与宽尾墩联合使用的消力池底板压强特性试验研究

Experimental study on the bottom pressure of a stilling basin combined with flaring gate piers

压强分布规律是决定消力池底板能否稳定的一个主要因素。本文通过水力学模型试验测试结果,对与宽尾墩联合使用的消力池底板时均压强与脉动压强分布规律进行了研究,研究发现,池底板时均压强可沿程分为冲击区、跳跃区和恢复过渡区,冲击区一般水流可能承受动水压强作用,且不同水流条件下,动水冲击压强会出现不同的变化规律,跳跃区时均压强会随着冲击区动水压强增加而减小。脉动压强变化一般主要集中在冲击区,且脉动压强会随着尾水深度及尾坎高度的增加而减小,随着消力池长度的增加而增加,采用X型宽尾墩后,脉动压强可能比采用Y型宽尾墩减小大约20%以上。

Pressure distribution is a crucial feature to the stability of stilling basin bottom.This paper presents a study of hydraulic model test on the time-average pressure and pressure fluctuations on the bottom of a stilling basin in combined use with flaring gate piers.It is found out that the spatial distribution of time-average pressure can be divided into three different regions characterized by impacting,jumping and restoring,respectively.The impact region is dominated by hydrodynamic pressure that varies under different inflow conditions,and the jump region is featured by time-average pressure lowering with the rising hydrodynamic pressure.Most of the pressure fluctuations are concentrated in the impact region,and they decay with the increase in tail water depth or tail bank height,while they grow with the basin length.They can be reduced by over 20% in the case of X-shaped flaring gate piers than Y-shaped piers.