青藏铁路运营期间低温冻土区片石气冷路基工程效果分析

Analysis of Engineering Effects of Slice Stone Air-cooled Embankment on Lower Temperature Permafrost Regions in Qinghai-Tibet Railway's Operation Period

冻土区筑路技术问题的关键是冻土的热稳定性,这种热学问题的力学表现是路基变形。通过对青藏铁路运营期间冻土区典型地段路基地温场和路基变形特征的分析,指出青藏铁路冻土区路基地温场形态控制了长期运营期间的路基变形总量和横向差异变形总量。这些变形主要由冻土季节融化层土体的冻胀融沉变形、冻土压缩变形、冻土长期蠕变变形组成。工程监测以及理论计算证明了片石气冷路基结构保护冻土效果的长期可靠性,证明了其减少运营期路基变形,保证冻土区路基工程的长期稳定性的效果。

Thermal stability is a key technology problem of road-building in permafrost area and the mechanics indication of such calorifics problem is embankment deformation. With the analysis on embankment geotemperature field and their deformation characteristic in typical section of permafrost during the operation of Qinghai-Tibet railway, it is concluded that gross embankment deformation and their transverse discrepancy are controlled by geotemperature field in the long-time operation of Qinghai-Tibet railway in the permafrost area. These deformations mainly include the following three： frost-swell thaw collapse deformation, permafrost compression deformation and permafrost long-term creep deformation caused by seasonally thaw layer. Long-term reliability of embankment structure of the air-cooled slice stone protecting permafrost and stable effect of decreasing embankment deformation in operation are testified by engineering monitoring and theoretical computation.