【作者】 曹帅；

【导师】 周水兴；

【作者基本信息】 重庆交通大学 ， 桥梁与隧道工程， 2010， 硕士

【摘要】 自应力钢管混凝土结构能充分发挥钢管和混凝土两种材料的作用,它是用自应力膨胀混凝土替代了普通混凝土而形成的一种新的钢管混凝土结构。由于自应力的存在,外包薄壁钢管有效约束了膨胀混凝土的膨胀变形,有效解决了普通混凝土收缩等引起的钢一混组合界面的粘结问题,从而保证两者协调工作,并且使得混凝土的内部结构更加密实,核心混凝土抗压强度得到提高;钢管充分利用了膨胀混凝土的膨胀能,能够产生较大的化学预应力,为核心混凝土提供较高的侧向预应力;同时自应力的存在也使钢管产生了初应力,钢管初应力使钢管屈服提前,影响钢管混凝土结构的承载力。本文以西部交通科技项目“自预应力钢管混凝土开发应用试验研究”(合同编号:200631881422)的子课题“自应力钢管混凝土构件承载力计算方法与数值分析研究”为研究内容,开展了以下研究工作:①在普通钢管混凝土本构关系的基础上,提出了能够计入自应力效应的核心混凝土本构关系;②应用极限平衡理论,在普通钢管混凝土极限承载力计算理论的基础上,推导了自应力钢管混凝土极限承载力的计算公式;③通过分析自应力钢管混凝土的轴压受力性能发现,存在一个最佳的自应力水平,即自应力水平为0.11~0.12,此时钢管混凝土的极限承载力达到最大,较普通钢管混凝土极限承载力可提高18%左右;④分析并阐述了自应力对钢管混凝土极限承载力的影响机理;⑤在引入基本假定的基础上,根据钢管混凝土的构造特点,数值模拟了自应力钢管混凝土轴压受力的全过程,分析了自应力钢管混凝土的轴压受力机理,自应力对核心混凝土裂缝的影响。并拟合了自应力钢管混凝土极限承载力的计算公式。更多还原

【Abstract】 Self-stressing concrete filled steel tube can make full use of steel tube and concrete’s fuction, which is a new steel concrete structure formed by the replacement instead of self-stressing expansive concrete with the ordinary concrete. Because of the presence of self-stressing, thin-walled outsourcing tube effectively restrain the expansion deformation of expansive concrete, and effectiveiy solve a mixed portfolio problem on steel bond interface caused by normal concrete shrinkage,as a result,they work together , make the internal structure of concrete more dense and improved compressive strength of concrete core. Steel tube take full advantage of the expansion properties of expansive concrete, have a greater chemical prestressing,and make higher lateral prestress for core concrete.At the same time,with the existance of self-stressing the steel tubes also produce initial stress which advance steel to yield,then that will affect the bearing capacity of concrete filled steel tubular structures.This paper study the contents of research on“capacity computational method and numerical analysis of self-stressing concrete filled steel tube structure”,which is the Sub-topics of“experimental research on self-stressing concrete filled steel tube development and Application”(contract Number: 200631881422).Following are the studies:①Based on ordinary steel concrete constitutive, It comes up with core concrete constitutive included self-stressing effect;②On the basis of general theory of calculation of ultimate bearing capacity of concrete filled steel tube, apply the limit equilibrium theory and derive formula of ultimate bearing capacity of self-stressing concrete filled steel tube;③Discovered by analysising self-stressing concrete filled steel tube’s performance under axial pressure,there is the best self-stressing lever, 0.11~0.12.Meanwhile ultimate bearing capacity of self-stressing concrete filled steel tube is at maximum which is 18% increase than that of ordinary concrete;④Apply and explain the impact mechanism of ultimate bearing capacity of concrete filled steel tube caused by self-stressing;⑤On the basis of applying basic assumptions and according to steel pipe concrete’s struction features ,I numerically simulate the whole process of steel pipe concrete under axial pressure ,analysis sustainability mechanism of self-stressing concrete filled steel tube and the effect of of the core concrete’s fracture from self-stressing,and fit formula of ultimate bearing capacity of self-stressing concrete filled steel tube.更多还原