大同地裂缝灾害形成机理

近年来，大同市在区域构造应力作用下，已产生9条地裂缝，总长30.8km，其展布为NE-SW或NEE-SWW方向。通过对地裂缝分布及其特征的研究，发现大同地裂缝的产生，主要是由于新生代以来，大同盆地受来自青藏高原和太平洋方向的侧向挤压，而导致右旋剪切拉张以及地幔上隆，使区内地壳减薄，基底地壳断裂发展到上地幔。于是，伴随着断陷作用而发生地震和地裂缝，而且地裂缝仍在扩展中。

The Formation Mechanism of Ground Fissure in Datong City

Recently,9 ground fissures have occurred in Datong City with 30.8*!km length altogether.The ground fissures spread out in the direction of NE-SW or NEE-SWW.According to the study of ground fissures distributions and characters,the authors found the reason that why the ground fissures show up.Because of the press come from the Plate of Tibet and Pacific,there are lots of the right-rotating faults and Earth Mantle Hunching in Datong Basin.Those made the crust of Datong Basin thin and the rock fault extended to the upper Mantle,so the earthquake and ground fissures occurred along with the fault depression in Datong Basin.