Construction method for dismantling truss type combined arch bridge

Abstract

The invention discloses a construction method for dismantling a truss type combined arch bridge. The construction method comprises the following construction steps: firstly, dismantling a bridge decksystem; secondly, installing slings; thirdly, dismantling the slings from the midspan to two arch foot sides in sequence in a manner of: dismantling solid web section side boxes, and then dismantlingupper chord side boxes, inclined web members and lower chord side boxes of a fourth section, a third section, a second section and a first section in sequence. According to the construction method, anold bridge arch ring is lifted and supported by means of a new bridge concrete-filled steel tube arch structure; in the arch opening process, the jack is arranged to slowly release the axial force ofthe arch structure, and the vertical limiting device is arranged to clamp the side box, so that it is guaranteed that an old bridge is stably converted into two independent cantilever systems from anindependent system, and the dismantling of the bridge is guaranteed.

Description

technical field [0001] The invention relates to a construction method for dismantling a truss-type composite arch bridge, which belongs to the technical field of bridge dismantling. Background technique [0002] Bridges are an important part of roads, and they are mainly erected on rivers, lakes, seas, and between adjacent mountain streams. With the rapid growth of our country's economy, the road transportation industry is also developing rapidly. Some bridges built 20 or 30 years ago are no longer able to transport demand, so new bridges need to be built to replace the old ones. Some of the old bridges need to be demolished, and the easiest and fastest way to demolish bridges is blasting. However, not all old bridges are demolished by blasting. For example, some bridges erected in nature reserves, scenic areas, drinking water areas, etc., if demolished by blasting, it is easy to cause damage to the environment and water sources in the area. , which is expressly prohibite...

AI Technical Summary

Problems solved by technology

However, after it is converted into two cantilever truss systems, the forces of the two systems cannot be mutually restricted. To a large extent, there will be a gap between the two systems due to the cutting seam during the separation cutting process or after the system is cut. The gap makes the two systems on both sides of the vault cutting seam appear relative displacement or even swing left and right. When the vault transitions from the closed state to the separated state, a large impact load will be generated instantaneously. This impact load may cause the two systems after separation to appear. collapse phenomenon

Moreover, after the bridge frame is cut into two separate cantilever truss systems, under its gravity, the cantilever truss system will have a tendency to deflect and move downward, which may also cause the two separated systems to collapse

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