CN111663385A - Construction method for completing rapid restoration of settlement of integral ballast bed in skylight period - Google Patents

Abstract

The invention discloses a rapid repairing construction method for finishing integral ballast bed settlement in a skylight period, which is used for repairing construction in the skylight period and comprises the following steps: the method comprises the steps of restoring linear positions by using a height-adjusting fastener, chiseling off original long sleepers and surrounding track bed concrete, laying new and short sleepers, implanting reinforcing steel bars, erecting templates and pouring by using polymer cement mortar. The sleeper is repaired in the skylight period, the construction method forms a new track bed structure through pouring and maintaining polymer cement mortar, the rapid restoration of the settlement of the whole track bed is realized, the construction method is small in field engineering quantity, the polymer cement mortar can rapidly harden the track bed, the repair construction period of the track bed is shortened, the influence on the operation is greatly reduced, the gap between the rail bottom and the track bed surface is increased through heightening the fastener, the space requirement for installing a steel rail emergency device during the emergency repair of the engineering work can be met, the emergency disposal time is shortened, and the influence on the train operation and the trip of passengers is reduced.

Description

Construction method for completing rapid restoration of settlement of integral ballast bed in skylight period

Technical Field

The invention relates to the field of rail transit, in particular to a construction method for completing rapid restoration of integral ballast bed settlement in a skylight period.

Background

With the continuous improvement of the level of urban modernization in China, the development of a rapid rail transit system becomes a necessary choice for urban public transport construction. However, the geological conditions of various cities are obviously different, and some cities such as Shanghai, Tianjin, Guangzhou, Hangzhou and Ningbo belong to soft soil areas, so that the geological conditions bring challenges to the stability of the tunnel after operation. In recent years, the settlement phenomenon of the subway tunnel in soft soil after operation is increasingly serious due to reasons of liquefaction of a saturated sand soil layer, vibration sinking of saturated clay, softening of granite residual soil and the like caused by uneven settlement of a soil body of a lower layer of the tunnel, adjacent construction influence, ground load and water level change, asynchronous deformation and leakage of the tunnel and a station and vibration excitation of a subway train.

Meanwhile, the connection channel of the shield tunnel constructed in the soft soil stratum is generally constructed by adopting a freezing method, namely, freezing holes which are basically parallel to the direction of the connection channel are arranged along the periphery of an excavated section, and then low-temperature brine is circulated in the freezing holes to freeze the water-containing stratum near the freezing holes to form a frozen soil curtain with high strength and good water sealing property, and the channel is constructed by secretly excavating under the protection of the frozen soil curtain. After the contact channel main structure construction is finished, the cooling is stopped, the soil body is naturally thawed, and the thawing process can cause the settlement of the tunnel near the contact channel. Such settlement is severe at the early stage of operation.

The subway tunnel subsides the in-process and inevitably can lead to the inhomogeneous settlement of circuit, causes the separation of ballast bed and section of jurisdiction to take off from this, the ballast bed fracture, section of jurisdiction damage, and then leads to structure percolating water, track state to worsen, train dynamic load increase etc. will influence the normal use and the driving safety of subway at last. Usually, a small amount of settlement can be repaired through the track bed fastener, and once the settlement exceeds the adjusting capacity of the fastener (the maximum height adjustment is generally 30mm), the track bed may need to be repaired to meet the requirement of track smoothness.

Because the subway is operated, the subway operation can not be interrupted, and the whole track bed settlement treatment construction can only be treated within the time range of the skylight. At present, the method for renovating and repairing the track bed usually adopts the steps of chiseling a sleeper, burying a new sleeve in a drill hole, and pouring cement mortar into a bearing rail table type track bed in situ, or adopts the steps of chiseling the sleeper and a track bed surface, burying a new sleeve in a drill hole, and pouring a sleeper-free track bed by using cement mortar. Its disadvantages are easy breakage and poor durability; the construction quality of the rail bottom slope is not easy to guarantee, so that the abrasion of the steel rail is aggravated; the gap between the rail bottoms is small, and the emergency repair installation of the steel rail emergency treatment device is very difficult when the rail is broken. The existing methods are time-consuming, labor-consuming and large in investment, normal operation of the subway needs to be guaranteed, construction difficulty is high, and construction period is long.

Disclosure of Invention

The invention aims to: aiming at the problems that the table track bed or the sleeper-free track bed of a cast-in-place rail bearing poured by cement mortar in the prior art is easy to damage and poor in durability, the construction quality of a rail bottom slope is not easy to guarantee, the abrasion of a steel rail is aggravated, the gap between the rail bottom is small, and the steel rail emergency treatment device is difficult to mount in emergency repair during rail breakage, the construction method for rapidly repairing the settlement of the whole track bed in a skylight period is provided.

In order to achieve the purpose, the invention adopts the technical scheme that:

a rapid repairing construction method for finishing integral ballast bed settlement in a skylight period is used for being carried out in the skylight period and comprises the following steps:

restoring the linear position by adopting a height-adjusting fastener;

chiseling the original long sleeper and the concrete of the surrounding track bed;

laying a new short sleeper;

implanting steel bars;

erecting a template;

pouring is performed by polymer cement mortar.

By the method, the sleeper is repaired in the skylight period, the construction method forms a new track bed structure through pouring and maintaining polymer cement mortar, the rapid restoration of the settlement of the whole track bed is realized, the construction method is small in field engineering quantity, the polymer cement mortar can rapidly harden the track bed, the repair construction period of the track bed is shortened, the influence on operation is greatly reduced, the gap between the rail bottom and the track bed surface is increased by heightening the fasteners, the space requirement for installing a steel rail emergency device during the emergency repair of work can be met, the emergency disposal time is shortened, and the influence on the operation of a train and the trip of passengers is reduced;

the method can ensure the construction quality of the rail bearing platform and the rail bottom slope, has good durability, and has the advantages of simple construction process, strong operability, convenient material purchase, simple mechanical equipment, high construction efficiency and good technical advantages and economic benefits compared with other ballast bed settlement repairing construction methods.

The skylight period in the present invention is typically 23: 40-4: and 40, dividing the skylight period into a first stage, a second stage, a third stage, a fourth stage and a fifth stage according to the actual condition of the construction site, and determining the construction steps required to be carried out in each stage according to the actual condition of the construction site.

As a preferred scheme of the invention, the height-adjusting fastener comprises a rail lower backing plate, a backing plate and a plate lower height-adjusting backing plate, wherein the rail lower backing plate is positioned at the top of the backing plate, and the plate lower height-adjusting backing plate is positioned at the bottom of the backing plate. Through the structure, the rail is heightened by 0-10mm by the rail lower backing plate, the rail is heightened by 0-60mm by the backing plate, and the rail is heightened by 0-30mm by the plate lower heightening backing plate.

As a preferred scheme of the invention, in the step of chiseling the original long sleeper and the concrete of the surrounding track bed, the sleeper in the renovation range is taken out from the concrete track bed by adopting the principle of dividing three parts by one part, and the chiseling surface of the track bed is kept rough;

in the range of the chiseled track bed, the bottom of the new sleeper has a space of 40mm-60mm, and the periphery of the new sleeper has a space of 70-90 mm.

As the preferred scheme of the invention, the new short sleepers are paved in the step of paving the new short sleepers, the new short sleepers are scattered and paved at the position of the original sleepers, and the common sleepers are adopted when the settlement of the track bed is within 50 mm; when the settlement of the track bed is more than 50mm and less than 100mm, the reinforced sleeper is adopted. Through the steps, the connection strength of the sleeper and the track bed can be enhanced by roughening the periphery of the common sleeper, and the durability is improved.

As a preferred scheme of the invention, after the new short sleeper is laid in the step, the originally designed fastener is installed, and the bolt is screwed down, so that the new short sleeper is suspended below the steel rail.

The originally designed fastener in the invention refers to a common fastener in the prior art.

As a preferred scheme of the invention, before the step of laying a new short sleeper, the method cleans the scraps, washes the chiseled surface and removes impurities;

the bed is then painted with an undercoating material in the gouged area.

As a preferred scheme of the invention, the steps of implanting the steel bars into a track bed at four corners of a sleeper, drilling holes in the track bed, implanting a first threaded steel bar, and arranging an upper layer and a lower layer of second threaded steel bars on the periphery of the sleeper;

the implanted first twisted steel is firmly bound with the upper and lower two layers of twisted steel, the bottom layer of twisted steel is flush with the height of the steel bar stretched out from the sleeper, the upper and lower two layers of twisted steel are welded with the steel bar stretched out from the sleeper, the welding length is not less than 60mm, and the height of the welding line is not less than 4 mm.

As a preferable aspect of the present invention, in the step of erecting the template, a template line is ejected on the road bed surface, and then the template is attached.

As a preferred scheme of the invention, after the step of erecting the template is completed, sundries are cleaned again;

then preparing polymer cement mortar.

As a preferred scheme of the invention, the steps are in pouring through polymer cement mortar, when pouring the polymer cement mortar, the cement mortar flows naturally from one side of the sleeper to the other side, then the vibration is carried out, after the bottom of the filled sleeper is vibrated to be compact, the forward pouring is continued, and the surface of the concrete of the track bed is subjected to plastering treatment;

cleaning the steel rail after the vibration is finished, and maintaining after the pouring is finished;

and after the pouring is finished, repeating the steps according to the principle of cutting three holes by one, until the sleepers in the renovation range are completely repaired.

In summary, due to the adoption of the technical scheme, the invention has the beneficial effects that:

1. the sleeper is repaired in a skylight period, the construction method forms a new track bed structure through pouring and curing polymer cement mortar, the rapid restoration of the settlement of the whole track bed is realized, the construction method has small field engineering amount, the polymer cement mortar can rapidly harden the track bed, the repair construction period of the track bed is shortened, the influence on the operation is greatly reduced, the gap between the rail bottom and the track bed surface is increased through heightening the fastener, the space requirement for installing a steel rail emergency device during the emergency repair of the engineering work can be met, the emergency disposal time is shortened, and the influence on the train operation and the trip of passengers is reduced;

the method can ensure the construction quality of the rail bearing platform and the rail bottom slope, has good durability, and has the advantages of simple construction process, strong operability, convenient material purchase, simple mechanical equipment, high construction efficiency and good technical advantages and economic benefits compared with other ballast bed settlement repairing construction methods.

Drawings

FIG. 1 is a flow chart of a construction method for completing rapid restoration of monolithic roadbed settlement in a skylight period according to the invention.

Figure 2 is a schematic structural view of a repaired track bed structure according to the present invention.

Fig. 3 is a partially enlarged view of the area a in fig. 2.

Figure 4 is a schematic plan view of the monolithic track bed structure of the present invention.

Fig. 5 is a schematic structural view of the height-adjusting fastener of the present invention.

Icon: 1-twisted steel bar I; 2-twisted steel bar II; 3-polymer cement mortar; 4-heightening fasteners; 41-rail lower backing plate; 42-a backing plate; 43-raising the base plate under the plate; 5-original long sleeper.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings.

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Examples

As shown in fig. 1 to 5, the embodiment provides a construction method for completing rapid restoration of monolithic track bed settlement in a skylight period, and the construction method performs construction in the skylight period and includes the following steps:

s1: the linear position is restored by adopting a height-adjusting fastener 4;

specifically, firstly, determining the ballast bed renovation range on site according to the result of the optimized line;

before the construction of the whole track bed, organizing technicians to carry out retest on the track laying base marks so as to ensure the precision of track construction, marking control points after the result meets the standard requirement, and performing attention to protecting control piles in the construction process;

transporting materials such as a heightening fastener 4, a short sleeper, a reinforcing steel bar, a template, mortar and the like to an operation section as required;

covering field communication, signals, power pipelines and equipment by using color strip cloth to prevent pollution;

arranging warning lines on a construction site, arranging red flashing lamps on two sides of a modified line, and well taking site safety measures;

except for construction related electricity consumption, other system facilities are ensured to be in a non-working state in the construction section so as to ensure the safety of constructors and equipment;

then in the first stage, measuring the line elevation and the plane position within the range of the settled ballast bed to be repaired, comparing the line elevation and the plane position with the theoretical design position of the line, and calculating and analyzing the height to be adjusted and the deviation adjustment amount of the track;

the calculation analysis formula is as follows:

theoretical design of rail elevation (track lifting amount), theoretical design of rail elevation after settlement, rail elevation and track deviation adjustment amount (theoretical design of line center after settlement), line center after settlement

In the second stage, a track inspection instrument, a right-angle track scale, a universal track scale and other measuring tools are adopted to finely adjust the line, the height-adjusting track fastener 4 is used for restoring to a theoretical design position, and an insulating track gauge pull rod is used for connecting a left steel rail and a right steel rail, so that the stability of the line is enhanced, the speed of the subway vehicle is limited to 15km/h and passes through the section, and the maximum height-adjusting amount of the fastener is not less than the settlement amount of the track bed to be repaired;

the height-adjusting fastener 4 comprises a rail lower backing plate 41, a backing plate 42 and a plate lower height-adjusting backing plate 43, wherein the rail lower backing plate 41 is positioned at the top of the backing plate 42, and the plate lower height-adjusting backing plate 43 is positioned at the bottom of the backing plate 42. The track is heightened by 0-10mm by the track lower backing plate 41, the track is heightened by 0-60mm by the backing plate 42, and the track is heightened by 0-30mm by the plate lower heightening backing plate 43;

s2: chiseling the original long sleeper 5 and the concrete of the surrounding track bed;

specifically, in the third stage, according to separating three chisel principle, every three sleepers chisel one promptly, chisel out former long sleeper 5, find out former railway roadbed structure reinforcing bar before chiseling out and arrange, then adopt utensil such as concrete cutting saw or pneumatic pick, take out the sleeper of renovating the scope from the concrete railway roadbed, chisel out the railway roadbed scope and have the space 40mm ~ 60mm deep according to guaranteeing newly to install the sleeper bottom, there is 70 ~ 90mm wide space all around the sleeper as the standard. And keeps the chiseled surface of the ballast bed rough. The chiseling of the ballast bed should adopt small-sized machine tools and equipment to avoid disturbance and damage to the adjacent ballast bed. When chiseling, the original ballast bed structural steel bars are protected;

then clearing and bagging the ballast bed concrete chips in the chiseling area, then washing the chiseling surface by using high-pressure water, and removing impurities such as floating slurry, dust and the like by using a dust collector;

and (3) coating a priming paint on the chiseled area of the ballast bed to strengthen the bonding of new and old concrete. The base coating material is selected from polymer cement paste or a special interface agent;

s3: laying a new short sleeper;

specifically, in the fourth stage, new short sleepers are scattered and paved at the original sleeper position. When the settlement of the track bed is within 50mm, a common sleeper can be adopted; when the settlement is more than 50mm and less than 100mm, a reinforced sleeper is adopted. In order to enhance the connection strength between the sleeper and the track bed and improve the durability, the periphery of the common sleeper can be slightly roughened within the range of less than 50mm from the rail bearing surface;

installing an originally designed fastener, and screwing down each bolt of the fastener according to specified torque so as to enable the short sleeper to be hung below the steel rail;

s4: implanting steel bars;

specifically, holes are drilled in a track bed at four corners of a sleeper, and bar planting glue is used for planting a threaded steel bar I with the diameter phi of 14 and the HRB400 grade, wherein the planting depth is more than 70 mm;

the periphery of the sleeper is provided with an upper layer of threaded steel bars II 2 with the diameter phi of 14, the HRB400 grade of N2 and the N3, the threaded steel bars II are firmly bound with the threaded steel bars I1 by binding wires, and the positions of the steel bars are controlled according to the thickness of the concrete protective layer of 35 mm. Note that the height of the bottom rebar two 2 should be flush with the tie extension rebar. If the track bed between the sleepers is damaged, the damaged track bed is removed, the deformed steel bars III are communicated, and 1 deformed steel bar II 2 is added between the sleepers;

and welding the second threaded steel bar 2 and the sleeper extending steel bar. The welding length is not less than 60mm, and the height of the welding seam is not less than 4 mm. If the reinforcing steel bars of the stray current collecting net of the original ballast bed are loosened and disconnected, the stray current collecting net is also welded to be communicated with the stray current collecting net of the original ballast bed, and the next procedure can be carried out after the stray current collecting net is qualified to be tested;

s5: erecting a template;

specifically, in the fifth stage, whether embedded parts such as stray current collecting terminals are omitted or not and whether the positions are accurate or not are checked, and the fact that the templates are installed correctly is guaranteed. Popping a template line on the surface of the road bed, connecting the steel templates by using a template clamp, cutting the ends by adopting a wooden template according to the actual situation on site, and removing the defects of slurry leakage formed by the gap between the template and the surface of the road bed, steps formed at the joint of the template and the like when the template is installed;

the roadbed template is firmly erected, and the allowable deviation is as follows: the position is +/-5 mm, and the verticality is 2 mm;

cleaning up sundries such as the concrete of the track bed in the chiseled area, chips around the sleeper, welding slag and the like again, and wetting the pouring area of the track bed without water accumulation;

accurately metering according to the proportion requirement of the polymer cement mortar 3, stirring for 3-5 minutes at a low speed by using an electric stirrer, wherein the polymer cement mortar 3 requires low shrinkage, early strength, good bonding property and good fluidity, and the mortar property needs to meet the quality control requirement;

s6: pouring is carried out through polymer cement mortar 3;

specifically, the environmental temperature of the polymer cement mortar 3 during construction is preferably 10-35 degrees C. When the polymer cement mortar 3 is poured, the mortar naturally flows from one side of the sleeper to the other side, is vibrated by a small-sized inserted vibrator, particularly, the tamping around the bottom of the concrete sleeper is strengthened, and the concrete is ensured to be filled fully and well combined with a track bed. After the bottom of the filled sleeper is vibrated to be compact, the sleeper can be continuously poured forwards. The steel rail, the sleeper and the template cannot be collided during vibration;

polymer cement mortar parameter requirements:

(a) the fluidity is more than or equal to 300

(b) Setting time: about 20 minutes

(c) Compressive strength

The compressive strength is more than or equal to 30MPa in 1 hour

The compressive strength of the product is more than or equal to 60MPa in 24 hours

The 28-day compressive strength is more than or equal to 90MPa

(d) Flexural strength

The rupture strength is more than or equal to 5MPa within 1 hour

The 24-hour flexural strength is more than or equal to 12MPa

The rupture strength is more than or equal to 15MPa after 28 days;

then, the concrete surface of the ballast bed is subjected to plastering treatment, and the plastering allowable deviation is as follows: the flatness is 2mm, the elevation is controlled according to the level of the surface of the adjacent ballast bed, and a reverse slope cannot occur so as to avoid affecting drainage;

after the vibration is finished, the steel rail is cleaned immediately to ensure that no concrete exists in the steel rail, the sleeper and the fasteners, the cleaning difficulty after the mortar is hardened is avoided, after the pouring is finished, geotextile covering, moisturizing and curing are carried out immediately to ensure that the compressive strength of the track bed reaches 30MPa or more after 2 hours;

and finally, repeating the steps according to the principle of cutting three holes at intervals until the sleepers in the renovation range are completely repaired, and cleaning all garbage, tools, equipment and the like on the site. And (5) the geometric shape and position of the fine adjustment line meet the requirement of acceptance specifications, and the fine adjustment line is recovered to operate at normal speed.

The construction method has the advantages that the construction method carries out the repairing construction on the sleeper in the skylight period, the pouring maintenance is carried out through the polymer cement mortar 3 to form a new track bed structure, the rapid recovery of the settlement of the whole track bed is realized, the construction method has small field engineering amount, the polymer cement mortar 3 can rapidly harden the track bed, the repairing construction period of the track bed is shortened, the influence on the operation is greatly reduced, the gap between the rail bottom and the track bed surface is increased through the heightening fastener 4, the space requirement for installing a steel rail emergency device during the emergency repair of the engineering work is met, the emergency disposal time is shortened, and the influence on the operation of a train and the trip of passengers is reduced,

the method can ensure the construction quality of the rail bearing platform and the rail bottom slope, has good durability, and has the advantages of simple construction process, strong operability, convenient material purchase, simple mechanical equipment, high construction efficiency and good technical advantages and economic benefits compared with other ballast bed settlement repairing construction methods.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims (10)

1. A construction method for completing rapid restoration of integral ballast settlement in a skylight period is characterized in that the construction method carries out construction in the skylight period and comprises the following steps:

the linear position is restored by adopting a height-adjusting fastener (4);

chiseling the original long sleeper (5) and the concrete of the surrounding track bed;

laying a new short sleeper;

implanting steel bars;

erecting a template;

pouring is carried out through polymer cement mortar (3).

2. The construction method for completing the rapid restoration of the integral track bed settlement in the skylight period as claimed in claim 1, wherein said heightening fastener (4) comprises a rail lower backing plate (41), a backing plate (42) and a plate lower heightening backing plate (43), said rail lower backing plate (41) is located at the top of said backing plate (42), and said plate lower heightening backing plate (43) is located at the bottom of said backing plate (42).

3. The construction method for completing the rapid restoration of the integral ballast settlement in the skylight period as claimed in claim 2, wherein in the step of chiseling the original long sleeper (5) and the concrete of the surrounding ballast, the sleeper in the renovation range is taken out from the concrete ballast by adopting the principle of three-in-one chiseling, and the chiseling surface of the ballast is kept rough;

in the range of the chiseled track bed, the bottom of the installed new sleeper has a space of 40-60 mm, and the periphery of the new sleeper has a space of 70-90 mm.

4. The construction method for completing the rapid restoration of the settlement of the whole track bed in the skylight period according to claim 1, wherein in the step of laying new short sleepers, the new short sleepers are scattered and laid at the positions of original sleepers, and when the settlement of the track bed is within 50mm, common sleepers are adopted; when the settlement of the track bed is more than 50mm and less than 100mm, the reinforced sleeper is adopted.

5. The construction method for completing the rapid restoration of the settlement of the integral track bed in the skylight period as claimed in claim 1, wherein after the new short sleeper is laid in the step, the originally designed fastener is installed, and the bolt is tightened to hang the new short sleeper below the steel rail.

6. The construction method for completing the rapid restoration of the integral track bed settlement in the skylight period as claimed in claim 1, wherein before the step of laying the new short sleeper, the method comprises the steps of cleaning up scraps, washing the chiseled surface and removing impurities;

the bed is then painted with an undercoating material in the gouged area.

7. The construction method for completing the rapid restoration of the settlement of the integral track bed in the skylight period according to claim 1, wherein in the step of steel bar implantation, holes are drilled in the track bed at four corners of the sleeper, a first threaded steel bar (1) is implanted, and a second threaded steel bar (2) with an upper layer and a lower layer is arranged on the periphery of the sleeper;

the implanted twisted steel I (1) is firmly bound with the upper and lower layers of twisted steel II (2), the height of the bottom layer of twisted steel II (2) is flush with the height of the sleeper stretching reinforcing steel bar, the upper and lower layers of twisted steel II (2) are welded with the sleeper stretching reinforcing steel bar, the welding length is not less than 60mm, and the height of the welding line is not less than 4 mm.

8. The method for completing the rapid restoration construction of the integral ballast settlement in the skylight period as claimed in claim 1, wherein in the step of erecting the formwork, a formwork line is ejected on the ballast surface, and then the formwork is connected.

9. The construction method for completing the rapid restoration of the settlement of the integral ballast bed in the skylight period according to claim 1, wherein the sundries are cleaned again after the templates are erected in the step;

then, polymer cement mortar (3) is prepared.

10. The construction method for completing the rapid restoration of the integral ballast settlement in the skylight period according to any one of claims 1 to 9, wherein the step is performed by pouring polymer cement mortar (3), the cement mortar naturally flows from one side to the other side of the sleeper when the polymer cement mortar (3) is poured, then the vibration is performed, after the bottom of the filled sleeper is vibrated to be compact, the forward pouring is continued, and the surface of the ballast concrete is subjected to surface plastering treatment;

cleaning the steel rail after the vibration is finished, and maintaining after the pouring is finished;

and after the pouring is finished, repeating the steps according to the principle of cutting three holes by one, until the sleepers in the renovation range are completely repaired.

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