水流攻击角影响群桩桥墩周围局部冲刷护圈防护效果研究

Study on Protective Effect of Water Flow Attack Angle on Local Scour Guard Ring around Pile Bridge Piers

护圈防护是一种减速不冲防护技术,通过室内水槽试验对清水冲刷条件下水流攻击角对护圈防护效果的影响进行研究。研究结果表明,水流攻击角小于7.5°时,群桩桥墩周围最大冲刷深度削减率为100%,此后随着水流攻击角度的增加,群桩桥墩周围最大冲刷深度削减率减小,水流攻击角增大到15°时,冲刷深度削减率下降为79.3%。

The protection of guard ring is a kind of slow-down and non-scouring protection technology. Under the condition of fresh water scouring, the influence of water flow attack angle on protective effect of guard ring is studied through the indoor water tank test. The results indicate that when the attack angle of water flow is less than 7.5 °, the maximum scour depth reduction rate around the pile bridge piers is 100%. With the increase of water flow attack angle, the reduction rate of maximum scour depth around pile bridge piers decreases. As the water flow attack angle is increased up to 15 °, the scour depth reduction rate drops to 79.3%.