Water-reducing improver for shield construction of water-rich stratum and construction method thereof

Abstract

The invention discloses a water-reducing improver for shield construction of a water-rich stratum and a construction method thereof. The water-reducing improver is prepared from water glass and concentrated phosphoric acid solution, wherein the water glass and the concentrated phosphoric acid solution react with water in slag soil to generate silica gel and form the water-reducing improver. The construction method of the water-reducing improver comprises the following steps: (1) when the water content and the water pressure of the stratum are large to cause a serious spewing phenomenon in theshield construction, starting an injection pump of water glass solution and concentrated phosphoric acid solution, and stopping operation of a spiral soil remover; (2) opening a grouting hole, firstlyinjecting the concentrated phosphoric acid solution with the concentration of 90%; (3) injecting the concentrated phosphoric acid solution for about 5-10 minutes, and after the concentrated phosphoric acid is fully mixed with the slag soil, stopping grouting and washing a grouting pipe; (4) opening the grouting hole, and injecting the water glass solution; (5) injecting the water glass solution for about 5-10 minutes, and leading the water glass solution and the concentrated phosphoric acid solution to react fully; (6) washing the grouting pipe and restarting the spiral soil remover to removeinternal slag soil.

Description

technical field [0001] The invention relates to the technical field of stratum excavation construction, in particular to a water-reducing improver and a construction method for shield construction in water-rich strata. Background technique [0002] The construction principle of the earth pressure balance shield is to balance the earth pressure and water pressure on the excavation surface by controlling the amount of muck in the soil chamber, so that the shield tunneling can reach a balanced state and ensure the safety of the tunneling. Soil improvement is a key technology in shield tunneling. For water-rich strata, the slag is already saturated. If the water pressure is high, a pressure difference may be generated at the outlet of the screw excavator, resulting in gushing. Therefore, the gushing prevention problem of water-rich strata has become an important problem to be solved in shield tunneling construction. [0003] For sand layer areas common in shield tunneling const...

AI Technical Summary

Problems solved by technology

However, when the water content in the formation is high or the water pressure is high, the normal improvement method may not be applicable, and gushing will still occur

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