高延性钢棒预应力混凝土管桩抗震性能分析

发布时间：2018-09-04 18:47

【摘要】：预应力混凝土管桩(PHC管桩)由于单桩承载能力高、施工速度快等优点,在工程建设中得到广泛的应用。但是,国内外的震害调查结果表明管桩的抗水平地震能力不足,限制了管桩的使用范围。因此,有必要采取合适的改进措施来提高PHC管桩的抗震性能。将PHC管桩中的预应力钢筋替换为相同数量的高延性钢棒,可以得到高延性钢棒预应力混凝土管桩(High ductility of steel bar for prestressed high strength concrete pile,HDPHC管桩)。本文利用ANSYS有限元软件建立HDPHC管桩模型,对管桩在往复荷载作用下的抗震性能进行有限元分析。首先,使用ANSYS有限元软件建立PHC管桩模型,进行拟静力数值模拟分析,将分析结果与PHC管桩的试验结果进行对比,验证模型的正确性;其次,在上述正确模型的基础上,用高延性预应力钢棒替换普通预应力钢棒,建立HDPHC管桩模型,进行低周往复荷载的数值模拟,分析HDPHC管桩的抗震性能;最后,分析体积配箍率、预应力筋配筋率、混凝土的有效预压应力和混凝土强度等级等影响管桩抗震性能的因素,研究其对HDPHC管桩抗震性能的影响。通过分析可以得到以下结论,HDPHC管桩的滞回曲线比PHC管桩滞回曲线更加饱满,其抗震性能更好;与PHC管桩的骨架曲线相比,HDPHC管桩的骨架曲线较光滑且有明显的下降段,说明HDPHC管桩的延性得到很好的改善;HDPHC管桩每一循环所得的滞回环包围的面积更大,说明其耗能能力更好,具有很好的降低地震反应、减轻地震破坏的能力;改变体积配箍率可以提高HDPHC管桩的抗震性能,高延性钢棒直径的增大对管桩抗震性能的提高较明显,混凝土有效预压力的增大不能提高管桩的抗震性能。
[Abstract]:Prestressed concrete pipe pile (PHC pipe pile) has been widely used in engineering construction because of its high bearing capacity and fast construction speed. However, the results of earthquake damage investigation at home and abroad show that the horizontal seismic resistance of pipe pile is insufficient, which limits the application range of pipe pile. Therefore, it is necessary to take appropriate improvement measures to improve the seismic performance of PHC pipe pile. By replacing the prestressed steel bar in the PHC pipe pile with the same number of high ductile steel bars, the high ductile steel bar prestressed concrete pipe pile (High ductility of steel bar for prestressed high strength concrete pile,HDPHC pipe pile can be obtained. In this paper, the HDPHC pipe pile model is established by using ANSYS finite element software, and the seismic behavior of pipe pile under reciprocating load is analyzed by finite element method. Firstly, the PHC pipe pile model is established by using ANSYS finite element software, and the quasi-static numerical simulation analysis is carried out. The results are compared with the test results of PHC pipe pile to verify the correctness of the model; secondly, on the basis of the above correct model, The HDPHC pipe pile model is established by replacing the common prestressed steel bar with the high ductile prestressed steel bar, and the numerical simulation of low cycle reciprocating load is carried out to analyze the seismic behavior of the HDPHC pipe pile, and finally, the volume hoop ratio, the reinforcement ratio of the prestressing tendons, the seismic behavior of the HDPHC pipe pile are analyzed. The effective preloading stress of concrete and the grade of concrete strength affect the seismic behavior of pipe pile. The influence of effective preloading stress and strength grade of concrete on the seismic behavior of HDPHC pipe pile is studied. The following conclusions can be obtained: the hysteretic curve of HDPHC pipe pile is fuller than that of PHC pipe pile, and its seismic performance is better than that of PHC pipe pile, and the skeleton curve of HDPHC pipe pile is more smooth and has obvious descending section than that of PHC pipe pile. It shows that the ductility of HDPHC pipe pile is improved very well. The hysteresis loop surrounding area of each cycle of HDPHC pipe pile is larger, which indicates that its energy dissipation ability is better, and it has the ability to reduce earthquake response and reduce earthquake damage. The seismic behavior of HDPHC pipe pile can be improved by changing the ratio of volume hoop, the seismic performance of pipe pile is obviously improved by increasing the diameter of high ductile steel bar, and the seismic performance of pipe pile can not be improved by the increase of effective preloading of concrete.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU473.1

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