筐网基桩群对桥墩冲刷保护之探讨

Protection of bridge scour using pile groups with porous basket

室内试验证明利用在基桩上部增设筐网,增大基桩对水流流速减少的效果,以提高基桩群对桥墩保护效率。在实际应用于桥墩冲刷保护时,将于桥墩上游布置三角形筐网基桩群,以减弱水流流速降低桥墩冲刷,同时可以阻挡漂流木对桥墩撞击,达到保护桥墩的功效。例举台湾3座桥墩保护,经由洪水作用后均能达到减少冲刷之效果,且漂流木不再冲击桥墩,对保护桥墩安全提供一良好的工法,值得善加应用。

The pile with porous basket can provide a better effect for velocity reduced than the one without porous basket in the lab tests. Therefore, group piles with porous baskets setting in the front of three bridges are used for protection in the field in Taiwan. From the results, the pile groups with porous baskets not only reduce the flow velocity owing to weaken scour depth of pier, but also resist the drifters to impact the piers. Hence, the method of the piles with porous basket to protect pier scouring is thought to be a very recommendable skill.