Corrugated steel web box girder bridge lining concrete structure
Technical Field
The invention relates to the field of steel-concrete composite bridge design, in particular to a design of a corrugated steel web box girder bridge lining concrete structure.
Background
A large-span corrugated steel web box-shaped continuous beam bridge and a continuous rigid frame bridge have large negative bending moment and shearing force near the pier top, and are complex in constraint conditions and stress states. In order to improve the stress performance of the corrugated steel web composite beam in the area, avoid buckling of the corrugated steel web and buckling of the steel flange and enable the shear force to be transmitted more uniformly, concrete is filled in the inner side of the corrugated steel web within a certain distance range near the pier top to form a steel-concrete composite section. Because the rigidity of the corrugated steel web and the rigidity of the concrete are different, the steel-concrete combined section has obvious stress concentration, the surface of the concrete has more cracks due to stress redistribution generated in the deformation coordination process of the two materials, and the prestress efficiency near the pier top can be obviously reduced by the steel-concrete combined section.
Disclosure of Invention
In order to overcome the technical defects of a steel-concrete combined section consisting of the traditional corrugated steel web and solid lining concrete, the invention provides a lining concrete structure of a corrugated steel web box girder bridge.
The invention is realized by the following technical scheme:
the utility model provides a corrugated steel web box girder bridge inside lining concrete structure, including the corrugated steel web of bridge box girder, its characterized in that: shear connectors are fixed on the inner side faces of the corrugated steel web plates of the bridge box girder, lining concrete layers are filled on the inner side faces of the corrugated steel web plates, each lining concrete layer comprises a concrete bottom layer and a concrete surface layer, the concrete bottom layers are concrete blocks connected with the shear connectors into a whole, the concrete surface layers are a plurality of concrete block units distributed at intervals in the longitudinal direction and the transverse direction, and the parts at intervals in the longitudinal direction and the transverse direction of the concrete block units are arranged in a manner of being diverged from the shear connectors.
A wave form steel web box girder bridge inside lining concrete structure which characterized in that: the shear connector is a stud or an open pore steel plate.
A wave form steel web box girder bridge inside lining concrete structure which characterized in that: the elongation of the combined web section formed by the corrugated steel web, the shear connecting piece and the lining concrete towards two sides by taking the fulcrum as a center is not less than the height of the middle fulcrum beam.
A wave form steel web box girder bridge inside lining concrete structure which characterized in that: the whole thickness (including the whole thickness on bottom and top layer) of inside lining concrete layer is not less than 0.07 times well fulcrum roof beam height, it is 10~40cm to indulge horizontal interval degree of depth.
The invention has the advantages of preventing the cracking of the lining concrete, having simple structural design and convenient construction, effectively solving the problem of the cracking of the concrete of the steel-concrete combined section near the supporting point of the corrugated steel web box girder bridge and having wide application prospect. Specifically, the beneficial effects of the invention compared with the prior art are as follows:
1. prevent inside lining concrete fracture, the structure bearing capacity increase: the novel lined concrete structure provided by the invention utilizes the principle that the lined concrete is pressed close to the corrugated steel web part and far away from the tensile force of the web part, and pours the tensile region concrete layer far away from the corrugated steel web part into discontinuous concrete, so that the lined concrete layer is integrally in a T-shaped structure, the concrete surface layer of the concrete of the steel-concrete combined section is prevented from cracking, and the bearing capacity of the structure is improved.
2. Improving the prestress efficiency near the fulcrum: the longitudinal compressive stress of the top surface of the bridge deck near the pivot of the traditional lined concrete box girder bridge is smaller than that of unlined concrete, which shows that the application efficiency of prestress in the area is reduced by arranging the lined concrete. This is because the free shrinkage deformation (wrinkle effect) of the corrugated steel webs is restrained by the lining concrete after the lining concrete is set. Through the finite element numerical simulation calculation in the previous stage, the surface layer discontinuous lining concrete provided by the invention reduces the constraint effect of the lining concrete on the corrugated steel web plate wrinkle effect, so that the prestress application efficiency of the area is improved.
3. Simple structure, it is convenient to be under construction: the discontinuous lining concrete structure provided by the invention is developed on the basis of the traditional lining concrete, so that special equipment is not needed in the construction process, the pouring of the whole concrete layer can be completed only by arranging a simple template at the longitudinal and transverse discontinuities, the operation is simple, and the construction is convenient.
Drawings
FIG. 1 is a schematic view of the structure of the present invention.
FIG. 2 is a schematic cross-sectional view of the present invention showing the position of longitudinal and lateral discontinuities.
The concrete bottom layer 1.1, the concrete surface layer 1.2, the corrugated steel web 2, the transverse discontinuity 3.1, the longitudinal discontinuity 3.2, the shear connector 4, the fulcrum diaphragm beam 5, the box girder roof concrete 6, and the box girder bottom plate concrete 7.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention are described in detail below with reference to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
The utility model provides a corrugated steel web box girder bridge inside lining concrete structure, is including the corrugated steel web 2 of the near position box girder of bridge fulcrum, all welds on the 2 medial surfaces of corrugated steel web a plurality of pegs 4 (or other shear connectors), all fill on the medial surface of corrugated steel web 2 and have inside lining concrete layer, inside lining concrete layer includes concrete bottom 1.1 and concrete top layer 1.2, and concrete bottom 1.1 is the concrete block that links into an integrated entity with shear connectors, and concrete top layer 1.2 is the concrete block unit of a plurality of vertical and horizontal interval distributions, the horizontal 3.1 positions that are interrupted of concrete block unit, the vertical 3.2 positions that are interrupted all with the shear connectors branch out and arrange.
A plurality of studs 4 (or other shear connectors) are welded at intervals on the inner side of a corrugated steel web 2 near a box girder bridge fulcrum, and then a concrete bottom layer 1.1 and an intermittent concrete surface layer 1.2 close to the web are filled in an area surrounded by a box girder concrete top plate 6, the corrugated steel web 2, a concrete bottom plate 7 and a fulcrum diaphragm beam 5 to form an integrated novel lining concrete layer 1 structure; in order to ensure that the corrugated steel web plate is resistant to buckling and uniform in shear force transmission, the total length of the section of the lining concrete layer 1 in the span direction of the bridge is not less than the maximum beam height of the middle fulcrum, the total thickness is not less than 0.07 time of the beam height (30-80 cm) of the middle fulcrum, and the longitudinal and transverse spacing depth is 10-40 cm.
The construction steps of the invention are explained in detail:
firstly, pouring concrete on the fulcrum diaphragm beam 5 in place;
secondly, hoisting the corrugated steel web 2 (containing the welded shear connector 4) in place;
thirdly, binding the bottom plate steel bars of the corrugated steel web box girder, and pouring bottom plate concrete 7;
fourthly, binding common steel bars of the steel-concrete combined section, and paying attention to avoid the position of the longitudinal and transverse discontinuity of the concrete surface layer, and installing the longitudinal and transverse discontinuity formwork of the concrete surface layer;
fifthly, pouring the concrete bottom layer 1.1 and the discontinuous concrete surface layer 1.2 in a grading manner, and paying attention to compaction vibration;
and sixthly, binding the steel bars of the top plate of the corrugated steel web box girder, and pouring top plate concrete 6.
And (5) combining the 6 steps, finishing the construction of the lined concrete structure of the corrugated steel web box girder bridge, and forming a new reinforced concrete combined section. The anti-cracking structure of the steel-concrete combined section is simple in design and convenient to construct, can improve the pre-stress efficiency near the fulcrum, and has wide application prospect.
It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.