the spacing is +/-20 mm, and the allowable deviation of the thickness of the protective layer is +10mm-5 mm;

5. after the steel bars are bound, placing the expansion joint cross template in place;

(5) Track panel assembly

1. Hoisting the sleepers to an assembly platform by adopting a gantry crane, manually paving the double-block sleepers in a matching way, and orderly and stably stacking the sleepers according to the marked designated positions, wherein the allowable deviation of the intervals of the sleepers is +/-5 mm;

2. picking a plastic cover on an embedded sleeve of a sleeper, putting down an elastic base plate at the center of a rail bearing platform to align a base plate hole with an embedded pipe hole, putting an iron base plate, wherein the iron base plate hole is aligned with the center of the embedded sleeve, and putting a lower rail base plate at the center of the iron base plate;

(6) Track panel in position and coarse adjustment

hoisting the assembled track bent frame in place by using a gantry crane, finishing coarse adjustment work of the track bent frame by using transverse and vertical adjusting studs of the track bent frame, adjusting the elevation and the level by using stud support legs, and adjusting the center of a track by using transverse inclined struts; after the rough adjustment is finished, the rail panel frames are connected by using a steel rail clamping plate; the position error of the track after coarse adjustment is controlled to be within-5 to-2 mm of elevation and +/-5 mm of a central line; repeating the measurement and confirming the track panel positioning;

(7) binding of upper layer steel bars and installation of grounding steel bars

after the track coarse adjustment is finished, the upper layer of the track bed plate is longitudinally and transversely installed with erecting steel bars, grounding steel bars and embedded parts, and grounding terminals are fixed on the grounding steel bars on the two sides of the track bed in a welding mode;

and (3) testing the insulation resistance: after the road bed slab steel bars are erected and before concrete is poured, measuring the insulation performance of each structural steel bar node;

(8) Formwork installation

The track panel frame longitudinal template is designed to be a floating structure, the whole set of template is combined with the track panel into a whole according to the width of the track bed, and when the track panel is adjusted up, down, left and right, the template follows up, so that the straightness and the width of the track bed can be accurately ensured;

(9) Track panel fine adjustment

1. a rail inspection trolley is adopted for fine adjustment of the ballastless track;

2. adjusting a center line: adjusting the left and right rail direction locking devices, and adjusting the center line of the rail;

3. Adjusting elevation: rotating the vertical stud by using a socket wrench to adjust the level and the superelevation of the track; after coarse adjustment, the top surface elevation is slightly lower than the designed top surface elevation;

4. After the track panel is finely adjusted, fixing the track panel frame through a track-oriented locker;

5. the time between the fine adjustment of the track and the pouring of the concrete is controlled within 6h, and the track panel measuring points are arranged at the positions of the track panel supporting frames to ensure the smoothness of the steel rails and the joints thereof;

(10) Pouring of concrete for road bed slab

(11) Vibrating, plastering and forming

1. Carrying out vibration operation while pouring concrete;

2. after the surface concrete is vibrated, finishing and leveling the exposed surface of the concrete in time, after the concrete is placed into a mold, finishing rough leveling by using wood, and after 1 hour, leveling by using steel;

3. after finishing plastering, cleaning the track panel, the sleeper and the fastener in time to prevent pollution;

4. After the concrete is initially set, 1/4-1/2 circles of vertical bolts are loosened, and meanwhile, fasteners and fishplate bolts are loosened, so that damage to the concrete caused by stretching of steel rails during temperature change is avoided;

(12) Dismantling of track panel and template

when the concrete of the ballast bed plate reaches a certain strength, firstly, sequentially lifting the vertical stud support legs by 1-2 mm; then loosening the rail fasteners, sequentially dismantling the bent frames, disassembling the templates, finally after confirming that the fasteners are completely loosened, hoisting the bent frames by the gantry crane to a rail panel assembly area for cleaning for standby use, and entering the next cycle construction;

Second, construction of ballastless track of bridge section

(1) CP III layout

1. CP III control points are embedded in pairs along the line, and the distance between adjacent point pairs is required to be 40-80 m;

2. The CP III control point is arranged on the top surface of the ballast retaining wall above the end of the bridge fixed support;

3. CP III control points are not embedded in the span of the continuous beam with the length within 80 m; a pair of CP III control points are buried in a continuous beam span with the length of 80-120 m; two pairs of CP III control points are embedded in a continuous beam span with the length of 120-180 m;

4. After mounting holes in the vertical direction are dug in pairs along two sides of a line on the top surface of the ballast retaining wall by CP III embedded parts, embedding the embedded parts by using bar-planting glue, wherein the exposed height of the embedded parts is not more than 3 mm;

(2) Base plate construction

1. Preparation for construction

2. Structural dimension line of setting-out base plate

After the bridge deck is cleaned, measuring and releasing the center line and two side lines of the base plate by using a CP III control net; e value of line traverse in curve segment; marking the bridge deck with ink lines as a steel bar binding control limit;

3. bridge floor connecting steel bar construction

before the base construction, the pre-embedded sleeve protective cover in the beam body is removed, and the base plate is connected with the bridge floor by a straight thread steel bar sleeve;

4. processing and binding base plate steel bars

After the bed plate steel bars are processed, the bed plate steel bars are conveyed to the position below a bridge by using a flat car, the truck crane is hoisted to the bridge and then is installed and bound, and for a high pier beam, the flat car is directly conveyed to the binding position of the bed plate steel bars of the bridge deck;

The lapping length of longitudinal steel bars in the base is not less than 500mm, the lapping rate in the same section is not more than 50%, and the net protective layer thickness of the base plate is 35 mm;

5. Construction of bed plate formwork

Firstly, a base plate and a groove template are combined and formed by adopting a shaping steel template and are connected by bolts, and the template installation is ensured to meet the design size requirement of the base plate;

Secondly, double faced adhesive tape is clamped between the base plate template plate seams for processing, and slurry leakage in the concrete pouring process is strictly forbidden;

Thirdly, after the base plate template is installed and reinforced, the groove template is installed according to the lofting plane position points, and the periphery of the groove template is additionally provided with embedded ribs for fixing the groove template; after the installation is finished, the total station remeasures the positions of the groove template and the base template;

Fourthly, the template is comprehensively checked before the concrete is poured;

Installing the lateral template according to the mark obtained by measurement lofting, wherein the plane position and elevation of the lateral template must be accurately in place, and ensuring that the template is tightly attached to the bridge floor;

6. Base plate concrete construction

checking the thickness of the steel bar protective layer again before pouring concrete; the stability of the template installation at least meets the operation requirement of the paving, leveling and vibrating machine;

before concrete pouring, sprinkling water for 2 hours in advance to wet the bridge deck, but no open water is obtained; the slump of the concrete is controlled within 160 mm-200 mm; the concrete is vibrated by a vibrating rod, and the concrete is forbidden to impact the reinforcing steel bars when vibrated; after the concrete is compacted by vibration, leveling the top surface, wherein the flatness needs to reach the requirement of 10mm/3m, the base plate cross slope of the curve section is larger, the concrete slump is controlled to be 180mm +/-5, the concrete in the ultrahigh range needs to be continuously supplemented by manpower in the concrete paving and leveling process, and finally, the concrete is leveled and compacted for two times;

the mold-entering temperature is not lower than 5 ℃ when the concrete is poured; it is also not preferable to exceed 30 ℃;

after the base plate is poured, sundry accumulated water in the limiting groove is cleaned in time;

7. Construction of isolation layer and elastic cushion layer

an intermediate isolation layer is arranged between the base plate and the track bed plate, and the isolation layer is 4mm of polypropylene geotextile with the design width of 2800 mm;

after the base concrete reaches over 75% of the design strength, the installation operation of laying an isolation middle layer and an elastic cushion layer is carried out; the polypropylene geotextile is laid to be smooth, wrinkle-free and damage-free, and the seams are butted and can not be overlapped;

after the geotextile on the top surface of the bed plate is laid, the geotextile on the inner bottom surface of the limiting groove and the elastic backing plates on the periphery are laid;

(3) Construction of road bed slab

1. clearing and construction lofting of ballast bed working face

Releasing track central line control points at intervals of 10m on the bridge isolation layer through the CP III control points according to the designed ballast bed plate position, accurately positioning by using steel nails, marking marks, and popping out the track central line by using ink lines;

Releasing the sleeper control sideline and the positions of the longitudinal and transverse template sidelines of the track bed plate by taking the track center control point as a reference;

Adopting ink lines to position the position of each longitudinal and transverse steel bar at the bottom layer of the bed plate according to the position of the center line of the popped track;

2. Arrangement of reinforcing steel bars at bottom layer of ballast bed plate

processing the roadbed slab steel bars in a steel bar processing shed, and binding and assembling on lines;

3、

Firstly, hoisting sleepers to be used on a sleeper groove on a track panel assembling platform by using a gantry crane, hoisting 5 sleepers each time, uniformly sleeper-arranging according to a positioning line of sleeper blocks on the assembling platform, and controlling the distance deviation of the sleepers within 5 mm; checking and adjusting the position of a sleeper block, arranging bolt holes on one side into a line by using elastic lines, wherein the deviation is less than 1mm, manually matching a gantry crane, aligning the bolt hole position of a fastener of the track panel frame with the bolt hole position of the sleeper, placing the panel frame on the sleeper, installing the fastener after no error exists, and fastening;

Secondly, cleaning a rail bearing table board before assembling the rail panel, and tightening a fastener bolt after the rail panel is qualified;

Checking the distance between sleepers to be controlled within 5mm after the track panel is assembled;

4. Track panel frame in place

the installed track panel is transported to the site by using a flat car, the track panel is hoisted to be in place by using a gantry crane, the track panel is sequentially and accurately in place according to the length of a slab section and the central line of the track, and the central line of a track panel frame is aligned to the central line of the track and is slowly positioned below the track; before the track panel falls to a track bed board, a plastic sleeve is sleeved on the vertical bolt supporting leg, and a track gap is adjusted by utilizing the allowable range error of the distance between two adjacent track panel sleepers;

5. coarse adjustment of track panel

the track panel coarse adjustment adopts a total station, and the track ruler completes the initial adjustment of the track panel; the adjustment principle is that the center line is firstly adjusted to the height;

6. binding of upper layer steel bars of ballast bed plate

marking the position of longitudinal steel bars on a sleeper steel bar truss according to the designed longitudinal steel bar interval, placing the longitudinal steel bars, installing an insulation clamp at the crossed part of the longitudinal steel bars and the sleeper truss steel bars, and binding the longitudinal steel bars and the sleeper truss steel bars in an inclined manner by adopting a plastic insulation buckle;

marking the positions of transverse reinforcing steel bars on two reinforcing steel bars on the outermost side of the track bed plate according to the designed transverse reinforcing steel bar interval after the longitudinal reinforcing steel bars are placed, installing the transverse reinforcing steel bars from one end of the track bed plate to the other end one by one, and installing insulating clamps at the intersections of the longitudinal reinforcing steel bars and the transverse reinforcing steel bars; after the transverse reinforcing steel bars are installed, diagonally binding the intersections of the longitudinal and transverse reinforcing steel bars by plastic insulating buckles according to the installation sequence and mode;

7. Installation of road bed plate formwork

The main operation content of the process comprises: inspecting and cleaning the template; installing a transverse template; installing a longitudinal template, and connecting a transverse template with the longitudinal template; the concrete construction sequence is as follows:

firstly, checking and cleaning a template;

Installing a transverse template: the transverse template is used at a broken joint, the position of the transverse template is overlapped with the transverse position of the base plate, after the rough adjustment of the track panel is finished, the transverse template is installed, the transverse template is hoisted to the middle position of a line at a required position by using a gantry in advance, the positions of two ends of the transverse template refer to the side line of the longitudinal template, and the installation error is 2 mm;

Installing a longitudinal template: the longitudinal template and the track panel frame are installed in a matched mode, the portal crane lifts the template, the bottom surface of the template is positioned on a plane after the template is manually matched in place, the edge of the template is guaranteed to be closely attached to the side surface of the concrete of the base plate, and slurry leakage during concrete pouring is avoided; two adjacent templates are connected by bolts, and the dislocation between the two adjacent templates is ensured when the two adjacent templates are connected by the bolts; after the longitudinal template is installed in place, the longitudinal template is connected with the vertical stud in a reinforcing way, and the top surface line of the road bed plate is marked on the inner side of the template by ink lines; the installation precision width of the longitudinal template is +/-5 mm, the center line position is 2mm, and the top surface elevation is not lower than that of the concrete top surface;

fourthly, after the longitudinal template is installed, connecting the transverse template with the longitudinal template to ensure that the longitudinal template is closely attached to the transverse template;

8. Comprehensive earth welding

Taking 3 longitudinal structural steel bars at the upper layer of each track bed board as longitudinal grounding steel bars, and taking 1 transverse structural steel bar at the middle part of the upper layer of each track bed board as transverse grounding steel bars;

Welding the longitudinal and transverse grounding steel bars, and welding the plate end grounding terminal and the longitudinal grounding steel bar; the welding should be: the length of the single-sided welding is not less than 100mm, the length of the double-sided welding is not less than 55mm, and the thickness of the welding seam is not less than 4 mm;

arranging an earthing terminal at each end of each track bed board, wherein the distance between the terminal and the board end is preferably between 100 and 150mm, connecting the track bed board longitudinally by using a stainless steel cable with the length of 0.4m to form an earthing unit with the length not more than 100m, and then carrying out single-point T-shaped connection earthing on the earthing unit and the embedded earthing terminal on the protective wall by using the stainless steel cable with the length of about 3.5 m;

fourthly, the grounding steel cable is made of stainless steel, and the section of the grounding steel cable is not less than 200mm 2;

insulation detection of steel bar

After the binding of the bed plate steel bars and the welding of the grounding steel bars are finished, an insulation resistance test is carried out, and a high resistance tester is adopted for testing;

9. Track panel fine adjustment

The main contents of the process are as follows: setting a total station; measuring orbit data; adjusting the center line of the track; adjusting elevation and locking track panel;

Setting up station for total station

The total station observes 4 continuous CP III points, automatically adjusts and calculates to determine the station setting position; if the deviation is larger than 2mm, resetting the station; after the position of the measuring station is changed, at least 4 CP III points utilized behind must be observed in a cross mode, and at least one group of track panels which are subjected to fine adjustment are retested;

Measuring orbit data

The rail inspection trolley is placed on the rail and is provided with a prism; the total station measures the prism at the top end of the track state measuring instrument, the trolley automatically measures track gauge, superelevation, horizontal position and the like, observation data is received, the data of the plane position, the level, the superelevation and the track gauge of the track are calculated through matched software, and error values are quickly fed back to a computer display screen of the track state measuring instrument to guide track adjustment;

Regulating track central line

Adjusting the left and right rail direction locking devices by using an open spanner, adjusting the center line of the rail, and adjusting 2 groups at a time; in the adjusting process, the total station always measures the prism of the track state measuring instrument, receives observation data, and quickly feeds an error value back to a computer display screen of the track state measuring instrument through matched software until the error value meets the requirement and then the adjustment is finished; after the central line is adjusted in place, one side of the elastic buckle is screwed under the monitoring of an instrument, and the adjusted central line cannot be disturbed in the process;

Adjusting the height of the track

After coarse adjustment, the elevation of the top surface is slightly lower than the elevation of the designed top surface by 0-minus 2 mm; rotating the vertical stud to adjust the level and the superelevation of the track; after adjustment, manually checking whether the screw is closely attached to the concrete or not to ensure that the bottom of the screw is not suspended;

Adjusting the stud slowly, rotating 120 degrees to change elevation by 1mm, checking whether the screw is stressed by hands after adjustment, and adjusting the screw nearby if the screw is not stressed;

Fifth, direct connection transition

after the adjustment of the previous station is finished, 8 to 10 sleepers adjusted by the previous station need to be overlapped when the adjustment of the next station is finished; the transition section starts from the first rail bent after the forward connection, and the data decrement value of each sleeper is preferably smaller than 0.2mm until the absolute deviation is close to zero;

After the track adjustment is finished, fixing the track bent through a track locking device; if the track panel is disturbed externally, or the placement time is too long, namely more than 10 hours, or the environmental temperature change exceeds 15 ℃, the track panel must be checked or adjusted again; the qualified report is checked by the supervision engineering report after the retest;

10. Concrete construction of ballast bed plate

Preparation work

cleaning sundries on a pouring surface, pouring a required power line, and comprehensively checking various construction equipment pump trucks, transport tank trucks and vibrating rods to ensure that the normal operation can be realized in the pouring process;

checking and confirming the retest result of the track panel

Before concrete is poured, if the track is placed for more than 12 hours or the environmental temperature change exceeds 15 ℃, or the track is influenced by external conditions, the track needs to be checked or adjusted again;

Mixing and conveying concrete

the concrete of the ballast bed plate is intensively mixed by a mixing station, and is poured in a direct unloading or pumping way by a concrete transport vehicle during construction;

fourthly, pouring concrete

In order to ensure that the concrete road bed board is not subjected to over-limit temperature crack pouring, the environmental temperature and the track temperature are monitored all day long during the concrete pouring process, a temperature curve is drawn, the concrete pouring can be carried out in a time period with a small temperature change range, and the concrete mold-entering temperature is controlled to be between 5 and 30 ℃;

One end of the concrete is continuously carried out towards the other end, and when the concrete automatically flows to the next sleeper from the lower part of the sleeper, the concrete can move forwards to the next sleeper to be continuously poured forwards;

When the concrete is directly unloaded and poured, the chute of the concrete transport vehicle is turned to the position above the track panel to be poured, and the valve is opened for discharging;

When concrete is pumped, the pipe orifice of the rubber pump is above the track panel, the blanking direction is basically vertical to the track panel, and the blanking height of the concrete is controlled by moving the blanking pipe;

Fifthly, plastering and cleaning

maintaining concrete

Maintaining the concrete of the ballast bed plate for at least 7 days by adopting moisture preservation and heat preservation;

Protection of the final product

11. formwork and track panel frame dismantling and cement mortar filling screw hole

firstly, the transverse formwork is dismantled

after the concrete compressive strength of the ballast bed plate reaches 5MPa, firstly connecting the longitudinal and transverse formworks and connecting the transverse formworks and loosening the transverse formworks and other connecting pieces, then tapping the formworks, after the formworks are loosened, hoisting the gantry crane out to the space between the formworks, and conveying the formworks to the next cycle by using a special formwork transport vehicle for cleaning;

The transverse formwork can be dismantled in the section where the longitudinal formwork is dismantled, and the transverse formwork is dismantled through the gantry crane and manual cooperation, and then the transverse fixing steel bars of the formwork are dismantled;

② dismantling the track panel frame

Sequentially lifting the vertical stud support legs by 1-2 mm in a rotating manner, loosening all fasteners of the unit rails, and taking down the unit rails for cleaning;

After the fastener is taken down, the bent is hoisted by a gantry crane to be transported to the next operation area for cleaning for standby, and the next cycle construction is carried out;

Thirdly, the cement mortar fills the screw hole

and (3) cleaning the plastic sleeve in the vertical stud hole, manually plugging the screw hole by using M40 high-strength non-shrinkage cement mortar, and leveling the surface.

2. the ballastless track construction method for tunnel group of heavy haul railway of claim 1, further comprising ballastless track construction of roadbed section

(1) setting up the CP III of the regional subgrade section

1. CP III control points are arranged at the positions of road shoulders;

2. Control points of ballastless track sections are arranged on the basis of contact network rods according to the related requirements of the specification of 2.0.2 of the newly-built passenger-cargo collinear ballasted track railway track control network surveying and designing supplement regulation (Total construction number [ 2013 ] 88 ]);

(2) the construction method of the base and the track bed board is similar to that of a bridge section, and the base and the track bed board need to be constructed after the settlement evaluation is qualified.