利用微动法快速探测岩溶塌陷区覆盖层厚度

为了能在大尺度范围内获得岩溶塌陷典型调查区覆盖层的厚度,采用微动法对柳州市柳城县东泉公社幅岩溶塌陷重点调查区进行了野外观测,并对调查区内已知的56处钻孔进行微动观测,提取特征频率,结合钻孔资料得出覆盖层厚度与特征频率的函数关系满足h=62.5/f。利用此函数关系,结合岩溶塌陷调查区野外微动实测数据提取的特征频率反演出覆盖层厚度。结果表明:该方法的尝试初步见效,经济快捷、适应性强、值得推广,特别适用于大尺度范围内调查岩溶塌陷区域覆盖层厚度分布,结合研究区的地质信息,可以在区域内对岩溶塌陷易发区做一个简单的评价。

Application of microtremor exploration in quick inspection of overburden layer thickness in karst collapse area

In order to obtain the thickness of the overburden layer in large scale of the typical area of karst collapse, we used microtremor method to make field investigation in the typical area of karst collapse of Dongquan commune in Liucheng County, Liuzhou City, and made microtremor observation on the known 56 boreholes in survey area to extract the characteristic frequency. Based on the drilling data, we derive a function " h = 62. 5/f", which reveals the relationship between the overburden layer thickness and the characteristic frequency. We use this function and the characteristic frequency from the measured data to in-verse the overburden layer thickness. The results show that this method, with initial success in practice and high adaptability, proves to be efficient, economic, recommendable and highly applicable in exploration of overburdern layer thickness in large scale of karst collapse area. Combined with geological information, it can be applied to do a simple and quick evaluation for the area prone to karst collapse.