季冻区典型土类动剪切模量阻尼比计算方法

发布时间：2018-12-13 02:04

【摘要】：采用专门设计的低温共振柱仪进行试验研究,研究典型土类动剪切模量阻尼比随负温的变化规律及计算方法。提出温度影响系数的概念,并以较为符合实际的固结压力和冻结过程,完成了黏土、粉土与砂土在常温及不同负温下的动力试验,给出了这3种典型土类不同负温下初始剪切模量、剪切模量比和阻尼比的计算公式。结果表明:无论何种土类,负温对其初始剪切模量、剪切模量比和阻尼比都有重要影响,相应的温度修正系数按Boltzmann与指数函数变化,均在0℃到-6.0℃快速变化之后趋于平缓,但变化程度和修正公式中的参数均与土类有关;随温度降低,3种土类初始剪切模量增长十分显著,完全冻结黏土、粉土和砂土分别为常温土初始模量的50倍、25倍和13倍;随温度降低,3种土类参考剪应变降低十分显著,但完全冻结后3种土的动剪切模量降低程度接近;随温度下降,3种土类最大阻尼比均显著减小,完全冻结后的黏土最大阻尼比降幅最大,砂土降幅最小,粉土居中。3种典型土类负温下动剪切模量阻尼比修正公式,其反映的现象和规律与国际上近期成果定性相符。
[Abstract]:The dynamic shear modulus damping ratio of typical soils with negative temperature is studied by means of a specially designed low temperature resonance column instrument. The concept of influence coefficient of temperature is put forward, and the dynamic tests of clay, silt and sand at normal and different negative temperatures are carried out with the practical consolidation pressure and freezing process. The formulas for calculating the initial shear modulus, shear modulus ratio and damping ratio of these three typical soils at different negative temperatures are given. The results show that the negative temperature has an important effect on the initial shear modulus, shear modulus ratio and damping ratio, and the corresponding temperature correction coefficient varies according to Boltzmann and exponential function. After changing rapidly from 0 鈩，

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