【摘要】 汶川地震的经验表明,高拱坝可能遭受远超其设计烈度的强地震作用.研究拱坝的地震损伤破坏情况,探究其地震超载潜力,对于防止发生严重的地震灾变具有重要意义.在拱坝的动力分析中,采用宏观均质假定基础上考虑混凝土细观非均匀性影响的地震损伤破坏模型,以及基于阻尼溶剂抽取法的拱坝-地基动力相互作用模型以考虑无限地基辐射阻尼的影响,研究了拱坝在不同地震超载水平下的损伤破坏情况.结果表明,算例采用的拱坝在1倍和2倍设计地震动作用下损伤程度很轻;在3倍地震动作用下出现较多微裂纹,但并未聚集贯通形成宏观裂缝,从而保持了坝体的整体性和蓄水功能.由于在3倍设计地震动以内非线性程度都不严重,应力分布和坝顶加速度时程都表现出一致的趋势和形态.总的来说,该坝具有良好的地震超载能力.更多还原

【Abstract】 As shown by the experience obtained from Wenchuan Earthquake,high arch dams are likely to experience ground motion much stronger than their design value.So it becomes extremely important for avoiding serious earthquake disasters to investigate the damage of arch dams subjected to earthquakes and examine their seismic overloading capacity.The damage of an arch dam subjected to earthquakes of different intensities is studied.The damage model for dynamic analysis of arch dams which incorporates the heterogeneity of concrete is employed.The radiation damping of unbounded media is also considered using the arch dam-foundation interaction model based on damping solvent extraction method.According to numerical simulation,the investigated dam only suffers negligible damage when subjected to design earthquake and twice the design earthquake.While for the case of three times the design earthquake,many microcracks occur,but are generally scattered and don′t form macrocracks,so the integrity and water-pounding function of the dam are retained.Since the degree of nonlinearity is not high within three times the design earthquake,the distribution of response of the dam is similar for different levels of earthquake intensity.In a word,this dam has remarkable seismic overloading capacity.更多还原