Laboratory Experimental Research Of Decreasing Saturation By Chemical Reaction Generated Gas To Improve Liquefiable Foundation

Sandy soil liquefaction triggered by the earthquake and causing some damage to the building environment is a geological disaster. In this paper, he studies a new kind of new reinforcement of liquefied foundation-Reduce the saturation method (Induced Partial Saturation,IPS is called for short) method. IPS method is to inject a certain amount of gas into the sand to reduce the saturation method, so as to improve the liquefaction resistance of the loose sand. This method can not only use for liquefied foundation reinforcement of the new buildings, but also can reinforce liquefied foundation of the existing buildings, which is a very promising liquefied foundation treatment technology.On the basis of the existing research, this paper uses the chemical method to inject gas. Through the laboratory model test in different conditions of water seepage state, studying the stability of the bubble in the sand. Selecting and designing the small shaking table model system. The test of different saturation soil by shaking table was conducted to study the reinforcement effect of sand by reduce saturation with the chemical method. The main research contents and results are the following.(1) Base on chemical method to reduce the soil saturation, analyzing the gas stability in the four different seepage flow conditions of static water, from the top to down, from the bottom to up, horizontal seepage in sandy soil, studying the content of air in soil which changes with the time, verifying the feasibility of chemical method to reduce saturation for reinforcing the liquefied foundation.(2) This article has carried on the design of the small shaking table test system. Through studying the table basic performance and the boundary effect of laminar shear model box, verifying the reasonability of the design of the small shaking table test system, preparing for shaking table model test of different saturation soil.(3) To study the different saturation soil liquefaction resistance by shaking table model test. Base on the conclusion and analysis of the vibration acceleration of shaking table, the model surface acceleration, excess pore water pressure in the sand, the settlement of foundation soil, horizontal displacement and so on, exploring the effect of chemical method reducing saturation to reinforce the liquefied foundation and demonstrating the effectiveness of the method, providing experiment guidance and basis to popularize this method.