Advance precipitation construction method of oversized-section double-side lower pilot tunnels of water-rich tunnel

Abstract

The invention relates to an advance precipitation construction method of oversized-section double-side lower pilot tunnels of a water-rich tunnel. Pilot tunnels on two side walls of a lower half section of a tunnel are adopted, and are partially closed to form rings; the advance precipitation is performed for the tunnel; the stability of arching legs of primary supports of the tunnel is guaranteed; the upper half section of the tunnel is dig by an arch pilot tunnel reserved core soil method; the arch part is dig in place once; the primary steel supports at the upper part of the tunnel are once spliced in place for closing to rings; the disturbance to surrounding rocks due to multiple splices is reduced; and the whole structure of the primary supports of the tunnel is quickly built. Compared with a traditional CD method, CRD method and double-side wall pilot tunnel method, the construction method is high in construction safety, quick in construction progress, short in construction period, low in part mechanical and labor resource configuration, low in once splicing construction deviation of the steel supports, high in construction quality of the primary supports, quick in building of the whole structure of the primary supports of the tunnel and low in vault crown settlement.

Description

technical field [0001] The invention relates to the field of tunnel construction, in particular to a construction method for advanced dewatering of a pilot pit on both sides of a super-large section of a water-rich tunnel. Background technique [0002] In today's society, the development of the transportation system directly restricts the development of the country's comprehensive strength. In the traffic construction in the west and central parts of my country, the construction of tunnels in the middle and lower reaches of the water-saturated sedimentary strata near the river is large and wide-ranging. The water-saturated powder fine sand stratum is different from the characteristics of ordinary soft rock and soil, and it has disturbed thixotropic fluidity. , resulting in difficulty in forming tunnels in this stratum, poor stability and difficult support. At present, the construction of tunnels and underground works in this stratum at home and abroad is basically carried ou...

AI Technical Summary

Problems solved by technology

[0003] The construction progress of the shield tunneling method and the freezing method is slow, the stability is poor, the construction safety is low, and the construction cost and energy consumption are high

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