Summary of the invention
The object of the present invention is to provide a kind of bridge-type shield construction method that improves the current speed limit of construction section, construction safety, a kind of box bridge that risk is little.
The object of the present invention is achieved like this: a kind of bridge-type shield construction method of box bridge, comprise the steps: (1) design height according to box bridge, and build the highway section side of box bridge at needs and carry out excavation of foundation pit; (2) make slide plate according to the length of bridge; (3) it is prefabricated to carry out box bridge according to designing requirement; (4) make the shield structure and carry out the installation of shield structure according to Box Bridge depth of beam, width; (5) as required circuit is carried out consolidation process; (6) order of digging fortune, shaft centerline measurement, box bridge jacking, jacking correction, the maintenance of way by sub-shield driving, the middle cubsoil box bridge jacking operation that circulates, (7) box bridge jacking back in place is recovered the normal operation of circuit and is also removed the shield structure.
The described shield structure of step (4) comprises shield structure parent and sub-shield structure two parts in the bridge-type shield construction method of above-mentioned box bridge, shield structure parent comprises pier stud again, many Pin girder and shield shell, the post of pier stud is wide to be fixed value 1.05m, clear height designs and produces by each hole rigid frame bridge design height with long, three to four layers of general branches, it at the bottom of the pier stud welding of thick steel slide plate of 20mm and skeleton, the high 1.3m of every Pin girder, wide 0.6m, grow with box bridge outer wide same, the middle centering spacing that girder is installed is 1.2m, be welded into whole steel structure bridge with I28# welding back and with each pier stud between Pin and Pin, pier stud and girder connect into a font or multi-door word combination shape, the shield shell is made by steel plate, divide top board, side plate is wrapped in girder top and the pier stud outside; The sub-shield structure case height 1.3m of sub-shield structure is identical with girder, presses the wide lattice setting of 0.75m, one to two lattice reducing wherein occurs, and an estrade shield structure is housed in the nose girder on every grid shield structure case, and is equipped with 2 on 30 tons of oil tops in every estrade shield structure; The shield structure correction plate that climbs is set under the preposition Pin beam, and sub-shield structure case is installed in the girder front end of shield structure parent, is connecting a drag reduction sheet iron plate with its width such as grade in each sub-shield structure top rear.
Step (5) adopts simple and easy reinforcement means in the bridge-type shield construction method of above-mentioned box bridge, the vertical rail bundle of rail track 2+3 button, and single line 2 bundles, two-wire are 3 bundles; Laterally the 1+2 button is worn 1 bundle every 2 sleepers, and is fastened on two vertical rail bundle tops; Former railway roadbed is the natural fulcrum of longitudinal and transverse rail bundle, between transverse rails bundle and stock rail with to inserting timber wedge fine setting circuit level.
The bridge-type shield construction method of above-mentioned box bridge, excavation method in the step (6) is, open translot before the sub-shield structure, open the excavation mode of vertical slot before the pier stud, excavation length 30~40cm is a working cycles, excavation area is sub-shield structure case and each pier stud sectional area, stretching into middle cubsoil in the girder span lags behind the some rice of groove and just begins to excavate when stopping the Box Bridge bottom, excavation length is about 1m, and remain and lag behind 1: 0.75 above excavation gradient, light section is finished in 3 working cycles the cubsoil excavation once.
Method of the present invention compared with prior art has following characteristics:
1. omit the hole digging pile of open cut and the supporting of tunneling, reduced on-line operation time and security risk;
2. construction site track switch, semaphore etc. all do not need interim migration;
Train, automobilism stability better, safety factor is big, can corresponding raising speed limit;
4. design span, the buried depth of bridges and culverts are unrestricted, do not have built on stilts worry of transfiniting.
5. can be fit to highway, railway, cross the genuine construction in street.
The specific embodiment
Consult shown in Figure 1ly, the bridge-type shield construction method of box bridge of the present invention comprises the steps: (1) design height according to box bridge, builds the highway section side of box bridge at needs and carries out excavation of foundation pit; (2) make slide plate according to the length of bridge; (3) it is prefabricated to carry out box bridge according to designing requirement; (4) make the shield structure and carry out the installation of shield structure according to Box Bridge depth of beam, width; (5) as required circuit is carried out consolidation process; (6) order of digging fortune, shaft centerline measurement, box bridge jacking, jacking correction, the maintenance of way by sub-shield driving, the middle cubsoil box bridge jacking operation that circulates, (7) box bridge jacking back in place is recovered the normal operation of circuit and is also removed the shield structure.
Consult shown in Fig. 2, Fig. 3, Fig. 4, the main member of the bridge-type shield structure described in the present invention is made up of five major parts such as pier stud 1, girder 2, shield shell 3, sub-shield structure case 4, auxiliary body, and preceding four major parts are by being welded into whole steel work.Wherein pier stud 1 adopts I28# to be welded, and the wide 1.05m of post is that fixed value, clear height and length design and produce by each hole rigid frame bridge design height underrange, generally divides three to four layers.1 end of pier stud is thick steel slide plate of 20mm and skeleton welding, and it is the basis of pier stud 1, and the holder post slides in the shield structure advances, and pier stud 1 both sides all are welded with steel plate parcel cylinder, in order to keep off soil and balance lateral pressure, also serve as the shear wall effect simultaneously.Girder 2 is welded by the I28# steel, every Pin girder 2 high 1.3m, wide by 0,6m, long and Box Bridge outer wide with, the spacing during installation between the girder 2 (middle centering) be 1.2m, between Pin and Pin with being welded into whole steel structure bridge after the I28# welding and with each pier stud 1.1 girder of each pier stud comprises below 2 does not all have attachment between the guide plate, pier stud 1 connects into a font or multi-door word combination shape with girder 2, so that the middle cubsoil that excavates that lags behind stretches in the door.Shield shell 3 is to be made by the 16mm steel plate, divides top board, side plate, is wrapped in girder top and the pier stud outside and plays retaining soil and structural re-enforcement.Sub-shield structure case 4 is welded by I28# and 16mm steel plate, and its profile is as huge mouth organ, and 1.3m is identical with girder 2 for height, presses the wide lattice setting of 0.75m, one to two lattice reducing wherein may occur, greater than 0.75m or less than 0.75m.In the nose girder estrade shield structure is housed on every grid shield structure case 4, push up 2 in order to advance sub-shield structure cutting front soil or to insert railway roadbed and be equipped with 30 tons of oil in every estrade shield structure, sub-shield structure case is installed in the girder front end of shield structure parent, is connecting a drag reduction sheet iron plate with its width such as grade in each sub-shield structure top rear.The effect that the sub-shield structure that stretches out from sub-shield structure case 4 is also being undertaken the balance soil pressure, when shield structure parent advances, sub-shield structure is subjected to front soil resistance and casing to do relative motion such as drawer-like is retracted in the casing, simultaneously, prevents that the drag reduction plate of circuit or road displacement from also finishing traction by sub-shield structure.Soffit of girder space is an operation path, and a preposition Pin girder 2 has the shield structure correction plate that climbs, and be sub-shield structure case 4 before the girder 2, and box plate links to each other and bears end load before the shield structure jointly with the plate of rectifying a deviation of climbing.Main auxiliary body: the rigid frame bridge propulsion system, bear down on one some by the 200T/ table oil, compositions such as pressure pumping plant and high-pressure oil passage, identical with traditional handicraft, be the propulsion system of pontic and shield structure.Hydraulic efficiency manipulator: be equipped with as required, excavate in order to the medium and small development end of shield structure, the big section of middle cubsoil is excavated by crawler-mounted excavator.Signal system: because noise is bigger in the hole, so need to adopt the remote control color lamp to command the work of sub-shield structure.The anti-pull system of hydraulic pressure: the anti-drag reduction plate that draws is controlled railway or road displacement.
Its support principle of bridge-type shield method of the present invention is: open translot before the sub-shield structure, open the excavation mode of vertical slot before the pier stud, excavation length 30~40cm is a working cycles, excavation area is sub-shield structure case and each pier stud sectional area, because each excavation area is little, soil pressure is balance easily, stretch into when the interior middle cubsoil of girder span lags behind with the some rice of groove bottom stopping Box Bridge and just begin to excavate, excavation length is about 1m, and remain and lag behind 1: 0.75 above excavation gradient, make the excavation face soil body keep natural self-stable ability, light section is finished in 3 working cycles the cubsoil excavation once.Bridge-type shield structure beam clear span is generally that 3~4m is wide to be established one and stride, and the girder amount of deflection was less than 1mm, to alleviate the covering layer construction Deformation when fullcharging carried.
Its guiding principle is: the utilization of middle cubsoil is one of key of this job practices, it is not only natural supporting, each pier stud keeps, and vertical, the stable direction of motion that reaches also is to finish balance by adjustment center earth lateral pressure, and in the bearing capacity of foundation soil location that do not meet the demands, the high bearing capacity rest shield structure of cubsoil upper board knot layer is controlled the best approach of jacking elevation especially in the utilization, pre-densification can be carried out to subgrade in the positive slope of pier stud slide plate setting simultaneously, to improve bearing capacity of foundation soil.
Its pavement displacement control principle: each sub-shield structure is drawing a drag reduction sheet iron plate with its width such as grade separately and is advancing when advancing in succession; top frictional force is removed branch; be not sheared destruction and displacement with the protection overburden soil; its top did not contact with the overburden soil on top when shield structure parent advanced with the case bridge; but band steel that the bridge top is laid at interval and shield structure top board and the friction of drag reduction plate bottom surface; its friction factor 0.1 only is 1/5 during with native direct friction; thereby play the tectal effect of protection once more; also reduced simultaneously the jacking resistance; and protected bridge top waterproofing course effectively; when group shield structure will pass roadbed (about 1 to 2 meter); its frontal drag meeting is gradually less than the frictional force of drag reduction plate and bridge end face; when the case bridge advances; the top can drive the drag reduction plate and shear disconnected plate upper caldding layer; make it displacement; when the more piece box bridge adopts the jacking of relaying method; when the first segment bridge is passed; the second joint top frictional force plays the anti-drag reduction plate effect of drawing; and second joint is when passing; first segment top frictional force greater than second joint top and the drag reduction plate frictional force, can not produce displacement so need not establish the drag unit covering layer again yet.When the single-unit box bridge is constructed, need to adopt the anti-drag reduction plate that draws of drag unit to control railway or road displacement.
The simple and easy reinforcement means of circuit among the present invention is, natural drainage in the railway bridges and culverts, contain the top design elevation and often do not stay overburden soil, the bridges and culverts top is directly passed from the railway roadbed bed course, for preventing that local ballast aggregate from accident occurring and stepping on and fall to influencing safe driving, during the jacking, circuit adopts the simple and easy rail of lifting, and vertically rail bundle 2+3 detains, single line 2 bundles, two-wire is 3 bundles, and is by that analogy multi-thread.Laterally the 1+2 button is worn 1 bundle every 2 sleepers, and is fastened on two vertical rail bundle tops.Former railway roadbed is the natural fulcrum of longitudinal and transverse rail bundle, and to finely tune the circuit level to inserting timber wedge, circuit is lifted rail and played safety effect between transverse rails bundle and stock rail.
Embodiment 1
Guangzhou-Shenzhen railway woods village 2-13m rigid frame bridge engineering
Being designed to 2 hole rigid frame bridge headroom is 13.03 * 6m, length 14m, and bridge spacing 5m, tread is worn two strands of seamless main tracks of high speed down to containing top 0.9m.Box bridge adopts single-unit integral prefabricated, adopts the bridge-type shield construction, and circuit is only done simple button rail during the jacking, does not establish hole digging pile and lifts beam, train operation speed limit 60Km/h to 80km/h during the jacking.The rigid frame bridge jacking puts in place, south bridge is lower than design elevation 6cm, and north bridge is higher than design elevation 4cm.
Embodiment 2
Wear Jingzhu express way under the 2-8m+2-12m rigid frame bridge
Engineering is positioned at Changsha people East Road, 72 ° of obliques, and ground is lam, bearing capacity 160kpa, no underground water.Bridge length is 35m, and it is prefabricated that box bridge is divided into three joints, bridge-type shield method and relaying method jacking construction, and the construction period vehicle is speed limit not, and jacking is superior in quality.This project adopts pipe shed method supporting jacking by former unit in charge of construction, and the road surface is by heavy damage, and the case bridge withdraws from after planting head, uses the bridge-type shield method instead and finishes.