A method for integrated construction of old deck arch bridge and newly-built cable-stayed bridge

Abstract

The application relates to a kind of old upper bearing arch bridge and new cable-stayed bridge dismantling integrated construction method, first, the beam body and pier of old bridge are removed by crawler crane, the abutment, side span pier and main tower of new cable-stayed bridge are constructed, then the side span of new cable-stayed bridge is constructed by support method, and the first two sections of main span steel box girder of cable-stayed bridge are assembled, the first two sections of main span are used as the transfer platform of cable crane, then the cable-stayed bridge main tower is used to set up the cable-stayed bridge arch ring dismantling cable-stayed bridge cable crane system and cable-stayed bridge cable crane system, and the arch ring is dismantled by cable crane, finally, the main span steel box girder of cable-stayed bridge is installed by cable crane, and the construction of old upper bearing steel truss arch bridge and new cable-stayed bridge is completed. Compared with the conventional construction method of first dismantling and then building, the bridge dismantling process and bridge building process are interleaved or synchronized, the construction period can be shortened, the bridge building and bridge dismantling equipment are universal, the temporary structure investment can be reduced, and the cost can be saved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of bridge construction and relates to an old deck arch bridge and a new cable-stayed bridge dismantling and building integrated construction method. BACKGROUND

[0002] The deck arch bridge is a common bridge type for crossing rivers and valleys in mountainous areas. The deck arch steel truss bridge uses arch ring to support the bridge deck system structure to be stable, but the net clearance under the bridge is small, and when the bridge under the bridge is upgraded, it needs to be dismantled and rebuilt. The cable-stayed bridge uses cables to transmit the bridge load to the cable tower, and the net clearance is high, which is the preferred bridge type for rebuilding bridges.

[0003] At present, for old bridge dismantling and reconstruction construction, the conventional construction sequence is: dismantling the old bridge-clearing the site-construction of the new bridge, and the construction period is long. Moreover, the arch bridge dismantling is different from other types of bridge dismantling. After the arch ring is opened, the cantilever section must be supported or slanted and hung. The conventional support method is the support method, but the support method has limitations in the river channel with navigation requirements, and the slanted and hung method needs to set up temporary facilities such as the tower, anchor and the like, which has a large amount of engineering, and when the new bridge is constructed, the slanted and hung system needs to be dismantled, which is a waste. SUMMARY

[0004] The purpose of the application is to provide an old deck arch bridge and a new cable-stayed bridge dismantling and building integrated construction method to shorten the construction period and save costs.

[0005] The technical scheme of the application is as follows:

[0006] An old deck arch bridge and a new cable-stayed bridge dismantling and building integrated construction method, the old deck arch bridge comprises a main span and a approach span, the main span comprises an arch ring, and a pier column for supporting the main span bridge deck system is arranged on the arch ring, the new cable-stayed bridge comprises a main span and two side spans, and the method is characterized by comprising the following steps.

[0007] (1) A crawler crane drives from the old bridge approach span to the old bridge main span bridge deck, and the crawler crane is used to dismantle the bridge deck system and bridge pier of the old bridge from the middle to both ends in sequence and symmetrically;

[0008] (2) The abutment, side span pier and main tower of the new cable-stayed bridge are constructed;

[0009] (3) A new bridge side span cast-in-place support is constructed on the outer side of the main tower, and a splicing support is erected on the inner side of each main tower, and the length of the splicing support in the bridge direction is not less than the length of two new cable-stayed bridge steel box girder segments;

[0010] Pouring new bridge approach from the pier to the midspan, after the completion of the side span pouring, the beam truck transports the cable-stayed bridge steel box girder segment to the assembling support through the side span, assembles the first two segments of the cable-stayed bridge main span steel box girder on the assembling support, and the two segments of the steel box girder on the assembling support are used as the transfer platform for subsequent cable crane construction; the cable-stayed bridge cable and the corresponding side span cable are installed and tensioned as the transfer platform of the main span steel box girder.

[0011] (4) According to the division of the old bridge arch ring segment, the buckle cable is installed on the arch ring, the main tower of the newly built cable-stayed bridge is used as the anchoring system of the buckle cable, and the tensioning end of the buckle cable is anchored on the permanent anchor beam of the main tower of the cable-stayed bridge; at the same time, the side span cable corresponding to the buckle cable is installed, and the side span cable is tensioned according to the cable force of the buckle cable;

[0012] The cable crane system is installed by using the two main towers of the cable-stayed bridge, the cable crane system comprises a cable and a cable crane walking on the cable, the cable saddle of the cable is installed on the upper cross beam of the main tower, and the two ends of the cable are anchored on the two piers of the cable-stayed bridge.

[0013] (5) The closure segment of the old bridge arch ring is removed by using the cable crane and transported to the transfer platform, and then transported away by the beam truck;

[0014] (6) The arch ring segment is removed segment by segment by using the cable crane, the corresponding buckle cable is removed, and the cable force of the side span cable corresponding to the buckle cable is released, until all the steel arch ring segments are removed;

[0015] (7) The beam truck successively transports the steel box girder segment to the transfer platform, and the cable crane is used for lifting and installing in the midspan, and after each steel box girder is installed, the midspan cable connected with the steel box girder is installed, and the midspan cable and the corresponding side span cable are tensioned at the same time, until the main span steel box girder of the cable-stayed bridge is closed, and the construction of the newly built cable-stayed bridge is completed.

[0016] The bridge dismantling process and the bridge construction process are combined organically, and the bridge dismantling process and the bridge construction process are interleaved or synchronized, which not only shortens the construction period, but also has the following advantages:

[0017] 1. The main tower of the newly built cable-stayed bridge is used to set up the cable-stayed buckle hanging system and the cable crane system for dismantling the old bridge arch ring, compared with the method of specially setting up the cable-stayed buckle hanging system for dismantling the arch ring, the engineering quantity is reduced, and the cost is saved;

[0018] 2. The cable crane for dismantling the old bridge arch ring is also used for the erection of the main girder of the new bridge, which improves the equipment reuse rate and further saves the cost.

[0019] 3. The side span cable of the cable-stayed bridge is used as the back cable corresponding to the buckle cable of the cable-stayed buckle hanging system, and the first two segments of the main girder of the cable-stayed bridge are used as the transfer platform of the cable crane, which improves the construction efficiency, reduces the investment of temporary equipment, and further saves the cost. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a construction flowchart of the present application;

[0021] Figure 2 is a schematic diagram of the state of removing the bridge deck system of the old bridge;

[0022] Figure 3 is a schematic diagram of the state of removing the pier of the old bridge;

[0023] Figure 4 is a schematic diagram of the state of the new bridge main tower and the completed construction of the pier and abutment;

[0024] Figure 5 is a schematic diagram of the state of the new bridge side span and the completed construction of the first two steel box beams of the main span;

[0025] Figure 6 is a schematic diagram of the state of the cable-stayed buckling and hanging system and the completed installation of the cable crane when the arch ring is removed;

[0026] Figure 7 is a schematic diagram of the state of the cable crane removing the arch ring closure section of the old bridge;

[0027] Figure 8 is a schematic diagram of the state of the cable crane removing the cantilever of the old bridge arch ring;

[0028] Figure 9 is a schematic diagram of the state of the cable crane hoisting the steel box beam section of the cable-stayed bridge;

[0029] Figure 10 is a schematic diagram of the state of the cable-stayed bridge closure. DETAILED DESCRIPTION

[0030] The construction method of the present application will be described below through a specific embodiment and in conjunction with the accompanying drawings.

[0031] In the present embodiment, an old and worn out deck arch bridge includes a main span and a bridge approach span, the main span includes an arch ring, and the arch ring is provided with pier columns supporting the deck system of the main span, and a cable-stayed bridge is to be newly built in situ by removing the old bridge, and the newly built cable-stayed bridge includes a main span and two side spans.

[0032] Figure 1 is a construction method flowchart of the present application, which specifically includes the following steps:

[0033] (1) As shown in Figure 2 , Figure 3 , the crawler crane drives onto the main span deck of the old bridge from the bridge approach of the old bridge, and the deck system 101 and the pier 102 of the old bridge are removed symmetrically from the middle to both ends in sequence by using the crawler crane; the remaining arch ring 103 of the old bridge is to be removed in the subsequent process.

[0034] The position of the pier foundation and the bearing platform of the approach bridge can be reserved to support the side slope without affecting the construction of the pier and the bearing platform of the new cable-stayed bridge.

[0035] (2) As shown in Figure 4 , the main tower 2, the side span pier 3 and the abutment 4 of the new cable-stayed bridge are constructed.

[0036] (3) As shown in Figure 5 , the new bridge side span cast-in-place support 5 is constructed outside the two main towers 2, and a splicing support 6 is erected inside the two main towers. The length of the splicing support in the bridge direction is not less than the length of two segments of the steel box girder of the new cable-stayed bridge.

[0037] The side span girder 7 of the new cable-stayed bridge is poured from the abutment to the midspan. After the side span pouring is completed, the girder transport vehicle transports the steel box girder segments of the cable-stayed bridge to the splicing support through the side span. The two segments of the steel box girder on the splicing support 6 serve as the transfer platform 8 for the subsequent cable crane construction. The stay cables 9 of the two segments of the main span steel box girder and the corresponding side span stay cables 10 are installed and tensioned.

[0038] (4) As shown in Figure 6 , according to the division of the arch ring segments of the old bridge, the stay cables 11 of the cable-stayed buckling system are installed on the arch ring 103. The main tower 2 of the new cable-stayed bridge is used as the anchoring system of the stay cables 11, and the tensioning end of the stay cables is anchored on the permanent anchorage beam of the main tower of the cable-stayed bridge. At the same time, the side span stay cables 10 of the cable-stayed bridge are installed between the main tower and the side span, which are used as the back cables of the arch ring cable-stayed buckling system, and the side span stay cables 10 are tensioned according to the cable force of the stay cables 11.

[0039] As shown in Figure 6 , the cable crane system is installed by using the two main towers 2 of the cable-stayed bridge. The cable crane system includes the cables 12 and the cable crane 13 walking along the cables. The cable saddle of the cable is installed on the upper cross beam of the main tower 2, and the two ends of the cable 12 are anchored on the abutment 4 of the cable-stayed bridge. The abutment 4 of the suspension bridge permanent structure is used as the anchoring system of the cable, and the vertical force of the cable crane anchoring point is resisted by the pile foundation of the abutment, and the horizontal force is transmitted to the main tower by the side span concrete beam and is resisted by the pile foundation of the main tower.

[0040] (5) As shown in Figure 7 , the cable crane 13 is used to remove the closure segment of the old bridge arch ring 103 and transport it to the transfer platform 8, and then the girder transport vehicle is used to transport it away.

[0041] (6) As shown in Figure 8As shown, the arch ring segments are dismantled by the cable crane 13 section by section, the dismantled arch ring segments are transported away by the beam transport vehicle on the transfer platform 8, one arch ring segment is dismantled at the same time, the buckle cable 11 buckled with the arch ring segment is dismantled, and the cable force of the side span cable 10 corresponding to the buckle cable is released, until all the arch ring segments are dismantled; after the arch ring is dismantled, the abutment can be reserved as the protection for reinforcing the slope.

[0042] (7) As shown in Figure 9 , Figure 10 , the beam transport vehicles successively transport the steel box girder segments to the transfer platform 8, and the cable crane 13 is used to hoist and successively hoist the segments to the midspan, every time a steel box girder 14 is hoisted, the main span cable 9 connected with the segment steel box girder is installed, and the main span cable 9 and the corresponding side span cable 10 are simultaneously tensioned, until the main span steel box girder of the cable-stayed bridge is closed, and the construction of the newly-built cable-stayed bridge is completed.

Claims

1. A method for integrated demolition and reconstruction of an old, upper-bearing arch bridge and a newly constructed cable-stayed bridge, wherein the old, upper-bearing arch bridge includes a main span and approach spans, the main span includes an arch ring, and piers supporting the main span deck are provided on the arch ring; the newly constructed cable-stayed bridge includes a main span and two side spans, characterized in that... The method comprises the following steps: (1) the crawler crane drives on the old bridge approach and reaches the old bridge main span, and the crawler crane is used to remove the deck system and piers of the old bridge symmetrically from the middle to both ends; (2) the abutment, side span pier and main tower of the new cable-stayed bridge are constructed; (3) the side span cast-in-place support of the new bridge is constructed outside the main tower, and a splicing support is erected inside both main towers, and the length of the splicing support in the bridge direction is not less than the length of two new cable-stayed bridge steel box girder segments; the side span of the new cable-stayed bridge is poured from the abutment to the middle, after the pouring of the side span is completed, the girder transporting vehicle transports the cable-stayed bridge steel box girder segments to the splicing support through the side span, the first two segments of the main span steel box girder of the cable-stayed bridge are spliced on the splicing support, and the two segments of the steel box girder on the splicing support serve as a transfer platform for subsequent cable crane construction; the stay cables of the main span steel box girder serving as the transfer platform and the corresponding side span stay cables are installed and tensioned; (4) according to the division of the arch ring segments of the old bridge, the stay cables are installed on the arch ring, the main tower of the new cable-stayed bridge is used as the anchoring system of the stay cables, the tensioning ends of the stay cables are anchored on the permanent anchor beam of the main tower of the cable-stayed bridge, and the side span stay cables corresponding to the stay cables are installed and tensioned according to the cable force of the stay cables; the cable crane system is installed by using the two main towers of the cable-stayed bridge, the cable crane system comprises cables and cable cranes walking on the cables, the cable saddles of the cables are installed on the upper cross beams of the main towers, and the two ends of the cables are anchored on the two abutments of the cable-stayed bridge; (5) the closure segment of the old bridge arch ring is removed by using the cable crane and is transported to the transfer platform, and is transported away by the girder transporting vehicle; (6) the arch ring segments are removed by using the cable crane, the stay cables corresponding to the arch ring segments are removed, and the cable force of the side span stay cables corresponding to the stay cables is released, until all the steel arch ring segments are removed; (7) the girder transporting vehicle transports the steel box girder segments to the transfer platform, the steel box girder segments are installed in the middle of the span by using the cable crane, the mid-span stay cables connected with the steel box girder segments are installed after the installation of each steel box girder segment, the mid-span stay cables and the corresponding side span stay cables are tensioned at the same time, until the main span steel box girder of the cable-stayed bridge is closed, and the construction of the new cable-stayed bridge is completed.

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