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石油污染土物理力学性质较差,改善其强度是实现工程再利用的前提。以滨海地区石油污染盐渍土为研究对象,采用石灰粉煤灰进行固化处置,借助无侧限抗压强度试验,量化固化效果及各个因素的影响程度。结果表明:石灰粉煤灰联合固化可使石油污染土的抗压强度大幅提高,12%石灰+20%粉煤灰固化石油污染土的强度满足《公路路基设计规范》(JTG D30—2015)中关于二级公路上下路堤及地基土置换的抗压强度要求,且控制石油污染水平8%以内时,可满足高速公路、一级公路上下路堤中抗压强度指标要求;固化石油污染土的应力–应变曲线由直线加载、非线性上升及下降3个阶段组成,破坏模式呈应变软化型,随石油污染水平加剧,塑性变形部分增强;固化土的强度随石油污染水平加剧而下降,石油污染减缓固化反应速率,弱化石灰–粉煤灰–土颗粒间固化作用;对于石油污染水平为0~12%的盐渍土,适宜耦合条件为:12%石灰+22%粉煤灰,养护龄期28 d。
The physical and mechanical properties of petroleum contaminated soil are poor, and improving its strength is the prerequisite for realizing the reuse of the project. Taking the petroleum contaminated saline soil in the coastal area as the research object, lime fly ash was used for curing treatment. With the aid of the unconfined compressive strength test, the curing effect and the degree of influence of various factors were quantified. The results show that the combined strength of lime fly ash can significantly increase the compressive strength of petroleum contaminated soil, and the strength of 12% lime+20% fly ash solidified petroleum contaminated soil can meet the requirements of the “Highway Subgrade Design Specification” (JTG D30-2015). With regard to the compressive strength requirements for the replacement of embankments and foundation soil on Grade 2 highways, and when the oil pollution level is controlled within 8%, it can meet the compressive strength index requirements for highways and highways on the first and second grade highways; the stress of solidified petroleum contaminated soils – The strain curve is composed of three stages: straight-line loading, nonlinear rising and falling. The failure mode is strain-softening. As the level of oil pollution increases, the plastic deformation increases; the strength of solidified soil decreases as the level of petroleum pollution intensifies, and oil pollution slows and solidifies. Reaction rate, weakening the lime-fly ash-soil particle solidification; for oil-salted soils with 0-12% saline soil, the suitable coupling condition is: 12% lime + 22% fly ash, curing age 28 days .