不同水分稻谷堆非线性临界状态与泊松比

Non-linear Critical State and Poisson′s Ratio of Rice Piles with Different Moisture Content

为了得出不同水分稻谷堆临界状态特性与切线泊松比,文章对不同含水率的稻谷进行了三轴固结不排气剪切实验,分析了含水率及围压对有效应力比、稻谷堆临界状态应力比以及稻谷堆应变关系模型参数的影响。研究结果表明:各含水率稻谷堆临界状态线均偏离直线临界状态线,其形式可用乘幂函数表示,临界状态表现为非线性,且随着含水率的增加,稻谷堆临界状态应力比整体呈增加趋势;采用二次函数ε_(a)^(2)=Lε_(r)^(2)+Tε_(r)对稻谷堆应变关系进行描述,随着含水率的增加,模型参数L、T呈向上下波动式变化,而切线泊松比计算式可通过该应变关系式求导得出。研究结果可用于粮仓内稻谷堆应力与变形的计算,为粮仓设计提供依据。

In order to obtain the critical state characteristics and tangential Poisson's ratio of rice piles with a variety of moisture content,a triaxial consolidation undrained shear test was carried out on rice with kinds of moisture,and the impacts of moisture and confining pressure on effective stress ratio,stress ratio of critical state and model parameters of strain relationship in rice piles were analyzed.The results indicated that the critical state lines of each rice pile deviated from the linear critical state lines,and performance for nonlinear,which could be said with power function multiplied by the constant.Meanwhile,the critical state of stress ratio increased roughly in line with the moisture content.The strain relation of rice piles was described by quadratic function ε_(a)^(2)=Lε_(r)^(2)+Tε_(r).the model parameters(L,T)fluctuated up and down with the rise of moisture.The formula for calculating tangent Poisson′s ratio could be derived from the derivative of strain relation.The study can be used to calculate the stress and deformation of rice grain pile,and provide theoretical support for bin design.