THE STUDY ON BASIC CHARACTERISTIC OF EARTH FISSURE IN LINFEN BASIN

There are many earth fissures in Linfen Basin as it is a growing basin. Though detailed investigation, distribution and developmental status of the earth fissures are ascertained. Plane distribution features are summarized in this paper. Trench excavation has been conducted to understand the sectional structure features of earth fissures. The hazard of earth fissures is then summarized. A total of 86 earth fissures are mostly distributed in the Linfen depressed unit, Houma depressed unit, Xiangfen convex unit and other new tectonic units, which are accordant and correlative with the faults in underground. The basic characteristics are the plane distribution features, sectional structure features, motion features and activity features. Plane distribution characteristics are stability of trend, banding development, variety of plane distribution and differential development along trend. Sectional structure features are fault terrace shaped, Y-shaped, and pectination shaped. Motion features are lateral horizontal tension and vertical differential fracture. Activity features of earth fissures are movement interrupted and controlled by rainfall, differential activity and continue to expand. The deformation characteristic of surface is divided into shearing type and tension type. The damage forms are shown as wall cracking, roof cracking, stairs cracking and deformation of doors and windows.