先张法预应力钢绞线高强混凝土大直径管桩受弯性能研究

Investigation on flexural behavior of pretensioned prestressed steel strand high strength concrete large-diameter pipe piles

为研究大直径钢绞线管桩的受弯性能,对3根不同直径钢绞线桩进行足尺试验、理论分析和有限元模拟,对比研究了大直径钢绞线桩的开裂弯矩、裂缝开展及分布、受弯承载力、变形延性和破坏特征等。结果表明:大直径钢绞线桩受弯破坏时受压区高强混凝土压溃,截面中心轴以下钢绞线都达到屈服强度,具有较高的受弯承载力和良好的变形延性;理论分析方法能够较好地预测大直径钢绞线桩的受弯承载力;建立的有限元模型可以合理地模拟大直径钢绞线桩的受弯性能,模型计算结果与试验结果吻合较好。

In order to study the flexural behavior of large-diameter steel strand piles, the full-scale test, theoretical analysis and numerical simulation for three steel strand piles with different diameters were carried out. The cracking moment, crack development and distribution, flexural bearing capacity, deformation ductility and failure characteristics of large-diameter steel strand piles were comparatively studied. The results show that the high-strength concrete in the compression zone is crushed and the steel strands below the central axis of the section reach the yield strength when the large-diameter steel strand piles undergo the bending failure, demonstrating high flexural bearing capacity and good ductility. The theoretical analysis method can predict the flexural bearing capacity of large-diameter steel strand piles well, and the established finite element model can reasonably simulate the flexural behavior of large-diameter steel strand piles, and the numerical results are in good agreement with the experimental results.