废机油污染膨胀土的压缩特性试验研究

Research on Compression Characteristics of Expansive Soils Contaminated by Used Oil

为了研究废机油污染土劣化规律,制备了4种不同浓度机油污染膨胀土,对不同浓度机油污染膨胀土进行了室内一维固结试验。结果表明：随着机油浓度的增加,土体的压缩系数增大,压缩模量和回弹指数均减小,废机油的污染改变了土粒的物理化学特性,破坏了土的结构性,使土粒间联结力丧失,对土体压缩特性影响较大。此外,对压缩曲线建立4次多项式模型和Harris模型,通过Casagrande经验作图法计算先期固结压力,对两类模型计算结果分析,Harris模型的拟合效果更符合试验土样的压缩曲线变化规律,机油污染后膨胀土的先期固结压力减小,扰动性增强。

In order to study the rules of degradation for soils contaminated by used oil,the consolidation characteristics of 4 different concentrations of expansive soils are studied by one-dimensional consolidation test.The results show that with the increase of the concentrations,the coefficient of compressibility increases,and the modulus of compressibility and rebound indexes decrease.Contamination of used oil has changed the physical and chemical characteristics of the soil particles and destroyed the structure of soil,resulting the loss of bonding between soil particles,hence has caused significant impact on properties of compressibility of soils.In addition,four degree polynomial models and Harris models are established for the compression curve.The results of two models are analyzed by using Casagrande graphing Method to calculate pre-consolidation pressure.The Harris model can better match the change rules of compression curve for test soil,and the pre-consolidation pressure of soils contaminated by used oil reduces and the disturbance of expansive soils is enhanced.