不同湿度状态下高液限粉土的强度特性

Strength property of high liquid limit soil under different moisture

为了掌握潮湿地区粉土的强度特性,为粉土路基设计和施工提供技术参数,通过控制初始干密度和含水量的方法制备试样,开展粉土和水泥改良粉土的无侧限抗压强度、直接剪切强度、承载比(CBR)强度等试验,获得了不同含水量或不同浸水条件下粉土和水泥改良粉土的强度指标。结果表明,粉土的强度受压实度和含水量的影响最大;粘聚力随含水量的变化先增大后减少;同等条件下掺4%的水泥以后粉土的内摩擦角约提高了2倍、粘聚力提高4倍。粉土的不浸水承载比强度要远大于浸水承载比强度,但制样含水量超过20%以后,即使不浸水其承载比强度也发生急剧衰减,因此粉土的强度对水十分敏感。

The strength property of silt is very important for the design and construction of subgrade. Specimens were prepared at different initial dry density and water content. The strength tests, such as direct shear test, unconfined compressive strength test, and California bearing ratio （CBR）test, etc. , were carried out for the silt and cement stabilized silt. And the strength parameters of them were obtained under different water content or moisture. The results show that the strength was seri- ously influenced by initial dry density and water content. Cohesion was increased with water content first, but was decreased afterwards. When the silt was stabilized with 4% cement, the cohesion and friction angle were increased about 4 times and 2 times, respectively. The CBR of the unsoaking specimens were greater than that of the soaking one. But the CBR would reduce dramatically when the water content was over 20% , even if the samples were under unsoaking condition. So, the silt is a kind of special soils, which is very sensitive to water.