CAJ | 학술논문

通过GDS双向动三轴系统对双向激振循环荷载作用下饱和软黏土的动模量与阻尼变化规律进行研究.结果表明:随着径向循环应力增加,孔压比增加,双向激振对孔压的影响仅限于对初始孔压的提高,且初始孔压提高的幅度近似与径向循环应力相等;双向激振对门槛循环应力比的影响不明显;径向循环应力对动模量与阻尼的变化规律有显著的影响,在动应变一定的情况下,随着径向循环应力比的增加,动模量降低,阻尼比增加.随着径向循环应力的增加,小应变弹性模量随之减小,且近似与径向循环应力比成线性关系,据此实现了Hardin公式的修正,建立了双向激振下小应变弹性模量经验模型.径向循环应力及围压对及关系曲线影响不明显,通过对双曲线型模型修正,建立双向激振下饱和软黏土动模量与阻尼随动应变变化的经验模型.
통과GDS쌍향동삼축계통대쌍향격진순배하재작용하포화연점토적동모량여조니변화규률진행연구.결과표명:수착경향순배응력증가,공압비증가,쌍향격진대공압적영향부한우대초시공압적제고,차초시공압제고적폭도근사여경향순배응력상등;쌍향격진대문함순배응력비적영향불명현;경향순배응력대동모량여조니적변화규률유현저적영향,재동응변일정적정황하,수착경향순배응력비적증가,동모량강저,조니비증가.수착경향순배응력적증가,소응변탄성모량수지감소,차근사여경향순배응력비성선성관계,거차실현료Hardin공식적수정,건립료쌍향격진하소응변탄성모량경험모형.경향순배응력급위압대급관계곡선영향불명현,통과대쌍곡선형모형수정,건립쌍향격진하포화연점토동모량여조니수동응변변화적경험모형.
Dynamic modulus and damping ratio of saturated soft clay under bidirectional cyclic loading are investigated by GDS dynamic triaxial system. It is observed that the pore water pressure ratio increases significantly with the increase of radial cyclic stress ratio. Radial cyclic stress has great effect on initial pore water pressure;and the increase of initial pore water pressure is approximately equal to the radial cyclic stress. The threshold of cyclic stress ratio changes little under bidirectional cyclic loading. The dynamic modulus and damping ratio are affected by radial cyclic stress significantly. By increasing the radial cyclic stress,the damping ratio increases while the dynamic modulus decreases. Small strain elastic modulus decreases as the radial cyclic stress increases and there is a linear relation between the small strain elastic modulus and the radial cyclic stress ratio. An empirical model for the small strain elastic modulus is obtained based on the modification of Hardin equation. The radial cyclic stress and confining pressure have little effect on the curves of - and -. By modifying hyperbolic model,the empirical models for describing the change of dynamic modulus and damping with dynamic strain are obtained.