一种新的长大深埋隧道围岩分级方法研究  

Research on A New classification Method of Tunnel Surrounding Rock

作　　者：马元 MA Yuan(China Railway Design Corporation,Tianjin 300308,China)

机构地区：[1]中国铁路设计集团有限公司,天津300308

出　　处：《铁道勘察》2025年第2期151-158,共8页Railway Investigation and Surveying

基　　金：中国铁路设计集团有限公司科技开发计划重点课题(2024A0226401)。

摘　　要：长大深埋隧道勘察设计精度常受地形及地表条件限制,导致围岩分级准确率不佳,进而遗漏不良地质风险,造成大量变更。因此,需要研究一种能够克服外部条件限制,又能够客观量化的围岩分级和开挖预警的方法。分析全国128座隧道的36821个电阻率及围岩分级样本相关性,并以东北某高铁隧道勘察为例,研究一种基于卡尼亚电阻率的新的围岩分级方法。通过测量相互垂直的电场和磁场,计算得到地下岩石电阻率,研究建立卡尼亚电阻率与岩体完整性相关关系;通过归一化电阻率,规避不同区域地质特性差异导致的物性参数标准不同等问题。通过对比验证,本方法获得的围岩分级、风险预警与施工图设计及实际开挖情况较为一致。研究结果表明,基于卡尼亚电阻率计算而得的岩体完整性系数Kr可以作为评价深埋隧道硬质围岩完整程度及开挖风险预警的量化指标。The investigation and design accuracy of deeply-buried long tunnels is often limited by terrain and surface conditions,resulting in substandard classification precision of surrounding rock,and then missing unfavorable geological risks and a lot of altered designs.A method of surrounding rock classification,which could overcome the external conditions,and take into account the objective quantification of surrounding rock classification and excavation pre-warning,were expected.36821 resistivity and surrounding rock classification samples from 128 tunnels were collected and analyzed,and a high-speed railway investigation in Northeast China was selected as an example to study and analyze a new grading method of surrounding rock based on Cagniard resistivity.By measuring the electric and magnetic fields that were perpendicular to each other,the resistivity of underground rock was calculated,and the correlation between Cagniard resistivity and the integrity of rock mass was established.By normalizing the resistivity,a new parameter to characterize the integrity of rock mass,Kr,was proposed to avoid the problems of different regional geological characteristics.Through comparison and verification,the surrounding rock classification and risk pre-warning obtained by the method were consistent with the construction drawing design and actual excavation of the three tunnels.The results show that the rock integrity coefficient Kr calculated based on Cagniard resistivity can be used as a quantitative index to evaluate the integrity of hard surrounding rock and the pre-warning of excavation risk.

关 键 词：高速铁路 深埋隧道 围岩分级 综合勘察 大地电磁 卡尼亚电阻率 归一化法 

分 类 号：U238[交通运输工程—道路与铁道工程] U452.1[建筑科学—桥梁与隧道工程]