Method for treating liquefiable sandy soil foundations by aid of microbial bubble

Abstract

The invention discloses a method for treating liquefiable sandy soil foundations by using microbial bubbles, mainly targeting at liquefiable sandy soil layers, using liquid injection nozzles, hollow drill pipes, connectors, catheters, compressors, bacterial liquid storage tanks, etc. The device injects pre-enriched and cultured denitrifying bacteria liquid into the soil to replace pore water, and the bacteria perform denitrification in the pores to produce inert gases nitrogen and carbon dioxide. The nitrogen produced by biological metabolism in the pores can effectively reduce the soil saturation, increase the shear strength of the soil, and improve the soil's ability to resist liquefaction. Nitrogen dioxide produced by biological metabolism can induce the precipitation of calcium ions in the bacterial fluid to form calcite. Calcite has strong cementing properties, which can effectively improve the cohesion between soil particles, increase the shear strength, and can fill the pores of the soil, increase the compactness of the soil, and further improve its ability to resist liquefaction.

Description

technical field [0001] The invention relates to a method for treating a liquefiable foundation, in particular to an operation method for reinforcing a liquefiable foundation with microbial air bubbles. Background technique [0002] my country is an earthquake-prone country. It is not only located in two world-class seismic belts, the Circum-Pacific Volcanic Seismic Belt and the Mediterranean-Himalayan Seismic Belt, but also has various seismic belts, large and small, such as the North China Plain Seismic Zone and the Fenwei Seismic Zone. , Tancheng-Yingkou seismic zone and Yinchuan-Hetao seismic zone, etc. As a main form of foundation failure during earthquakes, sand liquefaction can occur on a large scale and cause serious damage. The sand mainly relies on the friction resistance between particles to provide support in a solid state. Under the action of external forces, the sand particles gradually become discrete, the pore water pressure increases, the friction resistance ...

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Problems solved by technology

[0005] 1) The filling method has strict requirements on materials, which may not be able to obtain local materials, and the construction volume is huge and the cost is too high;

[0006] 2) The treatment depth of the dynamic compaction method is limited, and it has a huge impact on the surrounding area, and even causes damage to the surrounding buildings;

[0007] 3) In the liquefiable silty fine sand and silt, the vibrating method has a large loss of soil particles, and it is difficult to form a pile. The effect is not obvious, and the cost is relatively high;

[0008] 4) The compacted sand pile method, the gravel pile drainage method, and the mixing pile method are not only complicated in construction technology, but also have high requirements for materials, and the cost is relatively high

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