预应力混凝土管桩抗裂抗剪性能研究

Research on crack resistance and shear behavior of pre-stressed concrete pipe pile

在地震及作为支护桩使用时,管桩的抗剪性能是其主要承载指标。文章采用有限单元法,建立3组管桩模型,分析混凝土有效预压应力、壁厚及剪跨比对预应力混凝土管桩开裂剪力及开裂特征的影响。计算结果表明:随着混凝土有效预压应力和壁厚的增大,管桩开裂剪力提高明显,剪跨比对开裂剪力影响较小;剪跨比较小时管桩主应力迹线与矩形截面梁相反,裂缝沿桩身纵向开展。

Shear capacity is one of main indicators of bearing capacity of pre-stressed concrete pipe piles in the earthquake and support engineering. By using the finite element method, three groups models are established to analyze the influence of some factors like effective pre-stress, wall thickness and shear span ratio on the cracking shear and features of pre-stressed pipe pile. The results are as fol- lows： with the increase of the effective pre-stress and wall thickness of the pipe pile, the cracking shear improves significantly, while the shear span ratio causes little effect on the cracking shear; the principal stress tracing line of pipe pile is opposite with that of rectangular cross-section beams and cracks develop along the pile length when the shear span ratio is relatively small.