论文部分内容阅读
设计并完成了可液化饱和南京细砂自由场地基振动台试验。利用不同埋深处量测的加速度反应时程,采用线性插值法通过换算得到模型地基土剪应力和剪应变。进一步基于流体力学方法,研究了饱和砂土在孔压增长过程中表观动力黏度的变化规律。试验结果表明,在正弦波荷载作用下,饱和砂土液化前的表观动力黏度随着剪应变和剪应变率的增大而减小,表现出典型的“剪切稀化”非牛顿流体特性;超孔压比在饱和砂土的表观动力黏度发展变化中起着显著作用,表观动力黏度随着超孔压比的增大而减小,并且利用幂函数可以很好的拟合表观动力黏度与超孔压比的关系曲线。此外,表观动力黏度与孔压比的关系似乎不依赖有效上覆压力,该结论有待进一步验证。
Design and accomplish the shaking table test of liquefiable saturated fine sand free ground. Using the acceleration response time series measured at different burial depths, the shear stress and shear strain of the model foundation soil are obtained by the linear interpolation method. Based on the fluid mechanics method, the variation law of apparent dynamic viscosity of saturated sand in the process of pore pressure increase was studied. The experimental results show that the apparent dynamic viscosity of saturated sand before liquefaction decreases with the increase of shear strain and shear strain under the action of sinusoidal load, showing the typical shear thinning non-Newtonian Fluid properties; super pore-pressure ratio plays a significant role in the development and change of apparent dynamic viscosity of saturated sands, the apparent dynamic viscosity decreases with the increase of super pore-pressure ratio, and the power function can be very good Relationship between kinetic viscosity and excess pore water pressure ratio. In addition, the relationship between apparent dynamic viscosity and pore pressure does not seem to depend on effective overburden pressure. This conclusion needs to be further verified.