地下水渗流与地电场参数响应的定量研究

QUANTITATIVE STUDY OF GEOELECTRICAL PARAMETER RESPONSE TO GROUNDWATER SEEPAGE

开展均匀介质稳态渗流模拟试验、非均匀介质稳态渗流模拟试验和采动应力影响下的非均匀介质渗流模拟试验,运用回归分析方法讨论室内试验中一次场电流(激励电流)I与试验模型进水量Qi之间的相关关系;深入矿井开展为期一个多月的地下水渗流地电场动态监测试验,在试验期间发生了矿井突水事故,及时进行了突水水量Qo的测试工作,并讨论一次场电流I与突水水量Qo之间的相关关系。均匀介质稳态渗流模拟试验和非均匀介质稳态渗流模拟试验都表明,固水二相介质中,水未达饱和时,一次场电流I与模型进水量Qi呈线性相关关系。非均匀介质采动条件下的渗流模拟试验表明,在水文条件稳定(水源充足、流速稳定)的情况下,一次场电流I仍然呈现稳态渗流特征,即I与Qi呈线性相关关系,由此认为,在该种条件下,一次场电流主要响应于渗流场的演变和渗流过程的发展,而对岩体的破断与裂隙发育过程响应相对不明显。结合室内试验结论,运用相关分析方法分析井下探测数据,发现在矿井突水过程中,一次场电流I与探测区域出水量Qo呈正相关关系,基于相关分析方法,可以利用电流I的变化趋势实现对探测区域出水量Qo的变化趋势的预测。同时一次场电流与出水量相关度较高的电极,对渗流通道的位置具有指示作用,有助于视电阻率探测成果的分析与解释。

Three kinds of experiments on water seepage were carried out,including homogeneous media physical simulation,heterogeneous media physical simulation and heterogeneous media simulation affected by mining.The regression analysis method has been used to study the relation between primary field current I and water injection Qi of the physical model.Field investigations,including geoelectrical detection and water yield measurement,have been conducted in a coal mine where a water flood disaster happened during this field work.And correlation analysis method has been used to study the relation between primary field current I and water yield Qo of the field detection area.Physical simulation experiments of steady seepage both in homogeneous and heterogeneous media have indicated that before water-saturated,there exists a linear relationship between the variables of I and Qi.Experiments of seepage in heterogeneous media affected by mining have indicated that the primary field current I presents the steady seepage characteristics,there still exists a linear relationship between I and Qi.That is to say,primary field current I mainly responds to the groundwater seepage process;while the response to rock breaking and fracturing is not that obvious.According to these conclusions,correlation analysis method has been used to analyze the field detection data;and the result shows that during the water flood period,there is a positive correlation between primary field current I and water yield of the detection area Qo.Therefore,trend of Qo can be predicted by the trend of I.Meanwhile,the electrodes with high correlations between I and Qo can help to locate the groundwater flow channels,which can support the resistivity analysis and interpretation.