摘要
目前铁路隧道水文超前探测方法存在诸多难点,常规超前地质预报方法对富水区定位存在多解性、方向性差等问题。利用既有的隧道超前水平钻,在其中布置电阻率测线进行孔中电阻率法探测,不但可以扩大钻孔勘探范围,提高钻孔利用率,同时测线靠近异常体能大大地提高电阻率法勘探精度。首先对地质条件进行简化,建立地电模型,在钻孔中布置高密度电阻率法观测系统,并添加相应的异常体;然后对该模型进行数值模拟,得到预期效果后,进行实验室水槽实验。结果表明:孔中电阻率法能准确地定位钻孔周围异常体方位及分布范围,提高探测精度,克服电阻率法多解性、方向性差等难点,效果良好,可实现对隧道掌子面前方富水异常区等地质异常体的预测与评价,具有实际应用潜力。
At present, there are many difficulties in the advanced hydrological detection of railway tunnels. The conventional advanced geological prediction method has many difficulties in locating water-rich areas, such as multi-solution and poor directionality. If arranging resistivity measurement lines for in-hole resistivity method detection by using existing advanced tunnel drill, the exploration range of borehole can be enlarged, the utilization rate of the borehole is improved, and the exploration accuracy of resistivity method can be greatly improved as the measurement lines are close to the anomalous body. In this paper, firstly, the geological conditions are simplified to establish the geoelectric model, the observation system of high density resistivity method is arranged in the borehole and corresponding abnormal bodies are added. And then the model is numerically simulated. When the expected effect is obtained, the laboratory flume experiment is carried out. The results show that the borehole resistivity method can accurately locate the orientation and distribution range of abnormal bodies around the borehole, improve the detection accuracy, overcome the difficulties of multiple solutions and poor directivity of the resistivity method, and achieve good results, which can realize the prediction and evaluation of geological abnormal bodies such as water-rich abnormal areas in front of tunnel face, and has practical application potential.
作者
刘英
Liu Ying(China Railway Design Group Co.,Ltd.,Tianjin 300251,China)
出处
《工程地球物理学报》
2019年第5期706-712,共7页
Chinese Journal of Engineering Geophysics
关键词
直流电法
高密度电法
钻孔
三维
超前地质预报
direct current method
high density
drilling
three-dimensional
advanced geological prediction
