三种土层结构反应谱特征周期的统计分析

Statistic analysis of characteristic periods of response spectra for three soil layer constructions

本文人工合成了若干条能够反映不同地震动特征的基岩加速度时程,并将其作为土层地震反应分析的地震动输入。选取了若干个软弱夹层分别在底部、中部和顶部的场地剖面,利用工程上广泛应用的场地地震反应分析的一维等效线性化波动方法,计算了不同场地类别,3种土层结构在不同地震动输入下的地表加速度反应谱的特征周期。给出了不同土层结构在统计意义上的反应谱特征周期的平均值,并通过与正常剖面反应谱特征周期的比较给出了不同场地类别,3种土层结构的反应谱特征周期的影响系数。本文的研究结果对进一步考虑场地分类具有一定的意义。

Some acceleration histories that can express the characters of ground motions were formed artificially. They would be used as ground motion inputs. The typical profiles containing soft layer located at the bottom, in the mid or on the top of them were selected. With the use of 1-D equivalent linearization wave motion method that is widely used in ground response analysis at present, the characteristic periods of ground surface acceleration response spectra were calculated under different ground motion inputs for three soil layer constructions of different site sorts. The average values of the statistical characteristic periods were given for each soil layer construction,and the effect coefficients of response spectra's characteristic periods were obtained by comparing them with those of norm profiles. The results obtained in the paper have some significance for further considering site classification.