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基于水泥稳定碎石在寒区高速铁路路基基床中应用的工程背景,借鉴公路行业水泥稳定碎石工程性能评估方法并结合寒区高速铁路路基基床的特点,通过一系列室内试验,深入研究和分析了水泥掺量、颗粒级配对碎石基床压实效果、冻胀性能、渗透性能、冻融耐久性能和温干缩指标的影响规律。研究结果表明:试验配比条件下,水泥稳定碎石基床各项压实指标均满足或超过高铁路基基床压实标准。较大粒径土颗粒的缺失,削弱了水泥稳定碎石试样的冻胀敏感性,提高了渗透性,降低了强度和水稳定性;水泥的掺加有效地弥补了粒径缺失导致的强度降低现象,但却增大了温缩、干缩变形;抗压强度随冻融次数的增加呈现整体衰减的趋势,并在经历10次冻融后趋于稳定。工程实践中,建议选用细粒土含量3%、水泥掺量3%的级配碎石作为非渗水性基床填料,去除0.5mm以下颗粒、水泥掺量3%的级配碎石作为渗水性基床填料。
Based on the engineering background of cement stabilized gravel used in high-speed railway subgrade in cold region and using the method of cement stabilized gravel performance evaluation in highway industry combined with the characteristics of subgrade in high-speed railway in cold region, The effects of cement content, particle size distribution on compaction, frost heaving, permeability, freeze-thaw durability, and temperature-shrinkage index were analyzed. The results show that under the test conditions, all compaction indexes of cement stabilized macadam meet or exceed the compaction standard of high-speed railway subgrade. The absence of larger sized particles of soil weakens the frost heave sensitivity of cement-stabilized macadam samples and improves permeability and reduces strength and water stability; the incorporation of cement effectively compensates for the strength due to particle size loss Reduce the phenomenon, but increase the temperature shrinkage, shrinkage deformation; compressive strength with the increase in the number of freeze-thaw cycles showed an overall trend of decay, and after 10 freeze-thaw tended to be stable. In engineering practice, it is recommended to use graded crushed stone with 3% of fine-grained soil and 3% of cement as the non-seepage-infiltrating bed filler to remove particles less than 0.5mm and graded gravel of 3% Basement packing.