块石土层浅埋隧道综合勘察技术研究——以重庆万州北山隧道入口为例

Study of Comprehensive Geological Survey Technology on Tunnel in Rocky Soil——Taking the Entrance of Beishan Tunnel in Wanzhou,Chongqing as an Example

文章基于重庆万州北山隧道块石土层勘察过程中遇到的难题,重点阐述了解决块石土层取芯率低、抗剪和抗压强度较难确定的问题,并详细论述了解决面临难题所采取的综合勘察手段的确定、实施和成果,综合勘察手段包含区域地质资料收集、地质调查、单动双管钻探、高密度电法和钻孔波速测试,并对块石土抗剪和抗压强度进行了参数反演,与开挖揭露岩土体对比,取得了良好的效果。通过块石土层勘察技术的研究,指出了块石土层浅埋隧道综合勘察方法和手段以及注意事项。

Aiming at the problems encountered during the investigation of the rocky soil layer of the Beishan tunnel in Wanzhou,Chongqing,this article focuses on solving the problems of low core rate of the rocky soil layer and the difficulty in determining the shear and compressive strength of the rocky soil layer as well as the determination,implementation and results of the adopted comprehensive survey methods,which include regional geological data collection,geological survey,single-action dual-pipe drilling,high-density electrical method and borehole wave speed testing.The compressive strength parameters are inversely analyzed.Compared with the excavation exposed rock and soil,good results are achieved.Through the research on the exploration technology of the rocky soil layer,the comprehensive investigation methods and the announcements of the shallow-buried tunnel in the rocky soil layer are presented.