Pretensioning method for converting old simply supported beam bridge into continuous bridge

Abstract

Disclosed is a pretensioning method for converting an old simply supported girder bridge into a continuous girder bridge, including the following steps: pre-burying a first steel plate and a second steel plate respectively on both to-be-connected sides of the old simply supported T girder, and drilling holes on the steel plates in advance corresponding to the position paved with connecting prestressing tendons; wherein, the size of holes is big enough for the prestressing tendons to run through; threading the prestressing tendons in the holes of the steel plates, anchoring one end of each prestressing tendon, and connecting the other ends of the prestressing tendons which thread through the first steel plate and the second steel plate through a connector; wherein, the holes of the two prestressing tendons on the first steel plate and the second steel plate are opposite and the prestressing tendons are placed inside the holes; screwing down the connector and tensioning the prestressingtendons; propping and pushing the girder outwards through a jack; widening the to-be-connected ends of the T girders, arranging a lateral clapboard between the connected ends of the to-be-connected Tgirders, and casting concrete on the connected ends and the bridge deck; and removing the jack after the newly cast concrete reaches the designed tension. In this way, prestress can be transferred tothe negative moment area of the reinforced concrete T girder through the old and the new concrete interfaces.

Description

technical field [0001] The invention relates to a method for longitudinally forming continuous girders from old simply supported girder bridges by applying prestress, in particular to a pre-tensioning method for transforming old simply supported girder bridges into continuous girder bridges by changing the structural system for reinforcement. Background technique [0002] The simply supported reinforced concrete T-beam bridge is a bridge structure widely used in my country. After years of operation, under the influence of various external factors, the bearing capacity and stiffness of reinforced concrete T-beams can no longer meet the requirements of modern transportation. In recent years, the commonly used methods for strengthening old simply supported girder bridges include pasting steel plate method and pasting carbon fiber cloth method. Although the external reinforcement method is simple in construction, it has two major disadvantages: [0003] 1. The high-strength per...

AI Technical Summary

Problems solved by technology

After using this technology to connect the old simply supported girder bridge longitudinally into a continuous girder bridge, it overcomes the defects of multi-span long bridge deck expansion joints and frequent driving bumps.

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