CAUSATIVE RELATIONSHIP BETWEEN BASEMENT STRETCHING AND GROUND FISSURES FORMATION IN WEIHE BASIN

The Weihe Basin can be the most developed area of ground fissures and the associated geo-hazard in China and even in the world. Taking the Weihe Basin as the prototype, a numerical analysis with finite element method is made to study the stress and strain response characteristics of superficial ground and multistage fracture system subjected to the action of basement stretching. The germination relationship between deep structure activities and ground fissures development is revealed. Results show that the basement stretching can cause the tensile deformation of superficial ground. When this kind of action is coupled with normal dip-slipping tension of faults, it can inevitably form or aggravate the tension-shear fracturing, and establish the tectonic foundation for the development of ground fissures.