Q_4黄土改良土填筑高速铁路基床的试验研究

Experimental Study of Improved Q_4 Loess for High-speed Railway Subgrade

改良路堤填料是高速铁路路基的重要内容.研究内容是通过在Q4黄土中掺入水泥及石灰进行土质改良.通过大量的室内试验,进行了水泥改良土、石灰改良土的物理力学特性研究,得到了有价值的结论:对于石灰改良土,存在一最佳石灰掺量,约7%,石灰土在最佳掺灰量时,其强度存在一峰值.水泥改良土在不同掺和比条件下的物理力学性质指标均能够满足路堤填料的要求.出于安全及经济因素,认为路堤填料采用Q4黄土掺入5%水泥改良土为宜.含水量对改良土的工程性质影响很大,因而在工程施工中应使改良填料的含水量尽可能达到最优含水量.

Improved soil is very important for subgrade of highspeed railway. The main contents in this paper are making Q4 loess improved through Mingling Cement or Lime. The authors make researches on physical and mechanical characteristics of improved soil which are respectively improved by cement and lime through indoor experiments. Through study, the authors drew out several valuable conclusions. With regard to improved soil by lime,there is an optimal mixed ratio（7%） at which strength of it is maximum. With regard to improved soil by cement, physical and mechanical characteristics of improved soils by Mingling Cement at different ratioes all satisfy the requests of filling soils of subgrade. Considering safety and economy,the authors think it is suitable to mingle 5% cement in Q4 loess for filling in subgrade. The ratio containing water influences much largely for improved soils, so it should be keep at the optimal ratio during construction of engineering.