有限淋滤作用下石灰处治膨胀土的力学性能

Experimental Study of Mechanical Properties of Lime Stabilized Expansive Soil under the Condition of Eluviations

对南阳膨胀土的基本力学性能及经石灰处治后的力学性能进行了测试,探讨了石灰处治膨胀土的力学性能指标随掺灰比和龄期变化的规律,获得了最优掺灰比;同时,自行设计了一套针对石灰处治膨胀土的室内有限淋滤试验装置和试验方法,并利用此方法对南阳膨胀土进行了有限淋滤试验,分析了石灰处治膨胀土内Ca^(2+)含量、黏聚力及内摩擦角随淋滤天数变化的规律.结果表明:经石灰处治后,膨胀土的黏聚力随着淋滤天数增加而明显降低,其内摩擦角的变化较小;在降雨淋滤作用下,石灰处治膨胀土内Ca^(2+)含量的减少将引起路基强度的降低,从而对路基性能产生不利的影响.

In order to investigate the effect of eluviations on the mechanic performance of lime stabilized ex pansive soil, laboratory tests were conducted to reveal the influencing rules of lime proportion and age on the swell-shrink properties of stabilized expansive soil. An optimal lime proportion was derived, a measur- ing device of eluviations was designed and the detailed test steps were given for reference. Besides, the var- iation law of the content of Ca2＋ and the strength indexes with leaching days were discussed according to leaching tests. Based on the results of the laboratory tests, it is found that the cohesion force of the stabi lized soils decreases with the decrease of the content of Ca^2＋ , however, the internal friction angle remains constant. The influence of the decrease of the content of Ca^2＋ on the strength is disadvantageous to the long-term performance of subgrade.