吉沃希嘎隧道地热预测物探方法研究

Geophysical Prospecting Techniques for Geothermal Prediction in the Jiwoxiga Tunnel

拉日铁路建设中存在高岩温(地热)异常,最为典型的是吉沃希嘎隧道。勘察阶段发现吉沃希嘎隧道钻孔内最高温度达65.4℃。隧道施工中,进口DK117+910处掌子面孔内最高温度达50.8℃。从进口向大里程方向,随着隧道洞深的增加,温度呈上升趋势,严重影响隧道施工安全。通过隧道开挖段实测温度与多种物性参数对比分析,发现已开挖段岩体温度与电阻率之间的关系,并成功预测了未开挖段岩体温度,与开挖实测最高温度仅差0.5℃,实践证明物探方法是高岩温隧道预报的有益尝试。

The high rock temperature( geothermy) anomaly exists in the construction of Lhasa-Shigatse Railway,especially in the Jiwoxiga Tunnel. In the stages of survey,the maximum temperature of the tunnel is up to 65. 4 ℃. During construction,the maximum temperature at the entrance of DK117 + 910 inside the tunnel face is up to 50. 8 ℃. Temperature rises with the increase of tunnel excavation depth,from import to large mileage direction. This serious influences the tunnel construction safety. Through contrast and analysis of the measured temperature and a variety of physical parameters in the tunnel excavation section,the relationship between the temperature and the resistivity of rock mass is found out,and we successfully predict the rock temperature of virgin section,the difference between the highest measured temperature and the predicted temperature is only 0. 5 ℃. Practice has proved that the geophysical prospecting technique is a useful attempt in high rock temperature tunnel prediction.