Jacking system for main bridge of large-span tied arch bridge and jacking construction method

Abstract

The invention discloses a jacking system for a main bridge of a large-span tied arch bridge and a jacking construction method. The system comprises a left main bridge jacking device and a right main bridge jacking device, wherein each arch bridge superstructure comprises a left arch bridge composite structure, a right arch bridge composite structure and multiple crossbeams, each arch bridge composite structure is a steel tube concrete tied arch and comprises a girder and an arch rib, and each main bridge jacking device is arranged under each arch bridge superstructure. The jacking constructionmethod includes the steps of firstly, jacking device installation; secondly, jacking; thirdly, jacking device disassembling; and fourthly, bridge substructure jointing. The system is reasonable in structural design, simple and convenient to construct and good in use effect, the left main bridge jacking device and the right main bridge jacking device which are arranged symmetrically are adopted for vertically jacking the bridge superstructures, vertical jacking devices and auxiliary supporting structures are adopted in the main bridge jacking devices to cooperate for jacking, multiple steel bar supporting cushion blocks are adopted to form a temporary supporting structure below a jack, the supporting strength is large, the bearing effect is good, and no dismantling is required in the laterperiod.

Description

technical field [0001] The invention belongs to the technical field of bridge jacking construction, and in particular relates to a jacking system and a jacking construction method for a main bridge of a long-span tied arch bridge. Background technique [0002] Bridge jacking construction (also known as bridge jacking technology) refers to the adoption of the overall hydraulic synchronous lifting scheme, that is, using the original cast-in-place piles to bear the load, without destroying the original bridge deck pavement, railings, sidewalks, and beams and slabs. Connections, etc., first use the hydraulic jacking device to withstand the overall structure of the bridge, then cut off the columns under each pier and platform cap beam, and then operate the hydraulic jacking device to raise the bridge as a whole to the design height, and finally connect the long column steel bars Formwork pouring of the second stage concrete. The bridge superstructure refers to the general term f...

AI Technical Summary

Problems solved by technology

Among them, when jacking up the main bridge, there are the following construction problems: First, the project is located on the expressway, and the jacking construction must interrupt the traffic, and change the two-way traffic of the double-width bridge to the two-way traffic of the single-width bridge, which will affect the traffic of the expressway Larger, short road closure time, tight construction period, and the necessary closure time during construction is short, so a construction plan that has little impact on navigation must be adopted; second, the jacking weight of the main bridge is huge, and the single jacking weight is 7,000 tons ;Third, during the jacking process, the upper structure of the bridge is in a suspended state, and there are great potential safety hazards, and effective measures must be taken to resolve the above risks to ensure the safety of the bridge and construction personnel; Fourth, the jacking height is relatively high, and the jacking With a height of 2.16m, there are many temporary pads and jacking cycles, which put forward higher requirements for the overall stability of the supporting structure. It is necessary to ensure that the vertical and horizontal support system is firm, reliable and stable.

[0006] From the above content, it can be known that the jacking construction of the long-span concrete filled steel pipe tied arch bridge across the canal waterway is complicated, difficult, and has high safety risks, and the jacking height is more than 2m, the construction period is short, and the task is heavy. There is no successful experience for reference, and there are few technical materials available for reference

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