不同埋深的黄土填料特性及改良试验研究

Experimental Study on the Engineering Characteristics of Loess Filling and Its Improvement under Different Buried Depth

研究目的:本文通过室内试验,对不同埋深条件下天然黄土和改良黄土的工程特性进行了对比分析研究,以合理确定高速无砟轨道路基填筑中,黄土填料的改良方法、掺合料和掺量。研究结论:试验研究表明,由于黄土具有大孔隙性、水敏性和湿陷性等工程特性,对于工后沉降标准要求较高的无砟轨道路基,不宜直接用作路基填料,必须进行改良,改良后的黄土,其压缩系数显著降低,强度和水稳性大幅度提高,从土样构成上消除了黄土的湿陷性。在施工质量(配合比、含水量、摊铺厚度、压实机械和压实度等)得以保证的前提下,改良黄土是能够满足高速无砟轨道路基的填料要求的。该研究成果对广大黄土地区的铁路、公路建设具有重要意义。

Research purposes： Based on the indoor test,the analyses of the engineering characteristics of natural loess and improved loess under different buried depth are made for the purposes of seeking the way of improving loess and the mixture materials and its mixes quantity for the filling of high-speed ballastless track.Research conclusions：The study shows the natural loess is not suitable for being the filling of roadbed directly due to its the big porosity,water sensitivity and collapsibility for the ballastless track requiring less settlement,so the natural loess must be improved.After improvement,its coefficient of compression is lowered much,its strength and water stability of loess are highly improved,and its collapsibility is removed.The improved loess can be as highly qualified filling materials for high-speed ballastless track when the construction quality is guaranteed in mixture ratio,water content,laying thickness and compactness.