Construction method of shield tunneling in high-strength bedrock raised strata

Abstract

The invention discloses a high strength bed rock protrusion stratum shield construction method. The high strength bed rock protrusion stratum shield construction method comprises the following steps that (1) a shield machine is selected, and specifically a composite soil pressure balance shield machine is selected for tunneling construction; (2) a cabin-entry point is arranged, and a reinforced zone is arranged for the zone of the cabin-entry point; (3) a full soil pressure full-cabin tunneling mode is adopted to strictly control the slag discharge amount in the shield tunneling construction process, soil body is improved, synchronous grouting and secondary grouting are carried out, and when the shield tunnels to the cabin-entry point, workers enter a cabin under pressure to check whethera cutter has abnormal wear; (4) assembling construction of shield segments is carried out; and (5) after a shield tail deviates from the surface of the earth, the synchronous grouting amount is addedand complement grouting is carried out behind the walls of pipe segments. According to the high strength bed rock protrusion stratum shield construction method, the cutter can be checked and replacedin time, problems in a soil cabin are handled, the ability of rock breaking is guaranteed, the full soil pressure full-cabin tunneling mode prevents a tunnel face from being prone to collapsing in rapid fluctuation of the pressure, and the construction demands of stratum large torque such as upper soft and lower hard, sand layer and possible pre-split blasting are met.

Description

technical field [0001] The invention relates to the field of tunnel shield technology construction, in particular to a shield construction method for high-strength bedrock raised strata. Background technique [0002] The natural compressive strength of the high-strength bedrock raised strata reaches 160-204Mpa. The stratum is residual clay and fully weathered granite. There are moderate and light wind weathered granites (bedrock raised) locally. The water moving in the medium is blocked by the rock mass with extremely low porosity, and gathers into a water flow on the surface of the rock mass, and the water volume is abundant. During the construction process, it is easy to appear sticky cutterhead, mud cake, tunnel face collapse, earth pressure shield gushing, cutterhead Problems such as abnormal tool wear, poor working condition of the shield machine, and excessive settlement of buildings such as rainwater pipes and culverts have a great impact on tunnel shield construction...

AI Technical Summary

Problems solved by technology

[0005] In the existing project cases where the shield machine directly passes through the uneven soft and hard strata, the uniaxial compressive strength of the hard rock is mostly below 120Mpa, and the environment above the tunnel is single

Today, the extremely high-strength bedrock protruding soft-hard uneven strata in Xiamen area encounters extremely high-strength hard rock with an average uniaxial compressive strength of 160Mpa and a maximum strength of 206Mpa, and there is a complex working condition of large rainwater pipes and culverts 4m above the cave roof. There is no reference case at home and abroad

During the actual construction, there are mainly the following technical problems: the applicability of shield machine selection is difficult to grasp; during the construction process, it is easy to appear paste cutter head, mud cake, tunnel face collapse, earth pressure shield gushing; cutter head cutter Problems such as abnormal wear, poor working condition of the shield machine, and excessive settlement of buildings such as rainwater pipes and culverts