关键词: 西安, 地裂缝, 蠕滑, 双向破裂

Abstract: The ground fissure in the City of Xi' an show leftlateral and are characterized by prevailing orientation, en echelon, roughly constant step-intervals and southern blocks relatively falling down. The fissures have originally been created sporadically by the regional stress field and consequently enlarged by the groundwater activity. Tha appearance of fissures seems earlier in the north and gradually migrates to the south. The slips along these fiasures are not uniform, but with quaci-peroods of 4,20,400 and 750 years respectively, which seemingly correlate with the periods of seismicity in the region. This indicates that the ground fissures and earthquakes both are under the control of the same regional stress.

Key words: Xi’an, Ground fissure, Creep slip Bidirectional rupture