考虑弹性应变阈值的频率相关等效线性化方法

发布时间：2019-05-06 23:53

【摘要】：传统等效线性化方法由于原理简单、参数获取方便而广泛应用于工程场地非线性地震反应分析中.实际工程应用中发现,这种方法由于对各个频率分量采用了等效剪应变水平,使得地面最大峰值加速度和高频段计算结果明显偏低.若干实验表明,应变幅值对土的力学行为起着关键性作用,当应变低于弹性应变阈值时,土体处于线弹性状态,弹性应变阈值主要与土的塑性指数有关.本文在对各种频率相关等效线性化理论方法分析的基础上,结合弹性应变阈值理论,建立了考虑弹性应变阈值的频率相关等效线性化方法.运用本文方法对海口某实际场地进行了土层地震反应分析,对比了与传统等效线性化方法的差异;同时对不同覆盖层厚度遭遇不同地震动强度的地震动进行了计算分析,总结了不同覆盖层厚度下本文方法和传统等效线性化方法计算结果的差异及规律.
[Abstract]:The traditional equivalent linearization method is widely used in nonlinear seismic response analysis of engineering sites due to its simple principle and convenient parameter acquisition. In practical engineering application, it is found that due to the equivalent shear strain level used for each frequency component, the maximum ground peak acceleration and the calculation results of the high frequency section are obviously lower. Some experiments show that the strain amplitude plays a key role in the mechanical behavior of soil. When the strain is lower than the elastic strain threshold, the soil is in a linear elastic state, and the elastic strain threshold is mainly related to the plastic index of the soil. Based on the analysis of various frequency-dependent equivalent linearization methods and combined with elastic strain threshold theory, a frequency-dependent equivalent linearization method considering elastic strain threshold is established in this paper. This method is used to analyze the seismic response of soil layer in a practical site in Haikou, and the difference between the method and the traditional equivalent linearization method is compared. At the same time, the calculation and analysis of ground motion with different cover thickness and different earthquake ground motion strength are carried out, and the difference and regularity between the calculation results of this method and the traditional equivalent linearization method under different cover thickness are summarized.
【作者单位】：北京交通大学土木建筑工程学院;
【基金】：国家“973”计划项目资助(2015CB0578000)
【分类号】：TU435

【共引文献】