EPS 粒径对轻量土抗剪强度的影响规律

为了确定 EPS 粒径对轻量土抗剪强度的影响，通过直剪试验研究了水泥掺入比 12% 、 20% ， EPS 颗粒体积比 40% 的 3 种 EPS 粒径 混合土的抗剪强度特性。结果表明： 轻量土的剪应力–剪切位移关系曲线有硬化、软化两种形态，取决于水泥掺入比、法向应力等因素。抗剪强度包线为折线型包线，与传统结构性土体包线形态一致。水泥掺入比与 EPS 颗粒体积比相同时，随着 EPS 粒径增大，轻量土密度不变，抗剪强度减小，单价降低，但强度衰减率远远低于单价降低率；剪切面上 EPS 发生剪缩与剪断，受水泥掺入比、 EPS 粒径的控制；黏聚力随 EPS 粒径增大而减小，内摩擦角没有显著变化规律。轻量土剪切破坏过程，可以划分为变形协调、逐渐破损、纯摩擦 3 个阶段。提出了固化土、 EPS 3 界面接触抗剪强度模型，从理论上证明了混合土强度随 EPS 粒径增大而衰减的规律。根据混合土的强度衰减率低于单价降低率，推荐实际生产过程中可以采用 3 ～ 5 mm 的 EPS 球粒，进行配方寻优，适当降低造价。

Influence law of EPS size on shear strength of light weight soil

To determine influence of EPS(Expanded polystyrene) size on shear strength of light weight soil,the shear strength characteristics of mixed soil(cement mixed ratio of 12% and 20% and EPS volume ratio of 40%) with three kinds of EPS sizes are studied by means of direct shear tests.The results show that there are two types of shear stress-shear displacement relation curves: strain hardening and strain softening,and they are decided by cement mixed ratio,normal stress and so on.Its shear strength envelope is b...