高拱坝强震开裂与配筋效果研究

Seismic cracking of arch dams and effectiveness of strengthening by reinforcement

本文基于混凝土塑性损伤理论,引入配筋混凝土断裂能加权计算方法,采用组合式钢筋混凝土模型和等效裂缝宽度的概念,提出了一种拱坝坝面配筋混凝土在动力荷载下的等效开裂计算模型,对高拱坝进行了梁向配筋的抗震效果分析。该模型应用于大岗山工程210m高的双曲拱坝的开裂计算,结果表明,尽管坝面配筋无助于防止混凝土裂缝的发生,但能够较有效地控制坝体裂缝的扩展,限制裂缝宽度,对提高坝体整体性与减小横缝开度具有一定的效果。

An equivalent crack model of reinforced concrete for strengthened arch dams under dynamic loading conditions is presented. The model is based on the plastic damage theory and the composed model of reinforced concrete. The weighted method for fracture energy contribution of pure concrete and reinforcement effect as well as the calculation scheme for analysis of equivalent crack opening are adopted. The study demonstrates that although the reinforcements in arch dams cannot prevent cracks from initiation, it is capable of controlling the development and extension of cracks and reducing the width of crack. Meanwhile, the openings of contraction joints can be significantly reduced.