黄河泛滥平原第四系地面塌陷机理研究--以菏泽市牡丹区为例

Analysis on the Mechanism of Quaternary Ground Collapse Induced by Ancient Human Activity Relics in the Yellow River Flood Plain--Taking Mudan District in Heze City as an Example

本文以菏泽市牡丹区地质灾害风险普查为依托,从牡丹区已发生的24处第四系地面塌陷中选取9处塌陷点进行分析,并优选了1处塌陷通过高密度电阻率法、地质雷达、钻探、原位测试、分析化验等方法对其形成机理进行了研究。通过综合物探查出视电阻率低阻异常区,在异常区经钻探验证,并取样分析,在原塌陷坑处的物理力学性质明显比周围差。经研究分析可知:第四系地面塌陷的主要原因是由于原地下存在着建(构)筑物,当发育于全新世的黄河古河道改道时,掩埋了原建(构)筑物,形成了空洞,当受到地下水位波动频繁等外力作用时,打破了古建(构)筑物的应力平衡,当持力层遭到破坏后,便发生了第四系地面塌陷。

Based on geological hazard risk survey in Mudan district in Heze city,selecting 9 collapse points from 24 ground collapses in Quaternary and one collapse point,by using high-density resistivity method,geological radar,drilling,in-situ testing,analysis and laboratory testing,the formation mechanism of the collapse have been studied.Through comprehensive exploration,a low resistance anomaly area with apparent resistivity has been identified.Through drilling verification and sampling analysis in the anomaly area,it is found that physical and mechanical properties at the original collapse pit are significantly worse than those around it.Through research and analysis,it can be concluded that main cause of ground collapse in Quaternary system is the presence of buildings underground.When the ancient Yellow River channel developed in the Holocene changed course,it buried the original buildings(structures)and formed voids.When subjected to frequent fluctuations in groundwater level and other external forces,the stress balance of the ancient buildings(structures)was broken.When the bearing layer was destroyed,the Quaternary ground collapse occurred.