碾压混凝土拱坝等效本构模型研究

Study on equivalent constitutive model for roller compacted concrete arch dams

由于施工方式的影响,碾压混凝土坝在碾压层间出现结合面夹层,夹层的存在对其力学性能有较大的影响,夹层强度、刚度较低,形成结构破坏控制面。为计算层状结构体的应力应变分布,根据能量等效原理,把层状结构体转换为横观各向同性体,建立了一个连续等效模型,根据等效模型的计算结果进一步计算本体和夹层之间的应力、应变,使得计算工作量大大减少。连续等效模型与单元尺寸、夹层的数量无关,便于根据实际情况对坝体进行灵活的有限元网格剖分,通用性强,而且该模型能够计算夹层开裂后的情况,可用于坝体非线性损伤开裂分析。

Due to the compacted construction method for RCC dams, weak interface layers often occur between compacted layers, which may remarkably affect its mechanical properties and make the weak layer to be a failure control position of the dam structure because of its low strength and stiffness. In order to calculate the states of stress and strain for layered structure, based on energy equivalent principle, a continuum constitutive model is put forward by converting the layered structure into transversely isotropic body, then the stress and strain of main body and interlayer are obtained from the results of equivalent model at low calculation cost. Independent of unit size and the number of interlayer, the proposed model is convenient for the finite element gridding for RCC dam. And the constitutive law after cracked may be described by this model, which can be used to calculate the state of nonlinear damage and cracking for RCC dam.