Study On The Deformation Behavior And Seismic Response Of Sand Foundation With Weak Interlayer

With the development of economy and the advancement of science and technology,there are many increasingly complex forms of building structures.When an earthquake occurs,complex site conditions will aggravate the occurrence of various building damages.Soft interlayers are a common type.Complex site types,when some large buildings are located in such sites,because the weak interlayer has poor physical and mechanical properties,it is prone to deformation,which will seriously affect the stress and deformation performance of the structure above the foundation.Because the weak interlayer in the rock and soil body is often small and low in strength,it often has adverse effects on the actual project.Therefore,this paper takes this as the starting point,firstly sorts out the data obtained from the monitoring of the actual project,according to the geology.The exploration results establish a layered sand foundation model,and the deformation and stress analysis of the layered sand foundation with weak interlayer under static action are carried out according to the loaded load data.Through calculation and analysis,it is found that under the action of static force,the additional stress of the layered sand foundation is not evenly distributed,and the stress state of the base is complicated and the eccentric load is present,but with the increase of the foundation depth The additional stress is continuously transmitted in the vertical and horizontal directions,and the maximum load point of the base has a tendency to gradually move toward the center point of the base,thereby causing the maximum deformation point of the soil layer at different depths to continuously move.Calculate the results by comparing the deformation and stress of the foundation with weak interlayer.It is concluded that the contribution of the weak interlayer to the deformation of the sand foundation is more prominent under static action.Based on the static analysis,the seismic response analysis of the layered sand foundation with weak interlayer is carried out.The principle of time history analysis is used to input the seismic wave at the bottom of the model bedrock,and the reasonable soil is set.Influencing the parameters,using the mature finite element software to carry out finite element analysis.The calculated results are analyzed.It is concluded that the weak interlayer has a significant influence on the acceleration time history of the layered foundation under various seismic waves.Due to the different directions of the input seismic waves,the influence of the weak interlayer shows a significant difference in acceleration peak.The time of appearance is characterized by hysteresis.Although the time history of each depth acceleration response under different seismic waves is different,the time history curves do not change the original seismic wave waveform.When the amplitude of the seismic wave input,the thickness of the weak interlayer and the buried depth of the weak interlayer are changed under various working conditions,the calculation results show that the change of the acceleration shows the same increasing trend with the change of the buried depth of the soil layer.The maximum value appears on the surface of the layered sand foundation.