十雅玛尔河南移动冰丘.pdf

十六、雅玛尔河南移动冰丘 雅玛尔河南移动冰丘发育于雅玛尔河南岸，属断裂破碎带中部桥墩施工诱发上涌泉水汇 集于桥墩西侧经冬季冻结形成的椭圆形冰丘。2004 年3 月，雅玛尔河南移动冰丘长8m，宽 4m，高1.6m，呈近东西走向，发育于墩台西侧；在移动冰丘顶部，沿冰丘长轴发育宽20-40cm 的冰裂缝，低温泉水沿冰丘顶部冰裂缝流动，向东流向墩台，在墩台西侧冻结形成地表冰层。 2004 年 7 月，桥梁铺轨后通行运料列车，列车通过雅玛尔河南铁路大桥，导致断裂破碎带 桥基震动，在桥基部位诱发较大流量的上涌泉水，冬季能够形成较大规模的移动冰丘，产生 比较严重的灾害隐患。 PART 16 SOUTH YAMAERHE MIGRATING PINGO AND ITS POTENTIAL HAZARD South Yamaerhe migrating pingo formed in a branch fault in south Erdaogou basin cutting late Quaternary fluvial deposits in south of Yamaerhe River. As one typical example of migrating pingo induced by underground construction of bridge pier in fault zone, south Yamaerhe pingo appeared as oval-shaped and was 8m long, 4m wide and 1.6m high in March of 2004. Here existed no springs in summer and no pingo in winter before the construction of railway bridge in 2002. However, underground construction of bridge pier of Golmud-Lhasa Railway in fault breccia lead to huge accumulation of upward outflow of spring water in west of the pier in summer and autumn, and freezing of such spring water in winter further lead to growth of south Yamaerhe migrating pingo. Train moving across south Yamaerhe bridge in May-June of 2004 caused pier vibration in fault breccia, formed new fractures in permafrost and eastward migration of underground water along new fractures and resulted in upward rushing springs surrounding bridge pier in July of 2004. Such upward rushing spring water may change into larger and higher pingos surrounding the pier in severe cold winter to form potential geological hazard threatening the safety of south Yamaerhe Bridge. 图206 雅玛尔河南断裂破碎带 （镜头向北，摄于2004 年7 月） Fig.206 View northward in July of 2004 at breccia of the branch fault in south bank of Yamaerhe River 图207 雅