隧道底部不良地质体的地质雷达探测数值模拟及应用

Numerical Simulation of Geological Radar Detection for Unfavorable Geologic Bodies at the Tunnel Floor

地质雷达在探明隧道底部不良地质体情况时有着重要作用,掌握隧道底部各种不良地质体在地质雷达图像上的响应特征是有效实施探测的基础。文章通过建立隧道底部复杂地质地电模型,利用时域有限差分法(FDTD)进行了数值模拟,对隧道底部存在岩溶、断层、破碎带等不同地质情况下的地质雷达图像响应特征进行了分析,为隧道底部地质雷达探测图像的精确解释提供了依据;结合某客运专线隧道底部岩溶及破碎带探测地质雷达实例,证明了地质雷达在探测隧道底部不良地质体中应用的准确性。

Ground penetrating radar （GPR） plays an important role in detecting unfavorable geologic bodies at the bottom of tunnels. The response characteristics of various unfavorable geologic bodies reflected in radar images are the foundation of effective detection. By establishing a geoelectric model of the complex geology at a tunnel bottom, a numerical simulation was carried out by the finite difference time domain method （FDTD） and GPR images of the different geological conditions of karst, faults, and fracture zones were analyzed, providing a basis for the accurate interpretation of GPR images. The accuracy of GPR applied in detecting unfavorable geological bodies at the tunnel floor is determined using the case of a specific tunnel on a passenger-dedicated line.