高速铁路路基粗颗粒填料冻胀特性研究

Research on the Frost-heave Performances of Filling Material Consisted of Coarse Grained Soil for High-speed Railway Subgrade

研究目的:在季节性冻土区修建高速铁路,路基冻胀变形控制是关键性难题,影响轨道的平顺性与列车运营的安全性。粗颗粒填料是国内外路基工程包括高速铁路防冻层广泛采用的填料,研究高速铁路路基粗颗粒填料冻胀特性对高速铁路路基的防冻胀,保证轨道的平顺性具有重要的意义。研究结论:通过室内和现场试验,开展了不同配比粗颗粒土的冻胀特性研究。试验结果表明:(1)粗颗粒填料在满足路基压实条件的前提下,可有效控制路基冻胀变形;(2)通过改进的室内冻胀试验,能够使试验中土样的均匀性和压实效果更接近现场工程的实际情况,从而使得试验结果更加可靠;(3)通过合理控制粗颗粒填料组分、级配、细颗粒含量等设计参数,可以达到较好的防冻胀效果;(4)本研究成果可应用于严寒地区高速铁路路基的防冻层,能够有效抑制路基冻胀,保证轨道的平顺性。

Research purposes： In the seasonal frozen soil area to build high - speed railway, frost - heave deformation control of subgrade is a key problem, which can affect the track comfort and train operation safety. Coarse grained soil is a kind of filling material which is widely used in subgrade engineering including high speed railway at home and abroad. Therefore, it is of great significance to study the frost - heave characteristics of coarse grained soil in high speed railway. Research conclusions：Through the indoor and field tests, the frost - heave characteristics of coarse grained soil with different ratio were studied. The experimental results show that： （ 1 ） The filler of coarse grained soil can effectively control the suhgrade frost - heave deformation under the premise of satisfying the compaction conditions of subgrade. （2） Through the improved indoor frost -heave test, the uniformity and compaction effect of the soil sample in the test can be closer to the actual situation of the field project, thus the test results are more reliable. （3） The design parameters of the soil composition, gradation and fine particle content can be controlled reasonably to achieve better anti -frost effect. （4） The research results can be applied to the anti - freezing layer of high - speed railway subgrade in the cold region, which can effectively restrain the frost heave and ensure the smoothness of the track.