颗粒型砂介质的受压力学特征及屈服滑动

Mechanical Behavior and Yielding Slippage of Porous Sands Under Squeezing

提出颗粒型砂介质在压实过程中的两种特征 :孔隙填充状态和颗粒滑动状态 ;针对孔隙填充状态的力学行为特征 ,提出相对体积改变量 (压实量 )作为表征此状态的特征参量 ,研究了瞬时压缩模量与压实量的函数关系 ;针对型砂的颗粒滑动状态 ,提出具有强化效应的Mohr Coulomb屈服条件 ,推导描述颗粒屈服滑动状态的增量本构方程、以及三轴压实过程条件下的状态本构方程 ,最后 ,就不同侧向压力下的三轴压缩试验、带模样的型砂压实试验的大量试验数据进行处理和验证。

Based upon the experimental behavior of porous sand under squeezing, two types of status are defined to character the process: the filling of interval space, and the yielding slippage among sands. As for the first character, a relative volume change (named as squeezing valve) is defined to indicate the compression status of porous sand, then the relationship between the transient compression modulus and squeezing value is derived. For the yielding slippage of sands, the Mohr-Coulomb yielding condition with hardening effect, the constitutive equation of sand under three-axial squeezing state are studied. Finally some experiments and numerical applications are presented to review the proposed constitutive relations.