Steel case hybrid beam short bonding section structure of high-speed railway large-span
Technical Field
The invention relates to the field of design and construction of bridge engineering, in particular to a short combination section structure of a high-speed rail large-span steel box mixed beam.
Background
The concrete beam is adopted to the side span of steel-concrete combination box girder cable-stayed bridge, can weigh the dead weight of the balanced midspan large-span girder steel, and the side span concrete beam can also increase the overall rigidity of the girder. In addition, the side span concrete beam reduces the steel consumption of the full bridge, and improves the economy and the subsequent maintenance cost. The steel-concrete joint transmits huge internal force of the main beam between the two materials, and has the characteristics of complex structure, complex force transmission and the like; at present, most of existing mixed beam cable-stayed bridges are highway bridges, and the mixed beam cable-stayed bridges are rarely applied to railway bridges due to large railway load and high requirement on line stability.
In a railway large-span steel-concrete combined box girder cable-stayed bridge, a Ningbo railway junction river crossing grand bridge and a deep mao railway Tanjiang river grand bridge both adopt steel-concrete combined sections, the steel-concrete combined sections of the Ningbo railway junction river crossing grand bridge and the deep mao railway Tanjiang river grand bridge have the same form and are in the form of a cellular front and rear pressure-bearing plate, but the combined sections of the Ningbo railway junction crossing bridge and the deep mao railway Tanjiang river crossing are both longer, and although the advantages of uniform force transmission and coordinated deformation are achieved, the structure.
Disclosure of Invention
The invention aims to provide a short joint section structure of a high-speed rail large-span steel box mixed beam, which is characterized in that a steel box and a concrete material are connected together mainly through a prestressed steel beam, and the connection of steel and concrete is reinforced through members such as PBL (Poly-p-phenylene benzobisoxazole) perforated steel plates, shear nails and the like.
The purpose of the invention is realized by the following technical scheme:
a high-speed rail large-span steel box mixed beam short combination section structure comprises a steel top plate, a steel bottom plate and a bearing plate, wherein the bearing plate is clamped between the steel top plate and the steel bottom plate and divides the steel box mixed beam short combination section into a steel-concrete combination section and a steel beam transition section in a longitudinal bridge direction;
PBL perforated steel plates which are parallel in the longitudinal bridge direction are uniformly distributed at two ends of a steel top plate and a steel bottom plate in the reinforced concrete combined section, and a plurality of C-shaped perforated steel plates are respectively arranged between the PBL perforated steel plates at two ends of the steel top plate and between the PBL perforated steel plates at two ends of the steel bottom plate;
two parallel transition section steel webs are distributed in the steel beam transition section, the two transition section steel webs divide the steel beam transition section into a box girder outer chamber, a box girder compartment and a box girder inner chamber in the transverse bridge direction, one end of each transition section steel web is connected with a steel top plate in the steel beam transition section, and the other end of each transition section steel web is connected with a steel bottom plate in the steel beam transition section;
a plurality of transverse bridges are arranged in the box girder compartment and stiffened towards parallel saddle-shaped ends, a plurality of transition section prestressed reinforcement anchor chambers are distributed on transition section steel webs in box girder outer chambers and box girder inner chambers, steel top plates in steel girder transition sections and steel bottom plates in steel girder transition sections, a plurality of steel web stiffening ribs which are parallel to each other are further distributed on the transition section steel webs in the box girder outer chambers and the box girder inner chambers, one side of each transition section prestressed reinforcement anchor chamber is connected with the bearing plate, the other side of each transition section prestressed reinforcement anchor chamber is connected with the steel web stiffening ribs, the height of each transition section prestressed reinforcement anchor chamber is matched with the width of two adjacent steel web stiffening ribs, and transition section variable-height stiffening ribs are uniformly distributed on the steel top plates and the steel bottom plates in the box girder outer chambers and the box girder inner chambers;
PBL reinforcing steel bars transversely penetrate through the PBL steel plates with holes and the C steel plates with holes, concrete partition walls are poured in the steel-concrete combined section, longitudinal prestressed reinforcing steel bars are anchored in the transition section prestressed reinforcement anchoring chamber, and the prestressed reinforcing steel bars penetrate through the bearing plate and the steel-concrete combined section and are anchored in the concrete beam section to strengthen connection of the bearing plate and the concrete partition walls.
Furthermore, a plurality of shear nails are uniformly distributed on the steel top plate, the steel bottom plate and the bearing plate, the diameter of each shear nail is 10-25 mm, and the height of each shear nail is 100-200 mm.
Furthermore, holes for penetrating through the PBL steel bars are symmetrically formed in the PBL steel plate with holes and the C steel plate with holes.
Furthermore, the PBL steel plate with holes and the C steel plate with holes are welded in the steel-concrete combined section, grooves are formed in the edges of the PBL steel plate with holes and the C steel plate with holes, and the cross section of each groove is semicircular or corrugated.
Furthermore, the transition section prestressed reinforcement anchor chamber comprises a prestressed reinforcement anchor plate, a prestressed reinforcement stiffening plate and anchor indoor concrete, the prestressed reinforcement anchor plate and the prestressed reinforcement stiffening plate are connected end to form a reinforcement anchor chamber cavity, the anchor indoor concrete is poured in the reinforcement anchor chamber cavity, one end of each adjacent group of steel web stiffening ribs is respectively connected with the upper end and the lower end of the prestressed reinforcement anchor plate, and the prestressed reinforcements sequentially penetrate through the prestressed reinforcement anchor plate and the bearing plate to be connected with the cast concrete partition wall.
Furthermore, open air holes are formed in the steel web stiffening ribs at the top layer and the bottom layer in the box girder outer chamber and the box girder inner chamber.
Furthermore, a transition section heightening stiffening rib is provided with a heightening section at a position 2300-2400 mm away from the pressure bearing plate, the slope of the heightening section is 0.375, and the height section is arranged behind the heightening section.
Furthermore, transverse prestressed tendons are arranged at the lower part of the concrete partition wall poured in the steel-concrete combined section and penetrate through the PBL steel plate with holes and the C steel plate with holes.
The invention has the beneficial effects that:
1) the invention relates to a high-speed rail large-span steel box mixed beam short combined section structure, wherein a steel-concrete combined section is respectively provided with shear nails on a steel top plate, a steel bottom plate and a bearing plate of the combined section, a plurality of PBL perforated steel plates with parallel longitudinal bridge directions are arranged on the steel top plate and the steel bottom plate, a C-shaped perforated steel plate is arranged between the PBL perforated steel plates between the two ends of the steel top plate and the steel bottom plate, holes which are regularly arranged are uniformly arranged on the PBL perforated steel plates and are used for penetrating through PBL reinforcing steel bars to form PBL shear keys so as to strengthen the connection of the steel-concrete combined section in the steel-concrete combined section, the edge of the PBL perforated steel plate is provided with a semicircular or corrugated groove which strengthens the combination of the PBL perforated steel plates and the C-shaped perforated steel and concrete, prestressed reinforcement in a transition section prestressed reinforcement anchorage chamber in a steel beam transition section penetrates through the bearing plate to realize the connection of the steel beam transition section and the concrete, thereby connecting the steel-concrete combined section and, compared with the traditional steel-concrete combined section, the short combined section structure formed by the method effectively shortens the length of the combined section, and moreover, the short combined section structure is only 2m, the plate arrangement is more reasonable, and the stress and the force transmission among the plates are more definite.
2) The prestressed reinforcement can enhance the connection stability of the bearing plate and the concrete partition wall of the reinforced concrete section, and two kinds of PBL steel plates with holes are fixed on the steel top plate, the steel bottom plate and the bearing plate in a welding mode along the longitudinal bridge direction, so that the construction and installation of the short combined section are simple and convenient; the prestressed reinforcement is anchored in an anchor box consisting of a prestressed reinforcement anchor plate, a prestressed reinforcement stiffening plate and anchor indoor concrete, and after the prestressed anchoring grid chamber is filled with concrete, the stress and force transmission performance of the steel-concrete combined section can be improved.
Drawings
FIG. 1 is a schematic structural view of a short joint section of a steel box composite beam according to the present invention;
FIG. 2 is a schematic perspective view of a steel beam transition section of the steel box composite beam short joint section structure according to the present invention;
FIG. 3 is an exploded view of the short coupling section structure of the steel box composite beam of the present invention;
FIG. 4 is a schematic structural diagram of PBL perforated steel plate and C perforated steel plate of the short joint section structure of the steel box composite beam of the present invention;
FIG. 5 is a schematic structural view of a transition section prestressed rib anchor chamber of the short joint section structure of the steel box composite beam of the invention;
FIG. 6 is a cross-sectional view of a steel beam transition section of the present invention;
FIG. 7 is a schematic view of the cross-sectional structure a-a of FIG. 6;
FIG. 8 is a schematic view of the cross-sectional structure b-b of FIG. 6;
FIG. 9 is a schematic cross-sectional view of the structure of FIG. 6 taken along line c-c;
FIG. 10 is a schematic view of the cross-sectional structure d-d of FIG. 6;
in the figure, 1-steel top plate, 2-steel bottom plate, 3-bearing plate, 4-steel-concrete combined section, 5-steel beam transition section, 501-box girder outer chamber, 502-box girder compartment, 503-box girder inner chamber, 6-PBL perforated steel plate, 7-C perforated steel plate, 8-transition section steel web, 9-saddle type end stiffening, 10-steel web stiffening rib, 11-transition section prestressed tendon anchor chamber, 1101-prestressed tendon anchor plate, 1102-prestressed tendon stiffening plate, 1103-anchor indoor concrete, 12-transition section heightening stiffening rib, 13-PBL reinforcing steel bar, 14-concrete partition wall, 15-prestressed tendon, 16-shear nail, 17-shear nail, 18-groove and 19-transverse prestressed tendon.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without inventive effort based on the embodiments of the present invention, are within the scope of the present invention.
Example 1
Referring to fig. 1-10, the present invention provides a technical solution:
referring to fig. 1-3 and fig. 6, a high-speed rail long-span steel box composite beam short combination section structure includes a steel top plate 1, a steel bottom plate 2 and a bearing plate 3, wherein the bearing plate 3 is clamped between the steel top plate 1 and the steel bottom plate 2 and divides the steel box composite beam short combination section into a steel-concrete combination section 4 and a steel beam transition section 5 in a longitudinal bridge direction;
PBL perforated steel plates 6 which are parallel in the longitudinal bridge direction are uniformly distributed at two ends of the steel top plate 1 and the steel bottom plate 2 in the reinforced concrete combined section 4, and a plurality of C-shaped perforated steel plates 7 are respectively arranged between the PBL perforated steel plates 6 at two ends of the steel top plate 1 and between the PBL perforated steel plates 6 at two ends of the steel bottom plate 2;
two parallel transition section steel webs 8 are arranged in the steel beam transition section 5, the steel beam transition section 5 is divided into a box girder outer chamber 501, a box girder compartment 502 and a box girder inner chamber 503 in the transverse bridge direction by the transition section steel webs 8, one end of the transition section steel web 8 is connected with a steel top plate 1 in the steel beam transition section 5, and the other end of the transition section steel web 8 is connected with a steel bottom plate 2 in the steel beam transition section 5.
Referring to fig. 10, a plurality of transverse bridging parallel saddle end stiffeners 9 are provided in the box girder compartments 502, a plurality of transition section prestressed tendon anchor chambers 11 are distributed on the transition section steel web plates 8 in the box girder outer chamber 501 and the box girder inner chamber 503, the steel top plate 1 in the steel girder transition section 5 and the steel bottom plate 2 in the steel girder transition section 5, a plurality of parallel steel web stiffening ribs 10 are also distributed on the transition section steel web 8 in the box girder outer chamber 501 and the box girder inner chamber 503, one side of the transition section prestressed rib anchor chamber 11 is connected with the bearing plate 3, the other side of the transition section prestressed rib anchor chamber 11 is connected with the steel web stiffening rib 10, the height of the transition section prestressed tendon anchor chamber 11 is matched with the width of two adjacent steel web stiffening ribs 10, transition section height-changing stiffening ribs 12 are uniformly distributed on the steel top plate 1 and the steel bottom plate 2 in the box girder outer chamber 501 and the box girder inner chamber 503;
the transition section steel web plate is provided with a plurality of steel web plate stiffening ribs 10, a prestressed tendon anchor plate 1101 and a prestressed tendon stiffening plate 1102 are arranged between the two stiffening ribs, and for the smoothness of force transmission of the structure, a plurality of longitudinal bridges are arranged on the transition section steel top plate 1 and the transition section steel bottom plate 2 to change the stiffening ribs 12 to the parallel transition section and form a steel box mixed beam short combination section structure.
PBL reinforcing steel bars 13 transversely penetrate through the PBL perforated steel plates 6 and the C perforated steel plates 7 on the steel top plate 1 and the steel bottom plate 2, concrete partition walls 14 are poured in the steel-concrete combined section 4, and the PBL reinforcing steel bars 13 are used for improving the stress and force transmission performance of the steel-concrete combined section after concrete is filled in the transition section prestressed rib anchor chamber 11.
Longitudinal prestressed reinforcements 15 are anchored in the transition section prestressed reinforcement anchor chamber 11, and the prestressed reinforcements 15 penetrate through the bearing plate 3 and the steel-concrete combining section 4 and are anchored on the concrete beam section to reinforce the connection between the bearing plate 3 and the concrete partition wall 14; the prestressed reinforcement 15 can enhance the stability of the connection between the bearing plate 3 and the concrete partition wall 14 of the joint section; the prestressed reinforcement 15 makes the concrete box girder and the steel box girder combine closely, and in order to improve the anchoring effect, a mode of combining and arranging the prestressed reinforcement 15 with staggered length can be adopted.
Referring to fig. 1-3 and fig. 7, a plurality of shear nails 16 are uniformly distributed on the steel top plate 1, the steel bottom plate 2 and the pressure-bearing plate 3, and the shear nails 16 have a diameter of 10-25 mm and a height of 100-200 mm.
The shear pin 16 of the present invention functions as: the shear nails 16 can not only transmit the direct longitudinal shear force between the steel beam and the concrete, but also reinforce the bonding between the concrete and the steel structure.
Referring to fig. 4, holes 17 for penetrating the PBL steel bars 13 are symmetrically formed on the PBL steel plate with holes 6 and the C steel plate with holes 7.
The holes 17 are used for penetrating through the PBL reinforcing steel bars 13 to form connection of the PBL shear key reinforced steel-concrete combined section.
Referring to fig. 4, the PBL perforated steel plate 6 and the C perforated steel plate 7 are welded in the steel-concrete joint section 4, grooves 18 are formed in the edges of the PBL perforated steel plate 6 and the C perforated steel plate 7, and the cross section of each groove 18 is semicircular or corrugated.
The design of the groove 18 can strengthen the combination of the PBL steel plate with holes 6 and the C steel plate with holes and the concrete, and can avoid the bonding crack between the end part of the straight PBL steel plate and the concrete under long-term repeated stress.
Referring to fig. 5, fig. 1 and fig. 8, the transition section prestressed tendon anchor chamber 11 includes prestressed tendon anchor plates 1101, prestressed tendon stiffening plates 1102 and anchor indoor concrete 1103, the prestressed tendon anchor plates 1101 and the prestressed tendon stiffening plates 1102 are connected end to form a tendon anchor chamber cavity, the anchor indoor concrete 1103 is poured in the tendon anchor chamber cavity, one end of each of the adjacent steel web stiffening ribs 10 is connected with the upper end and the lower end of the prestressed tendon anchor plates 1101, and the prestressed tendons 15 penetrate the prestressed tendon anchor plates 1101 and the bearing plates 3 in sequence to be connected with the poured concrete partition 14.
Referring to fig. 2, the box girder outer chamber 501 and the box girder inner chamber 503 are provided with open air holes on the top and bottom steel web stiffeners 10.
In the invention, the prestressed tendon stiffening plate 1102 closest to the steel top plate 1 and the steel bottom plate 2 is provided with air holes, so that gas brought by pouring concrete into the anchor box is conveniently discharged, and the phenomenon that the anchoring of the prestressed tendons is influenced by forming cavities is avoided.
Referring to fig. 1-2 and fig. 9, the transition section heightening stiffening rib 12 is provided with a heightening section at a position 2300-2400 mm away from the pressure bearing plate, and the inclination of the heightening section is 0.375, and then gradually transits to an equal-height section with equal height.
The transition section heightening stiffening rib 12 of the invention has the following functions: the stability of girder steel changeover portion steel roof and steel bottom plate under the effect of strengthening bending stress, it is excessive even that it is second to make the rigidity of girder steel changeover portion to guarantee the homogeneity that the structure passed power.
Referring to fig. 7, a transverse tendon 19 is disposed at the lower part of the concrete partition 14 poured in the steel-concrete combining section 4, and the transverse tendon 19 is inserted into the PBL perforated steel plate 6 and the C-shaped perforated steel plate 7.
The transverse prestressed tendons 19 of the present invention function as: and transverse pressure is applied to the beam body, so that the transverse shear tensile stress of the concrete is avoided under the action of the torsional force of the beam body.
The invention relates to a high-speed rail large-span steel box mixed beam short joint section structure, wherein a steel-concrete joint section is respectively provided with shear nails 16 on a steel top plate 1, a steel bottom plate 2 and a bearing plate 3 of the joint section, a plurality of PBL perforated steel plates 6 which are parallel in the longitudinal direction are distributed on the steel top plate 1 and the steel bottom plate 2, a C-shaped perforated steel plate 7 is distributed between the PBL perforated steel plates 6 between the two ends of the steel top plate 1 and the steel bottom plate 2, regularly arranged holes 17 are uniformly formed on the PBL perforated steel plates 6 and are used for penetrating through PBL reinforcing steel bars 13 to form PBL shear keys so as to strengthen the connection of the steel-concrete joint section in the steel-concrete joint section 4, the edge of the PBL perforated steel plate 6 is provided with a semicircular or corrugated groove 18, the groove 18 strengthens the combination of the PBL perforated steel plates 6 and the C-perforated steel with concrete, a prestressed reinforcement 15 in a transition section prestressed reinforcement anchoring chamber 11 in a steel beam transition section 5 is penetrated through the bearing plate 3 to realize the, thereby connect steel-concrete combination section 4 and girder steel changeover portion 5 and form steel case hybrid beam short combination section structure jointly, this short combination section structure that this method formed compares in traditional steel-concrete combination section, has effectually shortened the combination section length, and this short combination section structure only has 2m, and its plate arranges more rationally, and the atress of plate is passed power more clearly.
The construction method of the high-speed rail large-span steel box mixed beam short joint section structure comprises the following steps:
the steel top plate 1, the steel bottom plate 2, the bearing plate 3, the C-shaped perforated steel plate 7, the PBL perforated steel plate 6, the shear nails 16, the transition section steel web 8, the transition section heightening stiffening ribs 12, the steel web stiffening ribs 10, the saddle-shaped end stiffening ribs 9, the prestressed tendon anchor plate 1101, the prestressed tendon stiffening plate 1102 and other components are accurately prefabricated in a factory according to drawings for standby, and holes 17 and edge corrugated grooves 18 of through steel bars of the PBL perforated steel plate 6 are machined for standby according to the design drawings during prefabrication.
After the components are prefabricated, the components can be assembled in a factory or in the field, the PBL steel plates with holes 6 and the C steel plates with holes 7 are respectively fixed on the steel top plate 1, the steel bottom plate 2 and the bearing plate 3 in a welding mode, the concrete implementation mode is determined according to the construction organization process, and the PBL steel bars 13 are assembled in the field.
After the construction of the steel structure is completed, a concrete template is built according to a drawing, and the pore channels of the longitudinal prestressed tendons and the transverse prestressed tendons 19 are reserved, so that the pouring compactness of the concrete partition wall 14 at the joint section is ensured.
After the concrete of the concrete partition wall 14 of the combined section reaches the required strength, the prestressed reinforcement 15 is penetrated into the reserved hole channel, an anchorage device is installed, the longitudinal prestressed reinforcement 15 and the transverse prestressed reinforcement 19 are stretched, after the control force is stretched, namely the prestressed reinforcement 15, one side of the longitudinal prestressed reinforcement 15 is anchored on the prestressed reinforcement anchor plate 1101, one side of the longitudinal prestressed reinforcement 15 is anchored on the concrete member, concrete is poured in the prestressed reinforcement anchor chamber 11 of the transition section, finally, cement paste is pressed in the reserved hole channel to protect the prestressed reinforcement from being rusted, the prestressed reinforcement 15 and the concrete are bonded into a whole, and finally, other sections of the poured steel-concrete combined section are constructed.
The foregoing is illustrative of the preferred embodiments of this invention, and it is to be understood that the invention is not limited to the precise form disclosed herein and that various other combinations, modifications, and environments may be resorted to, falling within the scope of the concept as disclosed herein, either as described above or as apparent to those skilled in the relevant art. And that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.