混凝土坝抗震加固中钢筋混凝土的动力本构模型

基于复合材料细观力学和混凝土塑性损伤理论，针对混凝土坝抗震钢筋的分布形式和钢筋混凝土材料的力学特征，提出了钢筋单方向分布情况下钢筋混凝土材料的等效模量、等效强度的简化公式，在此基础上建立了整体式钢筋混凝土动力本构模型，并以Koyna坝为例，根据配筋前坝体的地震塑性损伤分析设置了配筋方案，分别运用整体式和分离式钢筋混凝土动力本构模型对该坝进行配筋计算，并进行了三维非线性地震响应时程分析，得到了两种不同配筋条件下坝体的拉应力损伤因子分布及坝顶动位移响应。结果表明，两种模型计算结果比较接近，配筋抗震措施能够明显地减小坝体损伤区的范围，整体式钢筋混凝土动力本构模型在满足计算精度的前提下可提高计算效率、简化模拟计算。

Dynamic constitutive model for reinforced concrete in aseismic strengthening of concrete dam

Based on the micro mechanics of composite and plastic damage theory for concrete, with the layout form of reinforcement in concrete dam and mechanics characteristic of reinforced concrete taken into account, the simplified equations of equivalent module and equivalent strength for reinforced concrete with the rebar orientated in single direction are derived and an integral dynamic constitutive model for reinforced concrete is proposed. The model is applied to study the strengthening of the Koyna Dam, India. The reinforcement scheme according to the analysis on seismic plastic damage zone of the dam is calculated by integral dynamic constitutive model and discrete constitutive model respectively, and the tensile damage index of the dam and displacement of dam crest are obtained by 3_D nonlinear seismic response history analysis. The results of both models are very close and verify that the reinforcement measure can effectively reduce the damage zone and significantly control the extension of damage zone. The integral dynamic constitutive model for reinforced concrete not only improves the computational efficiency and accuracy but also simplifies the simulation computation.