基于谱能分析法的隧道仰拱质量检测技术

The Cause of Error of Invert Steel Support Testing by Spectral Energy Analysis

钢支撑数量、间距的判断一直是隧道仰拱检测中的难题,目前兴起的谱能分析法是一种对探测目标介质的频响强度分析的方法,能对深部反射回波的弱信号进行有效分析,加强了地质雷达的探测深度。本文基于谱能分析法对厦蓉高速某在建隧道仰拱隐蔽工程进行了质量检测,通过对理论与历史数据的分析,总结了推测结果与破检结果的差异原因。提出了在数据处理过程中通过"压抑水介质的物性特征对雷达波信号的影响、提高金属介质信号的反映"的数据后期处理技术,把雷达信号中物质"水"的低频信号进行过滤和压制,由原始信号中分离出物质"钢支撑"的信号,使原本不清晰的高频信号凸显,物探反演成果误差大大缩小,通过实例验证,本方法能够找到并消除富水情况下谱能分析法的误差,与实际开挖情况完全相符,进一步提高了谱能分析法在仰拱施工质量探测应用中的准确率和分辨率。

The judgment of the number and spacing of steel supports has always been a difficult problem in tunnel intrusion detection.The emerging spectral energy analysis method is a method for analyzing the frequency response intensity of the target medium,which can effectively analyze the weak signals reflected from the deep reflection and enhance the depth of detection of geological radar.Based on the spectral energy analysis method,the quality inspection of the undercut concealed project of a tunnel under construction in Xiamen-Chengdu Expressway was carried out.Through the analysis of theoretical and historical data,the reasons for the difference between the speculative result and the detection result were summarized.In the process of data processing,the data postprocessing technology was adopted to"suppress the influence of the physical property characteristics of the water medium on the radar wave signal and improve the reflection of the metal medium signal",and the low-frequency signal of the material"water"in the radar signal was filtered and suppressed.The signal of"steel support"was separated from the original signal,so that the unclear high-frequency signal was highlighted,and the error of the geophysical inversion result was greatly reduced.Through the example verification,the method can find and eliminate the spectrum energy analysis under the condition of rich water.The error of the method is completely consistent with the actual excavation,which further improves the accuracy and resolution of the spectral energy analysis method in the application of the quality detection of the invert arch.