截面型式对钢桩水平受荷的影响特征

Effect of cross-section shape on the lateral response of steel piles

目前针对异形截面桩的研究主要集中在现浇混凝土桩的竖向承载力承载特性,而对异形截面薄壁钢桩的水平向承载特性研究较少.基于数值模拟,研究3种不同截面桩型(空芯圆桩、空芯方桩及X形桩)、两种不同长径比(桩基嵌固深度与桩外径或宽度的比值)的钢桩水平承载特性.研究表明,对于半刚性桩,方桩、X形桩等异形截面桩的承载力比圆桩高,两者的承载力要比圆桩分别高9%和11%;对于柔性桩,方桩承载力比圆桩和X形桩均高约15%.在此基础上,通过对比桩身变形、最大弯矩等,探讨不同截面桩型的优缺点,得到3种桩型的力学特征之间的经验关系,以便于实际工程设计中参考.

Current researches on pile with special-shaped sections mainly focus on the vertical bearing capacity of cast-in-place concrete piles,but there is little research on the lateral response of thin-walled steel piles with special-shaped sections.By means of numerical simulation,this paper presents an extensive study on the lateral response of steel piles with three different cross-section shapes(including the circular pipe pile,square hollow pile and X-section pile)and two different aspect ratios(the ratio of pile embedded length to the outer diameter or width).The results show that:for semi-rigid piles,compared with that of the pipe pile having the same displacement at the pile head,the bearing capacity of the square hollow pile increases about 9%and X-section pile increases up to 11%.for flexible piles,with a given pile head displacement,the bearing capacity of square hollow pile is about 15%higher than that of pipe pile and X-section pile.Furtherly,this paper discusses the merit and demerit of these three cross-section pile by comparing their displacement and bending moment,from which,the relationships betweem them are developed to aid the industrial design.