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当前岩坡地震动力响应分析中,多采用极限平衡方法分析拟静力安全系数,采用Newmark滑块分析动力永久位移,假设较多,工程实用性受限。将刚体离散元方法引入岩坡地震动力稳定性评价工作中。通过与强度折减法、Newmark法中的永久位移评价相结合,提出一种复杂岩坡静动力稳定性分析方法。初步认识表明:(1)采用极大节理刚度可以减少节理刚度带来的弹性接触位移,使得刚体离散元用于求解岩坡楔形块体的静/动力稳定性问题。(2)刚体离散元强度折减法可以无需假设块体运动方向或假定滑动形式,直接求解获取安全系数、下滑力等结果,可以考虑复杂形状块体,相比传统方法更具优势和实用性。(3)与4个经典静力算例与3个动力算例的对比验证,表明提出的刚体离散元方法及程序实现的正确性。(4)采用提出的方法,研究幅值、节理面交线倾角等参数对岩坡地震响应永久位移的影响规律研究,表明刚体离散元方法可以根据参数变化得到正确的得到相应的结果变化规律。且对比发现在某些特定条件下拟静力安全系数不能正确反映岩坡地震响应的陡增程度。(5)在工程实例中,采用刚体离散元方法进行K1块体基于位移的地震稳定性评价,给出基于超越概率的支护设计方案。相比拟静力安全系数设计方案,在满足使用条件的前提下优化程度更高。研究可为岩坡静动力稳定性分析提供一种新的思路。
In the current seismic response analysis of rock slopes, the limit equilibrium method is mostly used to analyze the quasi-static safety factor, and the Newmark slider is used to analyze the permanent displacement of the power. Assuming more, the engineering practicability is limited. The rigid body discrete element method is introduced into the stability assessment of rock slope seismic force. By combining with the strength reduction method and the Newmark method of permanent displacement evaluation, a method of stability analysis of complex rock slope is proposed. The preliminary findings show that: (1) Using the maximum joint stiffness can reduce the elastic contact displacement caused by the joint stiffness, so that the rigid body discrete element can be used to solve the static / dynamic stability of the wedge block. (2) The strength reduction method of rigid-body discrete element method can directly solve the safety factor, sliding force and so on without assuming the direction of the block motion or the assumed sliding form. Considering the complex shape block, it is more advantageous and practicable than the traditional method. (3) Compared with 4 classic static and 3 dynamic examples, it shows the correctness of the proposed rigid-body discrete element method and the program. (4) The proposed method is used to study the influence law of amplitude and intersection angle of joints on the permanent displacement of seismic response of rock slope. The results show that the rigid-body discrete element method can get the correct result of the change of parameters according to the change of parameters. The comparison shows that under certain conditions, the pseudo-static safety factor can not correctly reflect the sharp increase of rock slope seismic response. (5) In the engineering example, the rigid-body discrete element method is used to evaluate the displacement-based seismic stability of K1 block, and the support design scheme based on transcendental probability is given. Compared to the pseudo-static safety factor design, to meet the conditions of use under the premise of a higher degree of optimization. The research can provide a new idea for the stability analysis of rock slope static and dynamic.