Construction method for reducing damaged segments and offset deformation by small-radius curved shield tunneling

Abstract

A construction method for reducing damaged segments and offset deformation by small-radius curved shield tunneling comprises the following steps: stopping a machine twice in a tunneling process of each circle of shield segments; stopping tunneling after tunneling by a distance of 40 cm every time; changing the current mode into a segment mounting mode; rapidly withdrawing all propulsion cylinders as long as a boot tree is separated from the segments; then placing all the boot trees of the cylinders on the segments; continuing tunneling; and eliminating a lateral force. Stress of the shield segments is analyzed by a boot tree withdrawing and releasing method, boot tree withdrawing and releasing construction is carried out at a reasonable time, cross component forces of thrust are reduced, negative effects of the thrust of the jack are reduced, integrity and offset deformation of the segments in a construction process are controlled, shield deviation rectifying efficiency is improved, and meanwhile, the quality of a formed tunnel is ensured.

Description

technical field [0001] The invention relates to a construction method for reducing segment damage and offset deformation by adopting small-radius curved shield tunneling. Background technique [0002] The development of cities drives the development of rail transit construction. In the selection of rail transit lines, due to the constraints of planning, construction and structures, the alignment of rail transit becomes more and more complicated. Although the alignment of small radius curves and steep tunnels is not good, there will be more and more applications. The limit radius advance construction of the shield section is an important and difficult problem in urban rail construction, and it is particularly important to adopt a method to reduce segment damage and offset deformation. At present, domestic small-radius propulsion usually adopts the method of selecting the turning ring and adjusting the thrust of the jack. This method is mainly suitable for the line shape of t...

AI Technical Summary

Problems solved by technology

At present, domestic small-radius propulsion usually adopts the method of selecting the turning ring and adjusting the thrust of the jack. This method is mainly suitable for the line shape of the shield tunnel with a large radius, but it can neither eliminate the side component force generated during the shield turning process, nor can it Quantitative shield segment damage and deflection deformation degree, so often due to improper construction operations, shield line deviation is too large, deviation correction is too severe, line deformation is too large, segment damage is serious, and the advancing process is harmful to the The degree of influence of the surrounding environment cannot be qualitatively judged, which will cause water leakage in the tunnel and affect the safety of running vehicles

[0003] Due to the traditional shield construction method aimed at the extreme small radius, the effect is not ideal, the efficiency is low, the shield line deviation is too large, and the segments are seriously damaged. The impact of the advancing process on the surrounding environment cannot be qualitatively judged.

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