考虑动态临界加速度的地震边坡永久位移研究
发布时间：2019-04-17 14:41
【摘要】：Newmark永久位移是评价边坡在地震时稳定性的一个重要指标,近年来广泛应用于地震边坡危险性评价中。传统Newmark永久位移法在计算临界加速度时假定其为常数,未考虑滑动面上抗剪强度参数的变化,过低估计了边坡的永久位移。为了解决这一问题,本文从岩土结构理论获得思路,详细分析滑块底面抗剪强度参数在地震中的变化过程,以边坡震动过程中黏聚力逐步丧失为基本思路,在黏聚力符合一定概率分布的基础上,提出了一种利用蒙特卡罗法模拟其动态减小过程从而实现临界加速度动态变化的计算方法。经过算例计算,黏聚力和临界加速度体现了地震过程中边坡滑块黏聚力和临界加速度的动态变化,位移大小符合地震边坡实际位移的常规数值。本文提出的蒙特卡罗法实现动态黏聚力和动态临界加速度的计算过程与地震时程相对应,不仅在一定程度上解决了抗剪强度参数的动态变化问题,还解决了传统Newmark位移计算中永久位移比实际位移偏小的问题。
[Abstract]:Newmark permanent displacement is an important index to evaluate slope stability during earthquake. It has been widely used in seismic slope risk assessment in recent years. The traditional Newmark permanent displacement method assumes that it is a constant when calculating the critical acceleration without considering the change of shear strength parameters on the sliding surface and underestimates the permanent displacement of the slope. In order to solve this problem, this paper obtains the train of thought from the geotechnical structure theory, analyzes in detail the variation process of shear strength parameters of the bottom surface of the slider in the earthquake, and takes the gradual loss of the cohesive force in the course of the vibration of the slope as the basic train of thought. On the basis of a certain probability distribution of the cohesive force, a Monte Carlo method is proposed to simulate the dynamic decreasing process of the cohesive force, so as to realize the dynamic change of the critical acceleration. The numerical results show that the cohesive force and critical acceleration reflect the dynamic changes of the cohesive force and critical acceleration of the slope sliders in the course of earthquake, and the displacement is consistent with the normal value of the actual displacement of the seismic slope. The Monte Carlo method proposed in this paper corresponds the calculation process of dynamic cohesive force and dynamic critical acceleration with the seismic time history, which not only solves the problem of dynamic variation of shear strength parameters to a certain extent, but also solves the problem of dynamic variation of shear strength parameters to a certain extent. It also solves the problem that the permanent displacement is smaller than the actual displacement in the traditional Newmark displacement calculation.
【作者单位】： 四川大学水力学与山区河流开发保护国家重点实验室水利水电学院;中国长江三峡集团;四川大学-香港理工大学灾后重建与管理学院;
【基金】：NSFC国际合作项目(41661134012) 国家自然科学基金(51509173)
【分类号】：TU435
本文编号：2459534
[Abstract]:Newmark permanent displacement is an important index to evaluate slope stability during earthquake. It has been widely used in seismic slope risk assessment in recent years. The traditional Newmark permanent displacement method assumes that it is a constant when calculating the critical acceleration without considering the change of shear strength parameters on the sliding surface and underestimates the permanent displacement of the slope. In order to solve this problem, this paper obtains the train of thought from the geotechnical structure theory, analyzes in detail the variation process of shear strength parameters of the bottom surface of the slider in the earthquake, and takes the gradual loss of the cohesive force in the course of the vibration of the slope as the basic train of thought. On the basis of a certain probability distribution of the cohesive force, a Monte Carlo method is proposed to simulate the dynamic decreasing process of the cohesive force, so as to realize the dynamic change of the critical acceleration. The numerical results show that the cohesive force and critical acceleration reflect the dynamic changes of the cohesive force and critical acceleration of the slope sliders in the course of earthquake, and the displacement is consistent with the normal value of the actual displacement of the seismic slope. The Monte Carlo method proposed in this paper corresponds the calculation process of dynamic cohesive force and dynamic critical acceleration with the seismic time history, which not only solves the problem of dynamic variation of shear strength parameters to a certain extent, but also solves the problem of dynamic variation of shear strength parameters to a certain extent. It also solves the problem that the permanent displacement is smaller than the actual displacement in the traditional Newmark displacement calculation.
【作者单位】： 四川大学水力学与山区河流开发保护国家重点实验室水利水电学院;中国长江三峡集团;四川大学-香港理工大学灾后重建与管理学院;
【基金】：NSFC国际合作项目(41661134012) 国家自然科学基金(51509173)
【分类号】：TU435
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