Integral lifting reconstruction method for high-span overweight continuous box girder

Abstract

The invention discloses an integral lifting reconstruction method for a high-span overweight continuous box girder. The method comprises the following steps of: cutting the top of a pier; reinforcing an upper box girder; welding a limiting device on the outer side of an upright post hoop, and integrating the limiting structure and a concrete pier into a whole to limit the lifting of the girder; debugging a lifting jack and a follow-up jack; lifting formally until the girder is lifted to a position which is 1cm higher than a designed elevation, screwing up a self-threaded device of the lifting jack, disassembling the follow-up jack, arranging a support and a permanent cushion block; loosening the self-threaded device on the lifting jack and allowing the jack to drop for 1 cm to the designed elevation; and disassembling the lifting device, the hoop and the limiting device and joining the lifted pier. The method can adapt to the high-span continuous box girder with limited height at the support, heavy weight, high requirements on a lifting hydraulic device and small width at the ribbed part of the box girder and can realize safe integral lifting of the continuous box girder with an accurate position.

Description

【Technical field】 [0001] The invention relates to the field of bridge engineering, in particular to a method for controlling the lifting of a bridge structure. 【Background technique】 [0002] At present, the existing bridge structure lifting control technology is to use the existing bridge pier cap structure to establish a support system, set up a lifting (lowering) bracket and a hydraulic lifting (lowering) system on the supporting system, and use the hydraulic jacking (lowering) system to simultaneously move the The upper structure of the bridge is raised (lowered) to the design elevation in a small range in sequence, and the high (lower) columns are connected, and finally the jacking (lowering) system is removed. The existing bridge lifting control technology has the characteristics of short construction period and small investment, and has become a main method in the reconstruction and construction of old bridges at home and abroad. Most of the existing jacking projects...

AI Technical Summary

Problems solved by technology

[0004] However, for such long-span and overweight bridges to be lifted, the position of the cap is very limited. If the traditional bridge jacking and underpinning method is used to use the rigid distribution beam, the cap-box girder bottom is used as the underpinning system for jacking. , the height of the steel distribution beam must be at least 4 meters, and it is difficult to ensure that the distribution beam and the bottom of the box girder are evenly stressed, and the cost performance and safety during jacking are low

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