煤矿多层采空区的瞬变电磁响应特征

发布时间：2018-01-14 23:06

本文关键词：煤矿多层采空区的瞬变电磁响应特征　出处：《太原理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：煤炭是我国能源结构中的重要组成部分,随着资源需求量的增加[1],煤矿在开采深度、开采强度、开采速度、开采规模上都有所提升,为此出现了单层或双层等复杂采空区,及时探明各种采空区分布位置和存在形式具有重要意义。通过对本采空区电性规律的研究,建立了固定埋深和固定电阻率值的单层低阻、单层高阻、双层低阻、双层高阻、双层低高阻(低阻在上部,高阻在下部)、双层高低阻(高阻在上部,低阻在下部)六种一维采空区层状地电模型。通过在模型正上方布置不同大小的线框,并运用Maxwell软件进行正演计算,通过对不同线框大小下不同模型的电压衰减曲线和均匀半空间的对比得出,单层模型在固定埋深下最佳的发射线框为120m×120m,双层模型最佳发射线框为150m×150m。分析不同模型的电压衰减曲线,可以看出初始响应的归一化电压值大小分别为单层低阻体双层低高阻双层低阻双层高低阻单层高阻双层高阻,单层低阻的初始响应电压值最大,双层高阻的初始响应电压值最小。为了研究复杂采空区瞬变电磁响应的影响范围,分别建立了单层采空区和双层采空区三维模型,重点研究了单层低阻、双层低阻、双层低高阻、双层高低阻瞬变电磁响应特征,得出单层低阻模型在沿着异常体走向方向,异常体影响的范围最远距离可以达到异常体边界80m,垂直于异常体的走向方向,影响范围最远距离可到达离异常体边界60m。双层低阻和双层低高阻模型,沿着异常体走向方向,异常体影响范围的最远距离可以达到异常体边界的80m,垂直于异常体的走向方向,影响范围最远距离可到达离异常体边界80m。当模型为双层高低阻时,异常体正上方测线的电压值变化不明显,但相对于均匀半空间响应电压值较高,沿着异常体走向方向异常体影响的范围可以达到异常体边界的40m,平行于异常体的走向方向,离异常体边界的影响范围不能很好的确定。通过长治某煤矿进行瞬变电磁的探测实验,发现煤层埋深为100m单层低阻采空区在地表对瞬变电磁勘探结果的影响范围可达60m,结果显示实际情况与模拟结果吻合较好,证明了模拟的正确性。
[Abstract]:Coal is an important part of China's energy structure, with the increasing demand for [1] resources, coal mine in the mining depth, mining intensity, speed of mining, mining scale have been improved, so the single or double complex goaf, timely proved a variety of goaf distribution and existence form has important significance through the study of the mining laws. Electric goaf, establish a fixed depth and fixed resistivity of low resistivity and high resistance monolayer, monolayer, double low resistance, high resistance layer, double low (low resistance and high resistance in the upper and lower layer in high resistance), high and low resistance (high resistance in the upper part. The low resistivity in the lower goaf) six kinds of one-dimensional layered model. Through the model is arranged above depending on the size of the wire frame, and use Maxwell software for calculation, through the comparison of different wire frame model size under different voltage decay curves and uniform half space The emission line at a fixed depth optimal monolayer model under the frame of 120m * 120m, double model best emission line frame for voltage 150m * 150m. analysis model of different attenuation curve can be seen, the initial value of normalized voltage response were single low resistance body double low and high resistance double layer double low resistance high and low resistance layer double high resistance high resistance and low resistance, the initial single response maximum voltage, initial double high resistance response voltage minimum. In order to study the complex mining influence scope of goaf of transient electromagnetic response, respectively establish a single goaf and double gob area three dimensional model, focusing on the single low resistance layer low resistance, high resistance and low double, double low resistance transient electromagnetic response characteristics of the single model in the low resistance abnormal body along the direction, range from the impact of abnormal body can reach the boundary of 80m anomaly, perpendicular to the abnormal body go To the direction, the distance can reach the influence range of body boundary 60m. often divorced double low resistance and high resistance of double low model, along the direction of the distance of abnormal body, abnormal body influence range can reach abnormal boundary 80m direction perpendicular to the anomalous body, the impact range of the distance can reach the body boundary often divorced when the 80m. model for the double level of resistance, voltage abnormal body just above the line values did not change significantly, but compared to the higher value of voltage response in homogeneous half space, the range along the direction of abnormal body abnormal body effect can reach abnormal boundary 40m direction parallel to the anomalous body, can not determine the influence scope of divorce often the boundaries of good. The transient electromagnetic detection experiment through a coal mine in Changzhi, found that the buried depth of coal seam is 100m single low impedance gob ring range in the surface on the transient electromagnetic exploration results. Up to 60m, the results show that the actual situation is in good agreement with the simulation results, which proves the correctness of the simulation.

【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD325.3;P631.325

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