双模式TBM施工海底隧道HSP法地质预报案例分析

A Case Study on HSP Geological Prediction for Subsea Tunnels Constructed by the Double Model TBM

由于TBM施工工艺特点与其独特的空间结构,限制了部分传统地质预报方法的应用。文章结合TBM的施工环境,分析了TBM施工隧道地质预报的重难点,介绍了适用于TBM施工的HSP法地质预报技术及其原理和探测方案,该技术以TBM刀盘滚刀剪切岩(土)时产生的振动信号作为激发震源,通过数字信号预处理、相关干涉与虚源提取、聚焦成像等,探测TBM掌子面前方的不良地质分布情况。以青岛地铁8号线大洋站一青岛北站区间TBM平行导洞为例,HSP法探测成果与揭露情况一致性较好,有效地指导了双模式TBM模式转换节点,为工程施工安全与高效组织提供了保障。应用结果表明,HSP法是适用于双模式TBM隧道施工地质预报的高效方法之一。

Due to the characteristics of TBM construction technology and TBM’s unique spatial structure,there are limitations concerning the application of traditional prediction methods.Taking into consideration the actual TBM construction scenarios,the authors in this paper analyze the major difficulties of carrying out geological prediction for TBM tunnelling,and introduced the principles of and solutions based on HSP method specifically designed for TBM tunnelling.This technology uses the vibration signal generated by the cutter when cutting rock(soil)as the excitation source,and detects the adverse geological conditions in front of the tunnel face by means of digital signal preprocessing,interference and virtual source extraction,and focused imaging.Taking the TBM parallel pilot tunnel between Dayang Station and Qingdao North Station of Qingdao Metro Line 8 as an example,the detection results of HSP method were consistent with the exposed conditions and have effectively guided the mode conversion of the double mode TBM,thus guaranteeing a safe and efficient construction process.It is demonstrated that the HSP method is one of the most effective geological prediction methods for double mode TBM tunnelling.