混凝土重力坝FRP片材表面加固抗震性能研究

如何提高混凝土重力坝薄弱位置的抗震性能是国内外大坝抗震研究的热点问题。本文基于等价静力非线性方法,采用考虑混凝土细观非均匀特性的混凝土损伤模型,研究FRP片材表面加固大坝薄弱位置的抗震有效性。以2座不同形态的混凝土重力坝A、B为例,分别进行坝踵FRP片材表面加固研究和折坡处FRP片材表面加固研究,分析加固前后坝体的应力状态、裂缝扩展情况和破坏形态。数值模拟结果表明：坝踵处采用FRP片材加固可以很好地增强坝体的抗震性能,有效地抑制裂缝的产生和发展;折坡处采用FRP片材加固在一定程度上可以提高坝体的抗震性能,下游坝身加固与否对提高大坝的抗震性能影响不大。

Study on Seismic Resistance Capacity of Concrete Gravity Dam Strengthened with Externally Bonded FRP-plate

Improving seismic resistance capacity of dam,especially its weak positions has become a hot spot of seismic research.Based on pushover method,a damage model of concrete considering its microscopic inhomogeneity was employed to analyze dam′s damage process during earthquake,also the effectiveness of externally bonded FRP-plate reinforcement was discussed.Taking two different concrete gravity dams for examples,researches on heel and head reinforcement were conducted respectively.Comparisons of stress distribution,crack propagation and failure forms before and after strengthening show that externally bonded FRP-plate reinforcement of heel could improve its seismic resistance,and restrain emergence and development of crack effectively;also that of head could promote its seismic resistance in certain extent,but whether dam body downstream is reinforced does little influence on the seismic resistance.