铁路膨胀土路基填筑试验研究

研究目的：本文结合时速200km铁路客货共线路基压实度要求，通过对不同膨胀土填料进行室内试验，提出满足路基工程要求的改良方案和质量检测方法。研究方法：收集国内外相关资料；进行现场填筑试验；研究满足时速200km客货共线铁路要求的路堤的压实施工工艺及压实质量检验方法、评判标准等。对石灰改良土进行粉碎、拌和、碾压等施工工艺研究，提出合理的施工参数及评判标准。研究结果：通过实验验证设计并探讨适宜的路基结构形式及边坡防护形式；对不同膨胀土填料进行室内改良试验，提出满足本线路基工程要求的改良方案；提出改良土粉碎、拌和及压实施工工艺的试验成果及适宜的路堤填筑质量检验方法。研究结论：石灰改良膨胀土的塑性指标，相对膨胀土有明显改善，液限含水量基本保持不变、塑限含水量提高、塑性指数降低；掺石灰后，最佳含水量得到增加，而最大干密度则减小。

Experimental Research on Filling Expansive Soil Subgrade of Railway

Research purposes:Aiming at the compactness requirement of the 200 km/h railway line for mixed passenger and freight traffic,the improvement program and quality inspection method are proposed in this paper through doing indoor experiment on the different filling materials for expansive soil,for the purpose of meeting the requirement of subgrade.Research methods:Through studying the information and doing site experiment on filling,the researches are doing on the construction technique,quality inspection method and quality evaluation standard for subgrade compact of 200 km/h railway line for mixed passenger and freight traffic.The rational construction parameters and evaluation standard are presented through doing research on the construction techniques,including the techniques of smashing,mixing and compacting rending improved soil.Research results:The improvement program is given for meeting the requirement of construction of the subgrade,the construction technique is presented for smashing,mixing and compacting improved expansive soil and the suitable quality inspection method is proposed for filling subgrade through making experiment,design and discussion on suitable structural mode for subgrade and prevention mode for side slope.Research conclusions:Compared with the expansive soil,the plastic index of improved expansive soil with lime is better,the liquid-limit water content remains no change basically,the plastics-limit water content is increased and the plastic index is lowered.The best water content is increased and the max.dry density is lowered after mixing lime.