Recent years have seen a large number of high-speed railways built and will be built in seasonal frozen soil regions ot China. Although high-speed railways are characterized by being fast, comfortable and safe, higher...Recent years have seen a large number of high-speed railways built and will be built in seasonal frozen soil regions ot China. Although high-speed railways are characterized by being fast, comfortable and safe, higher standards for defor- mation of the railways＇ frozen subgrade are required. Meanwhile, changes in subgrade soil temperatures are the main factors affecting the deformation of frozen subgrade. Therefore, this paper selected typical test subgrade sections of the Harbin-Qiqihar Line, a special line for passenger transport built in the deep seasonal frozen soil regions of China, to monitor field temperatures. Also, the temperature changing laws of railways＇ subgrade in this region was analyzed by using testing data, the aim of which is to provide a technical support for future design and construction of buildings and structures in a deep seasonal frozen soil region.展开更多
The freezing and expansion diseases of railroad roadbeds are prevalent in areas that experience seasonal freezing.This study aims to investigate the features of the freezing and expansion mechanism of seasonal frozen ...The freezing and expansion diseases of railroad roadbeds are prevalent in areas that experience seasonal freezing.This study aims to investigate the features of the freezing and expansion mechanism of seasonal frozen railroad roadbeds and the effects of the freezing and expansion diseases on the roadbeds.This article presents a study of the Shuo-Huang Heavy Duty Railway.Initially,on-site monitoring tests were conducted to analyze the roadbed temperature,water content and deformations due to freezing.Through these tests,the pattern of development of the roadbed freezing and swelling was understood,and the effect of this on the vibration response of the roadbed was investigated.Subsequently,load-free freezing tests were performed to investigate the freezing and expansion features of the roadbed.Through on-site monitoring,it has been determined that the seasonal freezing layer is approximately 0.5 m deep.The depth of the frozen expansion on both sides of the road shows clear differences.The frozen and expansion disease significantly amplifies the vibration acceleration of the roadbed,with a tendency towards low-frequency and high-amplitude vibrations.Through indoor testing,we compared the deformation of frozen specimens and their final freeze and expansion rates at different cold-end temperatures and various initial moisture content levels.We find that the initial moisture content has a greater impact on specimen freezing and expansion.The findings in this paper can be used as a reference for researching and addressing roadbed freezing and expansion problems.展开更多
基金supported by the scientific research test of China Railway Corporation(Z2013-038)the National Natural Science Foundation of China(Nos.51208320 and 51178281)the Key Subject of China Railway Corporation(Nos.2014G003-F and 2014G005)
文摘Recent years have seen a large number of high-speed railways built and will be built in seasonal frozen soil regions ot China. Although high-speed railways are characterized by being fast, comfortable and safe, higher standards for defor- mation of the railways＇ frozen subgrade are required. Meanwhile, changes in subgrade soil temperatures are the main factors affecting the deformation of frozen subgrade. Therefore, this paper selected typical test subgrade sections of the Harbin-Qiqihar Line, a special line for passenger transport built in the deep seasonal frozen soil regions of China, to monitor field temperatures. Also, the temperature changing laws of railways＇ subgrade in this region was analyzed by using testing data, the aim of which is to provide a technical support for future design and construction of buildings and structures in a deep seasonal frozen soil region.
基金funded by the National Natural Science Foundation of China(NSFC)(grant number:52078312).
文摘The freezing and expansion diseases of railroad roadbeds are prevalent in areas that experience seasonal freezing.This study aims to investigate the features of the freezing and expansion mechanism of seasonal frozen railroad roadbeds and the effects of the freezing and expansion diseases on the roadbeds.This article presents a study of the Shuo-Huang Heavy Duty Railway.Initially,on-site monitoring tests were conducted to analyze the roadbed temperature,water content and deformations due to freezing.Through these tests,the pattern of development of the roadbed freezing and swelling was understood,and the effect of this on the vibration response of the roadbed was investigated.Subsequently,load-free freezing tests were performed to investigate the freezing and expansion features of the roadbed.Through on-site monitoring,it has been determined that the seasonal freezing layer is approximately 0.5 m deep.The depth of the frozen expansion on both sides of the road shows clear differences.The frozen and expansion disease significantly amplifies the vibration acceleration of the roadbed,with a tendency towards low-frequency and high-amplitude vibrations.Through indoor testing,we compared the deformation of frozen specimens and their final freeze and expansion rates at different cold-end temperatures and various initial moisture content levels.We find that the initial moisture content has a greater impact on specimen freezing and expansion.The findings in this paper can be used as a reference for researching and addressing roadbed freezing and expansion problems.
