Study On The Influence Of The Characteristics Of The Sedimentary Soil In The Deep Site On The Seismic Response Characteristics Of The Site

A large number of theoretical analysis and earthquake damage investigation show that deep depression deposits have a very important influence on the seismic response of the site.For large central cities with rapid urbanization,it is particularly important to carry out theoretical analysis of site effects,numerical method analysis,simplified model establishment based on actual engineering sites,and in-depth analysis of seismic effects of large-scale sites.The results can provide basic data for sag deposits and similar sites in Suzhou research area.The main research contents and results are as follows :1.Firstly,the simplified model of the concave soil layer is taken as the research object,and the seismic response model and numerical calculation method suitable for the site are given.The theoretical and numerical calculation results are verified and analyzed to verify the correctness of the site effect analysis by this method.At the same time,the influence of the distribution characteristics of layered sedimentary soil on the seismic response of deep site is studied.2.Taking the depression deposits with practical engineering background as the research object,the law and mechanism of the influence of the distribution characteristics of the depression sedimentary soil on the seismic response of the deep site are revealed.3.Based on the rich and detailed geotechnical engineering drilling data in the Suzhou study area,a 10-20 km large-scale refined two-dimensional nonlinear model(depression sedimentary profile in the study area along Metro Line 3)is proposed.It is proposed to use the representative ground motion station records of near-field moderate-strong earthquakes and far-field large earthquakes with different frequency and amplitude characteristics at home and abroad.The soil dynamic constitutive model which can reasonably reflect the influence of the depth of the sedimentary environment domain of the soil in the Suzhou study area and the soil dynamic characteristic parameters of the standard section of the study area are given and integrated into the ABAQUS software to reveal the seismic response characteristics of the actual depression-like sedimentary site(taking Suzhou urban area as an example),and the recommended values of the ground motion parameters of the surface design in Suzhou urban area under different ground motion levels are given.