Stability assessment of the left bank slope of the Baihetan Hydropower Station, Southwest China
Stability assessment of the left bank slope of the Baihetan Hydropower Station, Southwest China
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DOI：
10.1016/j.ijrmms.2018.02.016
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发表时间：
2018-04
影响因子：
7.2
通讯作者：
Biao Li;Tao Li;N. Xu;F. Dai;Wenfu Chen;Yao-sheng Tan
中科院分区：
文献类型：
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作者：
Biao Li;Tao Li;N. Xu;F. Dai;Wenfu Chen;Yao-sheng Tan
近年来，我国西南地区已经或正在建设锦屏一级、大岗山、溪洛渡、乌东德、白鹤滩等大型水电站。高陡边坡的安全稳定是水利水电工程建设和运行的重要课题。通常，结构面和结构面对岩质边坡的稳定性有很大影响，这些特征的行为在稳定性评价中起着关键作用。1岩质边坡开挖过程中，卸荷引起的围岩应力调整和重分布，将引起结构面（如节理、层面和叶理）的活化，可能导致沿原有结构面沿着破坏。因此，山区岩质边坡的稳定性评价就显得尤为重要。2由于影响边坡稳定性的因素难以识别和测量，连续开挖条件下岩质边坡的破坏特征较为复杂。3岩质边坡稳定性评价已取得了许多显著的成果，包括物理模型、现场调查、数值模拟和现场实测。Che等人4进行了一系列振动台试验，以评估波传播对具有顺层不连续节理的高陡岩质边坡稳定性的影响。Adhikary等人5和Zhang等人6通过对小比例模型的离心试验研究了节理岩质边坡的弯曲倾倒破坏机理。Lin等3在野外观测和运动学分析的基础上，揭示了拉西瓦水库高深边坡的大变形机制。此外，随着计算机技术的发展，数值模拟已被广泛应用于复杂岩质边坡，特别是结构控制的层状岩质边坡的破坏机理和未来变形趋势的预测。各种数值方法，如极限平衡法（LEM），7，8有限元法（FEM），9，10，11和离散元法（DEM），12，13，14已被开发并用于边坡稳定性分析。由于地质条件、地应力和施工过程的复杂性，数值模型与实际情况并不完全吻合。现场测量（即，使用多点引伸计、锚测力计、裂缝仪或全球定位系统进行测量）已被证明是监测和分析岩石边坡稳定性的有效方法。然而，这些传统的测量技术只能检测到地表附近的岩体变形，并且很少有信息可用于了解深部岩体行为。15因此，在过去十年中采用了高精度和高性能的微地震监测技术来监测深层岩体中出现的微裂纹。与传统的监测方法不同，MS监测提供了三维可视化，可以在宏观变形之前揭示岩体的裂隙发育和渐进损伤。在过去的二十年里，MS监测技术已经发展成为评估岩石边坡、地下洞室15、16、17、18、隧道19、20、21、22、23和采矿稳定性的有效方法。24，25，26已发表的文献包括有关岩石边坡MS监测的宝贵信息。Lynch等人16通过应用MS数据建立了地表移动和MS数据之间的相关性。
In recent years, numerous large-scale hydropower stations, such as Jinping I, Dagangshan, Xiluodu, Wudongde and Baihetan, have been or are being constructed in Southwestern China. The safety and stability of high, steep slopes is an important topic for the successful construction and operation of a water conservancy and hydropower project. Generally, discontinuities and structural planes greatly influence the stability of rock slopes, and the behaviour of these features plays a critical role in stability evaluation. 1 During the excavation period of rock slopes, unloading-induced stress adjustment and redistribution of surrounding rock mass will cause the activation of discontinuities (eg, joints, bedding planes and foliations), which may result in landslides and failure along pre-existing structural planes. Therefore, the stability assessment of rock slopes becomes much more important when the slope is located in a mountainous area. 2The characterization of rock slope failures subjected to continuous excavation is complicated due to the difficulties of discerning and measuring the factors that affect slope stability. 3 Many remarkable achievements have been made in assessing the stability of rock slopes, including physical models, field surveys, numerical simulations and in situ measurements. Che et al. 4 performed a series of shaking table tests to evaluate the influence of wave propagation on the stability of a high, steep rock slope with bedding discontinuity joints. Adhikary et al. 5 and Zhang et al. 6 investigated the mechanisms of flexural toppling failure of jointed rock slopes via centrifuge tests on small-scale manufactured models. Lin et al. 3 revealed the large deformation mechanism of the high-deep slope at Laxiwa reservoir based on field observations and kinematic analysis. In addition, with the development of computer technology, numerical simulation has been widely used to understand failure mechanisms and to predict future deformation trends of complex rock slopes, especially structurally controlled layered rock slopes. Various numerical approaches, such as the limit equilibrium method (LEM), 7, 8 finite element method (FEM), 9, 10, 11 and discrete element method (DEM), 12, 13, 14 have been developed and adopted in slope stability analysis. Due to the complexities of geological conditions, geo-stresses and construction processes, the numerical models do not completely match the actual conditions. In situ measurements (ie, measurements taken using a multi-point extensometer, anchor dynamometer, crack gauge, or global positioning system) have been shown to be an efficient approach for monitoring and analysing rock slope stability. However, these traditional measurement techniques can detect rock mass deformation only near the surface, and little information is available for understanding deep rock mass behaviour. 15 Therefore, high-precision and high-performance microseismic (MS) monitoring technique has been adopted in the last decade to monitor the microcracks that occur in deep rock mass. Unlike traditional monitoring methods, MS monitoring offers three-dimensional visualization and can reveal the fracture development and progressive damage of rock mass prior to macroscopical deformation. Over the past two decades, the MS monitoring technique has been developed as an efficient approach for assessing the stability of rock slope, 15, 16, 17, 18 underground caverns, 19, 20 tunnels 21, 22, 23 and mining. 24, 25, 26 The published literatures include valuable information regarding the MS monitoring of rock slopes. Lynch et al. 16 established a correlation between surface movements and MS data by applying the MS …