石灰改良路基土的力学特性试验研究

以上海某新建道路工程浅层路基土为研究对象，对不同掺灰量的石灰改良土进行击实试验、界限含水率和三轴剪切试验，研究掺灰量对其最大干密度、最优含水率和液塑限的影响规律，以及掺灰量和围压对石灰改良土抗剪强度指标有效粘聚力c′和有效内摩擦角φ′的影响。试验研究结果表明:随着掺灰量的增加，石灰改良土最大干密度减小，最优含水率增加；掺灰量对石灰土的界限含水率指标影响较大，尤其是对液限的影响最为明显，对于塑限，9 %左右的掺灰量对其影响最大；当掺灰量大于某个值时，石灰改良土强度随着围压和掺灰量的增加而增加，随着掺灰量的增

Experimental Study on Mechanical Properties of Lime Improved Subgrade Soil

Taking subgrade soil in shallow layer of a new road engineering in Shanghai as the research object, the tests of compaction, limit water content and triaxial shearing in relation to lime improved soil with different ash contents were carried out, through which the effect of the ash content on the soil＇s maximum dry density, the optimal water content, and the liquid-plastic limit, as well as the effect of the ash content and the confining pressure on the the effective cohesion c＇ and the effective angle of internal friction φ＇, which are the shear strength indices of the soil, were studied. The results show that with the increase of the ash content, the maximum dry density of the lime improved soil decreases and the optimal water content increases ; the effect of the ash content on the limit water content is large, especially that on the liquid-plastic limit is most obvious, and for plastic limit, the effect of ash content about 9 % is maximum; when the ash content is more than a certain value, the strength of the soil may increase with the increase of the confining pressure and the ash content ; as the increase of the ash content, the effective angle of internal friction may increase, however, the effective cohesion may increase at first, and then decrease, and the cohesion close to the ＂optimal ash content＂ is largest.