The paper presents an experimental study on the effect of plastic fines content on the undrained behavior and liquefaction susceptibility of sand–fines mixtures under monotonic loading. The results of undrained monotonic triaxial compression tests conducted on mixtures of Hostun sand with varying amount (0–20%) and type (kaolin and calcigel bentonite) of plastic fines are presented. The specimens were prepared with different initial densities using the moist tamping method and consolidated at two different isotropic effective stresses. The results demonstrate that for both types of plastic fines, an increase in the fines content leads to a more contractive response and lower values of mobilized deviatoric stress. Despite similar relative density and fines content, the sand–kaolin mixtures showed a more contractive behavior than the sand–calcigel specimens. The steady-state lines (SSLs) in e–p´ space generally move downwards with increasing clay content. While the slopes of the SSLs for the clean Hostun sand and the mixtures with 10 and 20% kaolin are quite similar, the SSL lines for the specimens containing 10% or 20% calcigel run steeper or flatter, respectively. The inclination of the SSL in the q–p′ plane was found independent of clay type and content. The sand–kaolin mixtures were observed to be more susceptible to instability and flow liquefaction than the sand–calcigel mixtures.

本文提出了关于塑料细粒含量对单调载荷下砂-细粒混合物的不排水行为和液化敏感性影响的实验研究。介绍了对含有不同数量 (0-20%) 和类型（高岭土和钙化膨润土）的塑料细粒的 Hostun 砂混合物进行的不排水单调三轴压缩试验的结果。使用湿夯法制备具有不同初始密度的试样，并在两种不同的各向同性有效应力下进行固结。结果表明，对于这两种类型的塑料细粉，细粉含量的增加会导致更收缩的响应和更低的移动偏应力值。尽管相对密度和细粉含量相似，砂 - 高岭土混合物比砂 - calcigel 样品表现出更多的收缩行为。稳态线 (SSL)e – p´空间通常随着粘土含量的增加而向下移动。虽然干净的 Hostun 砂和含有 10% 和 20% 高岭土的混合物的 SSL 斜率非常相似，但含有 10% 或 20% calcigel 的试样的 SSL 线分别更陡或更平。发现SSL 在q-p ' 平面中的倾斜与粘土类型和含量无关。观察到砂 - 高岭土混合物比砂 - 钙凝胶混合物更容易受到不稳定性和流动液化的影响。