【摘要】 基于大量动三轴试验,针对滨海新区结构性软土,研究了其动应力-应变、动模量和阻尼比变化规律,并对振动波型、加荷频率以及固结应力比等影响因素进行了深入的研究,得出了如下的结论:振动波型对于结构性软土的动应力-应变类型影响不大,但是最大动弹模量Edmax和动剪切模量Gdmax的相差可达2.5倍左右;结构性软土具有明显的频率效应和门槛振动频率;半正弦波型条件下,当围压小于结构屈服压力时,最大动弹模量Ed随固结比的增加而递减,超过某一应变幅值时,最大动弹模量Ed将随着固结比的增加而减小;偏压状态下,低应变条件下固结比越大,阻尼比越大,当应变值超过0.004以后,随应变值的不断增大,固结比越大,阻尼比反而越小。所得出的结论对工程应用具有一定的指导意义。更多还原

【Abstract】 Based on a lot of dynamic triaxial tests,the variation laws of dynamic stress-strain,dynamic elastic modulus and damping ratio of structural soft soils were studied;meanwhile,the influences of vibration wave,frequency and consolidation ratio were investigated.It is concluded that the influence of vibration wave on the type of dynamic stress-strain is not evident;the value between the maximum dynamic modulus E dmax and dynamic shear modulus Gd max is 2.5 times or so.The effect of frequency on the structural soft soil is evident;and there is a threshold vibration frequency.The maximum dynamic modulus E dmax decreases with the consolidation ratio increasing as the confining pressure is less than structural yield pressure;and when strain exceeds a certain value,the maximum dynamic modulus E d decreases with the consolidation ratio increasing.At a lower strain and deviatoric pressure,the higher the consolidation ratio is,the larger the damping ratio is;and when strain exceeds 0.004,the consolidation ratio increases,meanwhile the damping ratio decreases as the strain value increases.The conclusions can provide a useful guidance for the engineering application.更多还原