CN109611102A - Construction of the flyover method is worn under a kind of cold excavation - Google Patents

Abstract

Construction of the flyover method is worn under a kind of cold excavation, the present invention relates to technical field of tunnel construction；Its construction procedure is as follows: leading pre-supporting construction；Tunnel cutting；Steelframe processing and installation；Grouting rock bolt construction；First branch gunite concrete；Tunnel Second Lining.Disturbance when reducing tunnel excavation to surrounding enviroment reduces construction risk, guarantees existing viaduct operation security.

Description

Construction of the flyover method is worn under a kind of cold excavation

Technical field

The present invention relates to technical field of tunnel construction, and in particular to wears construction of the flyover method under a kind of cold excavation.

Background technique

The situation of the existing bridge of urban track traffic Tunnel Passing is more and more, and when constructing tunnel should guarantee that bridge can Normal use ensures that engineering is smoothly carried out again, and stratum deformation and stress release that tunnel excavation generates will necessarily be to existing Bridge generates disturbance, to threaten the use and safety of bridge, therefore, probes into and is applied using reasonable safeguard procedures and correct tunnel Work method is extremely important.

Summary of the invention

In view of the defects and deficiencies of the prior art, the present invention intends to provide a kind of structure is simple, design rationally, make Construction of the flyover method is worn under convenient cold excavation, disturbance when reducing tunnel excavation to surrounding enviroment reduces construction risk, Guarantee existing viaduct operation security.

To achieve the above object, the technical solution adopted by the present invention is that: its construction procedure is as follows:

1, leading pre-supporting is constructed

1.1, advanced tubule supporting

1.1.1, the preparation of per-fore pouring liquid with small pipe equipment and injecting paste material: grouting equipment uses FBY double-fluid grouting machine；Note Pulp material uses the portland cement slurries of P.O42.5, and the ratio of mud is 0.5:1~1:1；It is first tested before slip casting, sample reaches Practical operation is carried out after to code requirement；Required water is first poured into agitator, then cement is poured into agitator, machine according to the proportion Tool stirring, it is after mixing evenly, spare, cement grout with mix with；

1.1.2, advanced tubule processing and installation: ductule is process using 42 seamless steel pipe of Ф, and front end is processed into Taper so as to inserting piling, and prevents slurries preshoot；6~8mm of Ф injected hole is bored at position among ductule, is in quincuncial arrangement, spacing It does not drill within the scope of 20cm, tail portion 1m, mortar leakage prevention, end weld-ring shape iron hoop, cracking ends when to prevent setting influence Grouting Pipe Connection, construction Shi Xianyong pneumatic pick drilling, air drill jacking；By the ductule connection after drilling and seal orifice；

1.1.3, per-fore pouring liquid with small pipe: grouting sequence, to there is water hole, by few water to more water holes, and needs tripping by no water hole Pressure injection；The length of every ductule, pressure injection time, slurry consumption amount and the live various problems occurred and solution are done in construction Method will charge to prescribed form record sheet；

1.1.4, per-fore pouring liquid with small pipe ending standard limits:

Single hole ending standard: high pressure after first slow rear fast, elder generation's low pressure is answered when slip casting, pressure is no more than when starting slip casting 0.2Mpa gradually increases pressure with grouting amount increase until design value (0.5~1Mpa), slip casting ending standard are single hole grouting amount Reach design value, the design value that grouting pressure reaches continues slip casting 2min, and grout absorption is less than the 1/4 of initial grout absorption, can terminate Slip casting；

Full section ending standard: all injected holes all terminate slip casting by standard, without apparent leakage point in tunnel；

1.1.5, advanced tubule inspection of quality；

1.2, steel tube shed supporting

1.2.1, the preparation of steel tube shed grouting equipment and injecting paste material: grouting equipment uses FBY double-fluid grouting machine, slip casting material Material uses the portland cement slurries of P.O 42.5, and the ratio of mud is 0.5:1~1:1, when underground water development or grout mixing When larger, grouting serous fluid should be cement-sodium silicate double liquid, and required water is first poured into agitator, by cement according to matching Than pouring into agitator, mechanical stirring is after mixing evenly, spare, cement grout with mix with；

1.2.2, steel tube shed processing and installation:

Conduit specification: heat pricks seamless steel floral tube, outer diameter 159mm, wall thickness 10mm, length left tunnel 26m, right tunnel 20m；Pipe away from: Circumferential spacing 35cm；Inclination angle: 0~3 ° of outer limb；Steel tube shed joint steel pipe is connect using Ф 180*10mm, long 40cm joint steel pipe Long, in order to make steel tube shed connector be staggeredly arranged, right tunnel number is that the segment Guan Peng of odd number hole location is arranged by 4*4.5m+2.0m, is compiled Number arranged for the segment Guan Peng of even hole by 2.0m+4*4.5m, left tunnel number be odd number hole location the segment Guan Peng by 5*4.5m+ 3.5m arrangement, number is that the segment Guan Peng of even hole is arranged by 3.5m+5*4.5m；Steel tube shed is processed using 159 seamless steel pipe of Ф It forming, front end processing is tapered, and steel reinforcement cage is added in conduit, and steel reinforcement cage is made of four C18HRB400 main reinforcements and fixed ring, Gu Ring is determined using short tube section, it is welded with main reinforcement, is arranged by 1m spacing, 10~16mm of Ф injected hole is bored at position among pipe canopy, is in Quincuncial arrangement does not drill within the scope of spacing 20cm, tail portion 1.5m；Steel tube shed is applied using pipe-following drilling method, to subtract small pipe shed It applies and causes surface subsidence problem；

1.2.3, steel tube shed slip casting: grouting sequence, to there is water hole, by few water to more water holes, and needs tripping pressure by no water hole It infuses, in construction all to the length of every root canal canopy, pressure injection time, slurry consumption amount and the various problem and solutions of scene appearance Prescribed form record sheet is charged to, to analyze front geological condition；

1.2.4, steel tube shed slip casting ending standard limits:

Single hole ending standard: grouting pressure gradually rises, and designs final pressure and stable 10min when reaching；Grouting amount is not less than Design grouting amount 80%；It is less than into slurry speed and starts 1/4 into slurry speed；

1.2.5, steel tube shed inspection of quality；

2, tunnel cutting

2.1, non-explosive excavation top bar 1. portion, applies 1. portion's preliminary bracing；Suspend after completing 1. portion's preliminary bracing 5m 1. portion is excavated, 5cm thickness C25 concrete enclosing face is sprayed；

2.2, non-explosive excavation top bar 2. portion, applies 2. portion's preliminary bracing；Suspend after completing 2. portion's preliminary bracing 5m 2. portion is excavated, 5cm thickness C25 concrete enclosing face is sprayed；

2.3, it is laid with inverted arch waterproof layer, perfusion in timePortion's inverted arch and side wall concrete；

2.4, perfusion inverted arch fillingPortion is to design height；

2.5, arch wall waterproof layer, disposal pouring are appliedPortion's arch wall concrete；

2.6, after two lining concrete strengths reach the 80% of design strength, it is next to repeat above-mentioned operation 2.1-2.6 progress Lining cutting circulation construction；

3, steelframe processing and installation

3.1, steelframe is processed: technical staff is according to drawing size to the skills such as steelframe dividing elements and every cell radius, arc length Art parameter is checked, and is issued and is confided a technological secret after errorless, and scene processes steelframe by sectional steel cold-bending machine；

Steelframe is processed in reinforcing steel processing shed unification by design size, and steelframe junction steel plate must be drilled using bench drill, no It obtains using electric welding or acetylene hole burning, each unit steelframe, which completes the process, must organize examination to spell, after inspection steelframe size and profile qualification It can produce in batches and come into operation；

3.2, measurement and positioning: excavation finishes, and after first pneumatically placed concrete, that is, carries out the installation of steelframe, steelframe positioning uses middle line Elevation method makes the middle line in tunnel according to total station, and the offset distance of steelframe end is symmetrically measured according to middle line, complies with design number Value, while using the elevation at the control points such as vault, arch springing, the inverted arch bottom of level measurement steelframe, adjustment steelframe, which complies with, to be set Meter requires；

3.3, steelframe is installed: after adjusting steelframe position, bolt between steelframe being tightened, 22 longitudinal direction Φ is set between two Pin and is connected Connect reinforcing bar, circumferential spacing 1000mm, single layer arrangement, connection reinforcing bar spreading uses two-sided overlap welding, and when welding guarantees two sides reinforcing bar On the same axis；

3.4, steel mesh is laid with: steel mesh uses 8 reinforcing bar of φ, spacing 200mm × 200mm, and reinforced mesh presses design in advance Arch spacing processes spare outside hole, and reinforced mesh processing is made of reinforcing-bar binding machine, and anchor pole carries out reinforcing bar after applying Net is mated formation；Steel mesh, which should be adjustable to circumstances, is close to just spray plane, beats shallow bore hole with impact drill and buries expansion bolt, steel mesh is fixed on bolt On, and welded with anchor pole tail portion；Fragment makes outside hole, and the lap of splice is not less than 10cm when installation；It is artificial to be laid with, it is sharp when necessary It is shored with air drill air leg, to be connected firmly with anchor pole and steelframe binding close to scar；When steel mesh and steelframe are bound, it should tie up Close to scar side；When pneumatically placed concrete, spray head is adjusted to by spray plane distance and wind pressure, steel mesh vibration is reduced, reduces rebound； Steel fibre reinforced concrete protective layer thickness is not less than 2cm；

4, grouting rock bolt is constructed

4.1, jewel hole: drilling machine is selected according to anchor pole type, specification and country rock situation；Hole location tolerance is ± 150 ㎜, drilling hole amount should meet design code；Jewel hole diameter has to be larger than anchor rod body diameter 15mm；Hole depth is no less than anchor pole bar Body effective length, but depth overlength value should not exceed 100mm；

4.2, it is in the milk: eyelet must be blown off before grouting；Cement mortar must mix it is uniform, with mix with；It is in the milk full, It uniformly carries out, must not interrupt since bottom hole, prevent that tube drawing is too fast, cause mortar to disconnect and be in the milk and be discontented with；Grouting Pipe must insert It at away from 5~10cm of bottom hole, slowly at the uniform velocity extracts with the injection of cement mortar, is immediately rapidly inserted into the body of rod, anchor rod body is inserted Enter the length in hole must not be shorter than design length 95%, if aperture is flowed out without mortar, it is necessary to which paddle, anchor are infused into body of rod extraction again Bar must not be tapped arbitrarily after installing, and end must not hang weight in 3 days；

4.3, rockbolt installation: reinforcing bar must derust alignment before installing；Reinforcing bar at the uniform velocity must be inserted into immediately after grouting, position Between two parties；Aperture can use the interim sealing of timber wedge；Reinforcing bar tail end protruded length is preferably slightly smaller than jetting thickness；Must not be tapped after installing and Collision, anchor pole insertion depth cannot be less than the 95% of design requirement；There is water location, when using anchor rod with cement mortar, such as hole Interior flowing water, nearby separately drilling is used as diversion pipe, carries out anchor pole operation again after water is discharged；

5, hollow grouting anchor is constructed

5.1, preparation of construction: carrying out rockbolt installation operation in time after first pneumatically placed concrete, checks whether bolthole is unimpeded；Inspection It looks into air compressor machine and its whether pipeline, air pressure gun is in shape；

5.2, armature boring: armature boring according to design requirement and is tied using the rock drilling machineries such as gas leg type air pressure gun, before drilling It surrounds rock occurrence and makes hole location, make label；By the position of drill bit alignment calibration, make drilling direction vertical-dipping bed structure as far as possible Face at the end of drilling, keeps the exposed segment length of anchor pole in 10~15cm to play better reinforcement effect；

5.3, borehole cleaning: after drilling to completion, with water or high-pressure blast borehole cleaning, drilling rod connector sleeve is unloaded after confirmation is unimpeded；

5.4, squeeze into anchor pole: the mode that air pressure gun heads into squeezes into anchor pole；

5.5, slip casting: slip casting uses link extrusion type grouting pump, and grouting serous fluid is M20 cement slurry, will only be starched with hole cap assembly set Plug squeezes into aperture 30cm or so by anchor pole exposed junction, checks grouting equipment, prepares cement slurry by match ratio, starts grouting pump note Slurry, until slurries are squeezed out from aperture periphery or termination when pressure gauge has reached design pressure value, for hollow grouting anchor, when slip casting Aperture pressure is 0.7~1.0MPa, and slip casting can be terminated by continuing 15min when reaching pressure, after the completion of slip casting, is washed with water in time Slip casting machine and pipeline；

5.6, backing plate, nut are installed: after institute's injection slurry intensity reaches predetermined strength, backing plate being installed, it is made to be close to rock Face tightens rod end nut, so that it is generated certain prestressing force, play the role of preferably reinforcing country rock, anchor pole should be protected with backing plate It holds vertically, and is come into full contact with jetting cement, nut must be tightened；

6, first branch gunite concrete

6.1, concrete raw material preparation is sprayed:

Cement: using the ordinary portland cement of design requirement label, intensity check test is done before use, performance meets Existing cement standard；

Fine aggregate: medium coarse sand, fineness modulus are greater than 2.5, are sieved with 5mm sieve；

Coarse aggregate: the mechanism rubble of partial size 5mm~15mm；

Water: tap water is used；

Accelerator: using liquid accelerator, does compatibility test with cement using preceding, tests with the net slurry of the ratio of mud 0.4 Meet the presetting period less than 5min, final setting time is less than 10min, and volume is less than the 5% of cement consumption, and strength retention is big within 28 days In 70%；

6.2, the stirring of concrete wet feed: being stirred using forced mixer, forms material spray, and mixing time is no less than 3 points Clock；Feed intake metering device used in periodic inspection stirring, and configuration deviation meets code requirement, cement-aggregate ratio: 1:3.5~1:4.0, water ash Than: 0.42~0.50,8~12cm of concrete slump；

6.3, construction of shotcrete: being handled by spray plane, and embedded jetting thickness mark, is connected geomantic omen electricity and is tried Machine transports material spray using mixer truck, and carries out just pneumatically placed concrete operation, after the completion of first pneumatically placed concrete operation, fills spray, adjusts cooperation Carry out multiple pneumatically placed concrete operation, last quality inspection again than after；

7, Tunnel Second Lining

7.1, basal plane cleaning, surveying setting-out: waterproof slab protective layer sundries is cleaned out, then two lining two of unwrapping wire pop-up The abutment wall position line, Control of floor line, control point spacing are not greater than 5m, not handy iron nail or bar dowel, in order to avoid prick bad waterproof layer；

7.2, water proof equipment is installed；

7.3, inverted arch reinforcing bar is bound: steel bar stress is rebuilding, and inverted arch cover to reinforcement is controlled using mortar pad；It is double Split heads control protective layer and positioning are set between layer reinforcing bar；Two lining main reinforcement Type Diameters are up to Φ 20, using two-sided welding, connector Position is staggered 35d；Steel bar stress connector is arranged in stress smaller part, and joint location is staggered 35d；Principal rod connector uses straight thread Connection, the connector being arranged in same component should mutually stagger, and the percentage of splice area meets specification and design requirement, Tensile region is not more than 50%；When reinforcing bar binding overlap joint, intermediate and both ends are bound at three altogether, it is necessary to individually after binding again and cross bar Binding；Main reinforcement and distributing reinforcement are other to be bound point iron wire with racking seizing and be buckled in addition to 2~3 column skeleton of deformation joint all binding At splayed configuration；Stirrup and main reinforcement crosspoint are all bound；

7.4, inverted arch concrete placings and maintenance: being set up using scaffold board on reinforcing bar and split heads before concrete placings and pour riding track, is prevented Only reinforcing bar deforms；Concrete placings use ground pump, and concrete slump is controlled in 120mm~160mm；The two lining left line 0.8m of concrete base plate thickness, Right line 1m, is poured using inclined plane delamination method, the lower ash by one end, hand close fit of vibrating, and keeps concrete with " catching up with slurry processes " It pushes ahead along board bottom, is struck off when vibrating with darby, wooden float compacting smoothes out, secondary pressure surface before initial set, to reduce concrete crack； It is conserved in time in 12h after concrete placings, curing time must not be less than 14d；

7.5, arch wall reinforcing bar is bound: cover to reinforcement is controlled using plastic cushion；" S " is set between two layers of reinforcing bar of arch wall Type connecting lacing wire controls distance of reinforcing bar, connecting lacing wire spacing 1m, quincuncial arrangement, the same base plate steel bar binding of other binding technical requirements；

7.6, arch wall concrete placings: pump concrete puts in storage from bottom to top, from placing section joint to non-placing direction, pours Before building, microlith concrete of the about 50mm thickness with wall concrete with label is first filled out in bottom, makes full use of template reserved window in casting process, The symmetrical casting concrete of layering keeps nozzle downward in 3~5m of discharge nozzle front end adjunction with diameter hose, avoids horizontal straight to concrete face Pump；When concreting face has been approached top, into the stage of binding, in order to guarantee that air can be excluded smoothly, in reserved slip casting Exhaust pipe is installed in hole, and exhaust pipe one end is leaned at the top of splash guard as far as possible, the exhaust pipe other end is fixed in formwork jumbo, and solid It is fixed secured；Continue with pouring, when discovery has water to flow out from exhaust pipe, that is, illustrates to be fully filled with coagulation in storehouse Soil stops casting concrete, dredges exhaust pipe and withdraws from pumping hose；Bind concrete when as far as possible from inward end mould direction fill Note, to exclude air, concrete is shunk the gap generated to vault slip casting and tamped by later-stage utilization exhaust pipe；

7.7, form removable: reach 80% rear collapsible die of design strength to concrete；

7.8, concrete curing: timely wet curing after arch wall concrete final set is in moisture state, curing time during maintenance 14d must not be less than.

Further, the part of backbreaking in the step 2.1 and step 2.2 excavation must backfill closely knit, and reserved slip casting Hole carries out secondary grouting filling.

Further, the step 2 is reduced to the greatest extent and is backbreak in the process of excavation, and strict control owes to dig, only in rock stratum Completely, compression strength is greater than 30MPa, when not influencing the stabilization and intensity of liner structure, (every square metre of the individual protrusions of rock It is interior to be greater than 0.1m) lining cutting can be invaded, intrusion volume is not more than 50mm；Section is forbidden to owe digging in the above 1m of arch springing, foundation.

Further, in the step 2 for the excavation of shallow-buried sector, must strict control subsidence, reduction follows Ring excavates drilling depth and places landslide, and concrete measure is as follows: being excavated using digging machine, pneumatic pick, the larger location of effect on building is reduced Construction penetration rate excavates drilling depth every time and is no more than a Pin；Reinforce the observation and feedback of surface subsidence, vault sinking, with guidance Construction.

Further, the steelframe processing allowable error in the step 3.1 is as follows: little along tunnel perimeter profile errors In 3cm, plane warping is less than 2cm, can be interchanged between connector connection request is similar；Steelframe each unit must specify type And unit number, and sub-unit be stacked at it is spare in semi-finished product storage area.

Further, the steelframe processing finished product in the step 3.1 is when carrying out structural test, on the table by steel The assembled cyclization of frame, outside solder paste footstock, using oil overhold, instrument is pressurizeed by design load.Use stress meter and convergence instrument amount Survey steelframe internal force and deformation.

Further, mounted steelframe must assure that arch plane and tunnel central axis in the step 3.3, Vertical verticality is measured using plumb bob, and longitudinal measurement uses method of equal intervals, and survey crew need to measure standard when each machine-team steelframe is installed True steelframe mileage simultaneously rectifies a deviation to a upper circulation.

Further, in the step 3.3 steelframe installation should on every section steelframe designated model and use position, prevent Only worker, which takes by mistake, delays the construction time；Rationally design the cutting length of every section steelframe, it is ensured that every section steelframe will not be too heavy, convenient for behaviour Make；Junction steel plate bolt hole is uniformly drilled using bench drill, guarantees that bolt hole docks one by one, convenient for operation；The installation of top bar steelframe When, steelframe arch springing junction steel plate bolt hole is wrapped up using geotextiles, and steelframe of getting out of a predicament or an embarrassing situation can be saved when constructing and be bolted the time.

Further, the first branch gunite concrete operation segmentation and slicing of the step 6 carries out, spraying operation from lower and On, steelframe and buttress gap portion are first sprayed, it is rear to spray part between two steelframes；Gunite concrete layering carries out, a jet thickness Depending on ejection electrodes and design thickness, arch is preferably 5cm~6cm, and abutment wall is 7cm~10cm, and rear one layer of spray should be previous It sprays after layer final set or afterwards every other hour；When injection from bottom to top, i.e., wall top after first foundation, vault after first arch springing, avoids dead Angle, helically rotational trajectory moves material beam, and a circle pressure half-turn, longitudinal to press snakelike injection, each snakelike spray penetration is 50mm；Spray Start sprinkling maintenance after penetrating concrete final set 2 hours, watering number should be with enough moisture states can guarantee concrete Degree, curing time must not be less than 14 days；It answers closely knit, smooth, free from flaw, fall off, drain spray, hollowing, leakage in gunite concrete surface Phenomena such as water, irregularity degree tolerance are ± 3cm.

Further, the points for attention of the step 6 are as follows:

1) strict control concrete construction match ratio, match ratio is tests determined, and concrete indices all must satisfy Design and code requirement, concrete mixing materials weighing accuracy have to comply with code requirement；

2) quality of strict control raw material, the indices of raw material all must satisfy requirement；

3) reasonable wind pressure is determined in construction of shotcrete, guarantees material spray uniformly, continuously.Reinforce the guarantor to equipment simultaneously It supports, guarantees its working performance；

4) spraying operation is operated by the injection hand for having experience, being skilled in technique, and guarantees that linking is tight between each layer of gunite concrete It is close；

5) installment work of advanced tubule, steel mesh, steelframe is first completed before gunite concrete by design requirement；

6) gunite concrete finds crackle red paint by special messenger's wet curing to reduce because cracking caused by the heat of hydration It marks, is observed and monitored, determine if to continue to develop, if finding out reason continuing to develop and dealing with；

7) firmly carry out " four are not " system: i.e. gunite concrete process is endless, and face does not advance, gunite concrete thickness Do not advance not enough, find the problem after concrete ejection it is unresolved do not advance, monitoring result shows dangerous not advance.The above system Execution is responsible for by live gang master, everyone has responsibility, and makes a record in engineering construction log in case checking；

8) first branch back-grouting: when first branch construction within the scope of arch wall pre-buried A42 slip casting steel floral tube, complete 3-5m in disposition Timely grouting methol afterwards, to ensure just Zhi Mishi.Grouting parameter: pipe range is that first Zhi Houdu adds 0.5m, wall thickness 4mm, Grouting Pipe 1.5 × 2.0m of spacing (ring × vertical), quincuncial arrangement, slip casting ratio of mud 0.5-1.0MPa.

Further, the construction precautions in the step 7 are as follows:

1) it checks trolley formwork and whether middle line, elevation meets the requirements, whether headroom size meets the requirements, trolley and stopper Whether mould installation positioning is firm；

2) whether form joint clogs closely, and whether release agent is brushed uniformly；

3) whether substrate cleaning is clean, and whether construction joint is handled；

4) whether sealing rod, waterstop installation meet design and code requirement.

Further, the Tunnel Second Lining of the step 7 uses section construction, i.e. YDK35+440~+445, meter 5m；YDK35+445~+450 counts 5m；YDK35+450~+455 counts 5m；YDK35+455~+460 counts 5m；Total 20m； ZDK35+448~+453 counts 5m；ZDK35+453~+458 counts 5m；ZDK35+458~+463 counts 5m；ZDK35+463~+ 468, count 5m；ZDK35+468~+474 counts 6m；Total 26m.

After above-mentioned steps, the invention has the following beneficial effects: wearing construction of the flyover under a kind of cold excavation of the present invention Method must carry out advance geologic prediction according to design and code requirement before construction.Pass through the advance geologic prediction information of feedback Guiding construction and amendment supporting parameter.Advanced tubule punching and slip casting work are carried out for V, IV grade of country rock, and according to country rock Joint construction and bleeding are adjusted the drilling arrangement of ductule.After the completion of advance support can tunneling, when construction combines Level of ground water, underground stress and joint can be with appropriate adjustments.According to design drawing, first steelframe must be tried before steelframe is installed It spells, is connected by screw bolts, it is necessary to assure junction steel plate is closely connected.Steelframe is closely connected with country rock as far as possible when installation, is positioned with connection reinforcing bar, And check the plane warping of steelframe, co-ordination deviation, protective layer thickness etc..Inverted arch laying waterproof material smooth after the completion of just propping up Material, then the construct lining of inverted arch two and inverted arch filling.Two lining construction must to Zhi Bianhua at the beginning of tunnel it is basicly stable after just can be carried out, And section center and vault elevation are checked again, tunnel clearance is controlled with linearly by last procedure, two linings are adopted With C35 form concrete, disturbance when reducing tunnel excavation to surrounding enviroment reduces construction risk, guarantees existing viaduct fortune The advantages that battalion's safety, the present invention have structure simple, and setting is reasonable, low manufacture cost.

Detailed description of the invention

In order to more clearly explain the embodiment of the invention or the technical proposal in the existing technology, to embodiment or will show below There is attached drawing needed in technical description to be briefly described, it should be apparent that, the accompanying drawings in the following description is only this Some embodiments of invention for those of ordinary skill in the art without creative efforts, can be with It obtains other drawings based on these drawings.

Fig. 1 is advanced tubule construction flow chart in the present invention.

Fig. 2 is advanced tubule structural schematic diagram in the present invention.

Fig. 3 is advanced tubule acceptable quality level table in the present invention.

Fig. 4 is that steel tube shed advance support is longitudinally arranged figure in the present invention.

Fig. 5 is steel reinforcement cage layout drawing in conduit in the present invention.

Fig. 6 is daguanpeng construction process flow chart in the present invention.

Fig. 7 is steel tube shed catheter configurations figure in the present invention.

Steel tube shed acceptable quality level table in Fig. 8 present invention.

Fig. 9 is reinforced mesh quality acceptance standard table in the present invention.

Figure 10 is suspension roof support quality standard table in the present invention.

Figure 11 is benching tunnelling method working procedure cross-sectional configuration schematic diagram in the present invention.

Specific embodiment

The present invention will be further described below with reference to the drawings.

Referring to as shown in Figure 1-Figure 11, present embodiment the technical solution adopted is that: its construction procedure is as follows:

1, leading pre-supporting is constructed

1.1, its construction technology process of advanced tubule supporting is shown in Fig. 1 advanced tubule construction flow chart

1.1.1, the preparation of per-fore pouring liquid with small pipe equipment and injecting paste material: grouting equipment uses FBY double-fluid grouting machine, should Slip casting machine can also realize single fluid grouting；Injecting paste material uses the portland cement slurries of P.O42.5, and the ratio of mud is 0.5:1~1: 1；It is first tested before slip casting, sample carries out practical operation after reaching code requirement；Required water is first poured into agitator, then will Cement pours into agitator according to the proportion, and mechanical stirring is after mixing evenly, spare, cement grout with mix with；

1.1.2, advanced tubule processing and installation: ductule is process using 42 seamless steel pipe of Ф, and front end is processed into Taper so as to inserting piling, and prevents slurries preshoot；6~8mm of Ф injected hole is bored at position among ductule, is in quincuncial arrangement, spacing It does not drill within the scope of 20cm, tail portion 1m, mortar leakage prevention, end weld-ring shape iron hoop, cracking ends when to prevent setting influence Grouting Pipe Connection, construction Shi Xianyong pneumatic pick drilling, air drill jacking；By the ductule connection after drilling and seal orifice；Ductule drawing See Fig. 2 advanced tubule schematic diagram

1.1.3, per-fore pouring liquid with small pipe: grouting sequence, to there is water hole, by few water to more water holes, and needs tripping by no water hole Pressure injection；The length of every ductule, pressure injection time, slurry consumption amount and the live various problems occurred and solution are done in construction Method will charge to prescribed form record sheet, to analyze front geological condition；

1.1.4, per-fore pouring liquid with small pipe ending standard limits:

Single hole ending standard: high pressure after first slow rear fast, elder generation's low pressure is answered when slip casting, pressure is no more than when starting slip casting 0.2Mpa gradually increases pressure with grouting amount increase until design value (0.5~1Mpa), slip casting ending standard are single hole grouting amount Reach design value, the design value that grouting pressure reaches continues slip casting 2min, and grout absorption is less than the 1/4 of initial grout absorption, can terminate Slip casting；

Full section ending standard: all injected holes all terminate slip casting by standard, without apparent leakage point in tunnel；

1.1.5, advanced tubule inspection of quality；Ductule acceptable quality level is shown in Fig. 3 advanced tubule acceptance quality mark It is quasi-

1.2, steel tube shed supporting

1.2.1, the preparation of steel tube shed grouting equipment and injecting paste material: grouting equipment uses FBY double-fluid grouting machine, the slip casting Machine can also realize single fluid grouting.Injecting paste material uses the portland cement slurries of P.O 42.5, and the ratio of mud is 0.5:1~1:1, when When underground water development or larger grout mixing, grouting serous fluid should be cement-sodium silicate double liquid, first fall required water Enter agitator, cement poured into agitator according to the proportion, mechanical stirring is after mixing evenly, spare, cement grout with mix with With；

1.2.2, steel tube shed processing and installation:

Conduit specification: heat pricks seamless steel floral tube, outer diameter 159mm, wall thickness 10mm, length left tunnel 26m, right tunnel 20m；Pipe away from: Circumferential spacing 35cm；Inclination angle: 0~3 ° of outer limb；Steel tube shed joint steel pipe is connect using Ф 180*10mm, long 40cm joint steel pipe Long, in order to make steel tube shed connector be staggeredly arranged, right tunnel number is that the segment Guan Peng of odd number hole location is arranged by 4*4.5m+2.0m, is compiled Number arranged for the segment Guan Peng of even hole by 2.0m+4*4.5m, left tunnel number be odd number hole location the segment Guan Peng by 5*4.5m+ 3.5m arrangement, number is that the segment Guan Peng of even hole is arranged by 3.5m+5*4.5m；Steel tube shed is processed using 159 seamless steel pipe of Ф It forms, front end processing is tapered, so as to inserting piling, and prevents slurries preshoot.In order to improve the bending resistance of conduit, added in conduit Steel reinforcement cage, steel reinforcement cage are made of four C18HRB400 main reinforcements and fixed ring, and fixed ring uses short tube section, it is welded with main reinforcement, It is arranged by 1m spacing, 10~16mm of Ф injected hole is bored at position among pipe canopy, is in quincuncial arrangement, spacing 20cm, tail portion 1.5m model It does not drill in enclosing；Mortar leakage prevention, end weld-ring u stirrup, cracking ends when to prevent setting influence Grouting Pipe connection.Steel tube shed is big Master drawing is shown in Fig. 7 super-front large pipe shed schematic diagram.Steel tube shed is applied using pipe-following drilling method, is applied with to subtract small pipe shed and is caused surface subsidence Problem；

1.2.3, steel tube shed slip casting: grouting sequence, to there is water hole, by few water to more water holes, and needs tripping pressure by no water hole It infuses, in construction all to the length of every root canal canopy, pressure injection time, slurry consumption amount and the various problem and solutions of scene appearance Prescribed form record sheet is charged to, to analyze front geological condition；

1.2.4, steel tube shed slip casting ending standard limits:

Single hole ending standard: grouting pressure gradually rises, and designs final pressure and stable 10min when reaching；Grouting amount is not less than Design grouting amount 80%；It is less than into slurry speed and starts 1/4 into slurry speed；

1.2.5, steel tube shed inspection of quality；Steel tube shed acceptable quality level is shown in Fig. 8 steel tube shed acceptable quality level

2, (tunnel cutting cross dimensions meets drawing requirement to tunnel cutting, that is, considers to backbreak and anticipated settlement, by indicating Excavation line carry out)

2.1 non-explosive excavation top bars 1. portion, applies 1. portion's preliminary bracing；Suspend 1. after completing 1. portion's preliminary bracing 5m Portion is excavated, and spray 5cm thickness C25 concrete enclosing face (excavates one Pin of a Pin supporting, by Pin cyclization)；

2.2, non-explosive excavation top bar 2. portion, applies 2. portion's preliminary bracing；Suspend after completing 2. portion's preliminary bracing 5m 2. portion is excavated, spray 5cm thickness C25 concrete enclosing face (excavates one Pin of a Pin supporting, by Pin cyclization)；

2.3, it is laid with inverted arch waterproof layer, perfusion in timePortion's inverted arch and side wall concrete；

2.4, perfusion inverted arch fillingPortion is to design height；

2.5, arch wall waterproof layer, disposal pouring are appliedPortion's arch wall concrete；

2.6, after two lining concrete strengths reach the 80% of design strength, it is next to repeat above-mentioned operation 2.1-2.6 progress Lining cutting circulation construction；

3, steelframe processing and installation

3.1, steelframe is processed: technical staff is according to drawing size to the skills such as steelframe dividing elements and every cell radius, arc length Art parameter is checked, and is issued and is confided a technological secret after errorless, and scene processes steelframe by sectional steel cold-bending machine；

Steelframe is processed in reinforcing steel processing shed unification by design size, and steelframe junction steel plate must be drilled using bench drill, no It obtains and uses electric welding or acetylene hole burning, the connection of bolt when being easily installed；Each unit steelframe, which completes the process, must organize examination to spell, and check Steelframe size and profile qualification rear can be mass and (the technical parameter IV d lining cutting type section of satisfaction of steelframe: steel that comes into operation Frame spacing 0.5m；V d type section: steelframe spacing 0.35,0.45m；The quality standard of steelframe meet steelframe assembly profile variation ± 30mm, plane warping ± 20mm；Welding requirements weld seam is full between steel plate and I-steel, and no solder skip, nothing are burnt, and welding slag is removed dry Only；Basal plane will be cleaned out, answer solid no residue before steelframe is installed；Steelframe installs necessary Vertical tunnel middle line, tolerance are as follows: Transverse direction ± 30mm, longitudinal direction ± 50mm, elevation ± 30mm, verticality 0.5%；It is 4cm, steelframe installation that steelframe, which installs interior external protection, Must satisfy design requirement must not invade secondary lining, and connecting plate installation is closely connected cannot angle, and connection bolt is high-strength bolt, Forbid to connect using reinforcing bar；Every Pin steelframe bottom must fall on hard firm bedrock surface, use the lumps of wood for hanging steelframe Or steel plate support pad；Adjacent two Pin steelframe is longitudinally connected using 22 spiral of Φ, and 1 meter of spacing, allowable error ± 50mm；Steel mesh Piece installation overlap joint 1~2 pitch of holes (30cm))；

3.2, measurement and positioning: excavation finishes, and after first pneumatically placed concrete, that is, carries out the installation of steelframe, steelframe positioning uses middle line Elevation method makes the middle line in tunnel according to total station, and the offset distance of steelframe end is symmetrically measured according to middle line, complies with design number Value, while using the elevation at the control points such as vault, arch springing, the inverted arch bottom of level measurement steelframe, adjustment steelframe, which complies with, to be set Meter requires；

3.3, steelframe is installed: after adjusting steelframe position, bolt between steelframe being tightened, 22 longitudinal direction Φ is set between two Pin and is connected Connect reinforcing bar, circumferential spacing 1000mm, single layer arrangement, connection reinforcing bar spreading uses two-sided overlap welding, and when welding guarantees two sides reinforcing bar On the same axis；

3.4, steel mesh is laid with: steel mesh uses 8 reinforcing bar of φ, spacing 200mm × 200mm, and reinforced mesh presses design in advance Arch spacing processes spare outside hole, and reinforced mesh processing is made of reinforcing-bar binding machine, and anchor pole carries out reinforcing bar after applying Net is mated formation；Steel mesh, which should be adjustable to circumstances, is close to just spray plane, beats shallow bore hole with impact drill and buries expansion bolt, steel mesh is fixed on bolt On, and welded with anchor pole tail portion；Fragment makes outside hole, and the lap of splice is not less than 10cm when installation；It is artificial to be laid with, it is sharp when necessary It is shored with air drill air leg, so that it is secured to connect (or spot-welded) with anchor pole and steelframe binding close to scar；Steel mesh and steelframe When binding, it should tie up close to scar side；When pneumatically placed concrete, spray head is adjusted to by spray plane distance and wind pressure, reduces steel mesh vibration It is dynamic, reduce rebound；(steel mesh quality standard is referring to Fig. 9, the paving of steel mesh not less than 2cm for steel fibre reinforced concrete protective layer thickness If must assure that steel mesh must remove corrosion before；Steel mesh must be connected firmly with anchor pole or other fixation devices, Steel mesh must not shake when jetting cement)；

4. grouting rock bolt is constructed

4.1, jewel hole: drilling machine is selected according to anchor pole type, specification and country rock situation；Hole location tolerance is ± 150 ㎜, drilling hole amount should meet design code；Jewel hole diameter has to be larger than anchor rod body diameter 15mm；Hole depth is no less than anchor pole bar Body effective length, but depth overlength value should not exceed 100mm；

4.2, it is in the milk: eyelet must be blown off before grouting；Cement mortar must mix it is uniform, with mix with；It is in the milk full, It uniformly carries out, must not interrupt since bottom hole, prevent that tube drawing is too fast, cause mortar to disconnect and be in the milk and be discontented with；Grouting Pipe must insert It at away from 5~10cm of bottom hole, slowly at the uniform velocity extracts with the injection of cement mortar, is immediately rapidly inserted into the body of rod, anchor rod body is inserted Enter the length in hole must not be shorter than design length 95%, if aperture is flowed out without mortar, it is necessary to which paddle, anchor are infused into body of rod extraction again Bar must not be tapped arbitrarily after installing, and end must not hang weight in 3 days.

4.3, rockbolt installation: reinforcing bar must derust alignment before installing；Reinforcing bar at the uniform velocity must be inserted into immediately after grouting, position Between two parties；Aperture can use the interim sealing of timber wedge；Reinforcing bar tail end protruded length is preferably slightly smaller than jetting thickness；Must not be tapped after installing and Collision.Anchor pole insertion depth cannot be less than the 95% of design requirement；There is water location, when using anchor rod with cement mortar, such as hole Interior flowing water, nearby separately drilling is used as diversion pipe, and carrying out anchor pole operation again after discharge water, (suspension roof support quality standard is referring to figure 10)；

5, hollow grouting anchor is constructed

5.1, preparation of construction: carrying out rockbolt installation operation in time after first pneumatically placed concrete, checks whether bolthole is unimpeded；Inspection It looks into air compressor machine and its whether pipeline, air pressure gun is in shape；

5.2, armature boring: armature boring according to design requirement and is tied using the rock drilling machineries such as gas leg type air pressure gun, before drilling It surrounds rock occurrence and makes hole location, make label；By the position of drill bit alignment calibration, make drilling direction vertical-dipping bed structure as far as possible Face, to play better reinforcement effect, at the end of drilling, keeping the exposed segment length of anchor pole in 10~15cm, (drilling should meet Claimed below: drilling should be justified and straight, and boring direction is preferably vertical with rock stratum primary structure face as far as possible；It is straight that anchor pole aperture should be greater than the body of rod Diameter 15mm)；

5.3, borehole cleaning: after drilling to completion, with water or high-pressure blast borehole cleaning, drilling rod connector sleeve is unloaded after confirmation is unimpeded；

5.4, squeeze into anchor pole: the mode that air pressure gun heads into squeezes into anchor pole；

5.5, slip casting: slip casting uses link extrusion type grouting pump, and grouting serous fluid is M20 cement slurry, will only be starched with hole cap assembly set Plug squeezes into aperture 30cm or so by anchor pole exposed junction, checks grouting equipment, prepares cement slurry by match ratio, starts grouting pump note Slurry, until slurries are squeezed out from aperture periphery or termination when pressure gauge has reached design pressure value, for hollow grouting anchor, when slip casting Aperture pressure is 0.7~1.0MPa, and slip casting can be terminated by continuing 15min when reaching pressure, after the completion of slip casting, is washed with water in time Slip casting machine and pipeline (if there is plugging phenomenon during slip casting, respectively check anchor pole, Grouting Pipe, grouting pump, are examining Before looking into, grouting pressure is subtracted first, avoids whitewashing from hurting sb.'s feelings, in place, stop grouting plug installs armature boring, extensive to air pressure in hole It is with accelerated cement mortar that the drilling filling other than stop grouting plug is closely knit after multiple, to guarantee that slurries will not scurry out in slip casting；Anchor pole It must not arbitrarily be tapped after installing, end must not hang weight in 3 days；Anchor pole end is welded on steel arch-shelf or steelframe as far as possible Together, to form common stress system)；

5.6, backing plate, nut are installed: after institute's injection slurry intensity reaches predetermined strength, installation backing plate (200 × 200 × The A3 steel plate of 10mm), so that it is close to scar, tighten rod end nut, it is made to generate certain prestressing force, plays preferably to reinforce and enclose The effect of rock, anchor pole should keep vertical with backing plate, and come into full contact with jetting cement, and nut must be tightened；

6, (the first Zhi Caiyong wet shotcreting in tunnel, solves the problems, such as dust, rebound, improves first branch gunite concrete The quality of gunite concrete, since finished product concrete has eliminated the cement granules of free state, in transport, feeding, injection Dust is not generated substantially in machine feeding procedure, protects operating environment.The raw material proportioning metering of wet shotcreting is by blender It control and completes, hydration is also since blender, thus hydration is abundant, and concrete quality is reliable)

6.1, concrete raw material preparation is sprayed:

Cement: using the ordinary portland cement of design requirement label, intensity check test is done before use, performance meets Existing cement standard；

Fine aggregate: medium coarse sand, fineness modulus are greater than 2.5, are sieved with 5mm sieve；

Coarse aggregate: the mechanism rubble of partial size 5mm~15mm；

Water: tap water is used；

Accelerator: using liquid accelerator, does compatibility test with cement using preceding, tests with the net slurry of the ratio of mud 0.4 Meet the presetting period less than 5min, final setting time is less than 10min, and volume is less than the 5% of cement consumption, and strength retention is big within 28 days In 70%；

6.2, the stirring of concrete wet feed: being stirred using forced mixer, forms material spray, and mixing time is no less than 3 points Clock；Feed intake metering device used in periodic inspection stirring, and configuration deviation meets code requirement, cement-aggregate ratio: 1:3.5~1:4.0, water ash Than: 0.42~0.50,8~12cm of concrete slump；

6.3, construction of shotcrete: being handled by spray plane, and embedded jetting thickness mark, is connected geomantic omen electricity and is tried Machine transports material spray using mixer truck, and carries out just pneumatically placed concrete operation, after the completion of first pneumatically placed concrete operation, fills spray, adjusts cooperation Carry out multiple pneumatically placed concrete operation, last quality inspection again than after；

7, (tunnel excavation, preliminary bracing, secondary lining take the construction alternately, promoted paragraph by paragraph to Tunnel Second Lining Process)

7.1, basal plane cleaning, surveying setting-out: waterproof slab protective layer sundries is cleaned out, then two lining two of unwrapping wire pop-up The abutment wall position line, Control of floor line, control point spacing are not greater than 5m, not handy iron nail or bar dowel, in order to avoid prick bad waterproof layer；

7.2, water proof equipment is installed；

7.3, inverted arch reinforcing bar is bound: steel bar stress is rebuilding, and inverted arch cover to reinforcement is controlled using mortar pad；It is double Split heads control protective layer and positioning are set between layer reinforcing bar；Two lining main reinforcement Type Diameters are up to Φ 20, using two-sided welding.Connector Position is staggered 35d；Steel bar stress connector is arranged in stress smaller part, and joint location is staggered 35d；Principal rod connector uses straight thread Connection, the connector being arranged in same component should mutually stagger, and the percentage of splice area meets specification and design requirement, Tensile region is not more than 50%；When reinforcing bar binding overlap joint, intermediate and both ends are bound at three altogether, it is necessary to individually after binding again and cross bar Binding；Main reinforcement and distributing reinforcement are other to be bound point iron wire with racking seizing and be buckled in addition to 2~3 column skeleton of deformation joint all binding At splayed configuration；Stirrup and main reinforcement crosspoint are all bound；

7.4, inverted arch concrete placings and maintenance: being set up using scaffold board on reinforcing bar and split heads before concrete placings and pour riding track, is prevented Only reinforcing bar deforms；Concrete placings use ground pump, and concrete slump is controlled in 120mm~160mm；The two lining left line 0.8m of concrete base plate thickness, Right line 1m, is poured using inclined plane delamination method, the lower ash by one end, hand close fit of vibrating, and keeps concrete with " catching up with slurry processes " It pushes ahead along board bottom, is struck off when vibrating with darby, wooden float compacting smoothes out, secondary pressure surface before initial set, to reduce concrete crack； It is conserved in time in 12h after concrete placings, curing time must not be less than 14d；

7.5, arch wall reinforcing bar is bound: cover to reinforcement is controlled using plastic cushion；" S " is set between two layers of reinforcing bar of arch wall Type connecting lacing wire controls distance of reinforcing bar, connecting lacing wire spacing 1m, quincuncial arrangement, the same base plate steel bar binding of other binding technical requirements；

7.6, arch wall concrete placings: pump concrete puts in storage from bottom to top, from placing section joint to non-placing direction, pours Before building, microlith concrete of the about 50mm thickness with wall concrete with label is first filled out in bottom, makes full use of template reserved window in casting process, The symmetrical casting concrete of layering keeps nozzle downward in 3~5m of discharge nozzle front end adjunction with diameter hose, avoids horizontal straight to concrete face Pump；When concreting face has been approached top (to be higher than die head as boundary), into the stage of binding, in order to guarantee air energy It is enough smoothly to exclude, exhaust pipe (using φ 20mm galvanized pipe) is installed in reserved injected hole, splash guard is leaned in exhaust pipe one end as far as possible The exhaust pipe other end is fixed in formwork jumbo by top, and fixation；Continue with pouring, when discovery has water (real Separating water, thin pulp for concrete surface layer) when flowing out from exhaust pipe, that is, illustrate to be fully filled with concrete in storehouse, stop Casting concrete dredges exhaust pipe and withdraws from pumping hose；Bind concrete when as far as possible from inward end mould direction be perfused, with exclude Concrete is shunk the gap generated to vault slip casting using exhaust pipe and carried out by air, later period (concrete strength reaches 70% or more design) It tamps；When with poker vibrator vibrated concrete, should meet the following requirements: mobile spacing is not preferably greater than acting radial of vibrator 1.5 times；The depth being inserted into lower-layer concrete is preferably 5~10cm, to guarantee that upper and lower level is well combined；Vibrator should be as far as possible It is perpendicularly inserted in concrete, such as condition difficulty, can slightly tilt, but angle with horizontal plane is not preferably less than 45 °；Vibrating spear is made firm by ramming When should insert, pull out slowly fastly, in the vibrating time of each hole location, no longer significantly sunk with concrete, moisture and bubble no longer escape simultaneously Start subject to bleeding, generally 10~30s；When vibrating must not collision slab, reinforcing bar and embedding pipe fittings, away from template it is vertical away from From no less than the 1/2 of vibrator effective radius；Concrete must vibration compacting, no leakage and over vibration phenomenon；Two lining side wall vibrations It smashes manually to vibrate for note, is no less than two injected holes in every group of reserved lining of arch crown part when pouring, two lining concretes reach 100% Backfill slip casting is carried out to gap between first branch and two linings after intensity, guarantees that just branch and two linings are closely connected.

7.7, form removable: reach 80% rear collapsible die of design strength to concrete；

7.8, concrete curing: timely wet curing after arch wall concrete final set is in moisture state, curing time during maintenance 14d must not be less than.

Further, the part of backbreaking in the step 2.1 and step 2.2 excavation must backfill closely knit, and reserved slip casting Hole carries out secondary grouting filling.

Further, the step 2 is reduced to the greatest extent and is backbreak in the process of excavation, and strict control owes to dig, only in rock stratum Completely, compression strength is greater than 30MPa, when not influencing the stabilization and intensity of liner structure, (every square metre of the individual protrusions of rock It is interior to be greater than 0.1m) lining cutting can be invaded, intrusion volume is not more than 50mm；Section is forbidden to owe digging in the above 1m of arch springing, foundation.

Further, in the step 2 for the excavation of shallow-buried sector, must strict control subsidence, reduction follows Ring excavates drilling depth and places landslide, and concrete measure is as follows: disturbing to reduce to country rock in construction, soft stratum, loose crushing Location is excavated using digging machine, pneumatic pick, the larger location of effect on building, reduces construction penetration rate, is excavated drilling depth every time and is no more than One Pin；Reinforce the observation and feedback of surface subsidence, vault sinking, with guiding construction.

Further, the steelframe processing allowable error in the step 3.1 is as follows: little along tunnel perimeter profile errors In 3cm, plane warping is less than 2cm, can be interchanged between connector connection request is similar；Steelframe each unit must specify type And unit number, and sub-unit be stacked at it is spare in semi-finished product storage area.

Further, the steelframe processing finished product in the step 3.1 is when carrying out structural test, on the table by steel The assembled cyclization of frame, outside solder paste footstock, using oil overhold, instrument is pressurizeed by design load.Use stress meter and convergence instrument amount Survey steelframe internal force and deformation.

Further, mounted steelframe must assure that arch plane and tunnel central axis in the step 3.3, Vertical verticality is measured using plumb bob, and longitudinal measurement uses method of equal intervals, and survey crew need to measure standard when each machine-team steelframe is installed True steelframe mileage simultaneously rectifies a deviation to a upper circulation.

Further, in the step 3.3 steelframe installation should on every section steelframe designated model and use position, prevent Only worker, which takes by mistake, delays the construction time；Rationally design the cutting length of every section steelframe, it is ensured that every section steelframe will not be too heavy, convenient for behaviour Make；Junction steel plate bolt hole is uniformly drilled using bench drill, guarantees that bolt hole docks one by one, convenient for operation；The installation of top bar steelframe When, steelframe arch springing junction steel plate bolt hole is wrapped up using geotextiles, and steelframe of getting out of a predicament or an embarrassing situation can be saved when constructing and be bolted the time.

Further, the first branch gunite concrete operation segmentation and slicing of the step 6 carries out, spraying operation from lower and On, steelframe and buttress gap portion are first sprayed, it is rear to spray part between two steelframes；Gunite concrete layering carries out, a jet thickness Depending on ejection electrodes and design thickness, arch is preferably 5cm~6cm, and abutment wall is 7cm~10cm, and rear one layer of spray should be previous It sprays after layer final set or afterwards every other hour；When injection from bottom to top, i.e., wall top after first foundation, vault after first arch springing, avoids dead Angle, helically rotational trajectory moves material beam, and a circle pressure half-turn, longitudinal to press snakelike injection, each snakelike spray penetration is 50mm；Spray Start sprinkling maintenance after penetrating concrete final set 2 hours, watering number should be with enough moisture states can guarantee concrete Degree, curing time must not be less than 14 days；It answers closely knit, smooth, free from flaw, fall off, drain spray, hollowing, leakage in gunite concrete surface Phenomena such as water, irregularity degree tolerance are ± 3cm.

Further, the points for attention of the step 6 are as follows:

1) strict control concrete construction match ratio, match ratio is tests determined, and concrete indices all must satisfy Design and code requirement, concrete mixing materials weighing accuracy have to comply with code requirement；

2) quality of strict control raw material, the indices of raw material all must satisfy requirement；

3) reasonable wind pressure is determined in construction of shotcrete, guarantees material spray uniformly, continuously.Reinforce the guarantor to equipment simultaneously It supports, guarantees its working performance；

4) spraying operation is operated by the injection hand for having experience, being skilled in technique, and guarantees that linking is tight between each layer of gunite concrete It is close；

5) installment work of advanced tubule, steel mesh, steelframe is first completed before gunite concrete by design requirement；

6) gunite concrete finds crackle red paint by special messenger's wet curing to reduce because cracking caused by the heat of hydration It marks, is observed and monitored, determine if to continue to develop, if finding out reason continuing to develop and dealing with；

7) firmly carry out " four are not " system: i.e. gunite concrete process is endless, and face does not advance, gunite concrete thickness Do not advance not enough, find the problem after concrete ejection it is unresolved do not advance, monitoring result shows dangerous not advance.The above system Execution is responsible for by live gang master, everyone has responsibility, and makes a record in engineering construction log in case checking；

8) first branch back-grouting: when first branch construction within the scope of arch wall pre-buried A42 slip casting steel floral tube, complete 3-5m in disposition Timely grouting methol afterwards, to ensure just Zhi Mishi.Grouting parameter: pipe range is that first Zhi Houdu adds 0.5m, wall thickness 4mm, Grouting Pipe 1.5 × 2.0m of spacing (ring × vertical), quincuncial arrangement, slip casting ratio of mud 0.5-1.0MPa.

Further, the construction precautions in the step 7 are as follows:

1) it checks trolley formwork and whether middle line, elevation meets the requirements, whether headroom size meets the requirements, trolley and stopper Whether mould installation positioning is firm；

2) whether form joint clogs closely, and whether release agent is brushed uniformly；

3) whether substrate cleaning is clean, and whether construction joint is handled；

4) whether sealing rod, waterstop installation meet design and code requirement.

Further, the Tunnel Second Lining of the step 7 uses section construction, i.e. YDK35+440~+445, meter 5m；YDK35+445~+450 counts 5m；YDK35+450~+455 counts 5m；YDK35+455~+460 counts 5m；Total 20m； ZDK35+448~+453 counts 5m；ZDK35+453~+458 counts 5m；ZDK35+458~+463 counts 5m；ZDK35+463~+ 468, count 5m；ZDK35+468~+474 counts 6m；Total 26m.

After above-mentioned steps, present embodiment has the beneficial effect that one kind described in present embodiment is cold and opens Construction of the flyover method of wearing is dug down, disturbance when reducing tunnel excavation to surrounding enviroment reduces construction risk, guarantees existing grade separation The advantages that bridge operation security, the present invention have structure simple, and setting is reasonable, low manufacture cost.

The above is only used to illustrate the technical scheme of the present invention and not to limit it, and those of ordinary skill in the art are to this hair The other modifications or equivalent replacement that bright technical solution is made, as long as it does not depart from the spirit and scope of the technical scheme of the present invention, It is intended to be within the scope of the claims of the invention.

Claims (9)

1. wearing construction of the flyover method under a kind of cold excavation, it is characterised in that: its construction procedure is as follows:

(1), leading pre-supporting is constructed

(1.1), advanced tubule supporting

The preparation of (1.1.1), per-fore pouring liquid with small pipe equipment and injecting paste material: grouting equipment uses FBY double-fluid grouting machine；Slip casting The portland cement slurries of materials'use P.O42.5, the ratio of mud are 0.5:1~1:1；It is first tested before slip casting, sample reaches Practical operation is carried out after code requirement；Required water is first poured into agitator, then cement is poured into agitator according to the proportion, it is mechanical Stirring, it is after mixing evenly, spare, cement grout with mix with；

The processing of (1.1.2), advanced tubule and installation: ductule is process using 42 seamless steel pipe of Ф, and cone is processed into front end Shape so as to inserting piling, and prevents slurries preshoot；6~8mm of Ф injected hole is bored at position among ductule, is in quincuncial arrangement, spacing It does not drill within the scope of 20cm, tail portion 1m, mortar leakage prevention, end weld-ring shape iron hoop, cracking ends when to prevent setting influence Grouting Pipe Connection, construction Shi Xianyong pneumatic pick drilling, air drill jacking；By the ductule connection after drilling and seal orifice；

(1.1.3), per-fore pouring liquid with small pipe: grouting sequence, to there is water hole, by few water to more water holes, and needs tripping pressure by no water hole Note；The various problem and solutions occurred in construction to the length of every ductule, pressure injection time, slurry consumption amount and scene Prescribed form record sheet will be charged to；

(1.1.4), per-fore pouring liquid with small pipe ending standard limit:

Single hole ending standard: answering high pressure after first slow rear fast, elder generation's low pressure, start pressure when slip casting and be no more than 0.2Mpa when slip casting, with Grouting amount increase gradually increases pressure until design value, slip casting ending standard are that single hole grouting amount reaches design value, grouting pressure Reach design value and continue slip casting 2min, grout absorption is less than the 1/4 of initial grout absorption, can terminate slip casting；

Full section ending standard: all injected holes all terminate slip casting by standard, without apparent leakage point in tunnel；

(1.1.5), advanced tubule inspection of quality；

(1.2), steel tube shed supporting

The preparation of (1.2.1), steel tube shed grouting equipment and injecting paste material: grouting equipment uses FBY double-fluid grouting machine, injecting paste material Using the portland cement slurries of P.O42.5, the ratio of mud is 0.5:1~1:1, when underground water development or grout mixing are larger When, grouting serous fluid should be cement-sodium silicate double liquid, and required water is first poured into agitator, cement is being fallen according to the proportion Enter agitator, mechanical stirring is after mixing evenly, spare, cement grout with mix with；

The processing of (1.2.2), steel tube shed and installation:

Conduit specification: heat pricks seamless steel floral tube, outer diameter 159mm, wall thickness 10mm, length left tunnel 26m, right tunnel 20m；Pipe away from: it is circumferential Spacing 35cm；Inclination angle: 0~3 ° of outer limb；Steel tube shed joint steel pipe uses Ф 180*10mm, long 40cm joint steel pipe spreading, is Steel tube shed connector is set to be staggeredly arranged, right tunnel number is that the Guan Peng segment of odd number hole location is arranged that number is even by 4*4.5m+2.0m The segment Guan Peng in number hole is arranged that left tunnel number is the segment Guan Peng of odd number hole location by 5*4.5m+3.5m cloth by 2.0m+4*4.5m It sets, number is that the segment Guan Peng of even hole is arranged by 3.5m+5*4.5m；Steel tube shed is process using 159 seamless steel pipe of Ф, preceding End processing is tapered, steel reinforcement cage is added in conduit, steel reinforcement cage is made of four C18HRB400 main reinforcements and fixed ring, and fixed ring is adopted With short tube section, it is welded with main reinforcement, is arranged by 1m spacing, 10~16mm of Ф injected hole is bored at position among pipe canopy, in quincunx It arranges, does not drill within the scope of spacing 20cm, tail portion 1.5m；Steel tube shed is applied using pipe-following drilling method, is applied with to subtract small pipe shed and is drawn Play surface subsidence problem；

(1.2.3), steel tube shed slip casting: grouting sequence, to there is water hole, by few water to more water holes, and needs tripping pressure injection by no water hole, The various problem and solutions occurred in construction to the length of every root canal canopy, pressure injection time, slurry consumption amount and scene will Prescribed form record sheet is charged to, to analyze front geological condition；

(1.2.4), steel tube shed slip casting ending standard limit:

Single hole ending standard: grouting pressure gradually rises, and designs final pressure and stable 10min when reaching；Grouting amount is not less than design Grouting amount 80%；It is less than into slurry speed and starts 1/4 into slurry speed；

(1.2.5), steel tube shed inspection of quality；

(2), tunnel cutting

(2.1), non-explosive excavation top bar 1. portion, applies 1. portion's preliminary bracing；Suspend 1. after completing 1. portion's preliminary bracing 5m Portion is excavated, and sprays 5cm thickness C25 concrete enclosing face；

(2.2), non-explosive excavation top bar 2. portion, applies 2. portion's preliminary bracing；Suspend 2. after completing 2. portion's preliminary bracing 5m Portion is excavated, and sprays 5cm thickness C25 concrete enclosing face；

(2.3), it is laid with inverted arch waterproof layer, perfusion in timePortion's inverted arch and side wall concrete；

(2.4), perfusion inverted arch fillingPortion is to design height；

(2.5), arch wall waterproof layer, disposal pouring are appliedPortion's arch wall concrete；

(2.6), after two lining concrete strengths reach the 80% of design strength, above-mentioned operation (2.1)-(2.6) is repeated and are carried out down One lining cutting circulation construction；

(3), steelframe processing and installation

(3.1), steelframe is processed: technical staff is according to drawing size to the technologies such as steelframe dividing elements and every cell radius, arc length Parameter is checked, and is issued and is confided a technological secret after errorless, and scene processes steelframe by sectional steel cold-bending machine；

Steelframe is processed in reinforcing steel processing shed unification by design size, and steelframe junction steel plate must be drilled using bench drill, must not be made With electric welding or acetylene hole burning, each unit steelframe, which completes the process, must organize examination to spell, and checking can after steelframe size and profile are qualified It produces in batches and comes into operation；

(3.2), measurement and positioning: excavation finishes, and after first pneumatically placed concrete, that is, carries out the installation of steelframe, steelframe positioning is high using middle line Cheng Fa makes the middle line in tunnel according to total station, and the offset distance of steelframe end is symmetrically measured according to middle line, complies with design number Value, while using the elevation at the control points such as vault, arch springing, the inverted arch bottom of level measurement steelframe, adjustment steelframe, which complies with, to be set Meter requires；

(3.3), steelframe is installed: after adjusting steelframe position, bolt between steelframe being tightened, it is longitudinally connected that Φ 22 is set between two Pin Reinforcing bar, circumferential spacing 1000mm, single layer arrangement, connection reinforcing bar spreading use two-sided overlap welding, guarantee that two sides reinforcing bar exists when welding On same axis；

(3.4), steel mesh is laid with: steel mesh uses 8 reinforcing bar of φ, spacing 200mm × 200mm, and reinforced mesh presses design arch in advance Frame spacing processes spare outside hole, and reinforced mesh processing is made of reinforcing-bar binding machine, and anchor pole carries out steel mesh after applying Mat formation；Steel mesh, which should be adjustable to circumstances, is close to just spray plane, beats shallow bore hole with impact drill and buries expansion bolt, steel mesh is fixed on bolt On, and welded with anchor pole tail portion；Fragment makes outside hole, and the lap of splice is not less than 10cm when installation；It is artificial to be laid with, it is sharp when necessary It is shored with air drill air leg, to be connected firmly with anchor pole and steelframe binding close to scar；When steel mesh and steelframe are bound, it should tie up Close to scar side；When pneumatically placed concrete, spray head is adjusted to by spray plane distance and wind pressure, steel mesh vibration is reduced, reduces rebound； Steel fibre reinforced concrete protective layer thickness is not less than 2cm；

(4), grouting rock bolt is constructed

(4.1), jewel hole: drilling machine is selected according to anchor pole type, specification and country rock situation；Hole location tolerance is ± 150 ㎜, Drilling hole amount should meet design code；Jewel hole diameter has to be larger than anchor rod body diameter 15mm；Hole depth is no less than anchor rod body Effective length, but depth overlength value should not exceed 100mm；

(4.2), it is in the milk: eyelet must be blown off before grouting；Cement mortar must mix it is uniform, with mix with；It is in the milk full, from Bottom hole starts uniformly to carry out, and must not interrupt, prevent that tube drawing is too fast, causes mortar to disconnect and be in the milk and is discontented with；Grouting Pipe must be inserted to At 5~10cm of bottom hole, slowly at the uniform velocity extracts with the injection of cement mortar, be immediately rapidly inserted into the body of rod, anchor rod body insertion Length in hole must not be shorter than the 95% of design length, if aperture is flowed out without mortar, it is necessary to which paddle, anchor pole are infused in body of rod extraction again It must not arbitrarily be tapped after installing, end must not hang weight in 3 days；

(4.3), rockbolt installation: reinforcing bar must derust alignment before installing；Reinforcing bar at the uniform velocity must be inserted into immediately after grouting, position occupies In；Aperture can use the interim sealing of timber wedge；Reinforcing bar tail end protruded length is preferably slightly smaller than jetting thickness；It must not tap and touch after installing It hits, anchor pole insertion depth cannot be less than the 95% of design requirement；There is water location, when using anchor rod with cement mortar, in hole Flowing water, nearby separately drilling is used as diversion pipe, carries out anchor pole operation again after water is discharged；

(5), hollow grouting anchor is constructed

(5.1), preparation of construction: carrying out rockbolt installation operation in time after first pneumatically placed concrete, checks whether bolthole is unimpeded；It checks Whether air compressor machine and its pipeline, air pressure gun are in shape；

(5.2), armature boring: armature boring according to design requirement and is combined using the rock drilling machineries such as gas leg type air pressure gun, before drilling Hole location is made in country rock occurrence, makes label；By the position of drill bit alignment calibration, make drilling direction vertical-dipping bed structure as far as possible Face at the end of drilling, keeps the exposed segment length of anchor pole in 10~15cm to play better reinforcement effect；

(5.3), borehole cleaning: after drilling to completion, with water or high-pressure blast borehole cleaning, drilling rod connector sleeve is unloaded after confirmation is unimpeded；

(5.4), squeeze into anchor pole: the mode that air pressure gun heads into squeezes into anchor pole；

(5.5), slip casting: slip casting uses link extrusion type grouting pump, and grouting serous fluid is M20 cement slurry, is covered with the assembly of hole cap by stop grouting plug Aperture 30cm or so is squeezed by anchor pole exposed junction, checks grouting equipment, prepares cement slurry by match ratio, starts grouting pump note Slurry, until slurries are squeezed out from aperture periphery or termination when pressure gauge has reached design pressure value, for hollow grouting anchor, when slip casting Aperture pressure is 0.7~1.0MPa, and slip casting can be terminated by continuing 15min when reaching pressure, after the completion of slip casting, is washed with water in time Slip casting machine and pipeline；

(5.6), backing plate, nut are installed: after institute's injection slurry intensity reaches predetermined strength, backing plate being installed, it is made to be close to scar, Rod end nut is tightened, so that it is generated certain prestressing force, plays the role of preferably reinforcing country rock, anchor pole should keep vertical with backing plate Directly, and with jetting cement it comes into full contact with, nut must be tightened；

(6), first branch gunite concrete

(6.1), concrete raw material preparation is sprayed:

Cement: using the ordinary portland cement of design requirement label, intensity check test is done before use, performance meets existing Cement standard；

Fine aggregate: medium coarse sand, fineness modulus are greater than 2.5, are sieved with 5mm sieve；

Coarse aggregate: the mechanism rubble of partial size 5mm~15mm；

Water: tap water is used；

Accelerator: using liquid accelerator, does compatibility test with cement using preceding, tests and meet with the net slurry of the ratio of mud 0.4 Presetting period is less than 5min, and final setting time is less than 10min, and volume is less than the 5% of cement consumption, and strength retention is greater than within 28 days 70%；

(6.2), the stirring of concrete wet feed: being stirred using forced mixer, forms material spray, and mixing time is no less than 3 minutes； Feed intake metering device used in periodic inspection stirring, and configuration deviation meets code requirement, cement-aggregate ratio: 1:3.5~1:4.0, the ratio of mud: 0.42~0.50,8~12cm of concrete slump；

(6.3), construction of shotcrete: being handled by spray plane, and embedded jetting thickness mark, is connected geomantic omen electricity and is tried Machine transports material spray using mixer truck, and carries out just pneumatically placed concrete operation, after the completion of first pneumatically placed concrete operation, fills spray, adjusts cooperation Carry out multiple pneumatically placed concrete operation, last quality inspection again than after；

(7), Tunnel Second Lining

(7.1), basal plane cleaning, surveying setting-out: waterproof slab protective layer sundries is cleaned out, then two lining both sides of unwrapping wire pop-up Wall displacement line, Control of floor line, control point spacing are not greater than 5m, not handy iron nail or bar dowel, in order to avoid prick bad waterproof layer；

(7.2), water proof equipment is installed；

(7.3), inverted arch reinforcing bar is bound: steel bar stress is rebuilding, and inverted arch cover to reinforcement is controlled using mortar pad；It is double-deck Split heads control protective layer and positioning are set between reinforcing bar；Two lining main reinforcement Type Diameters are up to Φ 20, using two-sided welding, connector position Set the 35d that is staggered；Steel bar stress connector is arranged in stress smaller part, and joint location is staggered 35d；Principal rod connector is connected using straight thread It connecing, the connector being arranged in same component should mutually stagger, and the percentage of splice area meets specification and design requirement, by Area is drawn to be not more than 50%；When reinforcing bar binding overlap joint, intermediate and both ends are bound at three altogether, it is necessary to individually be tied up again with cross bar after binding It pricks；Main reinforcement and distributing reinforcement are other to be bound point iron wire with racking seizing and be fastened as in addition to 2~3 column skeleton of deformation joint all binding Splayed configuration；Stirrup and main reinforcement crosspoint are all bound；

(7.4), it inverted arch concrete placings and maintenance: is set up on reinforcing bar and split heads using scaffold board before concrete placings and pours riding track, prevented Reinforcing bar deformation；Concrete placings use ground pump, and concrete slump is controlled in 120mm~160mm；The two lining left line 0.8m of concrete base plate thickness, the right side Line 1m is poured using inclined plane delamination method, the lower ash by one end, hand close fit of vibrating, and keeps concrete edge with " catching up with slurry processes " Board bottom is pushed ahead, and is struck off when vibrating with darby, and wooden float compacting smoothes out, secondary pressure surface before initial set, to reduce concrete crack；Concrete It pours and is conserved in time in rear 12h, curing time must not be less than 14d；

(7.5), arch wall reinforcing bar is bound: cover to reinforcement is controlled using plastic cushion；" S " type is set between two layers of reinforcing bar of arch wall Connecting lacing wire controls distance of reinforcing bar, connecting lacing wire spacing 1m, quincuncial arrangement, the same base plate steel bar binding of other binding technical requirements；

(7.6), arch wall concrete placings: pump concrete puts in storage from bottom to top, from placing section joint to non-placing direction, pours Before, microlith concrete of the about 50mm thickness with wall concrete with label is first filled out in bottom, template reserved window is made full use of in casting process, point The symmetrical casting concrete of layer keeps nozzle downward in 3~5m of discharge nozzle front end adjunction with diameter hose, and level is avoided directly to pump concrete face； When concreting face has been approached top, into the stage of binding, in order to guarantee that air can be excluded smoothly, pacify in reserved injected hole Exhaust pipe is filled, exhaust pipe one end is leaned at the top of splash guard as far as possible, the exhaust pipe other end is fixed in formwork jumbo, and fix tightly Gu；Continue with pouring, when discovery has water to flow out from exhaust pipe, that is, illustrate to be fully filled with concrete in storehouse, Stop casting concrete, dredge exhaust pipe and withdraws from pumping hose；Bind concrete when as far as possible from inward end mould direction be perfused, with Air is excluded, concrete is shunk the gap generated to vault slip casting and tamped by later-stage utilization exhaust pipe；

(7.7), form removable: reach 80% rear collapsible die of design strength to concrete；

(7.8), concrete curing: timely wet curing after arch wall concrete final set is in moisture state during maintenance, curing time is not It obtains and is less than 14d.

2. wearing construction of the flyover method under a kind of cold excavation according to claim 1, it is characterised in that: the step (2.1) and step (2.2) excavate in part of backbreaking must backfill closely knit, and reserved injected hole carries out secondary grouting filling.

3. wearing construction of the flyover method under a kind of cold excavation according to claim 1, it is characterised in that: the step (2) it in the process of excavation, reduces to the greatest extent and backbreaks, strict control owes to dig, only rock stratum is complete, compression strength is greater than 30MPa, no When influencing the stabilization and intensity of liner structure, the individual protrusions of rock (being greater than 0.1m in every square metre) can invade lining cutting, invade Enter amount no more than 50mm；Section is forbidden to owe digging in the above 1m of arch springing, foundation.

4. wearing construction of the flyover method under a kind of cold excavation according to claim 1, it is characterised in that: the step (2) for the excavation of shallow-buried sector in, palpus strict control subsidence reduces circulation and excavates drilling depth and placement landslide, tool Body measure is as follows: being excavated, the larger location of effect on building using digging machine, pneumatic pick, reduces construction penetration rate, excavate drilling depth every time No more than a Pin；Reinforce the observation and feedback of surface subsidence, vault sinking, with guiding construction.

5. wearing construction of the flyover method under a kind of cold excavation according to claim 1, it is characterised in that: the step (3.1) the steelframe processing allowable error in is as follows: being not more than 3cm along tunnel perimeter profile errors, plane warping is less than 2cm, connects It can be interchanged between head connection request is similar；Steelframe each unit must specify type and unit number, and sub-unit is stacked at It is spare in semi-finished product storage area.

6. wearing construction of the flyover method under a kind of cold excavation according to claim 1, it is characterised in that: the step (3.1) the steelframe processing finished product in is when carrying out structural test, on the table that steelframe is assembled cyclic, outside solder paste footstock, Using oil overhold, instrument is pressurizeed by design load；Steelframe internal force and deformation are measured using stress meter and convergence instrument.

7. wearing construction of the flyover method under a kind of cold excavation according to claim 1, it is characterised in that: the step (3.3) mounted steelframe must assure that arch plane and tunnel central axis, vertical verticality are measured using plumb bob in, indulge Method of equal intervals is used to measurement, survey crew need to measure accurate steelframe mileage and carry out to a upper circulation when each machine-team steelframe is installed Correction.

8. wearing construction of the flyover method under a kind of cold excavation according to claim 1, it is characterised in that: the step (6) first branch gunite concrete operation segmentation and slicing carries out, and spraying operation from bottom to top, first sprays steelframe and buttress gap portion, After spray part between two steelframes；Gunite concrete layering carry out, a jet thickness depending on ejection electrodes and design thickness, Arch is preferably 5cm~6cm, and abutment wall is 7cm~10cm, and rear one layer of spray after preceding layer final set or should spray afterwards every other hour； When injection from bottom to top, i.e., wall top after first foundation, vault after first arch springing, avoids dead angle, and helically rotational trajectory moves material beam, and one Circle pressure half-turn, longitudinal to press snakelike injection, each snakelike spray penetration is 50mm；Gunite concrete final set starts to sprinkle water after 2 hours Maintenance, watering number should be can guarantee that concrete has enough moisture states for degree, and curing time must not be less than 14 days；Injection Concrete surface answer closely knit, smooth, free from flaw, fall off, drain spray, hollowing, percolating water phenomena such as, irregularity degree tolerance be ± 3cm。

9. wearing construction of the flyover method under a kind of cold excavation according to claim 1, it is characterised in that: the step (7) Tunnel Second Lining uses section construction, i.e. YDK35+440~+445 counts 5m；YDK35+445~+450 counts 5m； YDK35+450~+455 counts 5m；YDK35+455~+460 counts 5m；Total 20m；ZDK35+448~+453 counts 5m；ZDK35+ 453~+458, count 5m；ZDK35+458~+463 counts 5m；ZDK35+463~+468 counts 5m；ZDK35+468~+474, meter 6m；Total 26m.