【作者】 柳墩利；

【导师】 刘艳青；

【作者基本信息】 铁道部科学研究院 ， 桥梁与隧道工程， 2004， 硕士

【摘要】 铁路路基是承受轨道结构重量和列车荷载的基础，其压实质量的好坏直接影响运输的安全和效能。过去新线建设并没有把路基当成土工构筑物来对待，路基填料性能优劣不一，压实标准低，致使路基病害不断。1994年开始提速后因为没有相应的改良措施路基状况不但没有改善，反而更加恶化。随着高速铁路和快速客货混运技术的发展人们意识到提高铁路路基压实标准，使之与线路上部结构和桥隧建筑物的标准相协调是铁路现代化的关键问题之一。为适应这一变化必须提出与之适应的路基设计标准，并严格控制工程质量。 论文结合大量室内外试验，分析国内外常用压实参数的工程意义、适用范围以及压实参数间的相互关系，认为宜采用物性指标配合力学指标来控制路基压实质量，较铁路路基设计规范TB10001-99中的单指标控制更为合理。从总体趋势上讲压实系数K_h越高压实土的强度、刚度和水稳定性越好，能起到控制自身相对密实度的作用。经过分析认为在现有填料分类的情况下K_h与K₃₀之间并没有一一对应的相关关系。对压实系数与各种力学指标的离散性和总趋势一致的现象进行分析建议基床部分采用K_h≥0.95，路堤本体的填料采用K_h≥0.90。吸收国外用含气率控制细粒土压实质量，能起到同时控制压实系数与含水量状态、提高水稳定性的优点，建议压实施工时规定“填料压实含水量应为最佳含水量的（-3～+2）”改为“填料压实含水量应不小于最佳含水量”。 综合以下因素提出时速140公里和时速200公里客货混运铁路路基压实标准方案。论文吸收国内外制定压实标准的精髓理念和压实标准中的先进合理之处，选择适合客货混运的路基压实参数。分析既有路基中实测动应力衰减情况，并通过编制程序计算路基动应力随深度衰减规律，确定路基各部位的动应力和基床厚度，根据双层弹性地基理论计算基床表层厚度和基床底层压实标准。对基床的功能进行强化，增强了轨道基础，降低了养护维修工作量，从结构上消除了翻浆冒泥的可能性，并规定了基床在防冻和防水方面要进行综合考虑，在地下水丰富的情况下必须设置排水层。更多还原

【Abstract】 The railway subgrade is the foundation to bear the track structure and train load, and whose compacting quality direct influent the transport safety and effectiveness. In the past the roadbed didn’t be built as earth structure in new line, the disparity of the roadbed fill performance and the lowness of the compacting criterion, all that caused subgrade defect continuously. The roadbed condition was not only unimproved, even more deteriorate after the beginning of lift speed in 1994. The development of the high speed railway and railway for mixed passenger and freight traff make people wake up to high the subgrade compacting criterion. The harmony of it, the tracker superstructure, the tunnel and bridge structures is the one of the key problems in the railway modernization. To fit the transformation, it is necessary to put forward new subgrade design criterion and control the construction quality strictly.This paper through large quantity of the laboratory experiment and field test, analyzed the engineering meaning, applicability and their interdependence of compacting parameter used in domestic and international commonly. In this paper adopting soil physical property index match mechanics index to control the subgrade compacting quality, and it is more proper than the single index control in railway subgrade design criterion TB10001-99. From the total tendency, higher the compacting factor Kh is, better the strength, rigidity and water stabilization of the compacted soil. It is effect to control itself relative compaction. However some factors analyzed in this paper lead that between Kh and K30 , the one by one corresponding dependency relation not existence in existing filling classification. From the analysis of the discreteness and total tendency uniformity of compacting parameter and kinds of mechanics indexes, we propose that compacting factor in subgrade bed Kh>0.95, compacting factor in embankment filling Kh>0.90. Using air void to control compacting quality of fine grained soil abroad can control compacting factor and moisture content state and improve water stabilization at the same time. So we suggest defining in compacting construction ’fill compacted moisture content should be optimum moisture content (-3~+2)’ to ’fill compacted moisture content should be less to optimum moisture content’.Absorbing the essence of the domestic and international experience, choose the suitable subgrade compacting parameter adapting to the railway line for mixed passenger and freight traff. Analyzing the measured dynamic stress attenuation in current subgrade and calculating the attenuation regular of the subgrade dynamic stress along with depth by program, to determine all parts dynamic stress and subgrade bed thickness. According to doubling elastic foundation theory to calculate the surface layer of subgrade bed thickness and bottom layer of subgrade compacting criterion. Strengthened the function of the subgrade bed, enforced the track foundation, reduced the maintenance and repair and eliminated the possibility of frost boiling from the construction. At the meantime regulate the subgrade bed should be special designing in Anti-freezing and waterproof aspects, and the drainage layer must be installed if the groundwater is abundant. Synthesizing the above factors put forward the subgrade compacting criterion scheme of railway line for mixed passenger and freight traff in speed per hour 140 kilometers and 160 kilometers.更多还原