隧道掌子面前方地质预报的进展

用物探技术在隧道施工时作掌子面前方不良地质预报，取得了好的进展，但还有大的发展空间，仍需要投入更大力量。弹性波类方法，需要解决在测量及使用横波方面有所突破。探查地下水不是弹性波法的强项，希望电法类方法有所突破。雷达探查的效果不错，但探距太小；目前已在研究的瞬变电磁法可望探查80m以远的地下水。实际上，目前还有一大问题要解决，这就是人们的认识问题：地质预报是施工地质的重要组分，应列入施工组织；地质物探要密切结合，要充分掌握勘测阶段和施工中调查得到的地质资料；每种物探方法均有使用条件、长处与弱点，物探资料有多解性，要采用综合物探，将力量多放在资料判释上；地面浅层地质勘探都遇到许多困难，不能满足人们愿望，隧道中条件远不如地面，困难更大；特别是对地质的认识也必须遵循认识的规律，在实践中不断改正和深化对地质情况的认识。

Progress of Geology Forecasting ahead of Tunnel Face by means of Geophysical Technology

Although the geology forecasting in tunnel construction has achieved great progress, it still has huge developing potential. For elastic wave reflection method, it is necessary to make breakthroughs in the measurement of rock's elastic wave speed and application of transverse waves. It is necessary to develop electric forecasting methods and electromagnetic forecasting methods, which are good to the detection of ground water. It is expected that ground water over 80m ahead of the tunnel face can be detected by means of transient electromagnetic method, which is now being studied. Geology forecasting is an important part of tunnel geological works and should be included in the tunnel construction procedure. Each geophysical forecasting method has its own application conditions, strong points and weak points and the data obtained by means of geophysical forecasting methods have several interpretation solutions, therefore comprehensive geophysical forecasting methods should be taken and more attention should be paid to the data interpretation. Geology forecasting in tunnel construction is more difficult than surface geology forecasting. The understanding on geology forecasting should be revised and improved in practice.