Device and method for treating deep seismic subsidence loess by combination of loess breakage by air injection and loess squeezing by air bag

Abstract

The invention discloses a device and method for treating deep seismic subsidence loess by combination of loess breakage by air injection and loess squeezing by an air bag. The device comprises an extensible double-layered steel sleeve, a top driver, an air distributing joint, a sand inlet, an air injection plug, the rubber air bag, a single-lobe non-return sand blasting opening and an adjustable gate valve, and is externally connected with an air compressor, a dry spraying machine and a lifting appliance. The method comprises the following steps: placing a device for breaking loess by air injection in seismic subsidence loess; synchronously injecting high-pressure air at a plurality of points to break macropore aerial structures of the loess; then expanding the air bag to squeeze the loose loess; releasing air in the air bag step by step after the loess is compact; refilling a hole by high-pressure sand filling; and repeating the steps piecewise so as to achieve the purpose of eliminating seismic subsidence of foundation loess finally. A process of loess breakage and a process of loess squeezing are finished continuously at a time, and the device and method are easy and convenient to operate and efficient. Moreover, owing to a water-free construction environment, possible secondary destruction caused by collapsibility of the loess meeting water is avoided, and the device and method are suitable for deep seismic subsidence loess foundations.

Description

technical field [0001] The invention relates to a device and method for treating deep seismic subsidence loess by combining air-jet soil breaking and air bag squeezing, and belongs to the field of foundation treatment methods and devices. Background technique [0002] In my country, most of the areas where the loess is located belong to the strong earthquake-prone areas. Under the action of moderate and strong earthquakes, loess is prone to geotechnical disasters such as earthquake subsidence and liquefaction. The so-called seismic subsidence of loess refers to the nature of loess foundation subsidence caused by the collapse of overhead structures under the action of dynamic loads such as earthquakes, and the large volume shrinkage. The metastable structure with overhead pores is the main reason for the seismic subsidence of loess. Under the action of gravity, the silt particles that make up the loess settle and contact each other, but because the force between the particl...

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Problems solved by technology

The compaction pile method has a certain effect on eliminating the seismic subsidence, but it cannot eliminate the seismic subsidence of loess under the action of moderate and strong earthquakes

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