基于Massflow的金沙江白格滑坡数值模拟及堵江风险预测

MASSFLOW MODEL-BASED RISK PREDICTION ON BAIGE LANDSLIDE IN JINSHA RIVER

2018年10月10日和2018年11月3日,金沙江白格先后两次发生特大型滑坡堰塞堵江事件,尤其是第二次滑坡后,滑坡区后缘及中后部两侧产生强烈变形,形成一系列潜在不稳定块体(残留体)。结合相关学者研究和应急勘查成果,在详细分析白格滑坡残留体特征及发展变化趋势的基础上,基于Massflow数值模拟软件对残留体堵江范围和高度进行了风险预测研究。结果表明:(1)滑坡残留体仍处在应力调整及变形状态,K2、K3及K1-2变形速率较大,滑槽弃渣堆积体雨季冲刷严重,存在再次发生滑坡堵江的风险。(2)残留体8种组合模型失稳后主要沿原滑槽方向运动,堵塞金沙江,形成长条形堰塞坝,最大厚度约58 m,部分颗粒残留在滑坡表面。(3)该方法对高位滑坡堵江风险预测具有一定的参考价值。

On October 10, 2018 and November 3, 2018, two large-scale landslide weir blockages occurred in Jinsha River. Especially after the second landslide, strong deformation occurred on both sides of the trailing edge and the middle and rear part of the landslide area, forming a series of potentially unstable blocks(residues). Based on the related academic research and emergency exploration results, a detailed analysis of the characteristics and the residue bishops landslide development trends. Massflow numerical simulation software is used to predict the extent and height of the residual plugging in the river. The results show the follows.(1)The residues are still in the state of stress adjustment and deformation, and the deformation rate is relatively high. The deposit on landslide trough is scour seriously in the rainy season, which increases the risk of blocking the river.(2)The residual body mainly moves along the direction of the original chute after instability. Scenario 8 is the most hazardous of all, that the maximum thickness of landslide accumulation is 58 m.(3)A simulation method of landslide blocking river is proposed, which can help predict landslide damming of high-position landslide.