自预应力钢管混凝土受压构件极限承载力的计算

采用在管内核心混凝土中添加膨胀剂使其发生体积膨胀的方法,改善了钢管混凝土特性,提高了钢管混凝土构件的极限承载力。以巫峡长江大桥"化学自预应力钢管砼在桥梁上的应用研究"课题试验成果为基础,针对自预应力钢管混凝土与普通钢管混凝土的区别仅在核心混凝土应力状态不同的特点,建立了混凝土的等效轴心抗压设计强度概念,导出了试件混凝土等效轴心抗压设计强度与膨胀剂掺量(膨胀量)的函数关系,为解决化学自预应力钢管混凝土受压试件极限承载力的计算提供了一种可行和有效的方法,为该种构件的应用和后续研究工作奠定了基础。

Calculation of Ultimate Bearing Capacity of Self-stressed Concrete Filled Steel Tube

By adding expansive agent and making expansion of the core concrete in the tube,the characteristic of concrete filled steel tube(CFST) and its bearing capacity were improved.According to the result of "Research on the Application of Chemically Self-stressed CFST to Bridges" for Wu Gorge Bridge on Yangtze River,the only distinctness is the different stress states of core concrete between common CFST and Self-stressed CFST.Based on experimental data,and by introducing the concept of Equivalent Axial Compressive Design Strength and applying commonly used CFST formulas,the formulas describing the relationship between the equivalent axial compressive design strength and content of expansive agent were built.The research provid a feasible and effective method to calculate the bearing capacity of chemically self-stressed CFST and laid a foundation for application and future study on this kind of structure.