Theoretical Analysis Of Seismic Response Of Underground Subway Structures And Its Application

A systematic study on the seismic analysis theory and its application ofunderground structures are presented in this dissertation. A time domainanalysis model for soil-structure dynamic interaction is proposed, which takesthe influence of static loads into consideration. Seismic responses of severalunderground subway structures in high earthquake intensity zones areanalyzed, and a static push-over analysis method for underground structures isproposed. The main achievements of this dissertation are described asfollows:(1) A unified viscous-spring boundary for static and dynamicapplications is proposed by combining the dynamic viscous-spring artificialboundary and the fundamental solution of static problems in half space. Staticand dynamic effects can be considered simultaneously with this boundary,which is a major problem of conventional dynamic models.(2) The wave input method for viscous-spring artificial boundary,calculating method of static boundary conditions on the proposed unifiedboundary and their numerical simulation techniques are studied. An assistantsubroutine VSBC on the MSC.Marc platform is presented.(3) An analysis model for soil-structure dynamic interaction problemscombining static and dynamic loads is presented based on the unifiedviscous-spring artificial boundary and the wave input method. The nonlinearproperties of structures and soil can be considered in this model.(4) Seismic responses of underground subway structures are analyzedsystematically, including the Northern Extension Line of Tehran Metro Line 1,Beijing Metro Line 5 and the Daikai subway station cracked in Hyogo-kenNanbu Earthquake (1995). Seismic performance of these structures indicatesthat the peak ground displacement relative to the bedrock is a more effectiveand reasonable indicator of the ground motion's damage effects onunderground structures, thus a better design parameter.(5) Based on the finite element method for soil-structure staticinteraction problems, a simplified quasi-static method for seismic analysis ofunderground structures, and a static push-over method for seismic analysis ofunderground structures are presented. Their validity is proved throughcomparing with static-dynamic coupling analysis method based on the unifiedviscous-spring boundary.(6) A time domain wave input method for Rayleigh waves is presentedbase on the viscous-spring artificial boundary. Preliminary study on dynamicresponse of underground structures during propagation of Rayleigh waves iscarried out.