摘要
崩塌滑坡等地质灾害可能在河流上形成堰塞坝。堰塞坝的稳定性决定其溃决风险,因而关系到下游众多人口的生命财产安全。本文通过在四川"5.12"震区大量的野外考察与实测工作,分析了堰塞坝泄洪道中河床结构对堰塞坝稳定性的影响。经统计发现,震区堰塞坝的泄洪道中常常发育一定的河床结构,使得结构强度Sp值上升,抵御水流侵蚀,改变了河流纵剖面等地貌特征。堰塞坝的保留坝高比与Sp值有明显的正相关关系。而粗颗粒成分比重较大的堰塞坝,形成的河床结构强度Sp值也往往较大。因此,可以根据坝体级配近似推测河床结构的发育,进而得出保存比例,并以此来评价堰塞坝稳定性。
Landslide dams could be formed by mass movements such as landslides and avalanches;their stability is crucial to the security of downstream population.In this paper,the influences of riverbed structures on landslide dams stability were studied through field survey and measurement in the ＇5.12＇ Sichuan earthquake-hit area.The results indicate that streambed structures developed in the spillways of many landslide dams and that the enhancement of structure intensity Sp impeded the erosion and altered the local geomorphology features such as longitudinal profiles.The preservation height of landslide dams was proportional to SP that took a larger value for a dam of coarser grain size.Thus,this reveals that the grain gradation could be used to estimate the development of streambed structures and the preservation proportion of dams,so that the stability of these dams could be assessed.
出处
《水力发电学报》
EI
CSCD
北大核心
2011年第3期98-103,共6页
Journal of Hydroelectric Engineering
基金
国家自然科学基金(5100909641001008)
南京水利科学研究院院基金(Y210003)
关键词
河流泥沙工程学
堰塞坝稳定性
河床结构
结构强度
保留坝高比
river sedimentation engineering
landslide dam stability
riverbed structures
structure intensity
preservation proportion
