Cold Regions Science and Technology ( IF 4.1 ) Pub Date : 2021-05-05 , DOI: 10.1016/j.coldregions.2021.103300 Honglei Wang , Zhizhong Sun , Jianming Zhang , Yongzhi Liu , Guoyu Li
Taliks are bodies or layers of unfrozen ground in permafrost areas. Suprapermafrost taliks (SPTs) formed between the active layer and permafrost table beneath embankments along the Qinghai-Tibet Railway (QTR) would reduce the stability of the embankments and thus threaten the safety of QTR operations, because the SPTs exhibit a lower bearing capacity than that of frozen ground. This study investigated the formation and evolution of SPTs beneath earth-filled embankments at two monitoring sites (P7 and P17) along the QTR in order to determine the SPTs formation mechanism. The SPTs under the left shoulder of the embankments at P7 and P17 were caused by thermal disturbance of filling and vertical heat accumulation, respectively. The mechanism of SPTs formation beneath the embankments was closely associated with the mean annual ground temperature and the height of embankment filling materials. The study findings can facilitate understanding the formation and evolution of SPTs beneath the embankments in similar sections along the QTR. In particular, the findings can serve as a guidance for the QTR administration bureau in implementing countermeasures for eliminating these unfrozen layers and increasing ground bearing capacity.
中文翻译:
多年冻土区青藏铁路沿土填筑路堤下覆冰霜滑石的形成与演化
Taliks是多年冻土地区的未冻结地面的物体或层。在沿青藏铁路(QTR)路堤下方的活动层和多年冻土层之间形成的超永久冻土滑石(SPT)会降低路堤的稳定性,从而威胁到QTR作业的安全性,因为这些SPT的承载力低于其冻土。这项研究调查了沿QTR的两个监测站(P7和P17)在填土路堤下SPT的形成和演化,以确定SPT的形成机理。在P7和P17处,路堤左肩下的SPT分别是由填充物的热扰动和垂直热量积聚引起的。路堤下方SPTs形成的机理与年平均地面温度和路堤填充材料的高度密切相关。研究结果可以帮助理解沿QTR的类似区域中路堤下方的SPT的形成和演化。尤其是,这些发现可以为QTR行政局实施消除这些未冻结层并增加地面承载力的对策提供指导。