ANALYSIS ON MECHANISM OF DISEASE ABOUT SUBGRADE DRAINAGE CANALS OF QINGHAI-TIBET RAILWAY IN PERMAFROST REGION

摘要

On the basis of site investigation, the main failure types of drainage canals of Qinghai-Tibet Railway subgrade are studied in permafrost region, including carbonization and fracture of concrete, collapse of canals, water infiltration and accumulation inside drainage canals.The diseases of canals are mainly caused by climate, construction quality of canals, uneven frost heaving and thawing settlement of foundation soil repeatedly, the terrain and geological conditions.Control measures of canal diseases could be made from two aspects, namely reducing frost heaving and thawing settlement, and using structure type of canal which might resist uneven deformation of soil.