Title Characteristics and mechanisms of embankment deformation along the Qinghai- Tibet Railway in permafrost regions
Author Ma Wei; Mu Yanhu; Wu Qingbai; Sun Zhizhong; Liu Yongzhi
Author Affil Ma Wei, Chinese Academy of Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, State Key Laboratory of Frozen Soil Engineering, Lanzhou, China
Source Cold Regions Science and Technology, 67(3), p.178-186, . Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0165- 232X
Publication Date July 2011
Notes In English. Based on Publisher- supplied data GeoRef Acc. No: 309686
Index Terms solidification; construction materials; creep; deformation; embankments; foundations; frost heave; ice; loading; permafrost; railroads; settlement (structural); soils; soil creep; soil temperature; stability; temperature; thawing; thaw consolidation; China--Qinghai-Tibet Railway; Asia; China; consolidation; crushed stone; Far East; field studies; frost heaving; monitoring; Qinghai-Tibet Railway; settlement
Abstract Based on field monitoring datasets, characteristics of embankment deformation were summarized along the Qinghai-Tibet Railway in four permafrost regions with different mean annual ground temperatures (MAGTs). Then, further analyses were carried out at some typical monitoring profiles to discuss mechanisms of these embankment deformations with consideration of detailed information of thermal and subsurface conditions. The results indicated that in regions with MAGT <--1.5C, embankments only experienced seasonal frost heaves, and of which the magnitudes were not significant. So, the embankments in the regions performed satisfactorily. Whereas in regions with MAGT >=-1.5C, both traditional embankment and crushed rock embankment experienced settlements, but characteristics and mechanisms of the settlements were different for the two kinds of embankment. For crushed rock embankment, the magnitudes of settlement and differential settlement between right and left embankment shoulders were not significant and increased slowly. In respect that upwards movements of permafrost tables and better thermal stability of permafrost beneath embankment, mechanism of settlements on the embankment was inferred as creep of warm and ice-rich layer often present near permafrost table. While for traditional embankment, particularly in warm and ice-rich permafrost regions, the magnitudes of settlement and differential settlement between right and left embankment shoulders were significant and still increased quickly. Considering underneath permafrost table movements and permafrost temperature rises, mechanisms of settlements on the embankment included not only creep but also thawing consolidation of underlying permafrost. Therefore, some strengthened measures were needed to ensure long-term stability of these traditional embankments, and special attention should be paid on temperature, ice content and applied load within the layer immediately beneath permafrost table since warming and thawing of the layer could give rise to considerable settlement.
URL http://hdl.handle.net/10.1016/j.coldregions.2011.02.010
Publication Type journal article
Record ID 65006412