基于钻孔多属性测试的地下岩体质量评价  

Quality Evaluation of the Underground Rock Mass Quality Based on Borehole Multi-attribute Test

作　　者：李炜 张占荣[1] 黄国良[1] 刘华吉 高阳 李慈航 Li Wei;Zhang Zhanrong;Huang Guoliang;Liu Huaji;Gao Yang;Li Cihang(China Railway Siyuan Survey and Design Group Co.Ltd,Wuhan Hubei 430063,China)

机构地区：[1]中铁第四勘察设计院集团有限公司,湖北武汉430063

出　　处：《工程地球物理学报》2023年第1期63-71,共9页Chinese Journal of Engineering Geophysics

基　　金：湖北省重点研发计划项目(编号:2021BAA050);国家重点研发计划项目(编号:2019YFC0605101)。

摘　　要：针对在复杂环境下利用钻探取芯的传统勘察方法探测地下岩土体结构特征信息存在精度低、地层结构识别准确度不高、数字化程度低等问题,依托某地铁站工程开展了钻孔多属性测试分析,得到了勘察区的孔壁影像、钻孔岩体波速及岩芯室内物理力学性质等数据,定量化分析了钻孔揭示的地下岩体结构面产状和宽度特征,评价了勘察区的地下岩体质量。结果表明:勘察区的地下岩体结构面产状近水平,存在两组主要走向,即NE(40°~60°)走向、NWW走向(280°~300°),其中前者与该区域的构造线方向基本一致,以构造节理、层面为主;地下岩体整体上呈砂质泥岩和砂岩互层,局部存在结构面发育带,根据孔壁岩体质量(Wall Rock Quality Designation,WRQD)指标,岩体质量较好及以上的比例为83.1%;勘察区岩体较完整,岩体质量较好,岩体基本质量分级为Ⅲ~Ⅳ。基于“点—线—面—体”相结合的钻孔多属性测试,为勘察区地下岩体工程地质信息综合评价提供了一种多手段综合勘探方法。To tackle the problems of low precision,low accuracy in stratum structure identification and low degree of digitization in the detection of underground rock and soil structure feature information by traditional drilling methods in complex environments,based on the idea of“point-line-surface-body”,the multi-attribute test of the borehole is carried out.Based on the multi-attribute drilling test analysis in a subway station project,and on the data of the borehole wall image,the wave velocity of the borehole rock mass,the physical and mechanical properties of the core chamber obtained in the survey area,this study analyzes quantitatively the occurrence and width characteristics of the underground rock mass structural plane revealed by drilling,and evaluates the quality of the underground rock mass in the survey area.The results show that the occurrence of the underground rock mass structure plane in the survey area is nearly horizontal,and there are two main trends,namely NE(40°~60°)and NWW(280°~300°),the former is basically consistent with the direction of the structural line in this area,mainly consisting of structural joints and planes.The underground rock mass is generally interbedded with sandy mudstone and sandstone,and there are structural plane development zones locally,according to the index of borehole wall rock mass quality(WRQD),the proportion of rock mass with good quality or above is 93.1%.The rock mass in the survey area is relatively complete,and the quality is good,the basic quality of the rock mass is classified as III~IV,which provides a multi-means exploration method for the comprehensive evaluation of underground rock mass engineering geological information in the exploration area.

关 键 词：地下岩体 钻孔摄影 波速测试 结构面 岩体质量 

分 类 号：TU45[建筑科学—岩土工程] P642[建筑科学—土工工程]