矽卡岩型铁矿采空区电法勘探应用

Application of Electrical Prospecting in Skarn Type Iron Ore Goaf for Railway

当铁路通过某矽卡岩铁矿采空区时,受矽卡岩型铁矿产状不规则、采空区情况复杂及附近高压输变电线等外在因素的影响,选取何种勘察方法成为本项目的难点。为了解决这一问题,在对比了多种物探勘测方法后,最终采用了高密度电法结合钻探资料及理论公式的综合勘测手段。研究结果表明,通过对物探结果垂直断面和水平切面的数据解译,可得到采空区的采空边界和影响边界,从而实现对采空区采空范围和影响范围的划分;根据理论公式可计算得到线路距采空区的最小安全距离。相较于以往的大面积钻探,大大降低了勘察成本,提高了勘察设计的工作效率。

When the railway passes through the skarn iron ore goaf, it is difficult to choose the prospecting method for this project due to the influence of external factors such as irregular shape of skarn type iron ore, complex goaf conditions and high-voltage transmission lines nearby. After comparing various geophysical prospecting methods, we adopted a comprehensive survey method combining high-density electrical prospecting with drilling data and theoretical formulas for this problem. The results show that the mined-out area boundary and affecting boundary of goaf can be obtained by interpreting the data of vertical section and horizontal section of geophysical prospecting results. According to the theoretical formulas, the minimum safe distance between the line and the goaf can be calculated. Compared with the previous large-scale drilling, the high-density electrical prospecting greatly reduces the cost of survey and improves the efficiency of survey.