青藏高原北部不冻泉移动冰丘及灾害效应

不冻泉移动冰丘发育于青藏高原北部常年冻土区断裂破碎带,2001年仅在青藏公路东南侧形成1个小型冰丘,2002年在青藏公路西北侧形成低矮冰丘群,2004-2005年发展成为大型冰丘群,2006年移动冰丘的发育高度和分布范围进一步增大。不冻泉移动冰丘不仅穿刺青藏公路路基,破坏青藏公路桥涵结构,蚕食青藏公路路堤,影响青藏公路的交通安全;而且导致输油管道拱曲变形,诱发地面塌陷和地裂缝,产生显著的灾害效应。采用适当的工程措施,通过地下疏导或地表排放沿断裂破碎带上涌的地下泉水,能够有效减轻或防治不冻泉移动冰丘的灾害效应。

Budongquan Migrating Pingos and Their Hazard Effects in the Permafrost North Tibetan Plateau

Budongquan migrating pingos form within NE-trending active faults in the permafrost north Tibetan Plateau.Only one small pingo formed in southeast margin of Golmud-Lhasa highway in 2001,and the pingos migrated to northwest of the highway along the buried Budongquan fault zone in 2002.The pingos migrated to northeast section of Budongquan valley and changed to larger-scale pingo groups in 2004-2005.And scale,height and covering area of Budongquan migrating pingos further increased in 2006.Budongquan migrating pingos not only piered and etched the highway,but also destructed the culvert,depressed ground surface,bended oil-pipeline and formed ground fracture zones.Hazards of Budongquan migrating pingos can be decreased or protected by taking engineering measures as building underground water conduits or draining off the upward rushing spring water near ground surface.