【作者】 欧阳永永；

【导师】 熊章强；

【作者基本信息】 中南大学 ， 地球探测与信息技术， 2011， 硕士

【摘要】 随着找矿工作向寻找盲矿与深部隐伏矿方向发展,传统金属矿勘查技术已不能完全满足深部资源勘查要求。在一定条件下,地震勘探方法能凭借其探测深度大、分辨率高等特点,突破传统非地震勘探方法的瓶颈,发挥其潜力与优势。基于金属矿地震勘探的复杂性,目前金属矿地震勘探研究尚属初步探索阶段,通过对金属矿地震数值模拟研究,可以提高我们对金属矿介质中地震波传播规律的认识,指导观测系统设计,验证地震地质解释准确性等。本文在分析研究地震波基本理论的基础上,由一阶速度-应力弹性波方程和声波方程出发,采用高阶交错网格技术对时间与空间导数进行差分近似,推导并建立了方程的差分格式,通过控制差分方程稳定性条件,并在边界加载PML吸收边界条件,实现了对简单不均匀体、透镜体、倾斜体、组合体以及火山口矿体等模型的正演计算。经数值模拟得到了相应介质模型的地震波场记录、声波场记录以及自激自收地震剖面,并对其波场特征进行分析。通过数值模拟与效果分析可以看出,采用时间二阶空间十阶差分格式,控制稳定性条件,加载PML吸收边界条件,可达到较高的计算精度,能较好的模拟地震波在金属矿介质中的传播。对模拟的地震波场特征分析发现,地震波在几何特征复杂的金属矿体中,容易产生散射、绕射、波的转换等,各种波相互干涉叠加,地震波场复杂。更多还原

【Abstract】 As the development of exploring blind mine and deeply concealed mine, Traditional exploring methods of metal mine can not fully meet the requirements of deeply exploration. Under certain conditions, Because of large exploring depth and high resolution features of seismic exploration,It can breaks defects of traditional non-seismic exploration methods,and refects their potentials and advantages. Based on complexity of metal mine, seismic exploration method of metal mine currently still stay in the initial stage, through seismic numerical simulation of exploring metal mines, can enhance understangding seismic wave of moving in metal media, improve surseying system, and verify the accuracy of seismic geological interpretation.Based on the analysis of seismic wave theory, from one order velocity-stress elastic wave equation and acoustic equation, the using of high order and staggered grids in time and space derivative of the difference approximation is derived,and the difference schemes of elastic wave equation and acoustic equation are established, space of grids and time sampling rate are controlled,PML conditions of absorbing boundary is added, and completing modelling metal mine typical models included simple heterogeneous,lens,tilt body,portfolio body,crater ore body. By the forward calculation of seismic waves,We can get seismic records of elastic wave and acoustic, seismic profile of self-percussion and self-receicing, and have a analysis of wave field.According to seismic numerical simulation and analysis in effect in using two orders in time and ten orders in space staggered finite-difference technique to simulate seismic waves in the metal mine,and controlling the condition of stablity, and adding PML absorbing boundary, we can achieve a good result of accuracy and modelling seismic wave which moving in metal media. We analyze the characteristics of seismic wave field, and find that seismic wave of metal mine media can scatter, diffraction, transform and mutually superpostion, the siesmic wave field is often complex.更多还原