摘要
某码头引桥防撞拦截系统(由防撞墩、拦截钢管排架和锚链组成)按旧规范驳船等效静力250kN设计。为了解该系统在新规范下的防撞能力,采用MIDAS软件建立模型,船舶撞击力按修正半正弦波荷载模型取值,计算撞击力分别作用于防撞墩和钢管排架时结构的位移和应力,并与新规范等效静力(1 000kN)结果进行对比。结果表明:撞击力作用在防撞墩时,防撞墩最大位移达0.36m并逐渐衰减,几乎无残余变形,钢管桩应力较大、已屈服但可正常工作;撞击力作用在钢管排架时,排架最大位移达3.74m并逐渐衰减,10s后残余变形稳定在2.27m,钢管桩应力接近极限强度但未倒塌,需维修加固方可工作,防撞拦截系统满足原防撞目标要求;当施加等效静力预判结构进入屈服时,应考虑进行动力分析。
The collision protection system for the approach bridges at a harbor,which comprises the collision resistant pier,steel-tube guarding bents and anchor chains,is designed as per the250 kN equivalent static force of barges in the previous codes.To examine if the collision protection capacity of the system was in compliance with requirements of new codes,the models were built up by MIDAS to calculate the displacement of and stresses in the structure when the collision forces act on the collision resistant piers and steel-tube bents,respectively,with the ship collision forces drawn from the modified half-sine wave load models.The results were compared with the data obtained when the equivalent static force was taken as 1 000 kN according to the new code.The comparison shows that when the force acted on the collision resistant piers,the maximum displacement of the collision resistant piers reached 0.36 mand gradually diminished,residual deformation was hardly observed,the stresses in the steel tubes were big,and the steel tubular pile had yielded,but could keep working as usual.When the collision force functioned on the steel-tube bents,the maximum displacement of the bents ascended up to 3.74 mand gradually decreased,and the residual deformation stabilized at 2.27 mafter 10 s,the steel tubular pile did not collapse,though the stresses were approximate to the ultimate values,which could resume working after strengthening,revealing that the collision protection system meets the requirements of initial collision protection objective.When using equivalent static forces to prognosticate if the structure begins to yield,the dynamic analysis should be considered.
作者
黄向平
HUANG Xiang-ping(CCCC Third Harbor Consultants Co.,Ltd.,Shanghai 200032,China)
出处
《世界桥梁》
北大核心
2020年第4期60-64,共5页
World Bridges
关键词
桥梁工程
防撞拦截系统
修正半正弦波荷载模型
撞击力
位移
应力
有限元法
bridge engineering
collision protection system
modified half-sine wave load model
collision force
displacement
stress
finite element method
