微动HVSR法在岩溶区探测地下河管道和溶洞的有效性研究

微动HVSR(Horizontal-to-Vertical Spectral Ratio)法是一种简单有效的被动源地震勘探方法,当测点下方介质存在明显的速度变化时,HVSR曲线会呈现相应的异常形态。为探索该方法在岩溶区探测地下河管道和溶洞的有效性,选择桂林毛村地下河流域内的大岩前村作为研究区,并在此开展野外试验。研究区发育有一条地下河管道,通过精准的洞穴测量,获得了此地下河管道的平面位置和洞高等信息。在研究区的地下河管道上方地面布设3条物探测线,均进行微动HVSR法测量,并用探地雷达法测量作对比。结果表明,两种物探方法的异常位置与测线下方地下河管道的实际平面位置基本一致,证明微动HVSR法可作为一种有效的地下河管道和溶洞探测方法。

Study on the effectiveness of the microtremor HVSR method in detecting underground river pipelines and caves in karst areas

The Microtremor HVSR (Horizontal-to-Vertical Spectral Ratio) method is a simple and effective tool in passive-source seismic exploration. When a significant change of velocity of the medium below the measuring site is present, the HVSR curve can exhibit corresponding abnormal shapes. The purpose of this work is explore the effectiveness of this method in detecting underground river pipelines and caves in karst areas. At the Dayanqian village in the Maocun underground river basin,field experiments were carried out,where exists an underground river pipeline exists.The plane position and cave height of this pipeline were determined by precise cave measurement.Three geophysical survey lines were arranged on the ground over the underground river pipeline in the study area, all of which were measured by the microtremor HVSR method and compared by the ground-penetrating radar measurement. The result shows that the anomaly position by the two geophysical methods are basically consistent with the actual plane position of underground river pipeline below the survey lines, which proves that the microtremor HVSR method can be used as an effective tool in the detection of underground river pipelines and karst caves.