基于强度折减法的桩基础试验与数值计算研究

Pile Foundation Test and Numerical Calculation Based on Strength Reduction Method

为研究桩基础在竖向荷载作用下的极限承载力,引入强度折减法来分析桩基础的极限荷载,给出将P-s曲线的突变尖点作为桩基破坏标志,依托ANSYS软件的Smart智能分网建立桩土体的有限元模型,通过桩基础室内模型试验与数值仿真结果对比,研究了基底为黏土的桩基极限承载力、桩侧摩阻力、桩端反力与桩顶位移的变化趋势,结果表明:强度折减法计算的极限荷载与静载荷试验方法判定的极限荷载基本一致,表明强度折减理论极限分析的可行性,也表明了试验结果的可靠性。将强度折减法运用到工程实例中,得到极限荷载值固定后,可降低工程桩验证数目,产生了良好的经济效益。

Strength subtraction method was adopted to analyze the ultimate load of pile foundation damage and ultimate bearing capacity under vertical load.Meanwhile,it is proved that the mutation point in P-s curve will be supposed to pile foundation damage.Finite element model of pole soil was established based on ANSYS software with the Smart intelligent network.Through experiment of model test of pile foundation,basal ultimate bearing capacity of pile foundation in clay,pile side friction and pile end the tendency of the reaction force and displacement of pole top are analyzed.The results show that the difference of limit load between the strength subtraction calculation and static load test method is small,which also shows that the reliability of test results.By applying the strength reduction method to an engineering example,the number of engineering piles can be reduced after the limit load value is fixed,and good economic benefits are produced.