改良黄土路基对比试验分析

Experiment Analysis of Improving Loess Subgrade

通过试验研究了典型黄土的物理力学性质、黄土改良后的颗粒组成、液塑限变化、击实特性、改良土强度及其主要影响因素。试验结果表明:黄土改良后塑性有所降低,亲水性减弱;改良黄土选择不同的掺料,最大干密度都有所减小,石灰改良土减小更明显;无论石灰还是水泥改良土,在一定时间内其抗压强度随着龄期的增长而增加,而强度增加中粘聚力增长幅度比内摩擦角要更加显著一些;黄土改良后的物理力学性能有明显改善,同时改良土水理性能也得到改善,为类似工程路基填料的使用提供重要参。

The chemical and physical properties of typical loess, the granulometric composition ,the variation of liquid and plastic limi, compaction characteristics, strength and its major influencing factors of improved-loess were studied in lab . Through experiments some results were obtained. The results show that plasticity index of the improved-loess decreases after improvement, at the same time,its hydrophilieity is weakened. As the variation of admixture kind, the optimum water content increases a bit, however, the maximum dry density decreases, and the changes of lime improved-loess is more obvious than cement ,reproved-loess. Other lime-improved loess or cement-improved loess, their strength increases with the curing time, at the increasing strength, the amplification of cohesion is superior to internal friction angle. The chemical and physical properties of typical loess and its water-resistance were obviously improved through improving properties by chemical method, this would provide useful data and references for the usage of filling of subgrode in similar engineerings.