综合物探技术在徐州市城市轨道交通6号线岩溶勘察中的应用

城市轨道交通穿过岩溶发育地区时,不可避免地会遇到各种岩溶问题,严重威胁着施工安全。物探技术具有经济、省时、高效和高精度优势,已广泛应用于城市轨道交通岩溶勘察。该文提出一种适用于城市轨道交通岩溶精细勘察的渐进式综合物探方法体系,该体系将瞬变电磁法、地质雷达和跨孔电磁波CT技术结合,地面和井间探测相互补充,为浅层岩溶勘察提供定量和综合探测数据。该方法在徐州市城市轨道交通6号线岩溶勘察中得到有效应用。应用结果表明,瞬变电磁法和地质雷达对确定破碎带和岩溶发育范围具有良好的效果,但测线易受工程场地和环境限制,导致探测深度不足;电磁波CT技术可较好揭露地下岩溶发育规模和特征,探测结果与钻孔揭露的岩溶发育基本重合。该方法体系的成功应用,为城市轨道交通岩溶精细勘察提供新思路,对于同类型工程建设岩溶探测具有很好的参考意义和推广价值。

When urban rail transit passes through karst development areas, it will inevitably encounter various karst problems, which seriously threaten the construction safety. Geophysical prospecting technology has the advantages of economy,time saving, high efficiency and high precision. It has been widely used in karst exploration of urban rail transit. In this paper, a progressive comprehensive geophysical exploration method system suitable for fine karst exploration of urban rail transit is proposed. The system combines transient electromagnetic method, ground penetrating radar and electromagnetic wave CT, so as to provide quantitative and comprehensive detection data for shallow karst detection. This method has been effectively applied in karst detection in Line 6 of Xuzhou urban rail transit. The detection results show that transient electromagnetic method and ground penetrating radar have good effects on determining the development range of fracture zone and karst, but the survey line is easy to be limited by engineering site and environment, resulting in insufficient detection depth;Electromagnetic wave CT technology can better reveal the scale and characteristics of underground karst development, and the detection results basically coincide with the karst development exposed by boreholes. The successful application of this method system provides a new idea for the fine karst detection of urban rail transit, and has a good reference significance and popularization value for the karst detection of the same type of engineering constructions.