A pier column underpinning method for a pier-beam consolidated continuous girder bridge

Abstract

The invention discloses a pier column underpinning method for a pier-beam consolidated continuous girder bridge. The original pier cap is used as the foundation of a temporary support structure, and a tray structure is poured or installed at the bottom of the original pier column close to the cap. A set of jacks are respectively arranged between the cap and the top of the beam and the main beam, and the same pressure as the dead load axial force of the original pier is applied before the underpinning. After the original bridge pier is cut and removed, the hydraulic synchronous jacking technology is used to control the upper and lower sets of jack cylinders to move upward and downward at the same speed respectively, so that the elevation of the main girder is dynamically stable during the underpinning process, thereby avoiding adverse events. Additional internal forces for structural safety of main girders. The method of the invention not only solves the problem of main girder settlement control in bridge pier underpinning construction, but also makes full use of the original bridge pier cap to bear the underpinning axial force, saves the temporary support structure in conventional construction methods, reduces construction cost and structural impact risk of instability.

Description

technical field [0001] The invention belongs to the technical field of beam bridge construction, and in particular relates to a pier column underpinning method of a pier-beam consolidated continuous girder bridge. Background technique [0002] With the rapid development of transportation infrastructure construction, new roads often need to pass under existing bridges. Restricted by factors such as overall line planning, surrounding land use, and existing bridge span layout, new roads sometimes cannot avoid the piers of some existing bridges, resulting in a contradiction in space utilization between the two. Existing piers moved out of clearance for new road. [0003] At present, the underpinning of pier-beam consolidated continuous girder bridge piers is usually carried out by installing jacks on the top of the temporary pier, raising the girder body and removing the existing pier, then pouring the columns and beams of the frame pier, and finally unloading the jack The mai...

AI Technical Summary

Problems solved by technology

[0006] However, the above method will inevitably change the elevation of the main girder during the process of jacking up and dropping the beam, resulting in unfavorable additional internal forces inside the main girder

Due to the shielding of the beams of the newly-built frame piers, it is difficult to use the existing pier caps as the foundation for the temporary support, and a temporary foundation needs to be built, which will undoubtedly increase the cost of the underpinning project

At the same time, when the height of the pier is large, the excessively high temporary support will also increase the risk of structural instability and bring hidden dangers to the safety of the project

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