【作者】 李龙；

【导师】 贡金鑫；

【作者基本信息】 大连理工大学 ， 结构工程， 2006， 硕士

【摘要】 圆形截面钢筋混凝土构件是工程结构中常用的构件之一，如港口工程中的混凝土灌注桩、建筑物的承载柱、桥梁桥墩以及基坑的支护排桩等。由于混凝土本身的抗拉强度小，易开裂的特性，所以实际工程中的许多混凝土构件都是带缝工作的。裂缝对混凝土结构的耐久性、安全性及承载能力有着明显的影响。因此，结构构件除需进行强度计算外，还需根据使用和耐久性要求进行裂缝宽度验算。国内外对裂缝宽度计算的问题已经进行了大量的理论和试验研究，但在圆形截面构件的裂缝计算方面研究还不多。本文是《港口工程混凝土结构设计规范》(JTJ 267-98)修订的研究专题，目的是提出简便实用的适用于港口工程中圆形截面钢筋混凝土构件裂缝宽度的计算方法。根据专题要求，主要进行了以下工作： (1)对国内外有关钢筋混凝土构件裂缝宽度的文献进行了分析研究，确定影响裂缝宽度的主要因素；比较国内及国外主要国家混凝土规范裂缝的控制方法，根据文献资料讨论了裂缝对钢筋腐蚀的影响。 (2)对12根大偏心受压、12根受弯、12根大偏心受拉、12根小偏心受拉和16根轴心受拉圆形和环形试件进行试验，测得了开裂荷载、每级荷载下试件的受拉钢筋和混凝土应变和裂缝宽度。 (3)建立了用钢筋应变和混凝土压力角表示的构件截面力和弯矩的平衡方程，并给出计算钢筋应变和混凝土压力角的数值分析方法；根据平衡方程优化计算的结果提出计算钢筋应力的简化公式。 (4)对圆形截面钢筋混凝土构件裂缝宽度的计算进行了研究，给出有效受拉钢筋配筋率的计算公式，根据裂缝宽度试验结果对钢筋应力简化计算公式做了进一步的简化。 (5)用提出的裂缝宽度计算方法对三个钢筋混凝土灌注桩进行了试算。更多还原

【Abstract】 Members with circular concrete sections have been used widely for piles in harbor engineering, columns of the building, bridge piers and support piles in deep foundation ditch engineering, etc. Many reinforced concrete members are cracking during their working time for the reason of small tensile strength of the concrete. Durability, safety and bearing capacity of the concrete members are affected obviously by the cracks. So the the crack width of the member must be calculated based on the application and durability of the structures except the calculation of the strength. Many theories of calculation and experimental studys on the concrete cracks have been developed by the researcher home and abroad, but only a little on the crack width calculation of the members with circular sections. This is the Revised matter of Deisign Code for Harbour Engineering Concrete Structure. The main Objective to develop Crack Width Calculation of Reinforced Concrete Members with Circular Sections which can be used in Harbour Engineering. Baseed on the require of the Revise, the main aspects of the research work are as follows:(1) Studying and analysis of the materials about the crack width of RC concrete members home and abroad to define the main effects. Compare the methods of crack control in the concrete code and discuss the influence of the crack width to the corrosion of the steel bar.(2) Twelve large eccentric compression specimens, twelve flexural specimens, twelve large eccentric tension specimens, twelve small eccentric compression specimens ,sixteen axial tension specimens are test and tensile strain of the steel bar and crack width under every class of load are obtained in this paper.(3) Equilibrium equation of force and bend which established through steel strain and compresion angle. Numerical analysis methods to solve the equation are given. The simplified equation which calculate the steel stress are established based on the results of the equilibrium equation.(4) Studying on the calculation of the crack width to establish the calculate equation of the effective ratio of the tensile steel bar and further simplified quation of the steel stress are given based on the experimental crack width.(5) The crack width of three RC piles are calculated by the equation which established in this paper.更多还原