A method for soil consolidation by microbial gas-liquid circulation grouting

Abstract

A microbial gas-liquid circulation grouting method for soil consolidation, the steps comprising: a. vertically driving the grouting flower tube 1 into the foundation 7; b. injecting the soil body 8 to be consolidated into the soil body 8 to be consolidated through the grouting flower tube 1 OD of 1.5 times the pore volume 600 = 1.2 of the bacterial solution 3, then inject urea and CaCl with a concentration equal to the volume of the bacterial solution 3 of 0.5mol / L to 1.0mol / L 2 The mixed cementing liquid 4; c. Utilize the air compressor 6 to inject compressed air with a pressure of 100KPa~200KPa and a volume of 1.5 times the pore volume of the soil to be consolidated into the soil to be consolidated 8, and place the soil to be consolidated in the soil 8 The pore liquid is ejected, so that the soil body 8 to be consolidated is in an unsaturated state, and left to stand for 12 hours; d. Inject the cementing fluid 4 of 1.5 times the pore volume of the soil to be consolidated 8 into the soil to be consolidated 8, and stand for 12 hours; e. . Repeat operation d once; f. Repeat operations b, c, d, and e until the strength of the soil body 8 to be consolidated reaches the requirement or the grouting liquid (bacteria liquid 3 or cementation liquid 4) cannot be injected into the soil body 8 to be consolidated , stop grouting.

Description

technical field [0001] The invention relates to a method for improving the uniformity of soil strength by microbiological gas-liquid circulation grouting for soil consolidation and improving the grouting process for enhancing soil strength, and belongs to the technical field of soil reinforcement. Background technique [0002] Microbial soil consolidation technology is a kind of ecological and environmental protection soil consolidation method. Existing microbial grouting soil consolidation is mainly through alternately injecting microbial bacterial liquid and cementing liquid, using microbial induced calcium carbonate crystallization technology (MICP technology), and finally in the soil particles Calcium carbonate crystalline cemented soil particles are precipitated in the pores. Microbe-induced deposition of CaCO 3 The crystals have the functions of cementation and filling, and the soil can be effectively reinforced. At present, microbial grouting is mainly used to solid...

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Problems solved by technology

[0019] Technical problems: The existing microbial grouting soil stabilization technology has a long grouting cycle, low efficiency, and low material utilization rate; the soil near the grouting port has poor permeability and is easy to block, which makes it difficult to reinforce the remote end and form a high-strength uniform Reinforcement body, the effective reinforcement range of single hole grouting is small

The purpose of the present invention is to use the gas-liquid circulation grouting soil consolidation technology of alternately injecting microbial liquid, compressed air and cementing liquid, and reduce the saturation of the soil to be consolidated by injecting compressed air, so as to achieve low CaCO 3 High strength is formed under the condition of crystallization amount, material consumption is saved, at the same time, the problem of reinforcement at the far end of the grouting port is solved, and the effective reinforcement range of single-hole grouting is expanded

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