在分析总结西安地裂缝基本特征的基础上,采用二维有限单元法,对西安地裂缝进行了数值模拟,并从土动力学角度探讨了地裂缝的形成机制.结果表明,西安市区超采地下承压水导致地面不均匀沉降是西安地裂缝产生和发展的主要原因.故认为只有通过对地下承压水的合理开采,控制西安市区地面的不均匀沉降,才是减缓西安地裂缝活动的根本对策.“,”In this paper, based on the analysis of basic features of ground fissures in Xi'an, the numerical simulation of ground fissures in Xi'an is made by using two dimensional finite element method. The mechanism of the ground fissure is discussed in terms of soil mechanics. The results show that the inhomogeneous ground subsidence induced by over-extraction of confined groundwater is the primary cause of ground fissures in the Xi'an city. So, extraction of the confined groundwater in a reasonable way to contr0l the inhomogeneous ground subsidence is a fundamental way for reduction of the activity of ground fissures in Xi'an.