CAJ | 학술논문

考虑地震荷载的随机性及强度、频率的非平稳性,基于作者提出的适用于非平稳随机过程的一般随机地震动模型,采用虚拟激励法,建立了非平稳随机地震反应分析方法,并将其应用于某实际均质土坝动力分析中.土石坝及坝基体系采用整体有限元离散,坝体和坝基材料的动力非线性性能以等效线性化方法考虑.首先,基于目标加速度时程的强度和能量信息,确定了作为输入的加速度时-频演变功率谱密度;其次,比较了确定性时程动力分析和非平稳随机分析的结果,探讨了频率非平稳随机地震激励下的土石坝地震反应特性;最后,比较了2种不同坝基条件下的土石坝非平稳随机地震反应,探讨了频率非平稳随机激励下的土石-坝基动力相互作用.分析结果表明:地震动的频率非平稳性对土石坝动力反应有一定影响;坝体-坝基动力相互作用在地震过程中的不同阶段表现有所不同,主震阶段的相互作用显著.
고필지진하재적수궤성급강도、빈솔적비평은성,기우작자제출적괄용우비평은수궤과정적일반수궤지진동모형,채용허의격려법,건립료비평은수궤지진반응분석방법,병장기응용우모실제균질토패동력분석중.토석패급패기체계채용정체유한원리산,패체화패기재료적동력비선성성능이등효선성화방법고필.수선,기우목표가속도시정적강도화능량신식,학정료작위수입적가속도시-빈연변공솔보밀도;기차,비교료학정성시정동력분석화비평은수궤분석적결과,탐토료빈솔비평은수궤지진격려하적토석패지진반응특성;최후,비교료2충불동패기조건하적토석패비평은수궤지진반응,탐토료빈솔비평은수궤격려하적토석-패기동력상호작용.분석결과표명:지진동적빈솔비평은성대토석패동력반응유일정영향;패체-패기동력상호작용재지진과정중적불동계단표현유소불동,주진계단적상호작용현저.
A method for the non-stationary stochastic seismic analysis is developed on basis of the general stochastic seismic motion model proposed by the first author to account for the randomness of the seismic loading as well as the non-stationarity of the stochastic process in the aspects of its intensity and frequency spectrum, and has been applied in a dynamic analysis of a homogeneous earth dam with the pseudo excita-tion method. The dam-foundation system is discretized by the finite element method, and its material non-linearity is considered with the method of equivalent linearization. Firstly, the input time-frequency evolu-tionary power spectrum is defined according to the intensity and energy information of target acceleration history. Secondly, the seismic performances of the earth dam during the frequency non-stationary seismic excitations are discussed through comparing the results from determinate time-history analysis and stochastic analysis. Finally, the dynamic dam-foundation interaction is discussed through comparing the seismic responses of the clam under two different conditions of the foundation. The analysis results indicate that the frequency non-stationarity of the seismic motion has some influence on the dynamic response of the dam. In different phases of the earthquake process, effects of the dynamic dam-foundation interaction are different. The interaction is rather prominent in the main shock phase.