我国岩溶塌陷分布规律的探讨

RESEARCH ON DISTRIBUTIVE REGULARITY OF KARST COLLAPSES AREA IN CHINA

我国岩溶塌陷具有以下几方面的分布规律:1.在地形地貌上,主要发生于丘陵地带或中低山的山前;2.在地层结构上,上部为一定厚度的松散覆盖层、软弱岩层或石膏盐岩,下伏开口的岩溶洞穴;3.在大地构造上,比较明显地受到新华夏系第二、第三隆起和阴山、秦岭与南岭三个巨型纬向构造体系的控制;4.在地质发展史上,主要出现在浅层岩溶作用强烈的时期。除了自身的基础条件外,现代岩溶塌陷主要由自然和人类活动双重作用所致,以人类活动的作用占主导地位。自然因素如地震、洪水或干旱造成急剧的盖层含水性变化和岩溶地下水位升降,人为因素如各种经济——工程活动造成的地表水下渗与地下水位变动、列车的反复振动疲劳作用和工程或军事爆破的冲击等。

Distrbutive regularity of karst collapses in China is as follows:1. occurred in the hilly land or foreland of middle - low mountain area in topography; 2. upper layers probably to be loose soils, soft rocks or gypsolithes in stratigraphic textures, and karst dolines under it; 3. controlled obviously by second and third upwelling areas of Neocathaysian structural system and three latitudinal megastructural systems of Yinshan,Qinling and Nanling in geotectonic frameworks; and 4. occurred mostly in the periods of strong shallow karst action in geological histories. Modern land collapses in karst area, except for some conditions of itself,are induced dominantly by double actions of antural and man - made factors, unually,man- made factors to be principal. Natural factors,such as earthquakes,floods or droughts,can cause changes of loose rocks or soil with water and rising or dropping of karst ground water table. Man - made factors make up karst collapses directly,such as engineering or economic development to cause surface water to move or change ground water table, vibration of train by moving back and forth and shock waves of explosion by civil engineering, or military affairs to be important.