Applications Of Vertical Borehole Array Records In Site Seismic Response Analysis

Site seismic response analysis is an important component of seismic safety evaluation.Based on the bedrock seismic motion and considering the effect of local site condition, itcan calculate the surface ground motions, which can provide reasonable ground motiondesign parameters for the aseismic design and reliability analysis of engineering structure.The vertical borehole array records can be used to verify the feasibility of current soilseismic response analysis methods, and they are also helpful to improve the soil calculationmodel and methods. So this paper conduct a study on the application issues of the verticalborehole array records in site seismic response analysis. The main researches are summedas follows:1. The theoretical basis and numerical calculation methods of site seismic responseanalysis are summarized, and the widely used1-D equivalent linear method is introducedin detail.2. Two general1-D site soil seismic response analysis programs of LSSRLI-1andDEEPSOIL are introduced, and their consistency in evaluating the soil layers seismicresponse in frequency linear domain is verified by calculation examples.3. The seismic response solutions of1-D soil model based on rigid and elasticbasement boundary are derived. Combining the calculation results of the two programs, itis put forward that when the vertical borehole array records are used as the incident wavesfor soil seismic response simulation, the rigid basement boundary should be applied in thesoil model.4. By using the vertical borehole array records and borehole profile data of the Chibasite, Japan, the seismic responses of this site are simulated using the equivalent linearmethod. By the comparison of the simulated results with the real site seismic records, it isfurther verified that the rigid bottom boundary should be applied for the soil model whenthe real underground records are directly used as the input for soil seismic responsecalculation. Meanwhile, for the seismic records and borehole profile data selected in thispaper, the equivalent linear method has considerable precision in evaluating the soilseismic response.