岩溶塌陷的类型、成因机制及防治途径──兼论武汉市岩溶塌陷勘查工作要点

CLASSIFICATION AND FORMATION MECHANISM OF KARST COLLAPSE AND ITS CONTROLLING APPROACH

按岩溶塌陷的类型 ,对其成因机制作了分析。在此基础上 。

In this paper,the karst collapse is classified into two types. One is the collapse of the roof of karst cave in limestone and another is the collapse of the roof of earth cave in cover formed by the movement of karstic groundwater. Furthermore, the later is also distinguished into two kinds, one is the collapse of clayey cave and another is the collapse of sandy cave. The formation mechanism of every type of karst collapse is expounded. The karst collapse occurring in Wuhan just is the collapse of sandy caves. The paper points out that the basic approach to prevent and control the collapses is to understand the cause for their formation. At first, one should clarify the destribution of karstitied limestone, especially the area in which the limestone is covered directly by sand layer is generally potential to collapse so it may be regarded as a high dangrous area. Secondly, it is necesary to understand the movement of karstic groundwater, especially the dynamic factor causing serious vertical variation of karst groundwater table, such as water puming from a deep well. To remove the dynamic factor could prevent the collapses essentially. The effective countermeasure to treat collapse pits seggested in the paper is filling up them and sealling up their passage to karst piping.