摘要
断层识别对于隧洞的安全施工及地质灾害的防控至关重要.基于岩石矿物学异常特征分析提出一种断层识别方法,将断层岩的矿物异常特征作为断层的识别标志.以新疆某引水隧洞为案例,通过便携式X射线衍射仪测定了隧洞沿线49+485-50+050里程范围内岩石的矿物成分和含量.钙碱性、碱性且相对富镁的华力西期花岗岩在断层应力和富含Fe和Mg的热液流体作用下发生绿泥石化和蛭石化,富镁黏土矿物蒙皂石+滑石+蛇纹石+海泡石的集合体表明F_(17)断层带内矿物转化模式为Mg流动转换.基于隧洞沿线不同里程蛭石和绿泥石异常富集及斜长石和黑云母异常减少的定量化差异,识别出F_(17)逆断层的内部结构.里程49+650-49+760位于F_(17)下盘破碎带内;里程49+760-49+850位于F_(17)断层核部;而里程49+850-50+000位于F_(17)断层上盘破碎带内.本研究提出的断层识别方法及案例分析可为隧道掘进机(TBM)穿越花岗岩隧洞时逆断层的识别提供参考和借鉴.
Fault identification is crucial to the safe construction of tunnels and the prevention and control of geological disasters.Themineral anomaly characteristics of rocks were used as identification signs of faults.In this study,we proposed a fault identification method based on the characterization analysisis of mineralogical anomalies of rocks,taking a water diversion tunnel in Xinjiang as an example.A portable X-ray diffractometer measured the mineral composition and content of the rocks with a mileage of 49+485-50+050 along the tunnel.The calc-alkaline,alkaline,and relatively Mg-rich Variscan granites were subjected to chloritization and vermiculitization by fault stress and Fe and Mg-rich hydrothermal fluids.Mg-rich clay minerals such as smectite+talc+serpentine+sepiolite assemblage indicated that the mineral transformation pattern was Mg-flux transformation in the F_(17)fault zone.We identified the internal structure of the F_(17)reverse fault based on the quantitative differences in the anomalous enrichment of vermiculite and chlorite and the anomalous decrease of plagioclase and biotite at different mileages along the tunnel.Mileage 49+650-49+760 is located in the damage zone of the footwall,mileage 49+760-49+850 is located in the fault core,and mileage 49+850-50+000 is located in the damage zone of the hanging wall.The fault identification method and case study analysis developed in this study can provide references and lessons for the identification of reverse faults when TBM excavates in granite.
作者
余腾飞
韩涛
林鹏
许振浩
YU Tengfei;HAN Tao;LIN Peng;XU Zhenhao(Institute of Geotechnical and Underground Engineering,Shandong University,Jinan 250061,China;School of Qilu Transportation,Shandong University,Jinan 250061,China)
出处
《应用基础与工程科学学报》
北大核心
2025年第2期422-435,共14页
Journal of Basic Science and Engineering
基金
国家自然科学基金优秀青年科学基金项目(52022053)
山东省自然科学基金杰出青年科学基金项目(ZR201910270116)
国家自然科学基金青年科学基金项目(52009073)。
关键词
矿物异常
断层识别
黏土矿物
隧洞
花岗岩
热液蚀变
X射线衍射
mineral anomaly
fault identification
clay mineral
tunnel
granite
hydrothermal alteration
X-ray diffraction
