Study on formation mechanism of ground fissures induced by underground engineering construction in Chongqing area

Abstract

Abstract The geological structure of Chongqing area is complex, many small and mediumsized faults are developed in the axis of anticline fold, and there are many structural fissures in rock strata, and karst landform is developed in some areas. With the development of economy, the construction of underground engineering is increasing, which leads to the rapid decline of groundwater and construction vibration, resulting in a large number of uneven ground settlement, and the formation of ground fissures. This paper introduces the various forms of ground fissures, analyzes the formation process of uneven ground settlement area in the process of underground engineering construction, establishes the stress model of soil surface cracks based on the fracture mechanics theory of cohesive soil cracks, uses the fracture judgment of I-II composite cracks to determine whether the cracks expand or not, and uses the formula of soil cracking angle to calculate its propagation direction, and preliminarily explains the fracture mechanism of soil in the ground fissure area. It provides reference for the further study of corresponding disaster mechanism.