石灰改良下蜀黏土作为高速铁路路堤填料的工程性质试验研究

Experimental Research on the Engineering Characters of Improved Xiashu-Clay with Lime as the Embankment Filling of High-speed Railway

研究目的:高速列车的安全和平稳运行必须有一个高平顺性和稳定性的轨下基础,路基作为轨道结构的基础形式之一,必须具有强度高、刚度大、稳定性和耐久性好,能抵抗各种自然因素的影响,这就对路基填料的工程性质提出了很高的要求。京沪高速铁路沿线优质填料较为缺乏,在宁镇一带广泛分布的下蜀黏土一般为D组填料,不能直接用作高速铁路基填筑,必须进行改良。本文通过石灰改良下蜀黏土的室内物理试验、静力学试验、动力学试验及现场填筑试验,对石灰改良下蜀黏土作为填料的工程性质进行系统的研究,对其作为高速铁路基床底层填料的可行性进行了评价。研究结论:下蜀黏土经石灰改良后,颗粒组成发生明显变化,水稳性显著加强,静力学性质明显提高,同时还表现出优良的动力学特性,压实质量能满足高速铁路基床底层压实标准,可用作高速铁路路堤填料。但在应用过程中,应注意石灰掺入量、含水率等因素的影响。

Research purposes： The safe and stable running of high - speed train needs a sub - rail tbundation of high regularity and stability. As one part of track structure, sub-ade must have features of high strength and rigidity and perfect stability and durability to resist the influences of all natural elements, so it requires perfect engineering character of subgrade filling. Since there is not enough high quality filling along Beijing - Shanghai High - speed Railway, the xiashu -clay has to be improved for the filling of high - speed railway, the systematical researches are done on the engineering characteristic of improving xiashu - clay with lime as filling through doing indoor physical tests, static mechanics tests, dynamic mechanics tests and site filling tests, and the evaluation is made on the feasibility of improving xiashu -clay with lime as the embankment filling of high -speed railway. Research conclusions：After improving with lime, the granule constitution of xiashu -clay is obviously changed, the water stability is evidently improved and the static mechanics character is obviously enhanced with excellent dynamic mechanics characteristic. The quality of the improved xiashu - clay with lime can satisfy the standard for bottom bedding of high - speed railway, the improved xiashu - clay with lime can be used as the embankment filling of high - speed railway, but the attention should be paid to the influence of lime content and water content ere in use of it.