不同配筋形式下微型桩的桩顶变形量研究

Study on the Deformation at Micropile Top Under Different Reinforcement Forms

基于对微型桩力学特性的研究,建立其桩顶水平位移的力学模型,分析同一外力作用下不同配筋形式微型桩桩顶变形情况。研究表明:不同配筋形式微型桩桩顶变形量主要取决于总配筋材料截面惯性矩的大小,两者成反比关系。理论计算分析得到桩周配筋桩的桩顶变形量最小,钢管桩的桩顶变形量最大;桩心配筋桩的配筋率虽等同于桩周配筋桩,但其桩顶变形量明显大于桩周配筋桩和锚筋桩。最后,通过数值模拟对理论计算分析进行了验证,结果基本一致,桩周配筋桩抗弯、抗变形的效果远甚于其他配筋形式微型桩,是锚筋桩和钢管桩的有效组合形式。

Based on the research on mechanical properties of micro-piles, the mechanical model of pile head horizontal displacement is built to analyze the deformation of pile top with different reinforcement forms under identical external force. Studies have shown that： the deformation of pile top with different reinforcement forms depends on the total size of inertia moment of reinforcement materials section, and one is inversely proportional to the other. The deformation at top of micropiles with surrounding reinforcement arrangement tends to be minimum and steel pipe pile to be maximum through theoretical calculation. Although the reinforcement ratio of micropiles with center reinforcement arrangement is equivalent to micropiles with surrounding reinforcement arrangement, the former＇s pile top deformation is greater than the later and anchor piles. At last, through numerical simulation of theoretical analysis to verify the results, it is found that they are basically the same. As for bending and anti-deformation, the micropile with surrounding reinforcement arrangement is far more effective than other forms of reinforcement micropile. It is eff mlcr ective combination of anchor piles and steel pipe piles.