高速铁路路基填料改良试验研究

【作者】 胡奇凡；

【导师】 张家生；

【作者基本信息】 中南大学 ， 土木工程， 2011， 硕士

【摘要】 高速铁路对路基填料的要求较普通铁路更加严格,我国幅员辽阔,地质条件复杂多样,土的地域性差异大。随着高速铁路修建工作在全国范围内广泛开展,能直接用于路基填筑的填料匮乏的情况普遍存在,通常需要对高速铁路建设沿线不合格填料进行改良后使用。因此,高速铁路路基填料改良的研究具有现实意义。本文针对不符合高速铁路基床底层和高速铁路基床以下路堤填筑的C组细砂填料进行了物理改良研究,现场填筑结果表明改良填料达到设计要求,改良取得了理想的效果。本文研究内容主要包括以下几方面：1.通过颗粒分析试验对原填料的基本属性进行了研究,确定了填料的类型和分组,对照《高速铁路设计规范(试行)》(TB10621-2009)对高速铁路路基填料要求,确定填料不能直接用于高速铁路基床底层和基床以下路堤的填筑,需要改良。2.总结分析了粗颗粒含量对粗粒土填料工程力学性质的影响,从填料自身特点出发,提出了增加填料中粗颗粒含量的方式对填料进行物理改良的方案,并研究确定了掺入粗颗粒的类型和级配组成。3.进行不同粗颗粒含量改良填料的重型击实试验和大型三轴剪切试验,研究了填料的密实特性,强度特性和变形特性随粗颗粒含量的变化规律,确定最优的粗颗粒掺入量。4.利用改良填料进行现场填筑,研究填料在不同碾压遍数下的压实程度以及填筑路基的承载力和变形特性,探讨了改良填料的填筑效果,根据填料填筑特性确定了填筑工艺。5.进行地基系数K30,二次变形模量Ev2和动态变形模量Evd之间的相关性研究,确定了K30、Ev2和Evd间的函数关系,提出通过动态变形模量间接判断地基系数和二次变形模量的检测方案。更多还原

【Abstract】 High-speed railway subgrade requires higher quality fillers than ordinary railways. China has a vast, complex and diverse geological condition,soil distribution characteristics are not the same, therefore, with the high-speed railway construction launched extensively throughout the country, the lack of high quality fillers will inevitably hanppen,and the unqualified fillers need to be improved for using, so studying on improving unqualified fillers for high-speed railway using is of great significance. This paper studies on physical improvement of C group fine sand, which is not qualified for the constructions of high-speed railway subgrade and embankment. Results of improved filler field filling experiment show that the improvement achieved the desired effect. The major work and research contents are as following:1. According to particle analysis test results, the type and group of the raw filler are studied to determine whether it is qualified for the constructions of high-speed railway subgrade.2. Based on theorectical research results and the naure of the filler, a raw filler improving programe is proposed, in which crushed stone is used to change the particle size distribution and improve the engineering properties, the particle size distribution of the crushed stone and the reseaching programe for determination of crushed stone content are also studied.3.The changing properties of density,strength and deformation of filler according to the content change of coarse particles are studied by heavy compaction test and large-scale triaxial shear test. According on the study results, the final filler improving programe is proposed.4. The density, strength and deformation properties of improved filler are studied by carrying out field filling experiment, according to the results,improved filler construction technique is defined.5.The relaitions between K30, Ev2 and Evd are studied, based on the results of which, a high efficiency quality testing methord is studied and suggested.更多还原