Engineering in the rugged permafrost terrain on the roof of the world under a warming climate

Permafrost is sensitive to both climate warming and engineering disturbance on the Qinghai–Tibet Plateau (QTP). These factors degrade the stability of infrastructure built on permafrost and reduce its service life. To counter these effects, cooling of the subgrade to lower permafrost temperature forms part of the engineering design on the QTP. Proactive cooling of the subgrade has been used in construction of the Qinghai–Tibet Railway (QTR), the Chaidaer–Muli Railway, the Qinghai–Tibet DC Power Transmission Line, and the Gonghe–Yushu Express Highway. As a consequence, there has been significant ground cooling and little permafrost thaw beneath these infrastructure projects. However, the QTR has experienced some problems, such as in the stability of transitions at bridge abutments, reductions to the convective capacity of crushed rock structures from infilling by eolian sand, and freeze–thaw damage. A monitoring network has been established to examine the influence of climate change for engineering stability on the QTP. Climate warming on the plateau will present significant challenges for engineering of proposed oil and gas pipelines, express highways and the high‐speed railway from Golmud to Lhasa.