天山深埋隧道复杂地质条件影响下地应力分布数值模拟分析对比  

Numerical Simulation and Comparison of Geostress Distribution under the Influence of Complex Geological Conditions in a Deep Buried Tunnel in Tianshan

作　　者：池建军[1] 滕杰[1] 尚彦军[2,3,4] 邵鹏 吴彤 闫晓石[1] 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)

机构地区：[1]中水北方勘测设计研究有限责任公司,天津300222 [2]中国科学院地质与地球物理研究所页岩气与地质工程重点实验室,北京100029 [3]中国科学院大学地球科学与行星学院,北京100049 [4]新疆地质灾害防治重点实验室(新疆工程学院),乌鲁木齐830023

出　　处：《科学技术与工程》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)。

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.

关 键 词：天山 隧道 地质构造 数值模拟 

分 类 号：U451.2[建筑科学—桥梁与隧道工程]