摘要
隧道开挖过程中经常遇到断层、节理发育密集带等地质异常段落,并且断层带易形成地下水的运移通道。提前查清此类地质问题,可以最大程度降低施工过程中的安全风险。隧道超前地质预报为前期勘察工作的延续,在施工期间通过物探、钻探等手段可以有效判释隧道开挖前方一定距离的地质情况。首次将TSP法与瞬变电磁成果三维化相结合,应用于某在建铁路隧道的超前预报工作中。根据前期勘察资料,结合TSP探测成果确定断层发育段落,然后在掌子面附近实施多角度瞬变电磁探测;基于Voxler软件实现瞬变电磁成果的三维化展示,通过三维成果判断断层的含水性,综合分析瞬变电磁低阻异常三维分布特征及TSP波速异常段落,圈定出断层破碎范围及富水性空间分布情况,并对富水区域提前进行钻探泄水。通过实际开挖验证分析,结果表明:2种方法相结合可以准确探测隧道开挖前方的围岩完整性及含水情况,有效降低施工风险,为隧道开挖方案优化提供有效资料。
In the process of tunnel excavation,geological abnormal sections such as fault zones and densely developed joint zones are often encountered,and the fault zones are prone to forming migration channels for groundwater.Identifying such geological issues in advance can minimize the safety risks during construction.The advance geological forecast for tunnels is a continuation of the preliminary investigation.During construction,geological conditions ahead of tunnel excavations can be effectively interpreted by geophysical prospecting,drilling and other means.For the first time,we combined the TSP method with the 3D transient electromagnetic results and applied it to the advance forecast for a railway tunnel under construction.The fault development sections were determined according to the preliminary investigation data and TSP detection results,and then the multi-angle transient electromagnetic detection was carried out near the tunnel face;the 3D display of the transient electromagnetic results was realized based on Voxler software,the water content of faults was judged based on the 3D results,the 3D distribution characteristics of transient electromagnetic low resistance anomalies and TSP wave velocity anomaly sections were comprehensively analyzed,the fault fracture range and the spatial distribution of water abundance were delineated,and drilling and drainage activities were carried out in advance for water-rich areas.The results of verification and analysis of actual excavation show that the combination of the two methods enables the accurate detection of the integrity and water content of surrounding rocks ahead of tunnel excavations,effectively reduces construction risks,and provides effective data for optimizing tunnel excavation schemes.
作者
张硕
甄大勇
刘康
易轲
ZHANG Shuo;ZHEN Dayong;LIU Kang;YI Ke(China Railway Eryuan Engineering Group Co.,Ltd.,Chengdu Sichuan 610031,China)
出处
《中国铁路》
北大核心
2024年第5期75-81,共7页
China Railway
关键词
TSP
瞬变电磁成果三维化
铁路隧道
波速异常
电阻率
超前地质预报
TSP
3D transient electromagnetic results
railway tunnel
wave velocity anomaly
resistivity
advanced geological prediction
