瑞利面波椭圆极化在盾构隧道地层扰动探测中的应用

Application of Rayleigh Wave Elliptic Polarization in Shield Tunnel Stratum Disturbance Exploration

为解决传统物探方法在城市盾构隧道工程中难以对地层扰动达到较好探测和监测目的,提出了主动源瑞利面波椭圆极化方法.采用二维有限元数值模拟对实际盾构隧道施工背景下的地层情况进行全波场正演模拟,并对其波场传播、速度频散和椭圆极化频散等特征进行分析;结合工程实例,进一步将椭圆极化方法和传统速度频散方法进行对比研究.研究结果表明:主动源瑞利面波椭圆极化方法在探测地下介质结构分布及监测地下空洞等异常结构的变化方面具有和传统速度频散方法同样的探测效果,但由于其不需要长大检波器排列,对周围环境震动等噪声抗干扰能力相对较强,因此更适合城市等场地受限和具有一定震动和噪声干扰的环境,从而具有更广阔的应用前景.

In order to solve the problem that traditional geophysical methods are difficult to achieve better detection and monitoring of stratum disturbance in urban shield tunnel engineering,the application of active source Rayleigh surface wave elliptical polarization method is proposed.Firstly,the 2D finite element numerical simulation is used to simulate the full-wave field forward modeling of the stratum under the actual shield tunnel construction background,and the characteristics of wave field propagation,velocity dispersion and elliptical polarization dispersion are analyzed.Then,the elliptical polarization method and the traditional velocity dispersion method are further analyzed and compared on the basis of a combination of examples.The results indicate that the active source Rayleigh surface wave elliptic polarization method has the same detection effect as the traditional velocity dispersion method in detecting the distribution of underground medium structure and monitoring the changes of underground cavity and other abnormal structures.However,because it does not need the arrangement of long and long geophones,it has relatively strong anti-interference ability to the vibration and other noise of the surrounding environment.Therefore,it is more suitable for the environment with limited sites such as cities and certain vibration and noise interference,so it has a broader application prospect.