【摘要】 砂土、地下水位和强烈地震动是场地液化的三个基本条件。本文基于场地液化的基本原理,在对比分析唐山大地震、汶川大地震、日本部分地震中场地液化分布特征的基础上,研究了地震烈度、地震震级、震中距等主要影响因素与场地液化的关系,并探讨了地形地貌对场地液化的影响。结果表明:我国场地地震液化主要分布在地震烈度Ⅶ度及其以上地区,引发场地液化的地震震级一般在7级及其以上,严重地震灾害的场地液化点距震中的距离可达数百千米;地形地貌可以作为场地液化的判据之一,严重场地液化主要发生在沿河、沿海地域,凸显出地下水位线是发生场地液化的重要条件。另外,提出了场地地震"再液化"的概念,并且阐释了其产生的原因及其危害,指出若遇强地震动,"再液化"的可能性比较高,工程中需要引起重视。本研究可为实施有效的抗液化工程对策与减轻液化危害提供理论依据。更多还原

【Abstract】 Sand,groundwater level and severe earthquake are three basic conditions for site liquefaction.Based on the basic theory of site liquefaction,this paper comparatively analyzes the distribution characteristics of site liquefaction in Tangshan earthquake,Wenchuan earthquake and some earthquakes in Japan,and analyzes the relationship between site liquefaction and earthquake magnitude,seismic intensity,epicentral distance and other factors.The analytical results show that,in China,site liquefaction mainly takes place in the area where the seismic intensity is Ⅶ or higher,earthquake magnitude is equal to or greater than 7.0,and the distance between the site liquefaction points and the epicenter of severe earthquake is within several hundred kilometers;topography can be used as one of the judging criteria of site liquefaction,and the severe liquefaction occurs mainly along rivers or in coastal areas,highlighting the water table is an important condition for the occurrence of site liquefaction.The paper also puts forward the concept of reliquefaction and introduces its cause and harm,and points out that the possibility of reliquefaction is quite high in the severe earthquake area.The study provides a theoretical basis for implementing anti-liquefaction engineering measures and mitigating liquefaction hazards.更多还原