【摘要】 采用三维多尺度时域有限差分法对矿井主要面临的顶底板层状含水体、充水陷落柱、充水断层地质灾害进行了数值试验.分析了不同位置和厚度的顶底板层状含水体模型响应特征和不同厚度模型的电阻率规律,得出了响应电压对不同厚度层状含水体区分能力较强,对不同位置层状含水体区分能力较弱.对不同位置、规模、填充和测点的顶底部充水陷落柱响应特征和不同位置模型的电阻率规律进行了分析,得出了顶部陷落柱的响应特征相比底部陷落柱明显,随着距离减小,规模增大,电阻率降低,测点接近陷落柱响应电压晚期幅值增大,并且尖点响应时间推迟.分析了不同位置和测点的顶底部充水断层响应规律,得出了随着接收测点与断层垂向距离的减小,响应电压幅值增大,随着接收测点与断层横向距离的减小,响应电压幅值减小,并且尖点响应时间延迟.数值试验得出,通过响应曲线的晚期响应幅值和尖点响应时间能够对含水体位置、规模和电阻率等参数进行判断,得出地面发射-井下接收瞬变电磁法具备探测矿井不同形态含水体的能力.更多还原

【Abstract】 The modeling algorithm was developed using multi-scale grid finite difference time domain(FDTD)method in three dimensions.The main geological disasters(water filled layers,water filled collapse columns,water filled faults)in mine were studied with numerical experiments.Firstly,the response characteristics of different positions and thicknesses,and the resistivity features of different thickness of roof and floor water filled layer model were analyzed.The response voltage and resistivity were sensitive to distinguish different thickness and were invalid to distinguish different locations of water filling layer.Secondly,the response characteristics of collapse columns with different locations,scales,receiver points,and the resistivity features of different locations were analyzed.The response voltage and resistivity of roof waterfilled collapse columns were more sensitive than that of floor collapse columns.The response voltage had a larger value of amplitude in later period and had a deferred sharp point with shorter distance,larger scale,lower resistivity and nearer receiver to collapse columns.Finally,response characteristics of water filled fault with different locations and receiver positions were analyzed.The response voltage had a strong amplitude with shorter vertical distance between receiver and fault,and had a weaker amplitude with a deferred sharp point when there was shorter horizontal distance between receiver and the fault.The results show that the response amplitude in later period and the sharp point can be used to identify different water filled structure location,scale and resistivity parameters and this configuration has the capacity to detect different water filled structures in mine.更多还原