临汾盆地地裂缝基本特征研究

临汾盆地属于成长型盆地,是地裂缝发育较多的地区。本文通过详细的野外调查,查清了地裂缝的分布概况,总结了地裂缝的平面展布特征,通过探槽揭示了地裂缝的剖面结构特征,并概括了地裂缝的灾害特征。临汾盆地86条地裂缝主要分布在新构造活动强烈的临汾凹陷、侯马凹陷以及襄汾凸起等新构造单元区,与下伏断裂具有一致性和相关性。地裂缝发育的基本特征有平面展布特征、剖面结构特征、运动特征和活动特征。地裂缝平面展布特征多样,具有定向性、多样性、成带性和分段发育特征; 剖面结构有阶梯型、Y字型和梳状型; 运动特征是横向水平拉张、竖直位错; 活动特征具有活动间断、受降雨控制、活动差异和持续扩展。地裂缝引起的地面变形特征可分为剪切型和拉张型。地裂缝对房屋建筑的破坏类型有墙体开裂、屋顶开裂、楼梯断裂和门窗变形。

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.