隐伏含水防空洞小极距电阻率成像特征研究

Study on Characteristics of Resistivity Imaging with Small Pole Distance in Concealed Water-bearing Air-raid Shelters

隐伏的地下防空洞给工程建设带来极大安全隐患,精确查明防空洞的空间分布对于建筑施工设计十分重要。本文针对隐伏含水防空洞采用小极距电阻率成像方法研究其成像特征,结果表明:含水防空洞电阻率成像通常呈矩形低阻异常,异常的中心与防空洞中心位置对应较好;受防空洞内水体向围岩的渗透扩散影响,防空洞边界的成像较实际范围偏大;垮塌的含水防空洞电阻率成像呈连通的低阻异常区,防空洞内水和淤泥含量的差异影响视电阻率值的变化范围。

The concealed underground air-raid shelter brings great hidden danger to engineering construction.It is of great significance to find out the space distribution of air-raid shelter precisely.In this paper, the imaging characte-ristics of concealed water-raid shelter are studied by using the small-pole distance resistivity imaging method.The results show that the resistivity imaging of water-raid shelter usually shows rectangular low resistance anomaly, and the anomaly center corresponds to the center of the air-raid shelter.Affected by the infiltration and diffusion of water inside the shelter to surrounding rock, the imaging of the shelter boundary is larger than the actual range.The resistivity imaging of the collapsed water-bearing air-raid shelter shows a connected low resistivity abnormal area.The difference of water and silt content in air-raid shelter affects the variation range of apparent resistivity values.