混凝土坝不同溃决方式下溃口水力学试验研究

Hydraulic Experimental Study on Concrete Dam Break with Different Break Modes

混凝土坝溃决一般在极短时间内发生,以往研究很少考虑其溃决过程和溃决方式。根据混凝土坝结构特征和受力特点,假定了滑动式、倾倒式、开门式3种可能的溃决方式,通过物理模型试验研究了3种溃决方式的溃口水力学特征,并同经验瞬溃计算结果进行了比较。成果表明:溃口峰值流量试验值一般比计算值要小,3种溃决方式中,滑动式溃口峰值流量最大,危害最大。试验考虑了混凝土的溃决过程和溃决方式对溃口水流特征的作用,可为经验公式修订和溃坝机理研究提供指导。

Concrete dam break generally occurs in a very short period of time.Previous studies seldom consider the process and mode of dam break.According to the structural characteristics of concrete dam and the stress characteristic,we assumed three possible dam break modes,namely,sliding,toppling over,and opening.We examined the hydraulic characteristics of breach under such three modes via physical model test,and compared the test results with empirical transient failure calculation results.Comparison revealed that the calculated values of peak flow rate at breach were higher than test values in general.Among the three break modes,sliding failure witnesses the maximum flow rate with the greatest harm.The results provide guidance for revising empirical formula of dam break by taking into consideration the influence of process and mode of dam break on the hydraulic characteristics of breach.