【摘要】 基于黏弹性理论,对土的动弹性模量和阻尼比确定方法进行探讨,并结合青藏铁路沿线黏土在一系列温度下的动三轴试验结果,给出冻结黏土的动弹性模量和阻尼比的确定方法.结果表明:冻结黏土的骨干曲线不是双曲线,建议通过滞回曲线求冻土的动弹性模量和动应变幅,从而获得它们之间的关系;不同计算方法得到的阻尼比随动应变幅的变化趋势基本相同,用滞后角法计算得到的阻尼比整体小于用能量损失法计算得到的阻尼比,建议采用相关函数法计算应变滞后于应力的滞后角,然后用滞后角法计算土的阻尼比;冻结黏土的阻尼比随动应变幅的增加而增大.更多还原

【Abstract】 The calculation methods of dynamic elastic modulus and damping ratio of soil were discussed on basis of visco-elastic theory.According to the result of a series of tri-axial test on frozen clays sampled along the Qinghai-Tibet Railway,suggestions about how to calculate the dynamic parameters were put forward.The result shows that the backbone curve of frozen clay is not a hyperbolic one.The dynamic elastic modulus and dynamic strain amplitude can be calculated through hysteresis loop,and then revealed their relationship.The relations between damping ratio and dynamic strain amplitude calculated with different methods are the same.The damping ratio under the lag angle method is less than that under the energy loss method.The lag angle of strain and stress can be obtained from correlation function method.It is recommended that using correlation function method to calculate the lag angle between strain and stress,and using the lag angle to calculate the damping ratio.The damping ratio of frozen clay increases with dynamic strain amplitude.更多还原