基于速率相关混凝土损伤模型的高拱坝地震响应分析

不同应变率下混凝土受拉及受压的动力试验表明,混凝土的弹性模量、抗拉强度、抗压强度及相应的极限应变等重要参数与应变率和加载历史密切相关。根据已有试验结果,通过引入损伤张量随应变率的变化建立了应变率相关的混凝土非线性损伤模型,对300米级的高拱坝的地震响应进行了计算,并分析了拱坝应变率和拉、压损伤的分布规律。结果表明,由于地震荷载引起的应变率在坝面的分布不同,坝面各处的动态性能变化并不一致,由此引起的混凝土强度和刚度的变化,对于高混凝土拱坝的动力响应和安全性评价有重要影响。

SEISMIC RESPONSE ANALYSIS OF HIGH ARCH DAM BASED ON STRAIN RATE - DEPENDANT CONCRETE DAMAGE MODEL

As is well known, Concrete appeared the strain rate - dependant behavior under dynamic Loading, that the important prameters of modulus of elasticity, tensile strength, compression strength and corresponding utimate strain etc. , are closely related with the strain rate and the loading history. According to the results of previous tests and through introducing damage tensor along the variation of strain rates, hence, a new strain rate - dependant plastic damage constitutive model suitable for seismic analysis is established in the paper, using the proposed damage model, the non - linear seismic response of 300 meters high concrete arch dam has been calculated, and the distribution regularity of strain rate, tesile damage and compres-sive damage of high concrete arch dam are analyzed. The results are shown that the distributions of strain rates caused by seismic loading are different on the dam face and the variations of dynamic behavior are differed at dam face, all of which can lead to change the strength and rigidity of concrete, therefore, the dynamic response and the safety evaluation of high concrete arch dam have an important influence.