| The short pile foundation was widely used in the high-rise buildings in the Nanning basin,which was related to the unique stratigraphic structure of the basin.At present,there were hundreds of such projects built and the scale of these buildings was nearly 100 billion.However,how about the earthquake response of such buildings under earthquake load and whether the overall earthquake resistance was favorable,all these engineering problems remain unresolved.Few people have studied them which are mainly related to the complexity of the seismic response and the difficulty of the analysis.In this paper,a nonlinear seismic response analysis method based on short pile foundation,soil and high rise structure interaction system was proposed and the parallel computing technology of ABAQUS software as a platform.The most representative residential building project located in the Nanning basin has been taken as the engineering background and the analysis method was successfully applied.The method provides a definite theoretical guidance for the design and engineering analysis of short pile foundation.The results of the study have important reference value for the aseismic research of similar projects and provide a solution for major engineering problems.The main work and innovation of this article were as follows:(1)The stratigraphic and geological conditions of the Nanning basin have been systematically investigated.6 typical stratigraphic combination models were summarized,and the physical and mechanical parameters of clay,silt,round gravel and mudstone in different areas of Nanning basin were studied in detail,which provide basic data for subsequent seismic response analysis.(2)Based on the method of numerical analysis,a nonlinear seismic response analysis method,which can consider the interaction of soil,short pile foundation and high rise structure system,was proposed.This method can effectively realize the overall seismic response analysis of short pile foundation building system.(3)A synthetic seismogram suitable for the formation conditions of the Nanning basin was fitted according to different transcendental probabilities based on the compiled MATLAB program.(4)A practical method for screening natural seismic waves was proposed,and according to the different probability of exceedance,suitable for Nanning basin two element stratum mode has been selected,and the seismic waves were corrected by the seismic wave correction program compiled with Matlab software.The results show that the corrected seismic waves effectively eliminate the drift of the velocity and displacement time history curves.(5)The contact unit of ABAQUS software has been developed for two times by using FORTRAN language.Combined with the specific examples,the validity of the developed contact unit was verified.(6)According to the geological conditions of the Nanning basin,the most representative practical project has been selected,and the three-dimensional finite element analysis model of the short pile foundation,soil and high rise shear wall structure system has been constructed.The nonlinear seismic response analysis of the system was completed under the rare condition of the rare horizontal earthquake.The main direction of the main earthquake was the most unfavorable earthquake direction.The nonlinear factors consider the nonlinear soil material nonlinearity and the pile-soil contact nonlinearity.The analysis results show that the two element formation of the Nanning basin was unfavorable to the earthquake resistance of the high-rise building structure,and the overall seismic performance of the short pile foundation soil high rise shear wall structure system was good.(7)Under the condition of rare horizontal earthquake,considering the material nonlinearity and the pile-soil contact nonlinearity,the influence of the parameter variation of the soil at the pile end and the side of the basement to the structural seismic response were analyzed.The results show that the elastic modulus E of the pile end soil has the most significant influence on the seismic acceleration response of the structure.However,the elastic modulus of the lateral soil on the side of the basement has a significant effect on the seismic acceleration response,displacement response and internal force response of the structure.(8)The influence of short pile,raft,basement and high rise structure system on the nonlinear seismic response of surrounding soil was studied under a rare horizontal earthquake.The results show that,compared with the free field seismic response,the existence of the short pile foundation-the basement-superstructure system made the peak acceleration and the relative displacement peak of the surface nodes in the surrounding soil decrease significantly.(9)Under the rare earthquake condition,combined with the engineering project analyzed in this paper,the seismic performance of high rise shear wall structure and short pile foundation were analyzed from many aspects.The results show that the seismic performance of short pile foundation-high rise shear wall structure system was good. |
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