金沙江白格滑坡运动过程分析及潜在不稳定岩体预测

Movement of Baige Landslide in Jinsha River and Prediction of Potential Unstable Rock Mass

2018年10月11日和11月3日于西藏江达县波罗乡白格村与四川省白玉县绒盖乡则巴村交界处,金沙江右岸先后发生两次滑坡,堵塞金沙江形成堰塞湖,经人工干预险情解除未造成严重损失。采用Voellmy流变模型,基于PCRaster环境使用MassMov2D模拟了两次滑坡的运动和堆积过程,并使用第二次滑坡的反演结果对白格滑坡滑源区的三处潜在不稳定岩体做了预测分析。模拟结果表明:MassMov2D可以用于金沙江白格滑坡这种滑坡-碎屑流的模拟,两次滑坡的主要堆积区域和堆积厚度均于实际情况接近;利用第二次滑坡模拟反演参数预测三处潜在不稳定岩体,假设三处不稳定岩土体同时失稳滑动,会形成64 m高的堰塞坝,可能再次堵塞金沙江形成堰塞湖。

On October 11 and November 3,2018,at the junction of Baige Village,Boluo Town,Jiangda County,Tibet,and Zeba Village,Ronggai Town,Baiyu County,Sichuan in the SW China,two landslides occurred on the right bank of the Jinsha River,blocked the Jinsha River valley,and formed barrier lakes.Luckily,the landslides did not cause serious losses due to human intervention.The movement and accumulation of two landslides were simulated using MassMov2 D in PCRaster environment in Voellmy rheological mode.Results show that MassMov2 D simulation well replayed the landslide-debris avalanche of the Baige landslide and showed similar accumulation areas and thickness of the two landslides to those of the real cases.The inversion parameters of the second landslide simulation were used to predict local three potentially unstable rock mass bodies,based on which a warning was made that if the three bodies could slide simultaneously,a 64-m high barrier dam would form,and the Jinsha River would be cut again with a barrier lake.