| 节理分布空间变异的地下洞室稳定性概率分析 |
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| 引用本文： | 王川,冷先伦,李海轮,李刚.节理分布空间变异的地下洞室稳定性概率分析[J].岩土力学,2021(1):224-232,244. |
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| 作者姓名： | 王川 冷先伦 李海轮 李刚 |
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| 作者单位： | ;1.中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室;2.中国科学院大学;3.中国电建集团北京勘测设计研究院有限公司 |
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| 基金项目： | 国家重点研发计划项目(No.2017YFF0108706,No.2017YFF0108705)。 |
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| 摘 要： | 以岩土材料力学参数空间变异性的"点估计-有限元"分析方法为基础,结合节理分析时自身存在几何模型、网格划分等特性,扩展了该方法在节理分布空间变异性分析方面的适用性,明确了具体的研究步骤与方法。以某抽水蓄能水电站为例,通过分析节理空间变异性对围岩变形与塑性区的影响,验证了扩展后该方法的准确性和合理性。对工程案例开挖揭露的1400余条节理进行概率统计,建立了节理空间变异性的有限元分析模型;采用扩展后的概率分析方法,研究了节理分布对地下洞室群围岩开挖稳定性的影响。研究结果表明:(1)对比概率分析得到的围岩变形概率分布与现场监测结果,发现剔除变形异常点后监测变形量值大部分位于得到的位移概率分布范围内,说明节理的空间变异性是导致监测变形波动的主要影响因素;(2)围岩变形概率分布的标准差能有效识别出围岩开挖变形受节理空间变异性的影响程度,对于所给出的案例依次为:机窝>边墙>顶拱;(3)围岩塑性区的概率分区能合理判断地下洞室群开挖时受节理影响较大的区域和范围,为工程施工的支护设计提供依据。
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| 关 键 词： | 地下洞室 节理产状 空间变异性 塑性区 变形 概率分析 点估计法 |
Probabilistic stability analysis of underground caverns considering spatial variation of joint distribution |
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| WANG Chuan,LENG Xian-lun,LI Hai-lun,LI Gang.Probabilistic stability analysis of underground caverns considering spatial variation of joint distribution[J].Rock and Soil Mechanics,2021(1):224-232,244. |
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| Authors: | WANG Chuan LENG Xian-lun LI Hai-lun LI Gang |
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| Institution: | (State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China;University of Chinese Academy of Sciences,Beijing 100049,China;PowerChina Beijing Engineering Corporation Limited,Beijing 100024,China) |
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| Abstract: | In this paper, based on the combined point estimation method and finite element method(i.e. PEM/FEM) for the spatial variability of geotechnical mechanical parameters, the application of PEM/FEM was extended to study the spatial variability of joint distribution through the geometric models and meshing characteristics of joints. A pumped-storage hydropower station in China was adopted as a case to verify the accuracy and rationality of the expanded PEM/FEM by analyzing the influence of spatial variability of joint distribution on the deformation and plastic zones of the surrounding rock mass in the underground caverns. A finite element analysis model for spatial variability of joint distribution was established through the probabilistic statistics of more than 1,400 joints in the underground caverns. The effects of spatial variability of joint distribution on the stability of the surrounding rock mass was comprehensively studied through the expanded PEM/FEM probability analysis method. Results show that:(1) The comparative analysis of the deformation probability distribution of the surrounding rock mass obtained by the expanded PEM/FEM and on-site monitoring shows that after removing some abnormal values, most of the monitoring deformation values are within the range of the displacement probability distribution, indicating that the spatial variability of joint distribution is the main factor that cause the fluctuation of the monitoring deformation.(2) The probabilistic distribution of the standard deviation of the deformation can be adopted to identify the incidences of the spatial variability of joint distribution on the deformation. For the studied case, the influence of the spatial variability of joint distribution on the deformation is the most significant in places near the floorsand least near the top arches.(3) The probabilistic zoning of the plastic zones of surrounding rock mass can reasonably determine the areas and ranges that are greatly affected by the joints during the excavation of the underground caverns, which provides a support for the design of engineering construction. |
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| Keywords: | underground cavern joint occurrence spatial variability plastic zone deformation probabilistic analysis point estimate method |
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