陇南市三家地黄土地震滑坡形成机理研究

研究目的:5.12汶川大地震给人民生命财产造成了极大损失。震后10年内,将是次生地质灾害频发期。其中,滑坡是最为广泛、危害最大的灾害之一。正确认识地震诱发型滑坡形成机制,是防治设计的基础和依据。研究结论:以陇南三家地黄土地震滑坡为例,认为黄土泥岩顺层缓倾结构是此地震滑坡产生的内在因素,地处两构造交汇地带为滑坡形成提供内在动力,泥石流异常发育是滑坡形成的主要外部因素,而地震波传播方向与坡体应力场方向耦合、地震波与黄土显微结构的耦合及地震波与突发地下水异常的耦合是该滑坡形成的诱发因素。针对滑坡形成机理提出了防治建议,对认识地震诱发型滑坡形成机理,有效降低地震诱发的次生灾害,促进灾后重建工作有一定指导意义。

Research on Formation Mechanism of Sanjiadi Loess Seismic Landslide in Longnan City

Research purposes: The 5·12 Wenchuan earthquake caused a big loss to the people’s lives and property.There will be secondary geological disasters period within 10 years after the earthquake.Among the disasters,the landslide is one of the most extensive and harmful disasters.The correct understanding of the landslide formation mechanism caused by earthquake is the base and basis for control of the disaster. Research conclusions:It is concluded that for the Sanjiadi seismic landslide in Longnan city,the slowly inclined structure of the loess mudstone interbedding is the internal factors of producing the landslide,its location in the joint zone of two structure is the internal power of producing the landslide,the abnormal development of debris flow is the main external factor of producing the landslide,and the coupling of seismic wave propagation direction with slope body stress field direction,the coupling of the seismic wave with the loess micro-structure and the coupling of seismic wave with groundwater anomalies are the factors of inducing the seismic loess landside.The proposal is made for control of the landslide according to formation mechanism.It has a certain guiding significance to the understanding of the formation mechanism of earthquake,the effective reduction of the secondary disasters induced by earthquake and the promotion of the post-disaster reconstruction work.