Water Seepage Leading To Variation Of Rock-Soil-Mass Resistivity And Dynamic Monitoring Technique

Liquid seepage in the rock and soil masses leads to some geology and environmental disasters. For example water seepage in the rock and soil masses causes water inrush in mine well and soil pollution. It is very important significance that we monitor liquid seepage to prevent and treatwater inrush in coal mine,to predict and cure liquid pollution by the direct current resistivity method. Liquid(taking water for example in the thesis) seepage in the rock and soil masses, factors of influencing resistivity and so on were researched by formula deduce, analysis and comparison, numerical simulation and physical experiment methods, and so on. The main research contents and conclusions are as follow:(1)Numerical models were built according to characteristics of water seepage in the rock and soil masses, which were simulated by the program AGI. Meanwhile experiments of water seepage in the homogenous sand and in the mine rock masses models which were designed based on some mine in the city of Huaibei and Xinyi were conducted. Simulation and physical experiment s show: the process of water seepage in the rock and soil masses can be monitored by direct current resistivity method, area of water seepage can be determined at any time.(2) Archie formula is the physical basis of monitoring water seepage in the rock and soil masses by direct current resistivity method. The parameter volume moisture content was introduced into Archie formula, The Archie formula contain moisture content. On the basis of Archie formula containing moisture content we propose two ratio methods to process datum. The one method is the ratio of apparent resistivity acquired at every moment and background resistivity. Some background noise was removed. It is easier to judge the process of water seepage. It can decide the area and boundary of water seepage at every moment. The other method is the ratio of apparent resistivity a time and the previous time. After datum processed by this method it is easier to determine area of water absorption and qualitatively water content at every moment.(3) Models of low resistivity geologic body with different volume and with different depths, geologic body with different resistivity were designed. Those models were simulated by AGI. Simulation results show: apparent resistivity is related to volume, depths of low resistivity geologic body and resistivity of geologic body. When depths and resistivity of geologic body is the same, the greater the volume of geologic body, the lower the apparent resistivity value; the smaller the volume of geologic body, the higher the apparent resistivity. When volumes and resistivity of geologic body is the same, The greater the depths of geologic body, the lower the apparent resistivity value; When volumes and depth of geologic body is the same,the lower the resistivity of geologic body, the higher the apparent resistivity value; the higher the resistivity of geologic body, the higher the apparent resistivity value. The volume, depth and resistivity value of geologic body all change in the process of water seepage, so apparent resistivity is related to process of water seepage. As follow, experiments of water seepage in rock and soil were conducted. We monitor process of water seepage during the experiment by the direct current resistivity method. Monitoring results show: apparent resistivity above point of seepage is related to seepage time. On early time, apparent resistivity quickly decrease with water seepage time, on the middle and last time, apparent resistivity gentlely decreases with water seepage time, or finally apparent resistivity is near one value. Decreasing sharply can be as seepage early sign to prevent for coal mine water inrush and to monitor soil pollution.(4) 2-dimension body and 3-dimension is defined. Models of 2-dimension and 3-dimension which contained aim geologic body simulated field and resistivity. The simulation results show: 2-dimension profile of 2-dimension body is related to 2-dimension profile of 3-dimension body. 2-dimension profile of 2-dimension informs 2-dimension profile of 3-dimension. According to relation between 2-dimension profile of 2-dimension and 3-dimension body, we propose correction ratio factor method. After 2-dimension profile of 2-dimension is corrected, its value and curve are nearly equal to 2-dimension profile of 3-dimension body. On this basis, we propose a physical experiment method that water seepage in the 2-dimension body(sands in the narrow glass box) approximate water seepage in the 3-dimension body. The process of water seepage can be observed. According to observing results we can verify results of monitoring by apparent resistivity method at real time.