【摘要】 基于等幅值循环荷载作用下低温三轴振动试验资料,研究冻结青藏铁路北麓河黏土在长期往返加荷情况下的变形特征。根据不同温度、动应力幅值、频率、围压等因素下冻土的应变与振次关系曲线,得到随着振动次数、动应力幅值、围压的增加残余应变增大;随着温度的降低残余应变值减小,高温冻土对动力作用敏感;存在某一临界频率(6Hz左右),当频率大于或小于临界频率,残余应变增加速度都将增大的结论,并合理解释冻土特有的振融沉陷的成因机理。更多还原

【Abstract】 Based on dynamic tri-axial test at low temperature,deformation behaviors of clay sampled from BeiLu River section of Qinghai-Tibet railway were studied under long-term cyclic loading.According to the relation curves between residual strain and vibration times of frozen soil at different negative temperatures,frequency,confining pressure and water content,three conclusions are drawn as follows: With the increase of vibration times,the dynamic loading and confining pressure,residual strain increase;with the decrease of the temperature,residual strain will decrease,the high temperature frozen soil is sensitive to the dynamic loading;there exists a critical frequency(about 6Hz).When the frequency is higher or lower than the critical frequency,the residual strain changes.Moreover,the mechanism of settlement for frozen soil was explained.更多还原