在线示踪试验在隧道建设前期勘察中的应用研究以重庆城开高速公路拟建旗杆山隧道为例

由于岩溶含水介质具有高度不均一性和复杂性，给隧道建设带来很多不确定因素。本文以城开高速公路城口拟建旗杆山隧道为例，利用在线示踪技术，获取高分辨率示踪数据，结合定量解译的方法，分析隧址区岩溶地下水潜在的流向及其流场情况。本次在钻孔内注入投放示踪剂，开展示踪工作，通过试验结果查清了投放示踪剂位置地下水与水文单元内几个大型暗河的水力联系，为划分地下水分水岭和计算隧址区岩溶管道流水力梯度提供了有力依据，该成果极大地提高了隧址区水文地质调查工作的精度。通过本例，表明在线示踪技术在我国西南岩溶区的地下含水介质研究及相关的勘察中具有较大的推广和应用价值。

APPLICATION OF TRACER TEST IN THE PRELIMINARY SURVEY OF TUNNEL CONSTRUCTIONA CASE STUDY OF THE PROPOSED QIGANSHAN TUNNEL IN CHENGKOU COUNTY,CHONGQING

Because of the high degree of heterogeneity and complexity of karst aquifer media, there are many uncertainties in the tunnel construction. This paper takes the proposed Qiganshan Tunnel of Chengkai Expressway in Chengkou county as an example, using on-line tracer technique, getting high-resolution tracer data, combining with the method of quantitative interpretation to analyze the potential flow direction and flow field of karst groundwater in the tunnel area. By putting the tracer into the borehole to carry out work, the test results identify the relation between the groundwater of the testsite and outlets of several underground rivers. This result could be a useful tool to identify the karst underground water ridge and calculate the hydro-stress gradient of the tunnel area. This test greatly improves the precision of hydrogeology investigation in the tunnel area. By this example, it is indicated that the on-line tracer technique is of great value for popularization and application in the study of aquifer media and its related exploration in karst areas of Southwest China.