RELATIONSHIPS BETWEEN CLIMATE WARMING AND ENGINEERING STABILITY OF PERMAFROST ON QINGHAI-TIBET PLATEAU

Climate warming and engineering actions impact and accelerate permafrost degradation, resulting in significant changes of engineering stability in permafrost regions. This article mainly discusses the relationship between climate warming and engineering stability from the view of permafrost changes and engineering hazards under the impacts of climate warming and engineering. We summarize the changes in active layer thickness and permafrost temperature under climate warming and in permafrost table and temperature under the embankment of Qinghai-Tibet Highway and Railway and their subgrade deformation. Especially, we summarize the engineering measures of preventing permafrost thaw under the embankment in Qinghai-Tibet Plateau and discuss the role of these measures of cooling underlying permafrost under the future climate warming and its impact on the engineering serviceability. The results show that the Plateau permafrost has undergone remarkable degradation during the past decades and engineering thermal impacts accelerated permafrost degradation under the embankment, resulting in engineering instability. Qinghai-Tibet Railway used some measures of cooling the underlying permafrost, which can adapt to climate warming of 1.0 ℃. Under the future climate warming of 1.5 ℃, reinforcement measures of Qinghai-Tibet Railway is required and has to be planned as soon as possible.