拉力作用下钢管桩剪力键的数值模拟研究

Numerical Simulation of Shear Key of Steel Tubular Pile under Tension Force

剪力键是连接钢管桩与其上部结构横梁的构件,目前对其受力的计算主要是参照腿柱与导管架之间剪力键的计算方法,即假设各键对荷载均匀分配,但在拉力作用下,剪力键位置处易产生剪切、拉伸、曲屈等破坏模式,说明各键对荷载均匀分配这一假设有待进一步商榷。为探寻各键在拉力作用下对荷载的分配规律,采用数值模拟方法建立了多对钢管桩剪力键的受力模型,通过3种不同的设计方案对实际的工程案例进行分析,得出各方案下各键的受力情况。研究发现各键对荷载并非均匀分配,越靠近桩帽处的键受力越大;各键之间存在相应的分配系数,分配系数这一概念的提出,为剪力键设计提供了一个新的方法与视角。

Shear keys are a structure to connect steel tubular pile and its upper structure cross beam.At present,the calculation of stress mainly refers to calculation method of shear keys located between leg column and jacket,which assume that load values are distributed by each key.But the shear keys are always broken under tension force.The common failure modes include shear,tension,buckling,and so on.It shows that the assumption needs to be further discussed.In order to find out the load distribution law of each key under tension force,this paper sets up a steel tubular pile numerical model with several pairs of shear keys.Through three different cases of the actual engineering,the stress of each key under all cases is obtained.The results indicate that the load value of each key is not uniformly distributed.The keys which are closer to the pile cap get bigger force.The distribution coefficients existed among shear keys.Moreover,the concept of distribution coefficients provides a new method and perspective for the design of shear keys.