冻土场地地震加速度反应谱研究

Research on earthquake acceleration response spectrum of frozen soil ground

根据波动理论考虑土体的非线性,得到地震反应谱的解答,应用求解水平层状场地地震反应谱的等效线性化程序,数值求解不同负温、不同覆盖层厚度多年冻土场地的地震加速度反应谱,季节冻土场地冬夏季地震加速度反应谱。计算结果表明:负温对多年冻土场地加速度反应谱的影响显著,随着冻结温度的降低,加速度反应谱的加速度峰值逐渐降低,并且其峰值前移,场地卓越周期减小;随着冻土覆盖层厚度的增加,反应谱峰值先增大后减小;季节冻土场地夏季的地震反应高于冬季,但在短周期阶段也出现了反超的现象。

According to fluctuation theory, considering soil nonlinearity, earthquake response spectrum answer is obtained. By using plane stratum earthquake response equivalent linearization program, earthquake response spectrum is calculated with different temperature and different overlay thickness on permafrost site and seasonal frozen soil site. It indicates that temperature has great influence to earthquake response spectrum on permafrost site, its acceleration peak value decrease and move forward with the temperature decrease, site predominant period decrease either; its value increase first and then decrease with the overlay thick increase; earthquake response is greater in summer than that in autumn, but it also has the results in reverse in short period.