针对隧洞施工过程中不同工程地质条件下何种超前地质预报方法预测更为准确、更为适用和单一方法精确度不够、适用性不强的问题,分别介绍了基于地震波法的长距离隧洞超前地质预报技术和基于电磁法的中、短距离隧洞超前地质预报技术原理及特点,依据其工作原理、工作方式、预报距离等特点,探讨了不同超前地质预报方法的优、缺点及其最适用的工作场景,总结出一套实用性强的综合超前地质预报流程。依托滇中引水工程大理Ⅱ段两个隧洞的工程实例,利用所提出的综合超前地质预报流程,分别介绍了结合长距离的隧道地震预报(TSP)法、中短距离的瞬变电磁法和探地雷达法对断层破碎带和裂隙水等不良地质体的综合预报研究。首先,通过长距离预报方法对地质灾害危险程度进行分级、识别高危地段,再通过短距离预报方法对不良地质体进行更精确的识别与定位,综合分析3种超前地质预报方法的地球物理响应特征,可以推断出不良地质体的类型及其空间分布特征;其次,通过探地雷达探测溶蚀波场特征的案例分析,可以推断出溶蚀的物性特征、规模及其空间分布特征。预报结果与隧洞掌子面开挖揭示的结果基本一致,验证了3种超前地质预报方法预报隧洞不良地质体的可靠性,也证实了所提出的综合超前地质预报流程的实用性,有助于指导物探工作者对不良地质体进行更精确的预报,确保隧洞施工安全。

During tunnel construction, determining which advanced geological prediction method is most accurate and applicable under varying engineering geological conditions could be quite challenging. Single methods often lack sufficient accuracy and applicability. To address these issues, this paper introduces the principles and characteristics of advanced geological prediction technologies for long-distance tunnels using seismic wave methods and for medium- and short-distance tunnels using electromagnetic methods. We discuss the advantages and disadvantages of different advanced geological prediction methods based on their working principles, methods, and prediction ranges, and outline their most suitable scenarios. We propose a practical, comprehensive advanced geological prediction process, demonstrated through engineering examples from the Dali II section of the Central Yunnan Water Diversion Project. This process combines long-distance TSP method, medium- and short-distance TEM, and GPR to predict adverse geological features such as fault fracture zones and fissure water. Initially, we use long-distance prediction methods to classify the risk levels of geological disasters and identify high-risk sections. Subsequently, short-distance prediction methods more accurately identify and locate adverse geological features. By analyzing the geophysical response characteristics obtained from the three prediction methods, we evaluate the types and spatial distributions of adverse geological bodies. We also present a case study using GPR to detect dissolution, analyzing its wave-field characteristics to infer the physical properties, scale, and spatial distribution of dissolution features. The prediction results align closely with findings from tunnel excavation, validating the reliability of the three advanced geological prediction methods and confirming the practicality of the proposed comprehensive prediction process. This approach provides valuable guidance for geophysical exploration, enhancing the accuracy of geological predictions and ensuring tunnel construction safety.