反应加速度法人工边界宽度参数研究

Research on the artificial boundary width parameter for the response acceleration method

为确定合理人工边界宽度参数,现设定某地质条件下的城市轨道交通箱型地下结构,并选择2种结构埋深(分别为5m和25m),分Ⅱ、Ⅲ、Ⅳ3种场地类别,使用时间历程法和反应加速度法分别计算结构的内力和位移。结果表明:若以时间历程法为基准,反应加速度法本身存在方法误差,随着人工边界宽度的增加,误差值逐渐趋于稳定;若以反应加速度法模型取50倍框架宽度为基准,误差逐渐减小,表明反应加速度法存在合理人工边界宽度。

Response acceleration method has been gradually accepted and promoted across China in recent years .In order to deter‐mine its reasonable artificial boundary width parameters ,one benchmark numerical example ,such as the urban mass transit un‐derground structure which was set at two burying depths (5 m and 25 m) ,was evaluated and the structural internal forces and displacement was calculated by using the time history method and response acceleration method ,respectively .It was found that if the time history method was selected as a benchmark ,the response acceleration method itself has methodic error .With the in‐crease of width ,the error tended to be stable .In addition ,if the response acceleration method with 50 times width model was se‐lected as a benchmark ,errors were gradually reduced .It was shown that the response acceleration method had a reasonable artifi‐cial boundary width .