曾庆利团队(2021):Engineering Geology

  • 胡冬雨
  • Created: 2021-03-05

文章题目:High mobility of the channelized ancient Linka rock avalanche within the Bangong - Nujiang suture zone, SE Tibetan Plateau

文章摘要:Large rock avalanches often result in loss of life and catastrophic damage to infrastructure far from their initial failure positions, predominantly due to their tremendous volumes, high velocities and long runouts. Studies of the surface morphologies and internal structures of rock avalanche deposits can reveal evidence of their movement and deposition mechanisms. Through field survey, satellite image interpretation and particle-size distribution analysis, we studied the ancient, long-runout Linka rock avalanche, which is next to the Nujiang River, southeast Tibetan Plateau. The Linka rock avalanche, with a source volume of ~310 Mm3 originated from a high, steep dip slope and then transformed into a channelized rock avalanche, showing high mobility with a superelevation back-calculated maximal velocity of 42 m/s, a travel distance of ~6200 m and a Fahrboschung of 0.24. The slope failure sequence consisted of an initial failure of an outer limestone slab and a second failure of an inner sandstone slab. The limestone avalanche had 2 or 3 surges, while the sandstone avalanche probably had only one surge. The high mobility of the Linka rock avalanche predominantly resulted from a buckling failure occurred on a high relief source, low-energy dissipation during the channelized flow, intensive rock fragmentation in the basal facies and possible water lubrication when propagating bi-directionally along the Waqu River. Our findings for the Linka rock avalanche support previous knowledge that multiple mechanisms have different roles at different stages in a long runout rock avalanche.

引用信息:Qingli Zeng, Jiewang Zhu, Liye Liao, Rongqiang Wei, Fengshan Ma, Xuping Ma, Bo Yuan, High mobility of the channelized ancient Linka rock avalanche within the Bangong - Nujiang suture zone, SE Tibetan Plateau, Engineering Geology,Volume 282, 2021, 105999.