土岩地基抗拔桩破坏模式数值模拟研究

Numerical Simulation of Failure Model of Uplift Pile in Soil and Rock Foundation

文中以贵州某高层建筑为例,利用抗拔桩现场试验和数值模拟手段分析抗拔桩的力学特性及破坏模式。结果表明,完全嵌土以及完全嵌岩条件下,随着抗拔桩长的增加,桩顶位移和极限承载力均不断增加。嵌岩组合条件下,随着抗拔桩长的增加,桩顶位移不断降低,极限承载力均不断增加。当桩长为4 m时,抗拔桩的桩顶位移为46.3 mm,极限承载力为5 153.62 kN;当桩长为6 m时,抗拔桩的桩顶位移为12.99 mm,极限承载力为14 597.98 kN,分别比桩长4 m条件下的桩顶位移低16.1%、比极限承载力高225.6%。完全嵌土地基、完全嵌岩地基以及嵌岩组合地基条件下,抗拔桩的破坏模式分别为圆柱面破坏、倒圆锥破坏、圆柱面和倒圆锥复合破坏。

Taking a high-rise building in Guizhou as an example,the mechanical properties and failure modes of pull-out pile are analyzed by field test and numerical simulation.The results show that the top displacement and ultimate bearing capacity of the pile increase with the increase of the length of the pile under the condition of full soil embedment and rock embedment.Under the condition of rock-socketed combination,with the increase of the length of the uplift pile,the displacement of the top of the pile decreases and the ultimate bearing capacity increases.When the pile length is 4 m,the top displacement of the uplift pile is 46.3 mm,and the ultimate bearing capacity is 5153.62 kN.When the pile length is 6 m,the top displacement of the uplift pile is 12.99 mm,and the ultimate bearing capacity is 14597.98 kN,which is 16.1%lower than that of the pile length 4 m,and 225.6%higher than that of the ultimate bearing capacity.Under the conditions of completely embedded soil foundation,completely embedded rock foundation and rock-embedded composite foundation,the failure modes of uplift piles are cylindrical failure,inverted cone failure,cylindrical failure and inverted cone composite failure,respectively.