土体非线性参数变异性与地表响应的概率关系

The Probability Relationship between Variability of Soil Nonlinear Parameters and Ground Response

场地土体非线性参数存在明显的变异性,因而与其相关的许多岩土工程问题都会受到其变异性的影响。采用数值模拟的方法研究了场地土非线性参数概率与场地地表加速度反应谱概率之间的关系。结果表明,场地土体动剪切模量比概率水平与场地地表加速度反应谱概率水平的关系随周期频段的变化而变化,粘性土在0.01 s～0.8 s周期内,无粘性土在0.02 s～0.7 s周期内,两者基本呈线性关系;场地土体阻尼比概率水平与地表加速度反应谱概率水平存在良好的对应关系,二者概率水平一致,且与反应谱的频段无关;在0.01 s～6.0 s周期频段内,无粘性土和粘性土的阻尼比概率与地表反应谱概率水平呈明显的线性关系。

Since soil nonlinear parameters show dramatic variability,many geotechnical problems relating to the soil nonlinear parameters are influenced by their variabilities.The relationship between the probabilities of site soil nonlinear parameters the probabilities of and surface ground acceleration responses is studied by numerical method.Results show that, the relationship between the probability of soil dynamic modulu ratio and the site responses changes in different frequency bands of the response spectra.For cohesive soil in the period interval of 0.01 s to 0.8 s and for non-cohesive soil in the period of 0.02 s to 0.7 s,the both probabilities show approximately linear relationship.The probability of soil damping ratio and that of ground surface acceleration response show remarkably linear relationship with same probability in all spectrum.And the probabilities of damping ratio and the probabilities of the response spectra for both cohesive and non-cohesive soils show obvious linear relationship in the period of 0.01 s to 6.0 s.