深切河谷区水电站厂址初始应力场规律研究及对地下厂房布置的思考

发布时间：2018-04-29 12:06

本文选题：岩石力学 + 锦屏一级水电站　；参考：《岩石力学与工程学报》2014年11期

【摘要】：针对深切河谷高地应力区水电站厂址区域初始地应力张量空间分布特征及其与洞室群布置相对关系识别问题,结合河谷历史发展过程分析、应力张量空间解析法和多核并行计算技术等,将复杂地质环境下三维地应力场模型与洞室群精细开挖计算模型相耦合,提出考虑河谷演化规律的厂址区域地应力场量化精细数值模型的建立方法和分析思路,识别锦屏一级水电站厂址区初始应力场分布规律并进行现场验证,结果表明:锦屏一级地下厂房洞室群位于深切河谷附近应力变化较大且应力水平相对较高的应力过渡区,由此形成初始高地应力环境,且主应力比为1.9~2.5,岩石强度应力比为1.5~3.0;在这种高地应力低强度应力比且高主应力比共同作用下,地下厂房洞室群施工期围岩出现的变形破坏规律及卸荷松弛深度超过同等规模的地下厂房工程,而现场围岩应力诱导型变形破坏的发生位置和分布规律,则佐证了所获得的厂址初始应力场的合理性,同时也验证了地应力场量化模型建立方法的科学性和可行性。在此基础上,建立一种考虑三维地应力、岩石强度应力比和岩体结构特征的高地应力区地下厂房洞室群结构布置设计方法,其本质上体现洞室荷载特征(三维地应力,包括最大主应力量值和方位,而且还考虑地应力场分布、主应力比等)、围岩结构特征及承载能力(岩石强度)等因素的协同耦合作用,并从定性角度建议确定主洞室位置、纵轴线、间距和洞型等一些原则和思路。
[Abstract]:In view of the spatial distribution characteristics of initial geostress Zhang Liang and its relative relationship with the layout of caverns in the site of hydropower stations in deep valley with high ground stress, the paper analyzes the historical development process of river valley. The spatial analytical method of stress Zhang Liang and multi-core parallel computing technique are used to couple the 3D geostress field model in complex geological environment with the fine excavation calculation model of cavern group. This paper puts forward the establishment method and analysis idea of the precise numerical model of the ground stress field in the site considering the evolution law of the valley, identifies and verifies the distribution law of the initial stress field in the site area of the first grade hydropower station in Jinping. The results show that the cavern group of the first class underground powerhouse is located in the stress transition area near the deep valley, where the stress level is relatively high, and the initial high stress environment is formed. And the ratio of principal stress to principal stress is 1.9 ~ 2.5 and the ratio of strength to stress of rock is 1.5 ~ 3.0.Under the combined action of this kind of high in-situ stress and low strength stress ratio and high principal stress ratio, The deformation and failure law of surrounding rock and unloading relaxation depth of underground powerhouse group during construction period are higher than those of the same scale underground powerhouse engineering, and the location and distribution of stress-induced deformation failure of surrounding rock on site are discussed. The rationality of the initial stress field obtained at the plant site is verified, and the scientific and feasible method of establishing the quantitative model of in-situ stress field is also verified. On the basis of this, a design method of underground powerhouse cavern group structure in high ground stress area is established, which takes into account the three dimensional in-situ stress, rock strength stress ratio and rock mass structure characteristics, which essentially reflects the loading characteristics of the cavern (3D in-situ stress). It includes the maximum principal stress value and orientation, and also considers the synergistic coupling of the distribution of in-situ stress field, the principal stress ratio, the characteristics of surrounding rock structure and the bearing capacity (rock strength), and suggests the location of the main cavern from a qualitative point of view. Vertical axis, spacing and hole shape and other principles and ideas.
【作者单位】：长江科学院水利部岩土力学与工程重点实验室;中国电建集团成都勘测设计研究院有限公司;
【基金】：国家自然科学基金资助项目(51379022,51179013) 国家重点基础研究发展计划(973)项目(2011CB710603)
【分类号】：TV731.6;TV221

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