Improvement of Discontinuous Deformation Analysis Incorporating Implicit Updating Scheme of Friction and Joint Strength Degradation
Improvement of Discontinuous Deformation Analysis Incorporating Implicit Updating Scheme of Friction and Joint Strength Degradation
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DOI：
10.1007/s00603-021-02459-2
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发表时间：
2021-05
影响因子：
6.2
通讯作者：
R. Hashimoto;Tomohiro Sueoka;T. Koyama;M. Kikumoto
中科院分区：
文献类型：
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作者：
R. Hashimoto;Tomohiro Sueoka;T. Koyama;M. Kikumoto
节理岩体的动力分析，如边坡稳定性评价，近年来得到了广泛的研究，非连续变形分析（DDA）是这一领域的可行方法之一。为了预测岩体的破坏模式、破坏动能和破坏后的到达距离，必须正确地计算岩体节理的摩擦特性。然而，传统的DDA往往不能很容易地确定合适的分析参数，可以准确地预测岩体之间的滑动位移，在最坏的情况下，计算失败。在这项研究中，以提高DDA的鲁棒性和准确性，摩擦力的更新过程进行了研究。在DDA中引入了一种基于弹塑性框架的摩擦力隐式修正格式，即所谓的返回映射算法和Newton-Raphson迭代。此外，还实现了静态摩擦和残余摩擦之间的过渡算法，以再现摩擦强度退化。通过数值算例验证了所提出的全隐式DDA的性能，并证实了该方法对岩石节理沿着滑动问题的鲁棒性、精度和计算效率的提高。
Dynamic analyses of jointed rock masses, such as slope stability evaluations, have been intensively studied in recent years; discontinuous deformation analysis (DDA) is one of the feasible methods in this field. To predict the failure mode, the kinematic energy, and the reaching distance after the collapse, the friction characteristics of the rock joints must be computed correctly. However, conventional DDA often cannot easily determine appropriate analysis parameters that can predict the sliding displacement between the rock masses precisely, and at worst, the computation fails. In this study, to enhance the robustness and accuracy of the DDA, the updating procedure of the friction force is investigated. An implicit updating scheme of friction force based on the elasto-plastic framework, the so-called return mapping algorithm, and the Newton–Raphson iteration is newly introduced to the DDA. Additionally, the transition algorithm between the static and the residual friction is also implemented to reproduce friction strength degradation. The performance of the proposed full implicit DDA is examined through the numerical examples and improvements in the robustness, accuracy, and computational efficiency for the dynamic sliding problems along the rock joint were confirmed.