摘要
埋深、岩性和地质构造影响地应力空间分布特征。在复杂地质条件下,地应力并不总是随深度呈线性增加而表现出受构造影响的复杂变化。以最大埋深达2268 m的天山隧道为例,在现场调查和实测数据分析基础上,对隧道工程及两侧约460 km^(2)广大范围采用有限差分软件FLAC 3D开展三维数值模拟,对地质构造影响下地应力变化有较清楚显示。断层两侧地应力突变和褶皱影响地应力起伏变化有5~10 MPa差异,尤其是临近断层上盘地应力会有局部集中现象,如硬岩区段施工中发生了中等以上岩爆。与邻近位置的实测地应力结果相比发现,数值计算结果偏大20~30 MPa,较好地量化了地质构造发育部位对地应力数值异常变化的较大影响,而这些部位正是现场地应力实测点都极力避开的位置。这说明数值模拟结果可弥补实际测点数量的有限性,进一步同实测结果结合对比可填补大量无实测数据的空白区。研究结果可为本区类似工程提供参考。
The burial depth,lithology,and geological structure affect the spatial distribution characteristics of geostress.Under complex geological conditions,in-situ stress does not always increase linearly with depth and is affected by changes in lithology and geological structure.Taking a tunnel with a maximum depth of 2268 m in the Tianshan Mountains as an example,based on site surveys and measurement data,the finite difference software FLAC 3D was used for three-dimensional numerical simulation in an area of about 460 km^(2).Results show a clear impact on abnormal varations of in-situ stress due to geological structures.There is a 5~10 MPa difference in the fluctuation of in-situ stress caused by sudden changes as folds on both sides of the fault,especially the local concentration of in-situ stress near the hanging wall of the fault.Such kind of concentration mostly contributes to the occurrence of rockburst once excavating at sections of hard rocks.Compared with the measured in-situ stress results at nearby locations,the numerical calculation results are 20~30 MPa larger,indicating a significant change in in-situ stress values due to the development of geological structures,which is also a location that the in-situ stress measurement points are trying to avoid in practice.The research results connecting simulation with measurement are expected to provide reference for similar projects in this area.
作者
池建军
滕杰
尚彦军
邵鹏
吴彤
闫晓石
CHI Jian-jun;TENG Jie;SHANG Yan-jun;SHAO Peng;WU Tong;YAN Xiao-shi(China Water Resources Beifang Investigation,Design and Research Co.,Ltd.,Tianjin 300222,China;Key Lab of Shale Gas and Geoengineering,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Xinjiang Key Laboratory of Geohazard Prevention(Xinjiang Institute of Engineering),Urmuqi 830023,China)
出处
《科学技术与工程》
北大核心
2024年第25期10936-10945,共10页
Science Technology and Engineering
基金
科技部第二次青藏高原综合科学考察项目(2019QZKK0904)
新疆第三次科考项目(2022xjkk1305)
新疆维吾尔自治区重点研发专项(2022B03001-2)。
关键词
天山
隧道
地质构造
数值模拟
Tianshan
tunnel
structural geology
numerical simulation
