中文摘要：

为使高速铁路路基填料符合填筑要求,探讨路基填料级配改良后的物理力学特性,对其填料进行级配改良试验研究。通过向素土中掺加不同比例的碎石,制成4种不同颗粒级配的改良填料,对素土和复合砾进行击实试验和大型三轴剪切试验,并对其中3种进行现场填筑试验。研究结果表明：试料的最大干密度随粗颗粒质量分数的增大呈先增大后减小的趋势,最优含水率随粗颗粒质量分数的增大呈线性减小;试样的黏聚力c、内摩擦角φ及切线弹性模量Et随粗颗粒质量分数的增大而增大;在现场填筑试验中,素土的压实性能较差,各项路基检测指标较低,而改良后的复合填料压实性能较好,各主要检测指标有较大幅度提高;路基填料经级配改良后,压实特性显著提高,能较好地应用于高速铁路路基填筑。

英文摘要：

The filler of high-speed railway subgrade was studied by gradation improvement test in order to meet its filling requirements and investigate the physical and mechanical properties of improved filler. Four kinds of improved fills of different particle size distributions were obtained by adding different proportions of gravels to the soil, then compaction tests and large scale triaxial tests were performed for soil and composite gravels, and three of them were tested by in-situ filling tests. The results show that with the increase of percentage of the coarse particles, the maximum dry density firstly increases and then decreases, and the optimum moisture content linearly decreases. The cohesion c, internal friction angleφ and the tangent modulus Et increase with the increase of percentage of the coarse particles. Non-improved soil has a bad compaction characteristic and low subgrade test indicators, while the composite gravels have better compaction characteristic and higher subgrade test indicators. The compaction characteristics of fillers can significantly be enhanced after gradation improvement and it can be better used in the construction of high-speed railway subgrade.