A kind of prefabricated concrete hollow slab bridge construction
The utility model belongs to civil engineering bridge technology field, is specifically related to a kind of prefabricated concrete hollow slab bridge construction.
The medium and small footpath prefabricated PC concrete hollow slab girder of striding, convenient because of this type bridge construction, better economy is widely used at field of traffic.By the end of the year 2009, Zhejiang Province's highway bridge total length has reached 205.3 myriametres, and wherein hollow slab bridge accounts for highway bridge total kilometrage ratio more than 90%.
Prefabricated concrete hollow slab; Common plate is wide to have two kinds of 1m, 1.25m; Wherein the 1m plate is wide is little hinge crack structure; Carry out " highway reinforced concrete and prestressed concrete bridge are contained design specifications " (JTJ 023-85) design, the 1.25m plate is wide to be big hinge crack structure, carries out " highway reinforced concrete and prestressed concrete bridge are contained design specifications " (JTG D62-2004) design.Present big hinge seam hollowcore slab standard drawing has carried out comprehensive improvement to traditional little hinge seam; And strict demand has been proposed construction technology; As cut with scissors and stitch cutter hair, hinge seam concrete vibration, the inspection of cutting with scissors the seam reinforcing bar and welding etc.; Bearing stress to hollowcore slab after in place has also proposed inspection requirements, avoids " three leg " to receive force phenomenon.
With big hinge seam prestressed cored slab is example; There are 10m, 13m, 16m, 20m, 25m, 30m in the common footpath of striding; The respective panels height is respectively 0.45m, 0.6m, 0.8m, 0.9m, 1.1m, 1.2m rice, and corresponding span-depth radio is respectively 22.2,21.7,20,22.2,22.7,25.Two kinds of 25m and 30m stride the footpath usually under bridge current headroom specific demand is arranged but deck-molding is limited, can't adopt under the situation of T beam or little case beam and adopt.
The prefabricated concrete hollow slab bridge, many Pin of direction across bridge hollow slab beam mainly relies on the rigidity, beam-ends of beam body self to support, formation integral body such as hinge seam, deck paving are stressed jointly between each plate-girder of direction across bridge.The important Force transmission parts that the hinge seam laterally connects for plate-girder.Lost efficacy in case hinge seam connects, drastic change will take place in single Pin plate-girder load cross direction profiles coefficient, and vehicular load moment of flexure, the shearing that the Pin plate-girder born that place an order will design supporting capacity above it.
2009, Zhejiang Province's highway bridge administrative department to run 1171 jackshafts of 12 speedways accumulative total more than 5 years inside the province, 1579 foot bridges have carried out complete investigation.Finding in the middle of 952 bridge blocks of disease, data result shows: the prestressed cored slab bridge, and vertically hinge seam cracking reaches 351 (accountings 37%), and base plate has longitudinal crack to reach 280 (accountings 29%).Therefore improving the bearing capacity and the durability of medium and small span hollow slab beam, reduce the disease of such bridge type in design reference period, is a vital problem.
Striding footpath big hinge seam hollowcore slab with 20 meters is example, and present way exists following not enough:
(1) the hollowcore slab beam-ends is not provided with near having the hinge seam in the long scope of the about 100cm of bearing, does not take to construct simultaneously the reinforcement treatment measures.
The fulcrum cross section is different with the spaning middle section size, damaged or the out-of-flatness of bearing horizontally set occur when bearing near the beam-ends, very easily causes this zone in deck paving leveling layer cracking and be extended to the hinge seam gradually ftractureing.
(2) hinge seam between adjacent plate-girder, narrow end opening suitable for reading is wide to be the back taper setting, and construction quality is difficult to guarantee.
Spanning interlude hinge seam top mouthful wide only 11cm, the hinge seam degree of depth but surpasses 2/3 deck-molding; To near near the beam-ends 100cm, cut with scissors seam top closure and have only 1cm for level interval.Hinge seam embedded bar field machining and connection workload are big, and hinge seam inner space is narrow and small, especially hinge seam top closing in, and the hinge seam concreting and the difficulty of vibrating, construction quality are difficult to guarantee.
(3) between hollow slab beam end face and deck paving steel concrete leveling layer; Only depend on after simple cutter hair or the scratch punishment promptly as bonding surface; The shear reinforcement diameter that shearing resistance connecting reinforcement or setting or not to each other usually is less, does not have according to the compound beam principle to consider that the effect of performance deck paving concrete cast-in-situ layer improves structural-load-carrying capacity.
Deck paving reinforced concrete cast-in-situ layer thickness is usually near 10cm at present; Receive the influence of antiarch after the plate-girder stretch-draw, concrete shrinkage and creep characteristic and hogging moment area anchoring tooth plate projecting plate top surface of the beam; Actual deck paving concrete cast-in-situ layer thickness thinnest part has only 4-8cm, and thickness is crossed thin unfavorable to guaranteeing integral bridge property.Hollowcore slab top board cutter hair degree also explicitly calls at present.
(4) relatively poor with the assembling hollowcore slab globality of hinge seam connection, the easy to crack or infiltration of hinge seam has reduced structural-load-carrying capacity.
The assembling hollowcore slab is according to the design of hinge seam Transfer of Shear, and hinge is sewn under the prerequisite in full force and effect between adjacent plate-girder, relies on the principle of compatibility of deformation, and the transfer shearing force difference is less between the hinge seam.But in fact, also transmit moment of flexure between the hinge seam.Under moment of flexure, shearing acting in conjunction, and reason such as quality control on construction is not tight, the hinge seam is prone to produce longitudinal cracking.Behind the hinge seam longitudinal cracking, transverse integral connects and will obviously reduce between plate-girder.And hinge seam is in case entirely ineffective, veneer the load that will bear will cause serious potential safety hazard above the design load value.The bridge floor infiltration also can be infiltrated the beam body through the hinge seam and the beam slab longitudinal crack of cracking, causes beam body corrosion of steel bar.These diseases have had a strong impact on the safety of bridge, have reduced structure durability and supporting capacity.
The domestic too much cause hinge seam that taken place destroys, and surpasses the accident that designing requirement is ruptured because of veneer is stressed.The various corrective measures of at present the hinge seam being carried out can't ensure that each beam slab does as a whole stressedly under the bigger situation of vehicular load, the hinge seam is a weak part of full-bridge all the time.
Summary of the invention
To the above-mentioned technological deficiency of existing in prior technology, the utility model provides a kind of prefabricated concrete hollow slab bridge construction, can improve the durability and the bearing capacity of hollow slab bridge girder construction.
A kind of prefabricated concrete hollow slab bridge construction comprises:
Connect the plate-girder layer that forms by some Pin hollow slab beams and row hinge seam; Described hollow slab beam comprises top board, base plate and two webs, and described top board, base plate and two webs surround beam body cavity; Be perfused with concrete in the hinge seam between the adjacent hollow plate-girder;
Be located at the bridge deck pavement on the plate-girder layer; Described bridge deck pavement comprises the concrete cast-in-situ layer of being located on the plate-girder layer and is located at the asphalt concrete layer on the concrete cast-in-situ layer;
Be provided with somely to steel strand in the described plate-girder layer, described steel strand laterally run through all hollow slab beams; Correspondence has some twisted wire ducts to supplying steel strand to pass on the web of described hollow slab beam; Arbitrary twisted pair wire duct is vertical arrangement;
Both sides are embedded with two row's shear reinforcement arrays respectively on the top board of described hollow slab beam, and described shear reinforcement array is made up of several shear reinforcements side by side.
Preferably, the external surface of the web of described hollow slab beam is a vertical plane; Can reduce difficulty of construction, help improving quality control on construction.
Preferably, described steel strand two ends respectively with the web anchoring of the hollow slab beam of plate-girder layer both sides; Can strengthen connection, more firm each other.
Preferably, for arbitrary twisted pair wire duct, open respectively in the H/3 place and the 2H/3 place of the web of hollow slab beam in following twisted wire duct and last twisted wire duct, and H is the plate hight of hollow slab beam; For striding the hollow slab beam of footpath less than 15m, have three twisted pair wire ducts on the web of hollow slab beam, open respectively in the two ends of web and L/2 place in three twisted pair wire ducts; For striding the hollow slab beam of footpath greater than 15m, have five twisted pair wire ducts on the web of hollow slab beam, two ends, L/4 place, L/2 place and the 3L/4 place in web opened in five twisted pair wire ducts respectively, and L is the footpath of striding of hollow slab beam; Can improve the ability of friction shear resisting between plate-girder, reach and improve the whole stressed and displacement coordination purpose of plate-girder, prevention and inhibition hinge seam longitudinal crack are had remarkable result, the durability that the raising hinge is stitched has very great help.
Preferably, the thickness of described concrete cast-in-situ layer is not less than 15cm.
The beneficial effect of the utility model is:
(1) the utility model is through setting up the bonding surface shear reinforcement on hollow slab beam; Can guarantee that deck paving concrete cast-in-situ layer and hollow slab beam are linked to be integral body effectively; Make the concrete cast-in-situ layer stressed as the part participation plate-girder of compound beam; Plate-girder self rigidity is enhanced, and individual plates load bearing beam ability also is improved; Can overcome existing medium and small common fault of striding footpath hollow slab bridge girder construction, strengthen the globality of structure and improve the supporting capacity of veneer.
(2) between each Pin plate-girder of the utility model employing direction across bridge the post tensioning prestress wire is set initial precompression is provided; Greatly improve the stiction of adjacent plate-girder at hinge seam place; Coordinate displacement each other between plate-girder through transmitting frictional force, effectively improve the shear resistance of hinge seam; Simultaneously because the existence of horizontal precompression is arranged, the prevention and the inhibition of hinge seam longitudinal crack there is remarkable result, the durability of hinge seam is improved very big, increase bridge application life.
(3) the utility model can reduce maintenance cost through improving the hinge crack structure, reduces because of the adverse effect of bridge maintenance to passing through and causing; And easy construction can guarantee construction quality, and it is basic identical that construction process processing and original precast hollow plate-girder are built flow process, and special-less process equipment has tangible economic benefit and social benefit.
Description of drawings
Fig. 1 is the structural representation of the utility model.
Fig. 2 is the cross-sectional view of Fig. 1 along AA ' direction.
Fig. 3 is the longitudinal section of Fig. 1 along BB ' direction.
The specific embodiment
In order to describe the utility model more particularly, be elaborated below in conjunction with accompanying drawing and the specific embodiment technical scheme to the utility model.
Like Fig. 1,2, shown in 3, a kind of prefabricated concrete hollow slab bridge construction comprises: plate-girder layer 1, concrete cast-in-situ layer 2 and asphalt concrete layer 3.
Plate-girder layer 1 is formed by 9 Pin hollow slab beams 4 and the connection of row hinge seam; Hollow slab beam 4 comprises top board 41, base plate 42 and two webs 43, and top board 41, base plate 42 and two webs 43 surround beam body cavity, and the external surface of web 43 is a vertical plane; Be perfused with concrete in the hinge seam 9 that the adjacent hollow plate-girder is 4; In this embodiment, the concrete of perfusion adopts polypropylene fiber concrete in the strand seam 9; The bottom width of hollow slab beam 4 is 125cm, and plate hight is 0.9m, strides the footpath and is 20m.
Concrete cast-in-situ layer 2 is located on the plate-girder layer 1; The thickness of concrete cast-in-situ layer 2 is 15cm in this embodiment.
Asphalt concrete layer 3 is located on the concrete cast-in-situ layer 2.
Be provided with five pairs of steel strand 7 in the plate-girder layer 1, steel strand 7 laterally run through all hollow slab beams 4, steel strand 7 two ends respectively with web 43 anchorings of the hollow slab beam 4 of plate-girder layer 1 both sides; Steel strand 7 in the present embodiment adopt does not have the bonding epoxy coating strand.
The two ends of hollow slab beam 4 webs 43, L/4 place, L/2 place and 3L/4 place all have the twisted wire duct 8 that a pair of confession steel strand 7 pass; Arbitrary twisted pair wire duct 8 is vertical arrangement, and H/3 place and the 2H/3 place in web 43 opened in following twisted wire duct and last twisted wire duct respectively; L is for striding the footpath, and H is a plate hight, so the distance between two adjacent arbitrarily twisted pair wire ducts is 5m, wherein at L/4 place and 3L/4 place, the end of steel strand 7 and web 43 are fastening through stiffening rib 10 local reinforcements.
Both sides are embedded with two row's shear reinforcement arrays respectively on the top board 41 of hollow slab beam 4, and the shear reinforcement array is made up of several shear reinforcements 6 side by side; Shear reinforcement 6 in this embodiment adopts HRB335 reinforcing bar, diameter 12mm, two limbs.