Experimental Study On Failure Mode Of Hollow Soil Between Piles Under Dynamic Load

The research on the stress analysis of anti-slide pile under static load is very mature,but there are few studies on the stress analysis and pile failure under dynamic load.It is of practical guiding significance to further study the stress characteristics of anti-slide piles under dynamic load and to understand the influence of the stress-strain effect of pile materials on the seismic design of foundation pit support engineering and the dynamic analysis of the depth structure.Based on the scientific research project of hunan province,"study on the failure of hollow soil between supporting piles",combined with the actual project,indoor model test and theoretical analysis were adopted to carry out the experimental study on the failure mode of hollow soil between piles under dynamic load.The research contents and results are as follows:(1)Design and complete the scale scale test model of the foundation pit anti-slide pile support chamber with the geometric ratio of 1:35,and adopt the small vibration table to simulate the failure modes of the hollow soil between piles under the action of seismic waves,sine waves and so on:This paper studies the factors influencing the failure of hollow soil between piles and explores the formation mechanism of the failure of soil between piles.(2)Simulation layered foundation pit excavation,indoor model test research to several different soil moisture content of the sand,clay foundation model in different wenchuan earthquake wave,sine wave and so on,under the action of different moisture content opening between the pile of sand,clay,difference and phenomenon,a failure mode under the condition of the same acceleration peak value,the differences of two wave force strength.(3)Through the shaking table test,the law of earth pressure change behind the pile and the law of acceleration response inside the soil are studied in the process of the hollow soil failure between the piles,so as to reveal the seismic response characteristics and law of the anti-slide pile.(4)According to the data of the model test,the acceleration response coefficient of the soil mass in the foundation pit presents nonlinear change with the elevation,and the maximum earth pressure point moves down under the action of earthquake,which provides the basis for further exploration of the anti-slide pile in the foundation pit for seismic and disaster reduction measures.