[关键词]
[摘要]
章古滑坡位于大渡河右岸,姑咱镇下游2.5 km处,体积约19000×104 m3,属特大型滑坡,且该区属高烈度区, 滑体一旦失稳,可能造成堵河和堰塞溃坝。为了分析滑坡的演化过程及发展趋势,通过野外调研、测绘、物探及室内测年等研究方法,利用三维有限元软件(FLAC-3D)进行数值模拟分析,对滑坡的演化机制和滑坡体的稳定性进行了研究。结果表明: 章古滑坡为古地震滑坡,滑坡体的形成经历了河谷卸荷松弛、大渡河侧蚀、强震滑坡和翻坝侵蚀四个阶段;目前,滑坡体整体处于稳定状态,但局部范围可能发生次级滑坡。
[Key word]
[Abstract]
The Zhanggu Landslide lies at the right bank of the Daduhe River and 2.5 km downstream of Guza Town, which is a super large-scale landslide with a volume of 19000×104 m3. This area belongs to the highly seismic region. Once the landslide is damaged, it can result in river blocking and dam break. In order to analyze the evolution process and develop trend of the landslide, the field investigation, geological mapping, geophysical prospecting, and laboratory dating methods were used to investigate the formation-evolution mechanism and stability of the Zhanggu Landslide based on the numerical simulation using the three-dimensional finite element software (FLAC-3D). The results showed that the Zhanggu Landslide is a palaeo-earthquakr landslide and its formation includes four stages: unloading and relaxation of the Daduhe River, lateral erosion of the Daduhe River, slope failure triggered by a strong earthquake, and river dam erosion. At present, the landslide is in stable condition but a secondary landslide may occur on the local scale.
[中图分类号]
[基金项目]
国家自然科学基金(2008CB425801),中国地质调查局工作项目(1212010914010),重点实验室基金(SKLGP2009Z001)