为分析光伏支架扩底桩的抗拔承载过程及确定极限抗拔承载力理论公式,本文运用MIDASGTS有限元软件分析了光伏支架扩底短桩由开挖到成桩再到施加荷载整个过程.通过模拟分析,扩底短桩的抗拔过程为:加载初期,土体塑性破坏首先发生在桩顶端和底端,抗拔承载力由桩侧摩阻力提供;当荷载继续增大,土体塑性破坏区域发生横向和纵向延申,抗拔承载力为扩大端所带动土体和桩侧摩阻力提供,且桩侧摩阻力出现增强现象;最终形成贯通塑性区域的破坏面呈现"倒圆台"型.通过抗拔过程的荷载-位移曲线发现其抗拔位移曲线为"缓变型",且通过分析破坏面和对应破坏时的荷载发现,光伏支架扩底短桩在该土层中的单桩极限抗拔承载力符合规范法的理论计算式.
In order to analyze the uplift bearing process and determine the theoretical formula of ultimate uplift bear-ing capacity,MIDASGTS finite element software was used to analyze the entire process from excavation of the expand-ed gauge column of photovoltaic support to pile formation and then to load.Through simulation analysis,At the ini-tial loading stage,the soil plastic failure occurs at the top and bottom of the pile,and the uplift capacity is provided by the lateral friction resistance of the column.When the load continues to increase,the potential failure area of soil is extended horizontally and longitudinally.The uplift capacity is provided by the friction resistance of soil and pile driven by the expanding end,and the friction resistance of column side increase.Eventally form penetration through the plastic are of failure surface rendering inverted frustum of a cone model,through the uplift process of load a dis-placement curve for slowly and through the analysis of broken ring true and corresponding damage when load found that photovoltaic stents expanded bore gague brigade in the ultimate uplift bearing capacity of the soil the single conforms to the standard method of theoretical calculation formula.