摘要
基于黏土心墙坝的漫顶溃决机理,提出一个模拟其溃决过程的数学模型.该模型基于坝体形状和漫顶水流特征确定下游坡冲蚀时的初始冲坑位置,采用宽顶堰流量公式计算溃口流量,并利用溯源冲刷公式模拟坝壳料的冲蚀;通过力矩平衡法与力学平衡法分别模拟了心墙的倾倒破坏与剪切破坏;为了模拟实际溃坝情况,模型考虑了坝体的单侧冲蚀、两侧冲蚀及坝基的冲蚀;采用按时间步长迭代的数值计算方法模拟溃坝时的水土耦合过程.选择国内外10个具有实测资料的心墙坝漫顶溃坝案例对模型进行验证,通过比对峰值流量、溃口最终宽度及溃坝历时等参数发现,模型计算结果与实测值的相对误差可满足工程需求,验证了模型的合理性.
Based on the breach mechanism of clay core dam due to overtopping failure, a numerical model for dam breaching process is put forward. In this model, the initial scour position on the downstream slope is determined by means of the characteristics of dam figuration and overtopping flow, the broad-crested weir formula is adopted to calculate breach flow discharge, and a time averaged backward erosion formula is adopted to simulate the dam shell breach. The moment and mechanical equilibrium methods are utilized to model the overturning and sliding failures of the core, respectively. In order to simulate the actual failure mode of the dam, one-and two-sided erosion, as well as dam base erosion, are taken into account. The model adopts the iterative calculation method to simulate the coupling process of water and soil during dam breaching. 10 clay core dam overtopping failure cases which have measured data are adopted to testify the present model. The comparison of measured data and calculated results on peak breach flow, final breach width and failure time shows that the calculated results can meet the engineering requirements, and the statistics of model＇s relative errors validate the reasonability of the present model.
出处
《中国科学：技术科学》
EI
CSCD
北大核心
2017年第9期992-1000,共9页
Scientia Sinica(Technologica)
基金
国家自然科学基金(51379129
51539006
51509164)
江苏省自然科学基金(BK20161121
BK20150077)资助项目
关键词
黏土心墙坝
漫顶
心墙破坏
数学模型
clay core dam
overtopping
core wall failure
numerical model
作者简介
E—mail：qmzhong@nhri．cn
