基于掌子面编录和地质雷达的综合超前预报技术

 结合一深埋长大隧道工程，提出并实践基于掌子面编录和地质雷达的综合超前预报技术。在区域工程地质资料分析的基础上，重点依托隧道内掌子面地质素描进行预报方案优化和选择预报时机；依据局部揭露的不良地质体产状、单壁始见位置，通过三角函数运算，求得该条带状不良地质体在隧道两壁上下和拱顶的边界位置及其影响长度；当接近特殊地质地段时，采用地质雷达进行更精确的短期预报，依据雷达反射波的振幅、相位及频率等变化探查断层和地下水的赋存情况。对于较大范围的不良地质体，采取连续跟踪预报的策略，通过多次预报成果的验证及反馈能够显著提高预报的可靠性。该综合超前预报方法在隧道穿越断层和涌水段施工中取得满意的效果。

SYNTHETIC ADVANCED FORECAST TECHNIQUE BASED ON GEOLOGICAL LOGGING FOR TUNNEL FACE AND GROUND PENETRATING RADAR

Synthetic advanced forecast technique based on geological logging for tunnel face and ground penetrating radar(GPR) is proposed and put into practice in the case of a certain deep and long tunnel project. On the basis of regional engineering geology data analysis，the forecast scheme and time are optimized depending on tunnel face geological logging. Meanwhile，according to the occurrence of adverse geological body which has been partially exposed and the location of single side wall which has been seen，the border and influence length of adverse geological body on the two side walls and apex of arch are calculated through trigonometric functions. When getting close to special geological sections，more accurate short-term forecasts have been obtained using GPR to detect faults and underground water storage situations based on radar-wave reflection amplitude，phase and frequency. For a wide range of adverse geological body，the reliability of forecast can be improved with the strategy of continuous forecast，which is useful for the confirmation and feedback of the forecast. This synthetic geologic forecast method is applied to the tunneling construction passing through faults and water inflow sections，and gives a satisfied effect.