膨胀土工程特性及其石灰改性试验研究

Experimental research on engineering propertiesof expansive soil and lime stabilized soil

系统地开展了弱、中膨胀土及石灰稳定土的物理力学试验。试验表明:中膨胀土具有较强的吸水膨胀软化特性,其 CBR 值低于3%,不能满足路基对填料的强度要求,用作路基填料必须改性;当压实含水量控制得当,弱膨胀土 CBR 可满足规范要求,其压实含水量宜按最优含水量加3%～4%控制;用石灰对中膨胀土改性效果显著,能有效抑制其胀缩潜势和提高土体强度,满足路堤填筑的要求。中膨胀土石灰改性的质量掺合比宜按5%控制。

Experiments on the physical and mechanical properties of low and middle expansive soil and lime stabilized soil have been done systematically.According to the results,middle expansive soil should be stabilized before filled into roadbed because it will expand and soften remarkably after wetted and its CBR is lower than 3%;the intensity of low expansive soil meets the regulations if the compacting water content is about 3-4% higher than optimum moisture content.After stabilized with lime,the trend of expansion and shrink of the middle expansive soil can be restrained effectively and the intensity of the soil can be enhanced remarkably to fill into roadbed.The optimum quality lime ratio is about 5%.