洪水型浊流砂体形成及分布的沉积模拟实验

Sedimentation simulation tests on formation and distribution of flood turbidity sandbodies

刘忠保 龚文平 王新海 张春生 罗顺社 江山

Liu Zhongbao Gong Wenping Wang Xinhai Zhang Chunsheng Luo Shunshe Jiang Shan

利用沉积模拟实验技术,通过大量洪水浊积砂体的原型资料,结合洪水型浊流的形成环境和条件,设计了洪水型浊流的模拟实验方案,论述了不同斜坡长度、坡度、初始流速、泥沙比例和含沙浓度等参数条件下洪水型浊流的形成过程,剖析了洪水型浊流沉积作用规律,揭示了洪水型浊流砂泥质的分布与沉积特征,分析了湖底地形对洪水型浊流沉积作用的控制,探讨了洪水型浊流砂体形成及发育的水动力机制.实验表明,斜坡带的坡度与高差、湖底地形、湖水位及初始流速等对参数对洪水型浊流沉积有重要影响,洪水型浊流的泥沙含量决定了其流动行为及沉积结构.

An experimental program for sedimentary simulation of flood turbidity current is described in this article.It is designed by using the sedimentation simulation test technology,collecting information concerning prototypes of flood turbidity sandbody,and integrating the forming environment and conditions for flood turbidity currents.The article also discusses the forming processes of flood turbidity current under different conditions,such as slope length and gradient,the initial velocity,mud-sand ratio and sand content,and etc;analyzes its deposition pattern;reveals the distribution and sedimentary characteristics of sand and muddy in flood turbidity current;dissects the controlling effect of lake-floor topography on flood turbidity sandbody and reveals the hydrodynamic mechanism for the formation and development of flood turbidity sandbody.The experimental results show that the flood turbidite deposition is influenced by various parameters,such as the slope gradient and elevation difference,the landform of the lake floor,the lake water level and the flow velocity,and that the contents of sand and mud in flood turbidity current determine its flow behaviour and sedimentary structure.

10.11743/ogg20080104