钢纤维高强混凝土四桩承台的受力性能-水工结构工程专业论文.docxVIP

摘要摘 摘要 摘 要 目前，随着城市高层建筑、道路桥梁、水利建筑的飞速发展，桩基础以承 载力高、能减少地基不均匀沉降和抗震性能好等优点，在实际工程中得到了广 泛的应用。桩基承台支承在桩上承受柱、墙荷载的作用，是桩基础中承上启下 的关键受力构件。因此，研究和改善承台的受力性能具有重要的意义。 本文将钢纤维高强混凝土应用在承台中，通过9个缩尺模型为1：5的钢纤维 高强混凝土四桩承台试件试验，研究钢纤维高强混凝土四桩承台的破坏形态， 并通过测量承台试件的荷载．挠度曲线、钢筋应变和混凝土应变，分析承台的受 力机理。主要研究内容如下： 1、通过分析试验现象和裂缝发展过程，研究钢纤维高强混凝土四桩承台的 破坏形态。结果表明，钢纤维高强混凝土四桩承台的破坏形态均为弯曲破坏， 钢纤维的掺入从很大程度上提高了承台的延性，使承台的后期能力增强。 2、结合钢纤维高强混凝土四桩承台受力性能的试验结果，分析钢纤维体积 率、承台有效厚度及配筋率对承台开裂荷载和极限承载力的影响。结果表明： 随着承台有效高度的提高，距厚比的减小，承台的承载力呈现不同程度的提高； 随着钢纤维体积率的增加，承台的抗裂能力及极限承载力显著提高；随着配筋 率的提高，承台的承载力也呈现不同程度的提高。 3、运用受弯构件理论，提出钢纤维高强混凝土承台承载力的计算公式，并 与试验结果进行对比，计算结果与试验数据吻合良好。 关键词：钢纤维高强混凝土四桩承台承载力钢纤维体积率配筋率 —————————————————————————————————————————————————————————————一 —————————————————————————————————————————————————————————————一 Abstract Abstract Nowadays，with rapid development of hi曲-rise building,water conservancy project,roads and bridges，the performance of the foundation has become more and more important．Pile foundation,which Can reduce the uneven settlement of foundation and has excellent seismic performance，has been applied widely in practical project．As a connecting link，the cap of pile supports on the piles under column and it is such an important specimen of foundation that the research on the mechanical properties of pile cap becomes very meaningful． Steel fiber was applied in reinforced high s仃ength concrete pile caps in the paper． Through the experiment of 9 specimens of steel fiber reinforced high strength concrete(SFHSC)four-pile caps in 1／5 ratio，the failure model of SFHSC four-pile cap WaS studied and the mechanical bearing of SFHSC four-pile cap was analyzed based on the curves of strain in reinforcing bar and the curves of concrete strain．The main contents are as follows． (1)Based on the description of experimental course and phenomcnla,the failure model of SFHSC four-pile cap belongs to flexural failure．Incorporation of steel fiber in high strength concrete has improved the ductility and deformation capacity of four-pile cap． (