石灰改性石油污染盐渍土的力学特性

以实现石油污染土的工程再利用为目的,借助无侧限抗压强度试验,探索石灰改性石油污染滨海盐渍土的强度分布规律。结果表明:石灰改性有助于提高石油污染土的抗压强度和抗变形性能,10%石灰改性污染土的无侧限抗压强度最小值为764 kPa,能够满足《公路路面基层施工技术规范》(TJJ034—2000)中二级和二级以下公路底基层强度标准(500 kPa)。石灰改性污染土的峰值应变平均值为2.04%,小于石油污染土的峰值应变(3%);石灰改性石油污染土的抗压强度随含油量的增加先增大再稳定后减小,随石灰掺量及养护龄期的增加而增大;经石灰改性处置,污染土的破坏模式由塑性大变形破坏转为脆性开裂破坏,且随养护龄期、石灰掺量及含油量的增加,土样裂缝宽度增大且边缘更加不规则;含油率对改性反应进程影响较小,且存在临界石油含量作用点,对于0~20%石油污染盐渍土,适宜石灰掺量为10%,养护龄期依旧为21 d。

Analytical and numerical solutions for shear mechanical behaviors of structural plane

The original descriptive model of shear stress and shear displacement only reflects the stress deformation characteristics of plastic structural plane.The index model was revised and piecewise index model was built to describe the stress deformation characteristics of plastic structural plane and brittle structural plane.The relation of stress and strain to the failure mode of structural plane considering the effect of its shape was investigated,and a model which could reflect the relation between undulate angle and shear strength was built.The result indicates that structural plane presents nonlinear characteristics,specifically,the value of undulate angle,as well as corresponding shear strength,becomes larger as the normal stress decreases.