基于性能的季节性河流栈桥钢管桩基础设计

Design of Steel-pipe Pile Foundation of Seasonal River Trestle Based on Performance

该文基于多层次设防设计思想,分析了季节性河流桥梁施工临时结构在不同设计状态下的抗洪性能,比较了不同布置形式钢管桩基础在水流力作用下的结构响应,为不同水深区域栈桥桩基础形式的选取提供依据。研究表明,斜桩布置形式在抵抗以水流力为主的侧向力最为有效,而直桩布置形式的效果最差,钢管应力水平和桩顶侧向位移指标远高于斜桩布置形式,因此,在位于深水区的单排双柱式钢管桩不宜采用直桩布置形式。而对于直+斜桩组合布置形式,各设计状态下的结构响应介于前两种方案之间,并满足设计要求。可见,在施工条件受限时,可采用直+斜桩组合布置形式钢管桩基础。

Based on the multi-level fortification design idea,the article analyzes the flood control performance of the temporary structures for the construction of the seasonal river bridge at the different design states,compares the structural responses of the differently arranged steel-pipe pile foundations at the flow force,and provides the basis for the selection of pile foundation types of the trestle in the different water depth areas.The study shows that the oblique arrangement of piles is most effective to resist the lateral force mainly by the water flow force,while the straight arrangement of piles is the worst,but its steel pile stress level and pile-top lateral displacement index are much higher than the oblique arrangement of piles.Therefore,the single-row double-column steel-pipe pile is not suitable in the straight arrangement type in the deep water zone.The structural response of the straight and oblique pile combined arrangement is between the above two at various design states,and satisfies the design requirements.It is thus clear that the steel-pipe pile foundation in the type of straight and oblique pile combined arrangement can be used when the construction conditions are limited.