CN109252455B - Cantilever assembling construction method of multi-main-truss steel truss girder structure - Google Patents
Cantilever assembling construction method of multi-main-truss steel truss girder structure Download PDFInfo
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- CN109252455B CN109252455B CN201811187706.8A CN201811187706A CN109252455B CN 109252455 B CN109252455 B CN 109252455B CN 201811187706 A CN201811187706 A CN 201811187706A CN 109252455 B CN109252455 B CN 109252455B
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- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01D—CONSTRUCTION OF BRIDGES, ELEVATED ROADWAYS OR VIADUCTS; ASSEMBLY OF BRIDGES
- E01D21/00—Methods or apparatus specially adapted for erecting or assembling bridges
- E01D21/10—Cantilevered erection
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Abstract
The invention discloses a cantilever assembling construction method of a multi-main-truss steel truss girder structure, which relates to the technical field of bridge construction and comprises the following steps: pre-installing an Nth internode bridge deck between the Nth internode side girder and the Nth internode middle girder; erecting an N +1 th internode side truss; fixedly connecting the Nth internode bridge deck with the Nth internode side girder and the Nth internode middle girder; erecting an N +1 th internode middle truss; and repeating the steps S1-S4, and assembling internodes by the cantilever until the side span upper pier and the midspan closure. The construction method can effectively control the height difference of the side and middle trusses of the multi-main truss steel truss girder structure within a small range, and ensures the line shape of the bridge deck.
Description
Technical Field
The invention relates to the technical field of bridge construction, in particular to a cantilever assembling construction method of a multi-main-truss steel truss girder structure.
Background
In order to fully utilize precious bridge site resources, more and more bridges are built by adopting a highway-railway combined construction mode, wherein the steel truss girder structure can adapt to layering of upper and lower highway surfaces and railway surfaces, and is an optimal bridge type for building highway-railway dual-purpose bridges. With the increase of bridge passing lines and design load, the width of a double-layer bridge deck is usually more than 30 meters, and the conventional double-main-truss structure is not suitable any more. At the moment, a multi-main-truss structure form of three main trusses and more can be adopted, and the transverse span of the bridge deck is reduced. The multi-main truss structure system mainly comprises: the side and middle girder main girder rod pieces, the upper and lower deck bridge deck slab, the node connection system and other members. The main truss members are connected through high-strength bolts, the bridge deck plate and the main truss members are connected in a bolted welding mode, namely, the bridge deck plate cross beam web and the main truss are connected through the high-strength bolts, and the bridge deck plate top plate and the main truss are welded. The multi-main truss bridge girder built and under construction in China at present comprises a Tianxing Zhou Yangtze river bridge, a Dasheng Guangjiang river bridge, a Shanghai Tongjiang river bridge and the like, and the bridges all adopt 3 main trusses.
The construction method of the conventional double-main-truss structural steel truss girder mainly comprises support assembly, cantilever assembly, pushing construction and the like, wherein the cantilever assembly is the most common. Temporary supports are arranged at the tops of the piers or the main tower columns, the No. 0 section is assembled, and then steel truss girder rod pieces are symmetrically installed on two sides of the steel truss girder rod pieces through cantilevers. The installation mode comprises the installation of parts and the integral installation of the segments after the pre-assembly is finished. The requirement of parts installation on machinery is low, the transportation and the installation are convenient, and the adaptability is stronger.
The multi-main truss structure can also adopt the three construction methods. When the cantilever assembly is adopted, the height difference of the side girder and the middle girder is easy to generate. According to the main girder cantilever assembling process, the bridge deck is firstly bolted with the main girder, and after all the bridge deck are installed in place, the bridge deck is formally welded. Before welding, the bridge deck plates are more closely and simply supported on the side girders and the middle girders, at the moment, the middle girders bear half weight of each of the left and right bridge deck plates, and the side girders bear half weight of one bridge deck plate. Due to different load sharing, deflection difference can be generated at the edge and the middle truss between the sections; in addition, the middle supporting point of the bridge deck crane is supported on the middle truss, and the two side supporting points are supported in the middle of the side truss, so that the self-weight difference of the crane shared by the side truss and the middle truss is caused, and the deflection difference of the side truss and the middle truss is also influenced to a certain extent.
When the cantilever is assembled, the height difference of the side and the middle truss between the installed sections forms a relative corner, and the height difference of the side and the middle truss between the subsequent installed sections is increased in a linear relation, so that the height difference is continuously accumulated. The height difference of the side and the middle trusses affects the structural linearity, so that the bridge deck system is transversely staggered, and the structural installation stress is increased.
Disclosure of Invention
Aiming at the defects in the prior construction technology, the invention aims to provide a cantilever assembling construction method of a multi-main-truss steel truss girder structure, which can effectively control the height difference of side and middle trusses within a very small range and ensure the line shape of a bridge deck.
In order to achieve the above purposes, the technical scheme adopted by the invention is as follows: a cantilever assembling construction method of a multi-main truss structure steel truss girder comprises the following steps:
s1, pre-installing an Nth internode bridge deck between the Nth internode side girder and the Nth internode middle girder;
s2, erecting an N +1 th internode side truss;
s3, fixedly connecting the Nth internode bridge deck with the Nth internode side girder and the Nth internode middle girder;
s4, erecting an N +1 th internode middle truss;
s5, repeating the steps S1-S4, and assembling internodes by the cantilever until the side span upper pier and the midspan are closed;
wherein N is a positive integer.
On the basis of the technical scheme, the method for pre-installing the nth internode bridge deck on the nth internode side girder and the nth internode middle girder comprises the following steps:
and a beam web of the Nth internode bridge deck plate is connected with the Nth internode side girder and the Nth internode middle girder by adopting small punch nails.
On the basis of the technical scheme, the method for fixedly connecting the Nth internode bridge deck with the Nth internode side girder and the Nth internode middle girder comprises the following steps:
and fixedly connecting a beam web of the Nth internode bridge deck with the Nth internode side girder and the Nth internode middle girder through high-strength bolts, and welding a top plate of the Nth internode bridge deck with the Nth internode side girder and the Nth internode middle girder.
On the basis of the technical scheme, the method further comprises the following steps:
splicing seams are reserved among the N +1 th internode, the N-th internode side and the middle truss;
when the height difference of the side girders and the middle girders exceeds a preset value, shortening the distance of the splicing seam between the (N + 1) th internode middle girder and the N-th internode middle girder at the upper chord node by X mm, and extending the distance of the splicing seam between the (N + 1) th internode side girder and the N-th internode side girder at the upper chord node by Y mm;
wherein X, Y is a positive number.
On the basis of the technical scheme, the method comprises the following steps:
m internodes are spaced, the distance between the N +1+ M internode middle truss and the splicing seam of the N + M internode middle truss at the upper chord node is lengthened by X mm, and the distance between the N +1+ M internode side truss and the N + M internode side truss at the upper chord node is shortened by Y mm;
wherein M is a positive integer.
On the basis of the technical scheme, the method further comprises the following steps:
when the N +1 th internode is the last internode of the side span and the height difference of the side and the middle trusses exceeds a preset value, erecting the N +1 th internode middle truss;
erecting an N +1 th internode side truss;
and sequentially installing and fixing the Nth internode bridge deck and the (N + 1) th internode bridge deck.
On the basis of the technical scheme, after the N +1 th internode middle truss is erected, the N +1 th internode middle truss is shoveled and cushioned at the top of the side pier.
On the basis of the technical scheme, after the N +1 th internode side girder is erected, the N +1 th internode side girder is not shoveled at the top of the side pier.
On the basis of the technical scheme, the method for sequentially installing and fixing the Nth internode bridge deck and the (N + 1) th internode bridge deck comprises the following steps:
and sequentially welding the beam web of the nth internode bridge deck and the (N + 1) th internode bridge deck with the edge girders and the middle girders through high-strength bolts, and welding the top plates of the nth internode bridge deck and the (N + 1) th internode bridge deck with the edge girders and the middle girders.
Compared with the prior art, the invention has the advantages that:
(1) the cantilever assembling construction method of the multi-main truss steel truss girder structure comprises the steps of firstly erecting the (N + 1) th internode side truss, then fixedly connecting the (N) th internode bridge deck with the (N) th internode side truss and the (N) th internode middle truss, and then erecting the (N + 1) th internode middle truss, wherein under the action of self weight, the (N + 1) th internode side truss is deflected downwards and increased, so that the height difference between the side truss and the middle truss generated by a bridge deck system is offset, and the line shape of the bridge deck is ensured.
(2) According to the cantilever assembling construction method of the multi-main-truss steel truss girder structure, when the height difference of the side trusses and the middle trusses exceeds a preset value, the height difference of the side trusses and the middle trusses is improved by adjusting the lengths of splicing seams of the middle trusses and the side trusses among joints at the upper chord nodes, and the line shape of a bridge deck is guaranteed.
(3) According to the cantilever assembling construction method of the multi-main truss steel truss girder structure, when the (N + 1) th internode is the last internode of the side span, and the height difference of the side and the middle trusses exceeds a preset value, the (N + 1) th internode middle truss is shoveled and cushioned at the top of the side pier, but the (N + 1) th internode side truss is not shoveled and cushioned, under the action of self weight, the downward deflection of the side truss is increased, the height difference of the side and the middle trusses is reduced, and the line shape of a bridge floor is ensured.
Drawings
FIG. 1 is a schematic plan view of a cantilever erection construction of a multi-main girder steel girder structure according to an embodiment of the present invention;
in the figure: 1-Nth internode side girder, 2-Nth +1 internode side girder, 3-Nth internode middle girder, 4-Nth +1 internode middle girder, 5-Nth internode bridge deck slab and 6-Nth +1 internode bridge deck slab.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples.
Referring to fig. 1, an embodiment of the present invention provides a cantilever assembling construction method for a multi-main-truss steel truss girder structure, including the following steps:
s1, pre-installing an Nth internode bridge deck 5 on the Nth (N is a positive integer) internode side girder 1 and the Nth internode middle girder 2;
s2, erecting an N +1 th internode side truss 2;
s3, fixedly connecting the Nth internode bridge deck 5 with the Nth internode side girder 1 and the Nth internode middle girder 3;
s4, erecting an N +1 th internode middle truss 4;
and S5, repeating the steps S1-S4, and assembling internodes by the cantilever until the side span upper pier and the middle span are closed.
Compared with the prior art, the cantilever assembling construction method of the multi-main truss steel truss girder structure comprises the steps of firstly erecting the (N + 1) th internode side girder 2, then fixedly connecting the (N) th internode bridge deck plate 5 with the (N) th internode side girder 1 and the (N) th internode middle girder 3, and then erecting the (N + 1) th internode middle girder 4, wherein when the (N + 1) th internode side girder 2 is erected, the (N) th internode bridge deck plate 5 is not fixedly connected with the (N) th internode side girder 1 and the (N) th internode middle girder 3, a corner is not restricted, the transverse rigidity is weak, under the action of self weight, the (N + 1) th internode side girder 2 is downwards bent and increased, the height difference between the side girder and the middle girder generated by a bridge deck system is offset, the structural stress is not influenced additionally, other additional mechanical equipment is not needed, and the height difference between the side girder and the middle girder is controlled within a small range.
In a preferred embodiment, when the nth internode bridge deck 5 is pre-installed on the nth internode side girder 1 and the nth internode middle girder 3, the beam web of the nth internode bridge deck 5 is connected to the nth internode side girder 1 and the nth internode middle girder 3 by a small punch nail.
In a preferred embodiment, when the nth internode bridge deck 5 is fixedly connected to the nth internode side girder 1 and the nth internode middle girder 3, the beam web of the nth internode bridge deck 5 is fixedly connected to the nth internode side girder 1 and the nth internode middle girder 3 by high-strength bolts, and the top plate of the nth internode bridge deck 5 is welded to the nth internode side girder 1 and the nth internode middle girder 3, whereby the stability of the installation of the bridge deck can be ensured.
As a preferred embodiment, splicing seams are reserved between the (N + 1) th internode and the connection of the N-th internode edge and the middle truss; when the height difference of the side girders and the middle girders exceeds a preset value, shortening the distance of the splicing seam between the (N + 1) th internode middle girder 4 and the (N) th internode middle girder 3 at the upper chord node by X mm (X is a positive number), and extending the distance of the splicing seam between the (N + 1) th internode side girder 2 and the (N) th internode side girder 1 at the upper chord node by Y mm (Y is a positive number); and M (M is a positive integer) internodes are spaced, the distance between the (N +1+ M) th internode middle truss 4 and the (N + M) th internode middle truss 3 at the splicing seam at the upper chord node is lengthened by X mm, and the distance between the (N +1+ M) th internode side truss 2 and the (N + M) th internode side truss 1 at the splicing seam at the upper chord node is shortened by Y mm. The height difference of the side girder and the middle girder is improved by adjusting the lengths of the splicing seams of the middle girder and the side girder at the upper chord node between the sections, and the line shape of the bridge deck is ensured.
As a preferred embodiment, when the (N + 1) th internode is the last internode of the side span and the height difference of the side girder and the middle girder exceeds a preset value, erecting the (N + 1) th internode middle girder 4, and padding the (N + 1) th internode middle girder 4 at the top of the side pier; erecting an N +1 th internode side truss 2, and not padding the N +1 th internode side truss 2 on the top of the side pier; install fixed nth internode decking 5 and N +1 internode decking 6 in proper order, specifically, pass through high strength bolted connection with the crossbeam web and the side purlin and the purlin of nth internode decking 5 and N +1 internode decking 6, weld the roof and the side purlin and the purlin of nth internode decking 5 and N +1 internode decking 6.
Because the lifting pad of the (N + 1) th internode middle girder 4 is arranged at the top of the side pier to support the (N + 1) th internode middle girder 4, but the lifting pad of the (N + 1) th internode side girder 2 is not arranged, the (N + 1) th internode side girder 2 is suspended in the air and is in a free state, under the action of self weight, the downward deflection of the side girder is increased, the height difference between the side girder and the middle girder is reduced, and the line shape of the bridge deck is ensured.
The present invention is not limited to the above-described embodiments, and it will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the principle of the present invention, and such modifications and improvements are also considered to be within the scope of the present invention. Those not described in detail in this specification are within the skill of the art.
Claims (9)
1. A cantilever assembling construction method of a multi-main-truss steel truss girder structure is characterized by comprising the following steps:
s1, pre-installing an Nth internode bridge deck between the Nth internode side girder and the Nth internode middle girder;
s2, erecting an N +1 th internode side truss;
s3, fixedly connecting the Nth internode bridge deck with the Nth internode side girder and the Nth internode middle girder;
s4, erecting an N +1 th internode middle truss;
s5, repeating the steps S1-S4, and assembling internodes by the cantilever until the side span upper pier and the midspan are closed;
wherein N is a positive integer.
2. The cantilever assembling construction method of multi-main truss steel truss girder structure as claimed in claim 1, wherein the N-th internode bridge deck is pre-installed on the N-th internode side girder and the N-th internode middle girder, comprising the steps of:
and a beam web of the Nth internode bridge deck plate is connected with the Nth internode side girder and the Nth internode middle girder by adopting small punch nails.
3. The cantilever assembling construction method of multi-main truss steel truss girder structure of claim 1, wherein the step of fixedly connecting the nth internode bridge deck with the nth internode side girders and the nth internode middle girders comprises the steps of:
and fixedly connecting a beam web of the Nth internode bridge deck with the Nth internode side girder and the Nth internode middle girder through high-strength bolts, and welding a top plate of the Nth internode bridge deck with the Nth internode side girder and the Nth internode middle girder.
4. The cantilever assembling construction method of a multi-main truss steel truss girder structure as claimed in claim 1, further comprising the steps of:
splicing seams are reserved between the N +1 th internode and the connection of the N-th internode side trusses and the middle trusses;
when the height difference of the side girders and the middle girders exceeds a preset value, shortening the distance of the splicing seam between the (N + 1) th internode middle girder and the N-th internode middle girder at the upper chord node by X mm, and extending the distance of the splicing seam between the (N + 1) th internode side girder and the N-th internode side girder at the upper chord node by Ymm;
wherein X, Y is a positive number.
5. The cantilever assembling construction method of a multi-main truss steel truss girder structure as claimed in claim 4, comprising the steps of:
m internodes are spaced, the distance between the splicing seam of the (N +1+ M) th internode middle truss and the splicing seam of the (N + M) th internode middle truss at the upper chord node is lengthened by Xmm, and the distance between the (N +1+ M) th internode edge truss and the splicing seam of the (N + M) th internode edge truss at the upper chord node is shortened by Y mm;
wherein M is a positive integer.
6. The cantilever assembling construction method of a multi-main truss steel truss girder structure as claimed in claim 1, further comprising the steps of:
when the N +1 th internode is the last internode of the side span and the height difference of the side and the middle trusses exceeds a preset value, erecting the N +1 th internode middle truss;
erecting an N +1 th internode side truss;
and sequentially installing and fixing the Nth internode bridge deck and the (N + 1) th internode bridge deck.
7. The cantilever assembling construction method of a multi-main truss steel truss girder structure of claim 6, wherein:
and (5) after the N +1 th internode middle truss is erected, the N +1 th internode middle truss is shoveled and cushioned on the top of the side pier.
8. The cantilever assembling construction method of a multi-main truss steel truss girder structure of claim 6, wherein:
and after the N +1 th internode side girder is erected, no lifting pad is arranged on the top of the side pier for the N +1 th internode side girder.
9. The cantilever assembling construction method of a multi-main truss steel truss girder structure of claim 6, wherein the sequentially installing and fixing the nth and N +1 th internode bridge decks comprises the following steps:
and sequentially welding the beam web of the nth internode bridge deck and the (N + 1) th internode bridge deck with the edge girders and the middle girders through high-strength bolts, and welding the top plates of the nth internode bridge deck and the (N + 1) th internode bridge deck with the edge girders and the middle girders.
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