【摘要】 基于极限分析的上限定理,提出一种土石坝极限抗震分析的新方法。该方法假定土体为理想刚塑性材料且满足相关联流动准则,将土石坝坡滑动体划分为若干水平土条,计算各滑动土条的外功率与内能耗散,然后通过能量平衡条件,利用优化算法确定土石坝的极限抗震能力。运用所提方法,对一典型心墙土石坝进行极限抗震能力分析,研究了水平条分数以及抗剪强度参数对极限抗震能力影响。计算结果表明,水平条分数对滑裂面形状影响较大而对大坝极限抗震能力影响较小。当水平条分数增加到一定数目时大坝极限抗震能力最终趋于一个稳定值。同时,堆石料的抗剪强度对大坝极限抗震能力影响较大。通过与传统的极限平衡法对比,验证了所提方法的正确性与可行性。更多还原

【Abstract】 A new approach based on the limit analysis upper bound theorem is proposed to study the seismic stability of earth-rock dams.First,according to the upper bound analysis,a perfectly plastic soil model is assumed with an associated flow rule.Then,the dam slope is divided into horizontal slices with regarding the sliding surface as an arbitrary surface.In order to obtain the maximum anti-seismic capability of dams and the corresponding sliding surface,the multivariate function is established by the energy-work balance equation and optimized by intelligent algorithm.For the study of the influences of shear strength parameters and horizontal slice number on the maximum anti-seismic capability and the sliding surface,the new approach is applied to a typical earth-rock dam with core wall.It is shown by the results that the horizontal slice number has a great influence on the sliding surface but a small influence on the maximum anti-seismic capability.When the horizontal slices achieve a certain number,the maximum anti-seismic capability of dams is ultimately a stable value.Meanwhile,the shear strength parameters of the rockfill materials have a great influence on the maximum anti-seismic capability.Compared with the limit equilibrium method the result illustrates the correctness and feasibility of the proposed method.更多还原