Title Characteristics of roadbed settlement in embankment-bridge transition section along the Qinghai-Tibet Railway in permafrost regions
Author Niu Fujun; Li Zhanju; Lu Jiahao; Liu Hua; Xu Zhiying
Author Affil Niu Fujun, Chinese Academy of Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, Lanzhou, China
Source Cold Regions Science and Technology, 65(3), p.437-445, . Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0165- 232X
Publication Date Mar. 2011
Notes In English. Based on Publisher- supplied data GeoRef Acc. No: 309954
Index Terms bridges; embankments; foundations; ground ice; ice; permafrost; railroads; settlement (structural); slopes; soils; China- -Qinghai-Tibet Railway; Asia; China; Chiqu Valley; Far East; ground-surface temperature; Qinghai-Tibet Railway; roads; settlement; Xidatan Basin
Abstract The Qinghai-Tibet Railway (QTR) project was finished on July 1, 2006, and has served for over 3 years. Judging from the present situation, the roadbed is stable and train speed in permafrost regions achieves 100 km/h as expected during the designing. However, as half part of the roadbed was constructed over the permafrost characterized by high ground temperature and high ice content, slight changes of the permafrost might lead to roadbed problems, of which the settlement in embankment-bridge transition section is an obvious and special one. Investigated results of 164 bridges and accounting to 656 positions from the Xidatan Basin to the Chiqu Valley along the QTR in 2009 showed that the settlement was influenced by factors including bridge orientation, embankment slope direction, embankment height, ground temperature, ground ice content of permafrost and local subgrade soil type. For the average value of the settlement, it was greater at the northern end of a bridge than that at the southern end, and was greater in sunny-slope than that in shady-slope. It was greater in high ice permafrost regions than that in low ice regions, and was greater in high-temperature permafrost regions than that in low- temperature regions. Additionally, it increased logarithmically with the height of the embankment. In regions where the subgrade soils were dominated by silt, silty clay or fine sand, the settlement amount was higher than that in bedrock regions. Correlation analysis results showed that there were good relationships between the settlement and the slope direction, embankment height, ground temperature and ice contents when some of the later items were quantified. The correlation coefficients were 0.234, 0.213, -0.21 and 0.151 respectively, when the factors were quantified.
URL http://hdl.handle.net/10.1016/j.coldregions.2010.10.014
Publication Type journal article
Record ID 65006898