青藏铁路冻土区土体冷生过程对路基变形影响

Influence of soil’s cryogenic course on deformation of roadbed in permafrost region of Qinghai-Tibet Railway

一般地区路基土体变形主要受土体压密过程控制,青藏铁路冻土路基变形则主要是受土体冷生过程影响和控制。通过对填土路基修筑后土体冷生过程以及工程实测数据分析,指出冻融过程不同阶段冻土路基变形与土体冷生过程有着密切关系。认为控制填土路基冷生过程稳定时间和填土路基地温场形态,是减少冷生过程和铁路长期运营过程中路基变形、保证冻土区路基工程长期稳定性的有效途径。此认识已经在青藏铁路冻土区路基工程建设实践中得到证明。

The deformation of normal roadbed is mainly controlled by compaction of soils, but that of the permafrost roadbed in Qinghai-Tibet Railway is mainly influenced and controlled by cryogenic course. The results obtained from analysis of the course after construction of the railway and the data from in-situ engineering tests have pointed out that there exists an intimate relationship between the deformation of permafrost embankment in different phases and the soil＇s cryogenic course. The results also show that if man can control the stabilizing time of the cryogenic course and the ground＇s temperature field configuration of the filling roadbed, then the deformation of the roadbed can be reduced during the cryogenic course and the long-term operation course of the railway; thus ensuring the long-term stability of the roadbed project in permafrost regions effectively. This has been proved right in the engineering practice of the construction of Qinghai-Tibet Railway on permafrost soils.