关键词: 温敏性, 固化石油污染土, 无侧限抗压强度, 应力?应变曲线

Abstract: Temperature is an important factor that affects properties of oil contaminated soil. This study considered the special characteristics of the climate environment in the coastal area and used unconfined compressive strength and stress-strain distribution to optimize the requirement for two kinds of ash solidified materials, and the temperature sensitivity was used as an evaluation criterion. Results indicate that the compressive strength of the oil contaminated soil significantly fluctuates, and it is up to two times in the temperature range of -20?40 °C. However, the fluctuation reduces to 10%?20% after soil solidification with two kinds of ash. Solidified materials can adsorb and enclose the temperature sensitive substances (oil, water and salt) in the gel body and even outside, and then it can enhance the resistance to the variation of environmental temperature. The unconfined compressive strengths of oil contaminated soil and solidified soil decrease first and then increase with the increasing of temperature, and 10 °C is the turning point, which is the lowest point. The results suggest that this temperature should be of particular concern in practical engineering. Under the action of temperature, the failure mode of solidified oil contaminated soil is strain-softening. With the increase of temperature and the contaminated level, the plastic deformation stage is prolonged, and the axial strain gradually increases. Finally, the surrounding layered damage occurs. The contaminated level of soil itself affects the solidified effect, and the fluctuation of compressive strength under a high level of contamination is about 40%. Therefore, in actual engineering, the solidified requirement should be adjusted according to the contaminated level. As to the soil with low contamination, the solidified requirement is only slightly higher than that of the uncontaminated soil, and too much solidification for the soil with low contamination is often counterproductive. Lime has more contribution than fly ash to soil stability under the same additive to soil ratio. As to the oil-contaminated saline soil with 6% contamination, the optional solidified condition is 10% lime +20% fly ash.

Key words: temperature sensitivity, solidified oil contaminated soil, unconfined compressive strength, stress-strain curve