高心墙堆石坝地震永久变形特性分析

Characteristics Analysis of Permanent Earthquake-induced Deformation of High Core Rock-fill Dam

针对坝体地震永久变形是控制高土石坝工程安全的重要因素之一。以200m高的心墙堆石坝为例，采用中国水利水电科学研究院通过试验得到的堆石料、心墙料的动应力一残余应变关系。基于三维有限元静动力分析．利用等效节点力法讨论了地震永久变形在不同动参数、峰值加速度和反应谱作用下的变形特性与分布规律。结果表明，在单一参数变化下，顺河向、竖向、坝轴向的永久变形等值线分布图基本保持不变，竖向最大永久变形发生在坝顶附近，坝顶1／3～1／2坝高区域内变化较为明显，峰值加速度、坝料模量衰减曲线和阻尼增长曲线的选取对结果影响较大。

Permanent earthquake-induced deformation of dam engineering is one of the most important factors to con- trol the safety of high earth-rockfill darn. Taking the 200-meters high core rock-fill dam for an example, the IWHR model is applied to establish the relationships between dynamic stress and residual strain on rock-fill materials and core wall ma- terials. Based on the static and dynamic three-dimensional finite element analysis, the characteristics and distribution of the permanent deformation in different dynamic parameters, peak acceleration and response spectrum are discussed by u- sing equivalent nodal force method. The results show that the contour maps of permanent deformation is almost the same under the single parameter change; maximum vertical permanent deformation occurs near the top of the dam~ however, the values are dilferent, especially in the region 1/3 to 1/2 height of the dam near the dam crest. Among these factors, peak acceleration and the selection of modulus decay curve and damping growth curve have large impact on the results.