深厚覆盖层350m级心墙堆石坝动强度计算分析

以建立在深厚覆盖层上350 m级心墙堆石坝工程实例为据,探讨了该类位于强震区域和深厚覆盖层上的超高心墙堆石坝中敏感性材料（心墙料、反滤料和砂层）的动强度稳定性.计算过程中,首先采用三维建模软件依据坝体结构特点建立了三维有限元计算分析模型,进而利用可模拟坝体填筑、蓄水过程的邓肯E-B模型对坝体进行三维有限元静力分析,得到各土体单元的剪应力比和固结比,最后在静力分析结果的基础上,采用等效粘弹性模型确定坝体在极限地震荷载的动力响应,依据Seed提出的动强度判别标准对坝体内心墙料,上游反滤料及坝基砂进行动强度验算.计算结果表明,在极限地震荷载作用下,坝基砂不发生液化,而心墙料、反滤料动强度安全系数将不满足规范要求,须采取必要的抗震措施进行加固.

Calculation and Analysis of Dynamic Strength of 350 m High Core Rockfill Dam on Deep Overburden Foundation

Based on actual engineering of 350m high core dam building on deep overburden foundation, the stability of dynamic strength of sensitive materials, which existed in super-high core rockfill dam located in meizoseismal region and overburden foundation is discussed. In the process of calculation, firstly, based on feature of dam structure and 3D-modeling software for building 3D-FEM analytical model is used; further the Duncan E-B model which simulated the construction and water impounding process of the dam is used for 3D- FEM static analysis; the stress ratio and consolidation ratio of every soil element are obtained; finally, on the foundation of static analytical results, the dynamic response of dam body under the action of limit seismic load is analyzed by adopting the equivalent viscoelastic model; the dynamic strength of the core-wall material, the filter material and the sand of dam foundation is calculated based on judgment of dynamic strength provided by Seed. The results show that under the action of limit seismic load the sand of dam foundation is not existed as liquefaction; but the dynamic strengths of core-wall material and filter material are insufficient, they must be reinforced by adopting necessary aseismatic measures.