CN113062197B - Assembly type stiffening large cantilever corrugated steel web PC combined box girder and construction method thereof - Google Patents

Abstract

The invention discloses an assembled stiffened large cantilever corrugated steel web PC combined box girder and a construction method thereof. The combined box girder consists of a corrugated steel web longitudinal beam, a corrugated steel rib cantilever beam, a prefabricated top plate, a prefabricated bottom plate, an upper supporting plate, a lower supporting plate, a transverse support, a top plate joint, a bottom plate joint, reserved hole post-cast concrete, transverse in-vivo prestressed steel bars and longitudinal in-vitro prestressed steel bars. The corrugated steel web longitudinal beam comprises a double-layer corrugated steel web, a web upper steel wing plate, a web lower steel wing plate and a longitudinal nail group. The corrugated steel rib plate cantilever beam comprises a double-layer corrugated steel rib plate, a rib plate upper steel wing plate, a rib plate lower steel wing plate and a transverse nail group. The double-layer corrugated steel web plate and the double-layer corrugated steel rib plate are only connected with the steel wing plate through bolts at the straight plate section, so that the wrinkle effect can be fully exerted, and the prestress application efficiency is improved; the corrugated steel rib plate cantilever beam can obviously reduce the stress level of the root part of the cantilever and improve the upper limit of the length of the cantilever; the construction method of the prefabricated assembly not only ensures the construction quality, but also greatly shortens the construction period.

Description

A prefabricated stiffened large cantilever corrugated steel web PC composite box girder and its construction method

technical field

The invention mainly relates to the field of bridge engineering and composite structure design, in particular to a PC composite box girder with a stiffened large cantilever corrugated steel web and a construction method thereof.

Background technique

At present, steel-concrete composite structures have been widely used in bridge construction in my country. Among them, PC composite box girder with corrugated steel web, as a new type of steel-concrete composite structure, not only has the advantages of light weight, beautiful appearance and fast construction speed, but also can improve the prestressing efficiency and eliminate the common problems of traditional PC box girder. Web cracking disease. However, the existing PC composite box girders with corrugated steel webs still have the following shortcomings: the corrugated steel webs are connected with the steel wings by full-length welds along the span direction, which limits the full play of the corrugated steel plate’s wrinkle effect and reduces the amount of prestress applied. Efficiency; the use of corrugated steel webs leads to weak torsional and anti-distortion capabilities of the beam body, so the beam width is generally difficult to meet the needs of large traffic; the construction includes a large number of welding, support and formwork erection, steel bar binding, concrete pouring and other work. It is difficult to guarantee the construction quality. For this reason, it is urgent to develop a PC composite box girder with corrugated steel webs that fully utilizes the wrinkle effect of corrugated steel plates, adapts to large traffic volumes, and is quick and easy to construct.

SUMMARY OF THE INVENTION

The purpose of the present invention is to propose a prefabricated stiffener for the problems that the existing corrugated steel web box girder does not fully utilize the wrinkle effect, does not adapt to the large traffic volume, the workload of on-site stud welding and concrete pouring is large, and the construction period is long. Large cantilever corrugated steel web PC composite box girder and construction method thereof. By improving the connection method between the corrugated steel plate and the steel wing plate, enhancing the rigidity of the cantilever plate, increasing the proportion of prefabricated assembly members and adjusting the construction process, the above-mentioned deficiencies of the existing corrugated steel web box girder can be overcome.

The purpose of the present invention is achieved through the following technical solutions: a prefabricated stiffened large cantilever corrugated steel web PC composite box girder, including corrugated steel web longitudinal beam, corrugated steel rib cantilever beam, prefabricated top plate, prefabricated bottom plate, upper support plate , Lower pallet, lateral support, joints on the top plate, joints on the bottom plate, poured concrete after reserved holes, transverse internal prestressed steel bars and longitudinal external prestressed steel bars;

The corrugated steel web longitudinal beam is composed of a double-layer corrugated steel web, a steel flange on the web, a steel flange under the web and a longitudinal nail group; the steel flange on the web and the steel flange under the web are made of The bolts pass through the screw holes and are only connected to the straight plate section of the double-layer corrugated steel web through the T-shaped steel connecting piece; The positions of the longitudinal joints of the corrugated steel webs are the same; longitudinal nail groups are arranged at intervals between the steel wings on the web and the steel wings under the web;

The corrugated steel rib cantilever beam is composed of a double-layer corrugated steel rib, a steel wing plate on the rib, a steel wing plate under the rib, and a transverse nail group; the double-layer corrugated steel rib adopts a variable height design; the rib The steel wing plate on the upper plate and the steel wing plate under the rib plate are only fixedly connected with the straight plate section of the double-layer corrugated steel rib by bolts passing through the screw holes and through the T-shaped steel connecting piece; Horizontal nail groups are arranged at intervals on the steel wing plate;

The prefabricated top plate and the prefabricated bottom plate are respectively prefabricated concrete slabs with joint reinforcement bars extending from the joints of the top plate and the bottom plate; the prefabricated top plate is provided with longitudinal reserved holes in the top plate and horizontal reserved holes in the top plate, and the prefabricated bottom plate is provided with longitudinal reserved holes in the bottom plate. Reserved holes; the prefabricated top plate uses the longitudinal reserved holes of the top plate and the horizontal reserved holes of the top plate to cover the longitudinal nail group and the horizontal nail group, and the prefabricated bottom plate uses the longitudinal reserved holes of the bottom plate to cover the longitudinal nail group, and is positioned and installed on the vertical nail group respectively. The upper surface of the steel flange on the web and the steel flange below the web; the prefabricated top plate, the prefabricated bottom plate, the corrugated steel web longitudinal beam and the corrugated steel rib cantilever beam are connected into a whole by pouring concrete after the reserved holes;

The upper support plate and the lower support plate are respectively connected with the steel wing plate on the web plate and the steel wing plate under the web plate with bolts, and their widths are slightly larger than the joints of the top plate and the bottom plate respectively; The steel wing plate under the plate is connected by bolts;

The transverse internal prestressed steel bars are only installed at the joints of the roof, and are anchored by flat anchors; the longitudinal external prestressed steel bars are installed inside the cavity of the box girder.

Further, the double-layer corrugated steel web and the double-layer corrugated steel rib are formed by the corresponding connection of two corrugated steel plates with wave crests, wave crests, wave troughs and wave troughs; the double-layer corrugated steel web can adopt 1600 type wave shape. The thickness of the corrugated steel plate in the double-layer corrugated steel web and the double-layer corrugated steel rib is selected according to the shear stress level in the plate.

Further, the double-layer corrugated steel rib of the corrugated steel rib cantilever beam, the steel wing plate on the rib, and the steel wing plate under the rib are all bolted to the corrugated steel web longitudinal beam; the double-layer corrugated steel rib The length of the board is 4-8m, and the longitudinal spacing is 2-4m.

Further, the thickness of the steel wing plate on the web, the steel wing plate under the web plate, the steel wing plate on the floor plate, and the steel wing plate under the floor plate is not less than 16mm, and the width should ensure that the outermost threaded bolt is away from the steel wing plate. The edge is not less than 25mm.

Further, the longitudinal spacing between the longitudinal nail groups is 1-2m, the lateral spacing between the transverse nail groups is 0.5-2m, and the longitudinal nail group and the threaded bolt spacing inside the transverse nail group are 50-150mm .

Further, the longitudinal nail group and the transverse nail group use large-diameter threaded studs, generally with a diameter of 22 mm; the height of the threaded studs is determined according to the thickness of the prefabricated top plate and the prefabricated bottom plate, and the number of threaded studs is determined according to the required resistance. The degree of shear connection is determined; the threaded studs are fixed on the steel plate with stud screws and stud nuts.

Further, the length of the prefabricated top plate and the prefabricated bottom plate is 5-10m, and the thickness is 25-30cm; The arrangement of the nail groups is determined; the shapes of the horizontally reserved holes in the top plate, the longitudinal reserved holes in the top plate and the longitudinal reserved holes in the bottom plate are chamfered sills that are large at the top and small at the bottom.

Further, the width of the joint of the top plate and the joint of the bottom plate is 0.4-0.6m, and the thickness is respectively the same as that of the prefabricated top plate and the prefabricated bottom plate; Concrete is made of lightweight high-strength concrete.

Further, the transverse internal prestressed steel bar is composed of multiple strands; the longitudinal external prestressed steel bar is composed of multiple strands, and its cross-sectional area and tensile stress are determined according to structural dead load and live load; wherein , the standard value of tensile strength of steel strand should not be less than 1860MPa.

A construction method for an assembled stiffened large cantilever corrugated steel web PC composite box girder, the method comprising the following steps:

(1) Install simple mobile construction supports between adjacent bridge piers and abutments, and transport all prefabricated components to the bridge site.

(2) Pass the bolt screw through the reserved bolt hole and fix it on the steel flange on the web, the lower steel flange on the web, the steel flange on the rib, the upper supporting plate and the lower supporting plate through the bolt nut. On the upper surface, longitudinal nail groups, transverse nail groups and distributed threaded studs are formed.

(3) Assemble two corrugated steel plates to form a double-layer corrugated steel web. Bolts pass through the screw holes and connect the straight plate section of the double-layered corrugated steel web with the steel flanges on the web and the steel under the web through the T-shaped steel connectors. The wings are fixedly connected to form corrugated steel web longitudinal beams.

(4) Assemble two variable-height corrugated steel plates to form a double-layer corrugated steel rib. Bolts pass through the screw holes and connect the straight section of the double-layer corrugated steel rib with the steel wings and ribs on the rib through the T-shaped steel connector. The lower steel wing plate is fixedly connected to form a corrugated steel rib cantilever beam.

(5) The two corrugated steel web longitudinal beams are hoisted to the simple mobile construction support and positioned, and several upper and lower supporting plates and lateral supports are installed between the two corrugated steel web longitudinal beams.

(6) Hoist several corrugated steel rib cantilever beams to the simple mobile construction support, and bolt the corrugated steel rib cantilever beams to the corrugated steel web longitudinal beams through the screw holes.

(7) To hoist several prefabricated bottom plates to the upper surface of the steel wing plate under the web, it is necessary to ensure that the longitudinal nail groups are set in the longitudinal reserved holes of the bottom plate.

(8) Concrete is poured at the longitudinal reserved holes of the bottom plate and the joints of the bottom plate.

(9) Hoist a number of prefabricated roof plates to the upper surface of the steel wing plate on the web, so that the longitudinal nail groups and the transverse nail groups are respectively sleeved in the longitudinal reserved holes of the roof and the transverse reserved holes of the roof.

(10) Install and stretch the transverse internal prestressing tendons at the joints of the top plate.

(11) Concrete is poured in the longitudinal reserved holes of the roof, the horizontal reserved holes of the roof, and the joints of the roof. When the strength of the concrete at the joints of the roof reaches 90% of the design strength, the transverse internal prestressing tendons can be released.

(12) Install and stretch the longitudinal external prestressed tendons, and then carry out the construction of bridge deck paving and ancillary facilities.

The beneficial effects of the present invention are as follows:

1. The double-layer corrugated steel web and the double-layer corrugated steel rib are only bolted to the steel wing plate in the straight section of the corrugated steel plate, which can give full play to the wrinkle effect of the corrugated steel plate, thereby improving the application efficiency of prestress.

2. The corrugated steel ribbed cantilever beam is introduced to reduce the self-weight and at the same time enhance the lateral stiffness of the beam body, significantly reduce the stress level at the root of the cantilever, and increase the length of the cantilever to meet the needs of large traffic volumes.

3. The corrugated steel web and corrugated steel rib are made of double-layer corrugated steel plates, which improves the cooperative working ability of the double-layer corrugated steel plates and greatly enhances the shear and buckling resistance of the structure.

4. The bottom plate is arranged on the steel wing plate under the web, and the latter can be used as a permanent formwork for the former. The nail group connection area between the two is simple in structure and reasonable in force, and the reserved holes for concrete pouring space are large, which is easy to ensure construction. quality.

5. The steel wing plate under the web is located below the bottom plate, which eliminates the hidden danger of the bottom plate being detached, and can also give full play to the advantages of the good tensile performance of the steel to prevent premature cracking of the bottom plate concrete, thereby improving the bearing capacity, stiffness and durability of the structure.

6. The transverse prestressed steel bar is stretched inside the roof joint, which can significantly reduce the design thickness of the roof, increase the concrete compressive stress reserve, and reduce the risk of concrete cracking.

7. The upper support plate, the lower support plate and the lateral support are used to connect the two corrugated steel web longitudinal beams, which not only improves the construction stability, greatly enhances the torsion resistance and anti-distortion performance of the completed structure, but also forms the construction of the top and bottom plates. The unique load-bearing structure and permanent formwork reduce the erection and dismantling work of the support formwork and avoid affecting the traffic under the bridge.

8. By increasing the proportion of prefabricated assembly components and designing the nail group-reserved hole structure, the workload of bracket template installation and removal, steel bar binding, concrete pouring and maintenance is reduced, stud welding work is avoided, and the construction period is greatly shortened. In addition, prefabricated components can be standardized in the factory, which guarantees quality, cost savings and easy transportation.

Description of drawings

Fig. 1 is the perspective view of the present invention;

Fig. 2 is the elevation view of the present invention;

Fig. 3 is the cross-section I-I, II-II figure of the present invention;

Figure 4 is the assembly drawing of the corrugated steel web longitudinal beam;

Figure 5 is the assembly drawing of the corrugated steel ribbed cantilever beam;

Figure 6 is a partial detailed view of the connection part of the corrugated steel web longitudinal beam;

Fig. 7 is the main construction step diagram of the present invention;

In the figure, 1—corrugated steel web longitudinal beam, 1-1—double-layer corrugated steel web, 1-2—steel flange on the web, 1-3—steel flange under the web, 1-4—longitudinal Nail group, 2—cantilever beam with corrugated steel rib, 2-1—double-layer corrugated steel rib, 2-2—steel flange on the rib, 2-3—steel flange under the rib, 2-4—transverse Nail group, 3—prefabricated top plate, 3-1—top plate longitudinal reserved hole, 3-2—top plate horizontal reserved hole, 4—prefabricated bottom plate, 4-1—bottom plate longitudinal reserved hole, 5—upper pallet, 6 - Lower pallet, 7 - Lateral support, 8 - Joint of top plate, 9 - Joint of bottom plate, 10 - Concrete after reserved hole, 11 - Transverse internal prestressed steel bar, 12 - Longitudinal external prestressed steel bar, 13 - Thread Bolt, 13-1—bolt screw, 13-2—bolt nut, 14-1—bolt screw, 14-2—bolt nut, 15—T-shaped steel connector.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

As shown in Figure 1, Figure 2 and Figure 3, the present invention provides an assembled PC composite box girder with a large cantilever corrugated steel web, comprising a corrugated steel web longitudinal beam 1, a corrugated steel ribbed cantilever beam 2, a prefabricated Top plate 3, prefabricated bottom plate 4, upper supporting plate 5, lower supporting plate 6, lateral support 7, top plate joint 8, bottom plate joint 9, reserved hole post-casting concrete 10, transverse internal prestressing steel bar 11, longitudinal external prestressing Rebar 12.

As shown in Figures 4 and 6, the corrugated steel web longitudinal beam 1 is composed of a double-layer corrugated steel web 1-1, a steel flange 1-2 on the web, a steel flange 1-3 under the web, and a longitudinal nail group. 1-4 composition; the steel wing plate 1-2 on the web and the steel wing plate 1-3 under the web are only connected with the double-layer corrugated steel web 1-1 by bolts passing through the screw holes through the T-shaped steel connecting piece 15 The straight plate section is connected; the steel flanges 1-2 on the web and the steel flanges 1-3 under the web should be disconnected along the longitudinal direction, and the disconnection position should be the same as the longitudinal joint of the double-layer corrugated steel web 1-1. The positions are the same; longitudinal nail groups 1-4 are arranged at intervals on the steel wings 1-2 on the web and the steel wings 1-3 on the lower web. The double-layer corrugated steel web 1-1 is only connected with the steel flange 1-2 on the upper web and the steel flange 1-3 under the web at the straight section of the corrugated steel plate, which can give full play to the wrinkle effect of the corrugated steel plate, thereby improving the pre- Stress application efficiency.

As shown in Figure 5, the corrugated steel rib cantilever beam 2 is composed of a double-layer corrugated steel rib 2-1, a steel flange 2-2 on the rib, a steel flange 2-3 under the rib, and a transverse nail group 2- 4 components; the steel wing plate 2-2 on the rib plate and the steel wing plate 2-3 under the rib plate are connected with the straight plate of the double-layer corrugated steel rib plate 2-1 only by using bolts through the screw holes through the T-shaped steel connecting piece 15 The sections are fixedly connected; the steel wings 2-2 on the upper rib and the steel wings 2-3 under the rib are arranged with transverse nail groups 2-4 at intervals; the double-layer corrugated steel ribs of the corrugated steel rib cantilever beam 2 The plate 2-1, the steel wing plate 2-2 on the rib plate, and the steel wing plate 2-3 under the rib plate are all bolted to the longitudinal beam 1 of the corrugated steel web. The double-layer corrugated steel rib 2-1 is only connected to the straight plate section of the corrugated steel plate with the steel wing plate 2-2 on the rib plate and the steel wing plate 2-3 under the rib plate, which can give full play to the wrinkle effect of the corrugated steel plate, thereby improving the pre- Stress application efficiency. In addition, the corrugated steel ribbed cantilever beam 2 reduces its own weight while enhancing the lateral stiffness of the beam body, significantly reducing the stress level at the root of the cantilever, and increasing the length of the cantilever to meet the needs of large traffic volumes.

The double-layer corrugated steel rib 2-1 adopts a variable height design, the length is 4-8m, and the longitudinal spacing is 2-4m.

As shown in Figure 4 and Figure 5, the double-layer corrugated steel web 1-1 and the double-layer corrugated steel rib 2-1 are formed by the corresponding connection of two corrugated steel plates with crests, crests, troughs and troughs; The corrugated steel web 1-1 can use 1600 type corrugated steel plate, and the double corrugated steel rib 2-1 can use 1000 corrugated steel plate; the double corrugated steel web 1-1 and the double corrugated steel rib 2 The thickness of the corrugated steel plate in -1 is selected according to the shear stress level in the plate. The double-layer corrugated steel web 1-1 and the double-layer corrugated steel rib 1-2 are obtained by combining the double-layer corrugated steel plates, which improves the cooperative working ability of the double-layer corrugated steel plates and greatly enhances the shear and buckling resistance of the structure. .

The thickness of the steel wing plate 1-2 on the web, the steel wing plate 1-3 under the web plate, the steel wing plate 2-2 on the floor plate, and the steel wing plate 2-3 under the floor plate is not less than 16mm, and the width should be guaranteed. The outermost threaded bolt 13 is not less than 25mm away from the edge of the steel flange.

The longitudinal spacing between the longitudinal nail groups 1-4 is 1-2m, the lateral spacing between the transverse nail groups 2-4 is 0.5-2m, and the threads inside the longitudinal nail groups 1-4 and the transverse nail groups 2-4 The pegs 13 are spaced 50-150mm apart.

The longitudinal nail groups 1-4 and the transverse nail groups 2-4 use large-diameter threaded studs 13, generally with a diameter of 22 mm; the height of the threaded studs 13 is determined according to the thickness of the prefabricated top plate 3 and the prefabricated bottom plate 4, and the threaded bolts The number of nails 13 is determined according to the required degree of shear connection; the threaded bolts 13 are fixed on the steel plate by means of a bolt screw 13-1 and a bolt nut 13-2.

As shown in Figures 1 and 2, the prefabricated top plate 3 and the prefabricated bottom plate 4 are respectively prefabricated concrete slabs with joint reinforcement extending from the joints 8 and 9 of the top plate and the bottom plate, with a length of 5-10m and a thickness of 25-30cm; The top plate 3 is provided with a longitudinal reserved hole 3-1 of the top plate and a horizontal reserved hole 3-2 of the top plate, and the prefabricated bottom plate 4 is only provided with a longitudinal reserved hole 4-1 of the bottom plate; a horizontal reserved hole 3-2 of the top plate and a longitudinal reserved hole of the top plate The size of the hole 3-1 and the longitudinal reserved hole 4-1 of the bottom plate is determined according to the arrangement of the horizontal group of nails 2-4 and the longitudinal group of nails 1-4; the horizontal reserved hole 3-2 of the top plate and the longitudinal reserved hole 3 of the top plate are determined. -1 and the longitudinal reserved hole 4-1 of the bottom plate are in the shape of a chamfered bezel with a large upper and a lower lower.

The prefabricated top plate 3 uses the longitudinal reserved holes 3-1 of the top plate and the horizontal reserved holes 3-2 of the top plate to cover the longitudinal nail groups 1-4 and the transverse nail groups 2-4, and the prefabricated bottom plate 4 uses the longitudinal reserved holes 4-4 of the bottom plate. 1 set on the longitudinal nail groups 1-4, respectively positioned and installed on the upper surface of the steel wing plate 1-2 on the web and the steel wing plate 1-3 on the lower web; The prefabricated bottom plate 4 is integrally connected with the corrugated steel web longitudinal beam 1 and the corrugated steel ribbed cantilever beam 2 . The prefabricated bottom plate 4 is arranged on the steel wing plates 1-3 under the web, the latter can be used as the permanent formwork for the former to install, the nail group connection area between the two is simple in structure, reasonable in force, and the reserved hole concrete pouring space is large. Easy to ensure construction quality. At the same time, the steel wings 1-3 under the web are located below the prefabricated bottom plate 4, which eliminates the hidden danger of the bottom plate being detached, and can also give full play to the advantages of the good tensile performance of the steel, preventing the premature cracking of the bottom plate concrete, thereby improving the bearing capacity and rigidity of the structure. and durability.

The width of the top plate joint 8 and the bottom plate joint 9 is 0.4-0.6m, and the thickness is the same as that of the prefabricated top plate 3 and the prefabricated bottom plate 4 respectively. The prefabricated top plate 3 , the prefabricated bottom plate 4 , the joints 8 of the top plate, the joints 9 of the bottom plate, and the post-casting concrete 10 of the reserved holes are all made of light-weight and high-strength concrete.

The upper support plate 5 and the lower support plate 6 are respectively connected with the steel wing plate 1-2 on the web plate and the steel wing plate 1-3 on the lower web plate with bolts, and their widths are slightly larger than the top plate joint 8 and the bottom plate joint 9 respectively; Distributed threaded bolts 13 are installed on the upper surfaces of the upper support plate 5 and the lower support plate 6; the lateral support 7 is connected with the upper support plate 5 and the lower steel wings 1-3 of the web by bolts.

The transverse internal prestressed steel bars 11 are composed of multiple strands of steel strands, which are only installed at the joint 8 of the roof and are anchored by flat anchors; the longitudinal external prestressed steel bars 12 are composed of multiple strands of steel strands, and their cross-sectional area and tensile stress are determined according to the dead load and live load of the structure; among them, the standard value of the tensile strength of the steel strand should not be less than 1860MPa. The transverse prestressed steel bar 11 is tensioned inside the roof joint 8, which can significantly reduce the design thickness of the roof, increase the concrete compressive stress reserve, and reduce the risk of concrete cracking.

As shown in Fig. 4, Fig. 5, Fig. 7, the construction method of a prefabricated stiffened large cantilever corrugated steel web PC composite box girder proposed by the present invention includes the following steps:

(1) Install simple mobile construction supports between adjacent bridge piers and abutments, and transport all prefabricated components to the bridge site;

(2) Pass the bolt screw 13-1 through the reserved bolt hole and fix it on the steel wing plate 1-2 on the web, the steel wing plate 1-3 under the web, and the rib plate through the bolt nut 13-2 The upper surfaces of the steel wing plate 2-2, the upper support plate 5 and the lower support plate 6 form longitudinal nail groups 1-4, transverse nail groups 2-4, and distributed threaded bolts 13;

(3) Assemble two corrugated steel plates to form a double-layer corrugated steel web 1-1, the bolts pass through the screw holes through the T-shaped steel connector 15 to connect the straight section of the double-layer corrugated steel web 1-1 to the steel on the web The flange 1-2 and the steel flange 1-3 under the web are fixedly connected to form a corrugated steel web longitudinal beam 1;

(4) Two pieces of variable-height corrugated steel plates are assembled to form a double-layer corrugated steel rib 2-1, and the bolts pass through the screw holes through the T-shaped steel connector 15 to connect the straight section of the double-layer corrugated steel rib 2-1 to the rib. The upper steel wing plate 2-2 and the lower steel wing plate 2-3 of the rib are fixedly connected to form a corrugated steel rib cantilever beam 2;

(5) Hang the two corrugated steel web longitudinal beams 1 to the simple mobile construction support, and position them, and install several upper support plates 5, lower support plates 6 and lateral supports between the two corrugated steel web longitudinal beams 1 7;

(6) Hang a number of corrugated steel rib cantilever beams 2 on the simple mobile construction support, and the bolts pass through the screw holes to fixedly connect the corrugated steel rib cantilever beam 2 and the corrugated steel web longitudinal beam 1;

(7) Hoisting a number of prefabricated bottom plates 4 to the upper surface of the lower steel wing plates 1-3 of the web, it is necessary to ensure that the longitudinal nail groups 1-4 are set in the longitudinal reserved holes 4-1 of the bottom plate;

(8) Concrete is poured at the longitudinal reserved holes 4-1 of the bottom plate and the joints 9 of the bottom plate;

(9) Hoist a number of prefabricated roof panels 3 to the upper surface of the steel wing panels 1-2 on the web, so that the longitudinal nail groups 1-4 and the transverse nail groups 2-4 are respectively sleeved on the longitudinal reserved holes 3-1 of the roof and the transverse nail groups of the roof. In reserved hole 3-2;

(10) Install and stretch the transverse internal prestressing tendons 11 at the joint 8 of the roof;

(11) Concrete is poured in the longitudinal reserved holes 3-1 of the roof, the horizontal reserved holes 3-2 of the roof, and the joint 8 of the roof. When the concrete strength of the joint 8 of the roof reaches 90% of the design strength, the transverse internal body can be released. Prestressed tendons 11;

(12) Install and stretch the longitudinal external prestressing tendons 12, and then carry out the construction of bridge deck paving and ancillary facilities.

By increasing the proportion of prefabricated assembly components and designing the nail group-reserved hole structure, the invention reduces the workload of mounting and dismantling the support formwork, binding steel bars, and pouring and curing concrete, avoids the welding of studs, and greatly shortens the construction period. At the same time, prefabricated components can be standardized in the factory, which can ensure quality, save costs and facilitate transportation. In addition, the use of the upper support plate 5, the lower support plate 6 and the lateral support 7 to connect the two corrugated steel web longitudinal beams 1 not only improves the construction stability, but also greatly enhances the torsional and anti-distortion performance of the completed structure, and can form The load-bearing structure and permanent formwork of the roof and bottom plate construction reduce the erection and dismantling work of the support formwork and avoid affecting the traffic under the bridge.

The above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be included in the protection of the present invention. within the range.

Claims (10)

1. An assembled stiffened large cantilever corrugated steel web PC composite box girder is characterized in that, comprising corrugated steel web longitudinal beam (1), corrugated steel ribbed cantilever beam (2), prefabricated top plate (3), prefabricated Bottom plate (4), upper support plate (5), lower support plate (6), lateral support (7), top plate joints (8), bottom plate joints (9), reserved holes and then poured concrete (10), horizontal Internal prestressed steel bars (11) and longitudinal external prestressed steel bars (12); The corrugated steel web longitudinal beam (1) is composed of a double-layer corrugated steel web (1-1), a steel flange (1-2) on the web, a steel flange (1-3) under the web and longitudinal nails. Groups (1-4) are formed; the steel wings (1-2) on the web and the steel wings (1-3) under the web are bolted through the screw holes through the T-shaped steel connectors (15) only connected to The straight plate sections of the double-layer corrugated steel web (1-1) are connected; the steel flanges (1-2) on the web and the steel flanges (1-3) under the web are longitudinally disconnected and arranged at the disconnected position. The position of the longitudinal joint of the double-layer corrugated steel web (1-1) is consistent; longitudinal nail groups ( 1-4); The corrugated steel rib cantilever beam (2) is composed of a double-layer corrugated steel rib (2-1), a steel wing plate (2-2) on the rib, a steel wing plate (2-3) under the rib, and transverse nails. group (2-4); the double-layer corrugated steel rib plate (2-1) adopts variable height design; ) is only fixedly connected with the straight plate section of the double-layer corrugated steel rib plate (2-1) by bolts passing through the screw holes through the T-shaped steel connecting piece (15); Horizontal nail groups (2-4) are arranged at intervals on the steel wing plate (2-3) under the plate; The prefabricated top plate (3) and the prefabricated bottom plate (4) are respectively prefabricated concrete slabs with joint reinforcement bars extending from the top plate joint (8) and the bottom plate joint (9). The reserved holes (3-1) and the horizontal reserved holes (3-2) of the top plate are provided, and the prefabricated bottom plate (4) is provided with longitudinal reserved holes (4-1) of the bottom plate; the prefabricated top plate (3) utilizes the longitudinal reserved holes of the top plate. (3-1) and the laterally reserved holes (3-2) of the top plate are sleeved on the longitudinal nail group (1-4) and the lateral nail group (2-4), and the prefabricated bottom plate (4) uses the longitudinally reserved holes (3-2) of the bottom plate. 4-1) Set on the longitudinal nail group (1-4), respectively position and install it on the upper surface of the steel flange plate (1-2) on the web plate and the steel flange plate (1-3) under the web plate; through the reserved holes The post-cast concrete (10) connects the prefabricated top plate (3) and the prefabricated bottom plate (4) with the corrugated steel web longitudinal beam (1) and the corrugated steel rib cantilever beam (2) into a whole; The upper support plate (5) and the lower support plate (6) are respectively connected with the steel wing plate (1-2) on the web plate and the steel wing plate (1-3) under the web plate by bolts, and their widths are respectively slightly larger than those of the top plate connection. joints (8) and bottom plate joints (9); the lateral support (7) is connected with the upper support plate (5) and the lower steel wing plate (1-3) of the web by bolts; The transverse internal prestressed steel bars (11) are only installed at the joints (8) of the roof, and are anchored by flat anchors; longitudinal external prestressed steel bars (12) are installed inside the cavity of the box girder. 2. An assembled stiffened large cantilever corrugated steel web PC composite box girder according to claim 1, characterized in that the double-layer corrugated steel web (1-1) and the double-layer corrugated steel rib ( 2-1) Both are formed by the corresponding connection of two corrugated steel plates with crests, crests, troughs and troughs. The plate (2-1) can be made of 1000-type corrugated steel plate; the thickness of the corrugated steel plate in the double-layer corrugated steel web plate (1-1) and the double-layer corrugated steel rib plate (2-1) is based on the shear stress level in the plate Select. 3. An assembled stiffened large cantilever corrugated steel web PC composite box girder according to claim 1, wherein the double corrugated steel rib (2- 1) The steel wing plate (2-2) on the rib and the steel wing plate (2-3) under the rib are all bolted to the corrugated steel web longitudinal beam (1); the double-layer corrugated steel rib (2) -1) The length is 4-8m, and the longitudinal spacing is 2-4m. 4. An assembled stiffened large cantilever corrugated steel web PC composite box girder according to claim 1, characterized in that, a steel wing plate (1-2) on the web and a steel wing plate ( 1-3), the thickness of the steel wing plate (2-2) on the floor and the steel wing plate (2-3) under the floor plate is not less than 16mm, and the width should ensure that the outermost threaded bolt (13) is away from the edge of the steel wing plate Not less than 25mm. 5. An assembled stiffened large cantilever corrugated steel web PC composite box girder according to claim 1, wherein the longitudinal spacing between the longitudinal nail groups (1-4) is 1-2m, so The transverse spacing between the transverse nail groups (2-4) is 0.5-2m, and the longitudinal nail group (1-4) and the threaded bolts (13) within the transverse nail group (2-4) are 50-150mm spacing. 6. An assembled stiffened large cantilever corrugated steel web PC composite box girder according to claim 1, wherein the longitudinal nail group (1-4) and the transverse nail group (2-4) are made of large The diameter of the threaded studs (13) is generally 22mm; the height of the threaded studs (13) is determined according to the thickness of the prefabricated top plate (3) and the prefabricated bottom plate (4), and the number of threaded studs (13) is determined according to the required The degree of shear connection is determined; the threaded bolt (13) is fixed on the steel plate by a bolt screw (13-1) and a bolt nut (13-2). 7. An assembled stiffened large cantilever corrugated steel web PC composite box girder according to claim 1, wherein the length of the prefabricated top plate (3) and the prefabricated bottom plate (4) is 5-10m, and the thickness is 5-10m. is 25-30cm; the size of the horizontal reserved holes (3-2) of the top plate, the vertical reserved holes of the top plate (3-1) and the vertical reserved holes of the bottom plate (4-1) are based on the horizontal group nails (2-4) and the arrangement of the longitudinal nail groups (1-4) are determined; the longitudinal reserved holes (3-1) of the top plate, the horizontal reserved holes (3-2) of the top plate and the longitudinal reserved holes (4-1) of the bottom plate are in the shape of Large upper and lower small chamfers. 8. An assembled stiffened large cantilever corrugated steel web PC composite box girder according to claim 1, wherein the width of the top plate joint (8) and the bottom plate joint (9) is 0.4-0.6 m, the thickness is the same as that of the prefabricated top plate (3) and the prefabricated bottom plate (4), respectively; the prefabricated top plate (3), the prefabricated bottom plate (4), the top plate joint (8), the bottom plate joint (9), the reserved The poured concrete (10) is made of lightweight high-strength concrete. 9 . The prefabricated stiffened large cantilever corrugated steel web PC composite box girder according to claim 1 , wherein the transverse internal prestressed steel bars ( 11 ) are composed of multi-strand steel strands; the longitudinal The external prestressed steel bar (12) is composed of multi-strand steel strands, and its cross-sectional area and tensile stress are determined according to the dead load and live load of the structure; among them, the standard value of the tensile strength of the steel strands should not be less than 1860MPa. 10. A construction method of the assembled stiffened large cantilever corrugated steel web PC composite box girder according to any one of claims 1-9, wherein the method comprises the following steps: (1) Install simple mobile construction supports between adjacent bridge piers and abutments, and transport all prefabricated components to the bridge site; (2) Pass the bolt screw (13-1) through the reserved bolt hole and fix it on the steel flange (1-2) on the web and the steel flange ( 1-3), the upper surface of the steel wing plate (2-2) on the rib plate, the upper support plate (5) and the lower support plate (6) to form a longitudinal nail group (1-4) and a transverse nail group (2- 4) Distributed threaded bolts (13); (3) Splicing two corrugated steel plates to form a double-layer corrugated steel web (1-1), bolts pass through the screw holes through the T-shaped steel connector (15) to connect the straight plate of the double-layer corrugated steel web (1-1) The segment is fixedly connected with the steel flange (1-2) on the web and the steel flange (1-3) under the web to form a corrugated steel web longitudinal beam (1); (4) Two pieces of variable-height corrugated steel plates are assembled to form a double-layer corrugated steel rib (2-1), and bolts pass through the screw holes through the T-shaped steel connector (15) to connect the double-layer corrugated steel rib (2-1). The straight plate section of the rib is fixedly connected with the steel wing plate (2-2) on the rib plate and the steel wing plate (2-3) under the rib plate to form a corrugated steel rib plate cantilever beam (2); (5) Hang the two corrugated steel web longitudinal beams (1) to the simple mobile construction support and position them, and install several upper support plates (5) and lower supporting plates between the two corrugated steel web longitudinal beams (1). pallet (6) and lateral support (7); (6) Hang a number of corrugated steel rib cantilever beams (2) on the simple mobile construction support, and connect the corrugated steel rib cantilever beams (2) to the corrugated steel web longitudinal beams (1) fixedly with bolts through the screw holes; (7) Hoisting several prefabricated bottom plates (4) to the upper surface of the steel wings (1-3) under the web, it is necessary to ensure that the longitudinal nail groups (1-4) are sleeved in the longitudinal reserved holes (4-1) of the bottom plate; (8) Concrete is poured at the longitudinal reserved holes (4-1) of the bottom plate and the joints (9) of the bottom plate; (9) Hoist a number of prefabricated roof plates (3) to the upper surface of the steel wing plates (1-2) on the web, so that the longitudinal nail groups (1-4) and the transverse nail groups (2-4) are respectively sleeved on the longitudinal prefabricated roof plates. In the reserved hole (3-1) and the horizontal reserved hole (3-2) of the top plate; (10) Install and tension the transverse internal prestressing tendons (11) at the joint (8) of the roof; (11) Concrete is poured at the longitudinal reserved holes (3-1) of the roof, the horizontal reserved holes (3-2) of the roof, and the joints (8) of the roof, until the strength of the concrete at the joints (8) of the roof reaches the design strength 90% of the transverse body prestressing tendons (11) can be released; (12) Install and stretch the longitudinal external prestressing tendons (12), and then carry out the construction of bridge deck paving and ancillary facilities.

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