A construction method for ultra-short steps in tunnels crossing operating highways

Abstract

The invention relates to a construction method of ultrashort steps crossing operational expressway tunnel. The construction method comprises the following steps: a long pipe shed is constructed; a guide wall and the pipe shed are respectively constructed; a slope is dig and brushed before the guide wall is constructed; the slope brushing gradient is 1: 1; the slope brushing gradient is adjusted to 1: 0.2 below a tunnel top digging line; two layers of supports are adopted; the tunnel adopt two layers of primary supports; an expressway is modified; a three-step temporary inverting method is used for constructing; an upper step, a middle step, a lower step and a bottom tunnel are dig in sequence; an inverting construction method is used for gradually constructing; the support structure is stressed by an automatic monitoring system; a monitoring device is arranged on the section of the tunnel for acquiring and processing information of tunnel displacement deformation and soil pressure change of the tunnel and monitoring the tunnel construction conditions in real time; and a secondary lining is followed up. Compared with a traditional construction method, the construction method has the advantages of high construction safety, quick construction progress, short construction period and low allocation of part machines and labor resources.

Description

technical field [0001] The invention relates to the field of tunnel construction, in particular to an ultra-short step construction method for a tunnel crossing an operating expressway. Background technique [0002] In today's society, the development of the transportation system directly restricts the development of the country's comprehensive strength. There are a large number of quicksand formations in the complex terrain of our country. The quicksand formation is different from the characteristics of ordinary soft rock and soil. It has rheological properties, which makes it difficult to form tunnels in this formation, with poor stability and difficult support. [0003] At present, the tunnel construction in the existing operating expressway section is difficult and the construction technology is complicated. The construction progress of the tunnel in this stratum is slow, the stability is poor, and the construction safety is low. [0004] In view of the above-mentioned ...

AI Technical Summary

Problems solved by technology

There are a large number of quicksand strata in the complex terrain of our country. The quicksand stratum is different from the characteristics of general soft rock and soil. It has rheological properties, which makes it difficult to form tunnels in this stratum, with poor stability and difficult support.

[0003] At present, the tunnel construction in the existing expressway section is difficult and the construction technology is complicated. The construction progress of the tunnel in this stratum is slow, the stability is poor, and the construction safety is low.

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