青藏铁路沿线83道班移动冰丘及工程治理

Migrating pingos at the 83rd Station of the Qinghai-Tibet Railway and their engineering controls

青藏铁路沿线发育6个典型移动冰丘,冰丘冻胀对线路工程具有严重破坏作用,导致桥墩扭裂、涵洞破裂与输油管道弯曲变形,产生显著的灾害效应。83道班移动冰丘发育于二道沟盆地南侧两组断层的交叉复合部位,属断层破碎带桥基施工诱发移动冰丘;夏季表现为上涌泉水,形成泉坑;冬季形成厚度达0.5m的冰幔和高达2.5m的冰丘,产生了比较严重的灾害隐患。在泉水富集部位,通过修筑堤坝、泉水池和排水通道,改变了泉水的运移路线,消除了移动冰丘及灾害隐患,确保了83道班铁路大桥的工程安全,为青藏铁路沿线移动冰丘的工程防治积累了成功经验。

There are six typical migrating pingos along the Qinghai-Tibet Railway and freezing and swelling of some of these pingos caused fracturing of bridge piers and culverts and bending of oil pipelines along the railway and highway. The migrating pingo near the 83rd station occurs at the site of intersection and compounding of two sets of faults at the south side of the Erdaogou basin and is a migrating pingo induced by the underground construction of bridge piers in a fractured zone. It consists of a 0.5 m thick ice mantle and a 2.5 m high pingo in winter and becomes spring water ponds in summer after melting of the pingo. The pingo was considered as one of the potential hazards to the railway. Dams, spring water pools and conduits were constructed at the site east of the railway bridge where spring water was concentrated. These engineering works changed the paths of surface and underground spring water, reduced the concentration of spring water at the bridge piers, eliminated the ice mantle and migrating pingo surrounding the bridge piers and successfully ensured the safety of the railway bridge east of the 83rd highway station. Engineering controls on spring water near the 83rd highway station provides new experience for controlling geological hazards of migrating pingos along the Qinghai-Tibet Railway.