【摘要】 含导水构造和岩溶裂隙水的探查是亟需研究和解决的关键问题。直流电阻率法以其对低阻体反映敏感、分辨率高等优点被引入到隧道掌子面前方含水构造的预报工作中。首先,推导出了无限全空间中球体含水构造直流电法超前探测的解析解公式,并在利用有限元数值方法进行正演分析的基础上,借助"比较法"将含隧道腔体的三维空间中超前探测视电阻率数据转换为无限全空间中的数据,并探讨了由MN电极附近电阻率不均匀所造成的干扰以及识别和去除这种干扰的方法。然后,设计了基于全空间球体含水构造超前探测解析公式的阻尼最小二乘反演方法,对隧道中多组球体含水构造模型进行了较为成功的反演。另外,探讨了其他形状的有限体积的含水构造超前探测异常规律,提出了"等效球体"的概念,亦在全空间球体含水构造超前探测解析公式的基础上设计了快速反演方法。最后,利用物理模型试验验证了有限元数值正演方法和阻尼最小二乘反演技术的可行性和有效性,为实际工程中含水构造的直流电法超前预报奠定了基础。更多还原

【Abstract】 The detection of water-bearing structures and karst-fractured groundwater is the key problem needed to be resolved. Due to its high resolution and sensitivity to the low resistivity body, the DC resistivity method is introduced to predict the water-bearing structures in the front of tunnel face. First, the analytical formula of the spheriform water-bearing structures advanced detection in the whole space is deduced. Based on the analysis of large forward modeling results with finite element numerical simulation method, the apparent resistivity data in 3-D space with tunnel is translated into the data of advanced detection in the whole space with comparison method. The disturbance induced from inhomogeneous resistivity around the MN pole is discussed; and the method to identify and eliminate this disturbance is studied. Then the damped least squares inversion method is designed on the base of the analytical formula of the spheriform structures detection in the whole space. With this method, the inversion for multi-group spheriform water-bearing structures models is done. In addition, the anomaly law of the advanced detection of water-bearing structures with other shape is studied; and concept of equivalent sphere is raised. A fast inversion method is designed on the base of the analytical formula of the spheriform structures detection in the whole space. At last, the result of physical model test verifies the feasibility and effectiveness of finite element numerical method and damping least squares inversion method, which lay a foundation for the advanced detection of water-bearing structures with DC resistivity method in practical engineering.更多还原