Tensile cracking at the position where geometry changes is a typical failure mode of gravity dams under strong earthquakes. Steel reinforcement has been proposed to reduce the degree of dam cracking. In this paper, a nonlinear model is presented to consider the interaction effect between the steel reinforcement and the dam concrete in a combined concrete damage model and distributed-steel model. In the model, a composite constitutive model of a steel reinforcement-concrete element is proposed. The approach can model the process of gradual degradation of the concrete loading capacity and load transfer to the steel reinforcement by establishing the concrete and steel models separately. Taking a typical gravity dam with positions where geometry changes upstream and downstream as a case study, the influence of steel reinforcement on seismic damage of the gravity dam is investigated. The analytical results show that the steel reinforcement strengthening prevents cracks thoroughly around the elevation of the downstream slope change. However, the cracking around the elevation of the upstream slope change extends to the downstream direction. This reflects the transfer of fracture energy release during the cracking process.

中文翻译：

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基于分布式钢模型的钢筋对混凝土重力坝地震损伤的影响

几何变化部位的拉伸开裂是重力坝在强震作用下的典型破坏模式。已经提出钢筋以减少大坝开裂的程度。在本文中，提出了一种非线性模型来考虑钢筋与大坝混凝土之间的相互作用，在组合混凝土损伤模型和分布钢模型中。在模型中，提出了钢筋-混凝土单元的组合本构模型。该方法可以通过分别建立混凝土和钢筋模型来模拟混凝土承载能力逐渐退化和载荷转移到钢筋的过程。以一个典型的重力坝上下游几何变化的位置为例，研究了钢筋对重力坝地震破坏的影响。分析结果表明，钢筋加固彻底防止了下游坡度变化标高周围的裂缝。然而，上游坡度变化高程附近的裂缝向下游方向延伸。这反映了开裂过程中断裂能量释放的传递。