CN117266037A - Suspension splicing construction method for main girder of cross-over overhead bridge - Google Patents

Abstract

The invention provides a construction method for hanging and splicing a main girder of a cross viaduct, which comprises the steps of constructing temporary bearing bodies on two sides of the existing viaduct, hoisting a second main girder and a first main girder in sequence, enabling the second main girder to be installed on the temporary bearing body on one side, installing one end of the first main girder on a second hanging and splicing section of the second main girder through a prefabricated hanging and splicing installation frame, installing the other end of the first main girder on the temporary bearing body on the other side, and keeping a certain distance from the side face of the existing viaduct during hoisting, so that interference between hoisting equipment and the existing viaduct is avoided, the length of the second hanging and splicing section and the length of the first main girder are increased to be greater than the width of the existing viaduct, and the problem of insufficient length of the main girder is solved.

Description

Suspension splicing construction method for main girder of cross-over overhead bridge

Technical Field

The invention relates to the technical field of bridge construction, in particular to a suspension splicing construction method for a main girder of a cross-over bridge.

Background

With the development of cities, the existing roads are difficult to meet more and more traffic flows, and the construction of viaducts on the existing roads is an effective method for relieving traffic pressure; the steel box girder used for construction of the existing viaduct is a common structural form of a large-span bridge, and has the advantages of being small in weight, high in strength, convenient to construct and the like.

As shown in fig. 1, the existing viaduct a is a viaduct which is put into use, and an overhead bridge B crossing the existing viaduct a needs to be erected according to city planning; the overpass B is formed by assembling a plurality of steel box girders, when the width of the existing overpass A is larger than the length of the steel box girders, the steel box girders above the pavement of the existing overpass A are difficult to assemble, and the construction difficulty is specifically as follows: because the existing viaduct A is put into use, if temporary supports for supporting the steel box girders are erected on the pavement of the existing viaduct A, the steel box girders are arranged on the temporary supports for assembly, the use of the road A can be affected, and the construction and the dismantling of the temporary supports are both labor and material resources; if hoisting equipment is used, the steel box girder is hoisted to the upper space of the existing viaduct A for assembly, and the suspension arms of the hoisting equipment can be interfered by the two side walls of the existing viaduct A, so that the steel box girder is difficult to hoist in place by the hoisting equipment.

How to use the steel box girder to finish the construction of a new overpass without affecting the use of the existing overpass when the width of the existing overpass is larger than the length of the steel box girder is a problem to be solved urgently by bridge construction departments.

Disclosure of Invention

The invention aims to solve the problems that: the construction method for completing the construction of the new viaduct by using the steel box girder without affecting the use of the existing viaduct when the width of the existing viaduct is larger than the length of the steel box girder is provided.

The invention solves the problems by adopting the following technical scheme: a construction method for hanging and splicing a main girder of a cross-over overhead bridge comprises the following steps:

s1: temporary bearing bodies for supporting the main girder are built on two sides of the existing viaduct;

s2: prefabricating a first girder and a second girder which are used for crossing the existing viaduct by using a steel box girder, prefabricating a suspension assembly mounting frame and a code plate; the rear section of the suspension assembly mounting frame is pre-fixed on a girder top plate at one end of the first girder, and the front section extends out from one end of the first girder;

s3: hoisting a second main beam to be fixed on a temporary bearing body at one side of the viaduct, and enabling one end of the second main beam to extend above the bridge deck of the existing viaduct to form a second suspension splicing section;

s4: hoisting the first girder, wherein one end of the first girder is erected on the second suspension segment through the front segment of the suspension assembly installation frame, and the other end of the first girder is erected on a temporary bearing body at the other side of the viaduct; fixedly connecting the front section of the suspension assembly mounting frame with the second suspension assembly section; fixedly connecting the other end frame of the first main beam with a temporary bearing body at the other side of the viaduct;

s5: a code plate is fixedly connected at the joint of the girder top plate of the first girder and the girder top plate of the second girder; fixedly connecting a code plate at the joint of the girder web plate of the first girder and the girder web plate of the second girder;

s6: repeating the steps S1-S5 along the length direction of the existing viaduct so that a plurality of main beams are arranged on the viaduct at intervals;

s7: a plurality of cross beams are arranged between every two main beams at intervals along the length direction of the main beams;

s8: a cross beam reinforcement construction platform is arranged below the two main beams; a constructor stands on the beam reinforcement construction platform, and the connection between the main beam and the beam is reinforced from below;

s9: erecting a side face widening section construction platform on a girder side plate of the outermost girder;

s10: lifting the widening sections respectively on two sides of a girder side plate of the outermost girder, and attaching the widening inner side plate of the widening section to the girder side plate;

s10: a constructor stands on the girder top plate to fix the upper edge of the widened inner side plate and the girder top plate; the constructor stands on the widening section construction platform to fix the lower edge of the widening inner side plate and the girder side plate.

Compared with the prior art, the temporary bearing bodies are built on two sides of the existing viaduct, the second girder and the first girder are sequentially hoisted through hoisting equipment, the second girder is arranged on the temporary bearing body on one side, one end of the first girder is arranged on the second suspension section of the second girder through the prefabricated suspension installation frame, the other end of the first girder is arranged on the temporary bearing body on the other side, and because the second girder and the first girder are hoisted on the outer side of the existing viaduct and keep a certain distance with the side surface of the existing viaduct, interference between the hoisting equipment and the existing viaduct is avoided, and because one end of the second girder extends above the existing viaduct to form the second suspension section, the length of the second suspension section and the length of the first girder are larger than the width of the existing viaduct, so that the problem of insufficient length of the girders is solved, and because the first girder extends to the end of the existing viaduct and can be fixed on the second suspension section through the suspension installation frame, the temporary support is avoided on the viaduct, and the influence on traffic is avoided.

According to the invention, as the code plates are fixedly connected at the joints of the first girder and the second girder and are matched with the suspension assembly mounting frame, temporary supporting force is provided for the first girder and the second girder together, and the first girder and the second girder are prevented from falling to the existing overhead bridge deck due to insufficient supporting force of the suspension assembly mounting frame, so that the follow-up construction is carried out safely; the beam reinforcement construction platform is arranged below the two main beams, so that constructors can stand on the beam reinforcement construction platform to construct the beams, temporary supports for beam construction are avoided being erected on the existing viaduct, and the influence on traffic is avoided; the side widening section construction platform is arranged, so that constructors can stand on the side widening section construction platform to construct the lower edge of the widening section, temporary supports for the widening section construction are avoided being erected on the existing viaduct, and the influence on traffic is avoided.

In the step S2, the number of the suspension splicing installation frames is two and the suspension splicing installation frames are arranged on two sides of a girder top plate of the first girder; through the design of two suspension installation racks, the gravity of first girder has been shared jointly, and two suspension installation racks set up in the girder roof both sides of first girder for both sides atress is balanced, is difficult for overturning.

The invention relates to a construction method for hanging and splicing a main girder of a cross-over overhead bridge, wherein a hanging and splicing installation frame comprises a T-shaped plate; the T-shaped plate comprises a transverse plate and a vertical plate which is perpendicular to the transverse plate; the lower end surface of the vertical plate is fixedly connected to the main girder top plate; a plurality of rib plates are arranged on two sides of the vertical plate; the upper end face of the rib plate is fixedly connected with the lower end face of the transverse plate.

The invention discloses a construction method for hanging and splicing a main girder of a cross-over bridge, which comprises the following substeps:

s41: hoisting the first main beam by using a crane, wherein the crane is gradually unloaded but does not loosen the hook;

s42: gradually unloading the suspension assembly installation frame arranged on the main beam top plate of the first main beam on the main beam top plate of the second main beam;

s43: gradually unloading the other end of the first girder to a temporary bearing body at the other side of the viaduct;

s44: after the crane is completely unloaded, welding a suspension assembly mounting frame on a top plate of a main beam of the second main beam, and fixing the other end of the first main beam with a temporary bearing body on the other side of the viaduct;

s45: the crane releases the hook.

Through the construction of the step S4, the crane is gradually unloaded but does not loosen the hook, so that the unloading safety of the first main beam is ensured, and the situation that the first main beam falls off due to insufficient supporting force of a temporary bearing body on the other side of the suspension assembly installation frame or the viaduct is prevented; after the crane is completely unloaded, carrying out welding construction to ensure that the welding seam position is in a stress-free state; after all the stacking measures are installed, the hooks are loosened recently so as to ensure the reliability of temporary reinforcement.

The invention discloses a construction method for hanging and splicing a main girder of a cross-over overhead bridge, which comprises the following steps of: the code plate comprises a plurality of reinforced code plates; a plurality of common code plates are arranged between every two reinforcing code plates; the reinforcing code plate and the common code plate are fixed through welding; through the setting of two kinds of different code plates, with hang the concatenation mounting bracket cooperation, the concatenation of second girder, first girder has further been strengthened.

The invention discloses a construction method for hanging and splicing a main girder of a cross-over overhead bridge, which comprises the following steps of: the beam reinforcement construction platform comprises a plurality of section steel bars, and two ends of each section steel bar are provided with a fastener; the profile steel strip is fixedly connected to the lower end faces of the main beams at two sides of the cross beam to be reinforced through fasteners arranged at two ends; a press-type steel plate is paved on the upper end surfaces of the plurality of the section steel bars; through lay profiled steel sheet's design on many section steel strips for crossbeam reinforcement construction platform has dismouting advantage simple, light in weight, intensity height.

The invention relates to a construction method for hanging and splicing a main girder of a cross-over bridge, which comprises the following steps of: the widening section construction platform comprises a transverse brace, and one end of the transverse brace is fixedly connected to the girder side plate; the other end of the transverse brace is provided with a protective strip; the protective strips are arranged vertically to the transverse braces; a supporting bar is obliquely arranged below the transverse brace; one end of the supporting bar is fixedly connected to one end of the transverse brace, which is far away from the girder side plate, and the other end of the supporting bar is fixedly connected to the girder side plate; a groove is formed in one side, close to the main beam side plate, of the transverse brace; a plurality of transverse braces are paved with press-type steel plates; the lower sections of the plurality of protective strips are paved with a pressing steel plate, and the upper sections are paved with protective nets; the design of laying profiled steel sheets on the plurality of transverse braces ensures that the construction platform of the widening section has the advantages of simple disassembly and assembly, light weight and high strength; the design of the protective strips ensures that the outer side surface of the construction platform of the widening section has safety guarantee; the support bar design ensures that the connection between the widened section construction platform and the girder side plate is firmer and has better bearing performance; through the design of recess, give constructor bigger operating space to the fixed of lower limb and girder curb plate of being convenient for.

The invention relates to a construction method for hanging and splicing a main girder of a cross-over bridge, wherein a profiled steel sheet comprises a plurality of supporting parts protruding upwards; a groove is arranged between every two supporting parts; the profiled steel sheet is bent or curled through the grooves; the profiled steel sheet has the advantages of light weight, high strength and easy transportation by the shape design.

Drawings

FIG. 1 is a schematic view of the construction road conditions of the present invention;

FIG. 2 is an end view of a newly built overpass;

FIG. 3 is a cross-sectional view of the main beam;

FIG. 4 is an enlarged view of a widened section of the construction platform;

FIG. 5 is an enlarged view of a beam reinforcement work platform;

FIG. 6 is an enlarged view of the connection structure of the first main beam and the second main beam;

FIG. 7 is a side view of a pendant mounting bracket;

FIG. 8 is a schematic structural view of a profiled steel sheet;

FIG. 9 is a schematic view of the structure of a temporary load carrier;

FIG. 10 is a schematic view of a concrete platform foundation.

Detailed Description

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of "including" or "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms "mounted," "connected," "supported," and "coupled" and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Furthermore, "connected" and "coupled" are not restricted to physical or mechanical connections or couplings.

Also, in the present disclosure, the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are merely for convenience in describing the present disclosure and simplifying the description, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus the above terms should not be construed as limiting the present disclosure; in a second aspect, the terms "a" and "an" should be understood as "at least one" or "one or more", i.e. in one embodiment the number of one element may be one, while in another embodiment the number of the element may be plural, the term "a" should not be construed as limiting the number.

It will be appreciated by persons skilled in the art that the embodiments of the invention described above and shown in the drawings are by way of example only and are not limiting. The objects of the present invention have been fully and effectively achieved. The functional and structural principles of the present invention have been shown and described in the examples and embodiments of the invention may be modified or practiced without departing from the principles described.

Embodiments of the present invention are further described below with reference to the accompanying drawings.

Referring to fig. 1-8, a construction method for hanging and splicing a main girder of a cross-over bridge comprises the following steps:

s1: temporary bearing bodies 2 for supporting the main girder 1 are built on two sides of the existing viaduct;

s2: prefabricating a first girder 1a and a second girder 1b for crossing an existing viaduct by using a steel box girder, prefabricating a suspension assembly mounting frame 3 and a code plate 8; the rear section of the suspension assembly mounting frame 3 is pre-fixed on a girder top plate 11 at one end of the first girder 1a, and the front section extends out from one end of the first girder 1 a;

s3: hoisting a second main girder 1b to be fixed on a temporary bearing body 2 at one side of the viaduct, and enabling one end of the second main girder 1b to extend above the bridge deck of the existing viaduct to form a second suspension splicing section;

s4: hoisting the first main beam 1a, so that one end of the first main beam 1a is erected on the second suspension splicing section through the front section of the suspension splicing installation frame 3, and the other end of the first main beam is erected on the temporary bearing body 2 on the other side of the viaduct; fixedly connecting the front section of the suspension assembly mounting frame 3 with the second suspension assembly section; fixedly connecting the other end frame of the first main beam 1a with a temporary bearing body 2 at the other side of the viaduct;

s5: the joint of the girder top plate 11 of the first girder 1a and the girder top plate 11 of the second girder 1b is fixedly connected with a code plate 8; the joint of the girder web 13 of the first girder 1a and the girder web 13 of the second girder 1b is fixedly connected with the code plate 8;

s6: repeating the steps S1-S5 along the length direction of the existing viaduct so that a plurality of main beams 1 are arranged on the viaduct at intervals;

s7: a plurality of cross beams 4 are arranged between every two main beams 1 at intervals along the length direction of the main beams 1;

s8: a cross beam reinforcement construction platform 5 is arranged below the two main beams 1; the constructor stands on the beam reinforcement construction platform 5 to reinforce the connection between the main beam 1 and the beam 4 from below;

s9: a side widening section construction platform 6 is erected on a girder side plate 12 of the outermost girder 1;

s10: lifting the expansion sections 7 respectively, placing the expansion sections 7 on two sides of the girder side plates 12 of the outermost girder 1, and attaching the widened inner side plates 71 of the expansion sections 7 to the girder side plates 12;

s10: a constructor stands on the main beam top plate 11 to fix the upper edge 711 of the widened inner side plate 71 and the main beam top plate 11; the constructor stands on the widening section construction platform 6 to fix the lower edge 712 of the widening inner side plate 71 and the main beam side plate 12.

In actual construction, the temporary bearing bodies 2 are built on two sides of the existing viaduct, the second main beam 1b and the first main beam 1a are sequentially hoisted through hoisting equipment, the second main beam 1b is installed on the temporary bearing body 2 on one side, one end of the first main beam 1a is installed on the second suspension section of the second main beam 1b through the prefabricated suspension installation frame 3, the other end of the first main beam 1a is installed on the temporary bearing body 2 on the other side, and continuing to refer to fig. 1, because the second main beam 1b and the first main beam 1a are hoisted on the outer side of the existing viaduct, a certain distance is reserved between the second main beam 1b and the side surface of the existing viaduct, the hoisting equipment does not need to hoist the main beam 11 to the center of the existing viaduct, so that the hoisting equipment can be pulled away from the side surface of the existing viaduct, interference between the hoisting equipment and the existing viaduct is avoided, and because one end of the second main beam 1b extends to the upper side of the existing viaduct to form a second suspension section, the length of the second suspension section is larger than the width of the existing viaduct, and the problem that the first main beam 1a cannot be fixedly connected to the existing viaduct is avoided due to the fact that the first suspension installation frame extends to the side of the existing viaduct is not to the side of the first main beam, and the suspension section is prevented from being temporarily suspended to be connected to the side on the existing viaduct.

After the second main beam 1b and the first main beam 1a are spliced, the joint of the first main beam 1a and the second main beam 1b is fixedly connected with the code plate 8, and the code plate is matched with the suspension splicing installation frame 3 to provide temporary supporting force for the first main beam 1a and the second main beam 1b together, so that the first main beam 1a and the second main beam 1b are prevented from falling to the existing overhead bridge deck due to insufficient supporting force of the suspension splicing installation frame 3, and the follow-up construction is safely carried out; the beam reinforcement construction platform 5 is arranged below the two main beams 1, so that constructors stand on the beam reinforcement construction platform 5 to construct the beam 4, temporary supports for the construction of the beam 4 are prevented from being erected on the existing viaduct, and the influence on traffic is avoided; the side widening section construction platform 6 is arranged, so that constructors can stand on the side widening section construction platform 6 to construct the lower edge 712 of the widening section 7, temporary supports for constructing the widening section 7 are prevented from being erected on the existing viaduct, and accordingly influence on traffic is avoided.

It should be noted that, as shown in fig. 9, in some embodiments, the temporary bearing body 2 is composed of 4 lattice columns, and distribution beams for bearing the main beams 11 are fixedly connected to the upper end surfaces of the lattice columns; a concrete cap foundation is correspondingly arranged below each lattice column to ensure stable support of the main beams 11.

As shown in fig. 10, specifically, the lattice column is composed of 4 column steel pipes, and web members for increasing stability and strength are provided between the 4 column steel pipes; the concrete strength of the concrete cap foundation is not lower than C30, a reinforcing steel bar net is arranged in the concrete cap foundation, an embedded part is arranged above the concrete cap foundation, and the column feet of the column steel pipes are welded with the embedded part, so that the strength of the temporary bearing body 2 is ensured.

With continued reference to fig. 2, in step S2, the number of the suspension mounting frames 3 is two and they are disposed on both sides of the girder top plate 11 of the first girder 1 a; through the design of two suspension installation racks 3, the gravity of first girder 1a has been shared jointly, and two suspension installation racks 3 are set up in the girder roof 11 both sides of first girder 1a for first girder 1a both sides atress is balanced, is difficult for overturning.

With continued reference to fig. 7, the suspension mount 3 includes a T-shaped plate 31; the T-shaped plate 31 includes a cross plate 311, and a riser 312 provided perpendicular to the cross plate 311; the lower end surface of the vertical plate 312 is fixedly connected to the main beam top plate 11; a plurality of rib plates 313 are arranged on two sides of the vertical plate 312; the upper end surface of the rib plate 313 is fixedly connected with the lower end surface of the transverse plate 311.

When the hanging assembly installation frame 3 is prefabricated, the hanging assembly installation frame 3 is formed by welding a transverse plate 311, a vertical plate 312 and a plurality of rib plates 313 distributed along two sides of the vertical plate 312, so that the hanging assembly installation frame 3 has the advantages of saving materials and being light in weight.

Referring to fig. 7, specifically, the rib plate 313 has a trapezoid shape, the rib plate 313 includes an upper bottom surface and a lower bottom surface, the length of the upper bottom surface is smaller than that of the lower bottom surface, the upper bottom surface is welded to the lower bottom surface of the transverse plate 311, and the lower ground is welded to the main beam top plate 11, so that the stability of the suspension assembly mounting frame 3 relative to the main beam top plate 11 is better due to the larger contact area of the lower ground.

With continued reference to fig. 1 and 7, step S4 includes the following sub-steps:

s41: hoisting the first main beam 1a by using a crane, wherein the crane is gradually unloaded but does not loosen the hook;

s42: gradually unloading the suspension assembly installation frame 3 arranged on the main beam top plate 11 of the first main beam 1a on the main beam top plate 11 of the second main beam 1 b;

s43: gradually unloading the other end of the first main girder 1a to a temporary bearing body 2 at the other side of the viaduct;

s44: after the crane is completely unloaded, welding a suspension assembly mounting frame 3 on a main beam top plate 11 of a second main beam 1b, and fixing the other end of the first main beam 1a with a temporary bearing body 2 on the other side of the viaduct;

s45: the crane releases the hook.

Through the construction of the step S4, the crane is gradually unloaded but does not loosen the hook, so that the unloading safety of the first main beam 1a is ensured, and the situation that the first main beam 1a falls off due to insufficient supporting force of the suspension assembly installation frame 3 or the temporary bearing body 2 on the other side of the viaduct is prevented; after the crane is completely unloaded, carrying out welding construction to ensure that the welding seam position is in a stress-free state; after all the stacking measures are installed, the hooks are loosened recently so as to ensure the reliability of temporary reinforcement.

It should be noted that the material of the suspension assembly mounting frame 3 is preferably Q345B, and the suspension assembly mounting frame 3 and the main beam top plate 11 are welded by fillet welding, preferably, the welding angle is 18mm.

With continued reference to fig. 3 and 6, in step S5: the code plate 8 comprises a plurality of reinforcing code plates 81; a plurality of common code plates 82 are arranged between every two reinforcing code plates 81; the reinforcing code plate 81 and the normal code plate 82 are fixed by welding.

Specifically, the reinforcing code plate 81 and the common code plate 82 are rectangular steel plates with different specifications; the material of the reinforcing code plates 81 is preferably Q345B, and the reinforcing code plates 81 are uniformly arranged on the girder top plate 11 and the girder web 13 respectively, preferably, 2-4 reinforcing code plates 81 are arranged on one surface, and the welding mode of the reinforcing code plates 81 and the girder top plate 11 or the girder web 13 is preferably open-slope welding; the standard of the common code plates 82 is smaller than that of the reinforcing code plates 81, the common code plates 82 are arranged at intervals between the reinforcing code plates 81, and the welding mode of the common code plates 82 is preferably single-side fillet welding; through the setting of two kinds of different code plates 8, with hang the concatenation mounting bracket 3 cooperation, further strengthened the concatenation of second girder 1b, first girder 1 a.

Referring to fig. 2 and 5, in step S7: the beam reinforcement construction platform 5 comprises a plurality of section steel bars 51, and two ends of each section steel bar 51 are provided with a fastener 52; the section steel bars 51 are fixedly connected to the lower end surfaces of the main beams 1 on two sides of the cross beam 4 to be reinforced through fasteners 52 arranged at two ends; the upper end surfaces of the plurality of profile steel strips 51 are paved with profiled steel sheets 9; through the design of laying profiled steel sheet 9 on many shaped steel strips 51 for crossbeam consolidates construction platform 5 has easy, the light in weight of dismouting, advantage that intensity is high.

It should be noted that, when prefabricating the main girder 1, the connection structure may be prefabricated at the same time at the position where the connection with the fastener 52 is required; when the girder 1 is erected, a constructor can set up a fastener 52 on the connection structure mechanism, and then set up a steel bar 51 and a profiled steel sheet 9.

With continued reference to fig. 2 and 4, in steps S8 and S9: the widening section construction platform 6 comprises a transverse brace 61, and one end of the transverse brace 61 is fixedly connected to the main beam side plate 12; the other end of the transverse brace 61 is provided with a protective strip 62; the protective strips 62 are arranged vertically to the cross braces 61; a supporting bar 63 is obliquely arranged below the transverse brace 61; one end of the support bar 63 is fixedly connected to one end of the transverse brace 61 away from the girder side plate 12, and the other end is fixedly connected to the girder side plate 12; a groove 611 is formed on one side of the transverse brace 61, which is close to the main beam side plate 12; profiled steel sheets 9 are paved on the plurality of transverse braces 61; the lower sections of the plurality of protective strips 62 are paved with profiled steel sheets 9, and the upper sections are paved with protective nets; the design of laying the profiled steel sheets 9 on the plurality of transverse braces 61 ensures that the construction platform 6 of the widened section has the advantages of simple disassembly and assembly, light weight and high strength; the design of the protective strips 62 ensures that the outer side surface of the construction platform 6 of the widening section has safety guarantee; the support strips 63 are designed, so that the connection between the widened section construction platform 6 and the girder side plates 12 is firmer, and the widened section construction platform has better bearing performance; by the design of the groove 611, a larger operating space is provided for the constructor to facilitate the fixation of the lower edge 712 and the girder side plates 12.

It should be noted that, in combination with actual working conditions, such as convenience of prefabrication, transportation and hoisting, and the sizes of the main beam 11 and the existing overhead bridge deck, the widened section construction platform 6 may also be prefabricated on the main beam 11 at the outermost side in the step S2; if the prefabrication conditions are met and the widened section construction platform 6 is prefabricated in advance, repeated erection is not needed after the girder 11 is erected, and the construction difficulty is reduced.

The invention relates to a construction method for hanging and splicing a main girder of a cross-over bridge, wherein a profiled steel sheet 9 comprises a plurality of supporting parts 91 protruding upwards; a groove 92 is arranged between every two supporting parts 91; the profiled steel sheet 9 is bent or curled by the grooves 92; the profiled steel sheet 9 has the advantages of light weight, high strength and easy transportation by the shape design.

The foregoing is illustrative of the preferred embodiments of the present invention and is not to be construed as limiting the claims. The present invention is not limited to the above embodiments, and the specific structure thereof is allowed to vary. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims (8)

1. The construction method for the suspension splicing of the main girder of the cross-over bridge is characterized by comprising the following steps of:

s1: temporary bearing bodies (2) for supporting the main girder (1) are built on two sides of the existing viaduct;

s2: prefabricating a first girder (1 a) and a second girder (1 b) which are used for crossing the existing viaduct by using a steel box girder, prefabricating a suspension assembly mounting frame (3) and a code plate (8); the rear section of the suspension assembly mounting frame (3) is pre-fixed on a girder top plate (11) at one end of the first girder (1 a), and the front section extends out from one end of the first girder (1 a);

s3: hoisting a second main girder (1 b) to be fixed on a temporary bearing body (2) at one side of the viaduct, and enabling one end of the second main girder (1 b) to extend above the bridge deck of the existing viaduct to form a second suspension splicing section;

s4: hoisting the first main beam (1 a), wherein one end of the first main beam (1 a) is erected on the second suspension segment through the front segment of the suspension erection frame (3), and the other end of the first main beam is erected on the temporary bearing body (2) at the other side of the viaduct; fixedly connecting the front section of the suspension assembly mounting frame (3) with the second suspension assembly section; fixedly connecting the other end frame of the first main beam (1 a) with a temporary bearing body (2) at the other side of the viaduct;

s5: a code plate (8) is fixedly connected at the joint of the girder top plate (11) of the first girder (1 a) and the girder top plate (11) of the second girder (1 b); a gusset plate (8) is fixedly connected at the joint of the girder web plate (13) of the first girder (1 a) and the girder web plate (13) of the second girder (1 b);

s6: repeating the steps S1-S5 along the length direction of the existing viaduct so that a plurality of main beams (1) are arranged on the viaduct at intervals;

s7: a plurality of cross beams (4) are arranged between every two main beams (1) at intervals along the length direction of the main beams (1);

s8: a cross beam reinforcement construction platform (5) is arranged below the two main beams (1); a constructor stands on the beam reinforcement construction platform (5) and reinforces the connection between the main beam (1) and the beam (4) from below;

s9: erecting a side widening section construction platform (6) on a girder side plate (12) of the outermost girder (1);

s10: lifting the expansion sections (7) on two sides of a girder side plate (12) of the outermost girder (1) respectively, and attaching a widened inner side plate (71) of the expansion sections (7) to the girder side plate (12);

s10: a constructor stands on the main beam top plate (11) to fix the upper edge (711) of the widened inner side plate (71) and the main beam top plate (11); the constructor stands on the widening section construction platform (6) and fixes the lower edge (712) of the widening inner side plate (71) and the girder side plate (12).

2. The construction method for hanging and splicing the main girder of the viaduct according to claim 1, the method is characterized in that in the step S2: the number of the suspension assembly installation frames (3) is two, and the suspension assembly installation frames are arranged on two sides of the girder top plate (11) of the first girder (1 a).

3. The construction method for hanging and splicing the main girder of the viaduct according to claim 2, wherein the construction method comprises the following steps: the suspension assembly mounting frame (3) comprises a T-shaped plate (31); the T-shaped plate (31) comprises a transverse plate (311) and a vertical plate (312) which is perpendicular to the transverse plate (311); the lower end surface of the vertical plate (312) is fixedly connected to the main girder top plate (11); a plurality of rib plates (313) are arranged on two sides of the vertical plate (312); the upper end face of the rib plate (313) is fixedly connected with the lower end face of the transverse plate (311).

4. A method of constructing a suspension assembly of a main girder of a bridge of an overhead bridge according to claim 3, wherein the step S4 comprises the following sub-steps:

s41: hoisting the first main beam (1 a) by using a crane, wherein the crane is gradually unloaded but does not loosen the hook;

s42: gradually unloading the suspension assembly installation frame (3) arranged on the main beam top plate (11) of the first main beam (1 a) on the main beam top plate (11) of the second main beam (1 b);

s43: the other end of the first main girder (1 a) is gradually unloaded to a temporary bearing body (2) at the other side of the viaduct;

s44: after the crane is completely unloaded, welding a suspension assembly mounting frame (3) on a girder top plate (11) of a second girder (1 b), and fixing the other end of the first girder (1 a) with a temporary bearing body (2) on the other side of the viaduct;

s45: the crane releases the hook.

5. The method of construction of a bridge girder suspension of claim 1, wherein in step S5: the code plate (8) comprises a plurality of reinforced code plates (81); a plurality of common code plates (82) are arranged between every two reinforcing code plates (81); the reinforcing code plate (81) and the common code plate (82) are fixed through welding.

6. The method of construction of a bridge girder suspension of claim 1, wherein in step S7: the beam reinforcement construction platform (5) comprises a plurality of section steel bars (51), and two ends of each section steel bar (51) are provided with a fastener (52); the profile steel strips (51) are fixedly connected to the lower end faces of the main beams (1) on two sides of the cross beam (4) to be reinforced through fasteners (52) arranged at two ends; profiled steel sheets (9) are paved on the upper end surfaces of the plurality of profile steel strips (51).

7. The method of construction of the bridge girder suspension of claim 1, wherein in steps S8 and S9: the widening section construction platform (6) comprises a transverse brace (61), and one end of the transverse brace (61) is fixedly connected to the main beam side plate (12); the other end of the transverse brace (61) is provided with a protective strip (62); the protective strips (62) are arranged vertically to the transverse braces (61); a supporting bar (63) is obliquely arranged below the transverse brace (61); one end of the supporting bar (63) is fixedly connected to one end of the transverse brace (61) far away from the girder side plate (12), and the other end of the supporting bar is fixedly connected to the girder side plate (12); a groove (611) is formed in one side, close to the main beam side plate (12), of the transverse brace (61); profiled steel sheets (9) are paved on the plurality of transverse braces (61); the lower sections of the plurality of protective strips (62) are paved with profiled steel sheets (9), and the upper sections are paved with protective nets.

8. The construction method for hanging and splicing the main girder of the bridge of the cross-over bridge according to claim 6 or 7, wherein the construction method comprises the following steps: the profiled steel sheet (9) comprises a plurality of upwardly convex supporting parts (91); a groove (92) is arranged between every two supporting parts (91); the profiled steel sheet (9) is bent or curled through the grooves (92).