Summary of the invention
The technical issues that need to address of the present invention are: a kind of construction process of pushing in long and large box culvert under taxiway in airport is provided, can guarantee that aircraft constructs under the condition of not suspending, ensure the flight Normal Take-Off And Landing and slide safety, prevent to prick head, fine solution butt joint problem, engineering precision height, cost are low.
Technical solution of the present invention is: construction process of pushing in long and large box culvert under taxiway in airport, comprise little pilot tunnel laying, pre-timbering with tubular prop, crest enters box culvert and road face settlement Control technology, it is characterized in that: described little pilot tunnel is positioned at the box culvert bottom, some I20 i iron are laid at the end of little pilot tunnel, by the gradient mix up, leveling, fixing with the support welding, thereafter pumping C20 concrete pouring bar shaped slideway, the i iron end face flushes with the concrete end face, in the box culvert jack-in process, with excavator little pilot tunnel is abolished; Described pre-timbering with tubular prop process using: wireless signal remote control is surveyed and is received and the emission instrument, record directed three-dimensional coordinate and the attitude angle of drill bit in soil of boring, make the guiding sole at drill bit place to theory orientation deflection by rotation, thereafter give the drilling rod applied thrust, make it to advance along the correction of guide strip bevel direction, thereby finish the pilot hole of long 148m, after utilizing the interior drill rod end of pilot hole to install the enlarged footing of band jetting cutting soil additional, pilot hole is extended to about 350mm, with the mud cover hole wall is protected simultaneously, finish reaming after, draw with drilling rod, with φ 325mm diameter, the steel pipe of thick 10mm is after progressively weldering connects, be used as power with large-scale hauling pipe rig steel pipe is dragged to the other end from Kong Yiduan, afterwards measurement and positioning errorless after, in pipe, pump into the C25 concrete, form the beam on the elastic foundation in the soil; Described road face settlement Control technology comprises: the road face is arranged net, and monitors sedimentation with precision level, and the T-S curve is associated to putting distance L with containing end, draws T-S-L figure, finds out the position that needs slip casting, the contingent sedimentation value in prediction the place ahead; The Comprehensive Control measure mainly contains in the hole: native jacking is eaten in strictness; Guarantee the two-edged pin side plate outside sky that do not collapse; Guarantee that face does not reveal the landslip of pipe canopy, dew sword pin; Containing the front end base plate does not backbreak; Slip casting pressure regulation and pressurize; Pipe canopy stress, strain measurement, the anti-pipe canopy amount of deflection of asking; Contain back of the body soil pressure measurement; Local ground grouting and reinforcing anti-settling outside the road face.
The present invention compared with prior art has following advantage: 1, little pilot tunnel builds up, at first verify the top and contained front of tunnel heading geology, the pre-supporting of face provides foundation during for jacking, next has reduced in the soil and has seeped water, behind the soil body discharging consolidation, intensity increases substantially, face stability strengthens, the most important thing is to contain the suitable chute surface in the end advances, thoroughly solved a problem of pricking, merging precision is far above code requirement, the discrepancy in elevation<20mm of the present invention, left-right deviation is within 50mm, and settlement Control is in three one thousandths.2, the pre-timbering with tubular prop technology of growing up adopts φ 325mm, L=148m, engineering precision 24cm.3, box culvert jacking in soil, total frictional resistance equals following 5 top sums, promptly contains upper and lower, left and right face pressure and takes advantage of soil body friction factor to add the frontal drag of sword pin.This engineering is contained the top buried depth and is reached 6m, and the pressure of such 4 faces is just very big, more than 20,000 ton of total top power, more rare at home, box culvert top easily splits, and back also may push up race, the present invention selects a kind of daily output chemical grout for use, it is constant for a long time that its better performances, Main Feature are that viscosity can keep, and meets underground water and do not decompose, in soil, do not permeate, drying shrinkage knot is hard, and box culvert is not by locking when resetting more than 3 months stopping to tunnel more than several days total pushing tow time to have guaranteed box culvert.The mud resistance-reducing efficiency reaches 60%-80%, and two joint culverts one are pushed up simultaneously and needed more than 8000 ton top power, are kept to more than 2400 ton, for smooth jacking successfully provides prerequisite.4, the aircraft taxi load reaches 4000kN, much larger than railway or highway load, thereby the security protection requirement is higher, and box culvert shallow embedding (the tunneling buried depth is 2.7m only), the long 142m of top journey, the jacking of not suspending, pavement slab does not have faulting of slab ends, road face sedimentation curvature ≯ 1/3000, sedimentation ≯ 30mm, little to the influence of surface structures facilities such as airport, thoroughly solve freight and cross the L taxiway interference of aircraft Normal Take-Off And Landing and safety problem, increase substantially shipping efficient.5, cost is low, and method is simple, remarkable in economical benefits, and every cavitation rice is 90,000 yuan, and adopts tunneling to be about 120,000 yuan, every cavitation rice is saved 30,000 yuan, saves 4,400,000 yuan altogether.
Specific embodiments
Describe embodiments of the invention below in detail.
Empty side line road engineering, pushing in long and large box culvert under taxiway in airport engineering length is 148m, width is 13.7m, height is 6.45m, is designed to diplopore 6m rectangle box culvert, adopts relay well method jacking construction, the chemical mud pit body lubrication drag reduction of Japan, little pilot tunnel control is pricked head and is come back.
1, the bassoon canopy protects the top in advance and pays nurse's skill in advance
During the box culvert jacking, the front edge pin is subjected to rigidity control and box culvert to prick head to be influenced, can not design oversizely, 2.5m only, and the high 6.5m of soil body face, press lam angle of friction 11 degree angles from containing the end, after calculating the soil body plane of fracture, ten meters thick soil body slump districts will be arranged at box culvert front end face and top, the pipe shed support that present domestic underground construction circle adopts mostly is φ 159mm pipe, and length only is about 60m, is applicable to the pure bored tunnel of little span, the long 148m of this engineering, the disposable φ 325mm pipe canopy beyond example still at home of getting through.
The present invention adopts wireless signal remote control to survey and receives and the emission instrument, record directed three-dimensional coordinate and the attitude angle of drill bit in soil of boring, make the guiding sole at drill bit place to theory orientation deflection by rotation, thereafter give the drilling rod applied thrust, make it to advance, thereby finish the pilot hole of long 148m along the correction of guide strip bevel direction.
After utilizing the interior drill rod end of pilot hole to install the enlarged footing of band jetting cutting soil additional, pilot hole is extended to about 350mm, with the mud cover hole wall is protected simultaneously.After finishing reaming, draw with drilling rod, with φ 325mm diameter, the steel pipe of thick 10mm, after progressively weldering connected, being used as power with large-scale hauling pipe rig was dragged to the other end with steel pipe from Kong Yiduan.Afterwards measurement and positioning errorless after, in pipe, pump into the C25 concrete, form the beam on the elastic foundation in the soil, canopy is firmly contained the front end certain limit top soil body, effectively prevents landslide.
2, little pilot tunnel and glide path technology
Bundle in a box culvert jack-in process phenomenon is difficult to avoid, and domestic engineering circle is headache for this reason always, and so big box culvert on weak soil, is certain to prick head again, can't solve the butt joint problem in case prick head.The present invention adopts containing the end and digs a little pilot tunnel, and for the making slideway provides the space, little pilot tunnel is of a size of wide 1.3m * high 1.9m, periphery with linked network spray 10cm, thick C20 concrete is a supporting and protection structure, by a Pin bow member, to be that φ 50mm steel pipe is curved be welded into bow member every 0.5m.
At the bottom of little pilot tunnel, lay 3 I20 i iron, by the gradient mix up, leveling, fixing with the support welding, the slideway of pumping C20 concrete pouring bar shaped thereafter, size 1.0m is wide * 0.6m is thick, the i iron end face flushes with the concrete end face, thereby slideway formation.In the box culvert jack-in process, little pilot tunnel supporting and protection structure is abolished with excavator.
3, chemical slurry lubricating process
Box culvert is jacking in soil, and total frictional resistance equals following 5 top sums, promptly contains upper and lower, left and right face pressure and takes advantage of soil body friction factor to add the frontal drag of sword pin.Use daily output chemical grout better performances, it is constant for a long time that Main Feature is that viscosity can keep, and chance underground water does not decompose, in soil, do not permeate, drying shrinkage knot is hard, guarantee box culvert stop to tunnel more than several days, total pushing tow time, box culvert was not by locking when resetting more than 3 months.
Stirring pumping is pressed by mud lubrication of the present invention system, and pumping pressure 0.15-0.4Mpa, pipeline are by house steward, branch diameter φ 40mm, and the slip casting one way valve is formed.
By spacing 3m, case end distance 1.5m place's cloth pipeline and one way valve connect long φ 40 high-pressure rubber pipes of one section 5m at each relay well place of casing around the box culvert appearance, and branch road starting point end mounting ball valve is with flexible control slip casting position and grouting amount.
4, road face settlement Control technology
The road face is arranged net, and monitors sedimentation with precision level, monitors the tense sedimentation at each control point.The T-S curve is associated to putting distance L with containing end, draws T-S-L figure, to find out the position that needs slip casting, the contingent sedimentation value in prediction the place ahead.
The Comprehensive Control measure mainly contains in the hole: 1) native jacking, 2 are eaten in strictness) guarantee the two-edged pin side plate outside sky that do not collapse, 3) guarantee that face does not reveal the pipe canopy, reveals the landslip of sword pin, 4) contain the front end base plate and can not backbreak 5) slip casting pressure regulation and pressurize.
Pipe canopy stress, strain measurement, the anti-pipe canopy amount of deflection of asking.
Contain back of the body soil pressure measurement.
Local ground grouting and reinforcing anti-settling outside the road face.
5, two-way jacking closure section tunneling and joint treatment process
Two-way closure point position is chosen in beyond the taxiway, reduces like this slideway settlement influence, and is stressed also safer.
Sword pin spacing 3-5m is advisable, and mainly considers the influence of an end pushing tow to the other end, and when connecting soon, the other end face soil body can cave in, and is dangerous.
Sword pin steel plate is not dismantled, and still plays the effect of retaining soil.The vertical distribution reinforcement φ 16 of box culvert, φ 20 adopt boring bar planting technology to connect.Box culvert hoop steel bar stress because its broken end will cut the about 30cm scope of length in oblique triangle sword pin concrete, adopts overlap welding to connect.Waterproofing course will be attached to sword pin steel plate inboard, two ends, carries out cushion rubber, will glue the bloated sealing rod of the square chance freight of 50 * 50mm at culvert plate end face.
Principal rod colligation order: outer earlier, internal layer again, back envelope template.
Locate to irritate concrete from low to high, press lift-up method to build concrete with the bottom-up band of concrete pump line.Establish exhaust, plasma discharge mouth at highest point.
Select large fluidity for use, high-strength self-compacting concrete.Irritate when concrete seals arch at last and want slow, pump once stops, treats that air water arranged, and the concrete of emerging is starched to filling.Pre-buried madjack pipe, back ftercompction cement paste.
6, box culvert relay well and joint waterproofing technology
The every joint of the present invention is contained long 15m, and the place has established relay well and risen nest at every joint seam, and first joint must be established relay well, and other can establish one group of relay well by 2 joints, and to reduce seam, the culvert joint is long also to be adjustable to about 20m.
The internode waterproof: adopt the diameter at internode extruding φ 80mm, thick 1.5cm rubber tube is aided with joint filling cream grouting for water blocking later on again.