花岗岩地区地铁风井深基坑工程地质条件研究  

Study on the Geological Conditions of Deep Excavation Engineering for Metro Wind Shafts in Granite Areas

作　　者：岳建刚 YUE Jiangang(China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan 430063,China)

机构地区：[1]中铁第四勘察设计院集团有限公司,武汉430063

出　　处：《铁道勘察》2024年第2期50-57,共8页Railway Investigation and Surveying

基　　金：中国铁路总公司科技研究开发计划课题(2017G008-J);山东省交通厅科技计划项目(2022-B089)。

摘　　要：为研究区域断层构造影响带内的深基坑工程地质条件,以“面→线→点”的总体思路,采用地质调查、地面物探、孔内物探、机动钻探、岩土测试等“五位一体”的综合勘察手段,查明基坑范围内的断层产状及宽度、地层分布规律、岩土体力学性质等,归纳适用于复杂地质条件的深基坑工程的勘察方法。首先,开展地质调查,从“面”上查明基坑工程位于F2区域断层影响带内,发育3组交错节理,断层构造加剧了节理裂隙的发育程度,导致基坑范围内岩体破碎、差异风化严重;然后根据瞬变电磁法,从“线”上获得断层及影响带宽55~65 m,初步建立基坑结构与断层构造的空间关系;最后根据机动钻探及孔内电阻率测试,从“点”上揭示基坑纵向岩土体“软硬相间”的分布特征,地层受构造挤压严重,断层影响深度达60 m,岩体风化程度高、强度低,以散体状为主,间夹碎块状,空间上无规律性,表现为典型的断层构造带特征。研究表明,通过利用不同勘探手段的优势,相互验证、综合分析,可查明复杂地质条件下深基坑工程的地质条件和岩土力学特征,为设计方案提供可靠的地质依据。In order to study the engineering geological conditions of deep foundation pit in the zone affected by regional fault structure,with the general idea of“surface→line→point”,the comprehensive investigation means of“five in one”,including geological survey,ground geophysical exploration,in-hole geophysical exploration,motorized drilling and geotechnical testing,were adopted to find out the fault occurrence and width,formation distribution law and geotechnical physical properties within the scope of foundation pit.The investigation methods of deep foundation pit engineering suitable for complex geological conditions were summarized,which could provide reference for other similar projects.It was found from the geological survey that the foundation pit engineering was located in the fault affected zone of F2 region,and three groups of staggered joints were developed.The fault structure aggravated the development degree of joint cracks,resulting in severe rock fragmentation and differential weathering within the scope of the foundation pit.According to the transient electromagnetic method,the fault and the influence bandwidth of 55~65 m were obtained from the“line”,and the spatial relationship between the foundation pit structure and the fault structure were initially established.According to the maneuverable drilling and the resistivity test in the hole,the distribution characteristics of“soft and hard”of the longitudinal rock mass in the foundation pit were revealed from the"point".The strata were severely affected by tectonic compression,the depth of fault was up to 60m,the weathering degree of rock mass was high,the strength was low,and the rock mass was mainly scattered,intermixed with fragments,and the space was irregular,showing the typical fault structural zone characteristics.By using the advantages of different exploration means,mutual verification and comprehensive analysis,the geological conditions and geo-mechanical characteristics of deep foundation pit engineering under complex geolog

关 键 词：地铁 深基坑 综合勘察 断层构造带 差异风化 瞬变电磁 电阻率测井 

分 类 号：U231[交通运输工程—道路与铁道工程] TU93[建筑科学—结构工程]