隧道超前地质预报检波器耦合介质理论及试验研究

隧道超前地质预报是隧道施工中的重要部分,其准确性影响着隧道施工安全。为提高隧道超前地质预报的准确性,对隧道超前地质探测中检波器耦合介质开展针对性研究具有重要意义。本文通过对隧道检波器耦合结构开展理论建模,探讨了耦合介质在检波器与围岩耦合过程中发挥的作用。在此基础上,选用工业黄油、石蜡、石膏、环氧树脂以及黏质土5种耦合介质进行了现场耦合试验。最后,根据理论建模结果采用数值模拟手段对不同耦合介质的耦合过程进行了分析,并就介质厚度对耦合效果的影响进行了探讨。结果表明:材料的耦合效果与其固化强度呈正相关关系,基于理论公式的数值模拟结果很好地验证了试验结论;耦合介质厚度影响耦合效果的主要因素在于厚度过大会引起地震波损耗,厚度过小会产生较大的谐振现象。研究成果可服务于工程实际应用,进一步提高隧道超前地质预报的准确性。

Theoretical and Experimental Study on Geophone Coupling Medium in Advance Geological Prediction of Tunnel

Tunnel advance geological prediction is an important part of tunnel construction, and accuracy affects tunnel construction's safety and smooth progress. Studying the geophone coupling medium in tunnel advance geological exploration is critical for improving the accuracy of tunnel advance geological prediction. Through the theoretical modeling of the coupling structure of the tunnel geophone, this paper discusses the role of the coupling medium in the coupling process between the geophone and the surrounding rock. Accordingly, field coupling tests are carried out with five coupling media: industrial butter, paraffin, gypsum, epoxy resin, and clay. Finally, according to the theoretical modeling results, the coupling process of different coupling media is analyzed by employing numerical simulation, and the influence of medium thickness on the coupling effect is discussed. The results show a positive correlation between the coupling effect of the material and its curing strength. The numerical simulation results based on the theoretical formula verify the experimental conclusion. The main factor that the thickness of the coupling medium affects the coupling effect is that the larger thickness will cause more considerable seismic wave loss, and the smaller thickness will produce a more significant resonance phenomenon. The relevant research conclusions can serve the practical engineering application and further improve the accuracy of tunnel advanced geological prediction.