The Research On Formation Mechanism Of Geological Disasters In Shapotou District,Zhongwei City,Ningxia

Based on the project-"Geological Disasters Detailed Investigation in Shapotou District,Zhongwei City".In this study,after the field work and in-house work with data compilation,combined a comprehensive analysis of development characteristics and distribution law of geological disasters in Shapotou District.This study research on different types of characteristics and formation mechanism of the geological disasters analysising.The representative cases of geological disasters were selected to illustrate their developmental characteristics and signs of deformation activities,and their formation mechanism and launch conditions were analyzed,and their respective stability were evaluated by means of grey-relational analysis and the finite element method,which provided a basis for the future geological disaster prevention and plan in Shapotou District.The main research results are as follows:(1)There are three types of geological hazards in Shapotou District: debris flow,collapse,unstable slope.The geological disasters in the whole region are characterized by large numbers,concentrated distribution,sudden outburst and huge difference.(2)The type of debris flow is mainly of dilute-gully type in Shapotou District,and the scale is small and medium.The collapse is divided into rock mass collapse and soil mass collapse,the scale is small,mainly developed in Xiangshan mountain area,and also distribution in the human engineering activities such as more intense mining and road repair areas.The unstable slope is mainly dominated by rock slope,and the soil slope is second,mainly man-made slope formed by human engineering activities.(3)The formation and development of geological disasters in this district are influenced by topography,stratigraphic lithology,geological structure,surface water and groundwater,and human engineering activities.(4)The general rule of typical geological disaster formation and start-up in this district are as follows: the main source of debris flow and circulation in the mountainous area or the mountainous area and the transitional zone of the plain.The collapse and unstable slope mainly occur in the crack and bulk structure.The bad structural plane is an important factor affecting the instability of unstable slope.Physical weathering on the one hand,destroyed the integrity and stability of the rock and soil mass,provide conditions for the occurrence of collapse and unstable slope,on the other hand the weathering products into the valleys for the occurrence of debris flow provenance.Rainfall is an important motivating factor for the occurrence and launch of debris flow and collapse.