【作者】 徐娜；

【导师】 傅学怡；

【作者基本信息】 哈尔滨工业大学 ， 结构工程， 2014， 博士

【摘要】 复杂超高层建筑已广泛采用大截面矩形钢管混凝土柱（LRCFT柱），它对整个结构的安全至关重要。共同工作是LRCFT柱应用的基本问题，对构件及结构的工作性能有着重要的影响。针对LRCFT柱的共同工作问题，本文提出了一种新型的传力机制，即在矩形钢管混凝土柱楼层节点区钢管内设传力构件——分配梁和内环肋，来协调钢管壁与核心混凝土的变形，迫使组成矩形钢管混凝土柱的钢管和核心混凝土共同工作。主要研究内容包括以下几个方面：（1）基于LRCFT柱的共同工作性能，提出了一种新型的传力机制，给出了传力构件的具体构造和布置形式，分析了设传力构件的矩形钢管混凝土柱的受力原理。对比分析了轴压作用下不设传力构件﹑设环向加劲肋﹑设环向加劲肋及栓钉、设传力构件的矩形钢管混凝土柱的共同工作性能，揭示了设传力构件对保证LRCFT柱共同工作性能的重要性和必要性。进行了矩形钢管混凝土柱的轴压试验研究和相关的数值分析，试验结果与有限元结果吻合较好，进一步验证了利用摩擦粘结作用来保证LRCFT柱的共同工作可靠性不够，设传力构件有效地改善了矩形钢管混凝土柱的受力性能，充分地保证了LRCFT柱的共同工作。（2）基于设传力构件的LRCFT柱受力原理的分析，提出了共同工作的理论模型，用弹性地基梁温克尔假定来模拟分配梁沿梁长传递外荷载于核心混凝土的共同工作性能。将分配梁与混凝土的相互作用视作弹性地基梁，作为分配梁支座的钢管壁提供弹簧刚度，核心混凝土简化为弹性地基，分配梁简化为梁，建立了混凝土工作承担系数的计算方程。结合设分配梁的矩形钢管混凝土柱的实际边界条件，给出了混凝土工作承担系数的解析计算方法。在真实的模拟分配梁与钢管壁及核心混凝土之间的力学行为基础上，给出了LRCFT柱各组成部分刚度的求解方法和公式，保证了混凝土工作承担系数的顺利求解。研究了分配梁的力学行为，给出了分配梁的设计方法，指导工程设计。进行了具体算例的分析，验证了本文给出的理论解析方法的有效性和较好的实用性。（3）基于共同工作的理论模型，研究了混凝土工作承担系数与LRCFT柱各组成部分刚度的关系，得出了分配梁尺寸的选取范围。从刚度的控制方程出发，考虑因素间的两两耦合，采用非线性回归方法，得到了各刚度系数的简化计算公式。讨论了计算公式的误差，验证了简化计算公式的合理性。通过简单的计算公式能够快速计算出LRCFT柱各组成部分刚度值，从而求得混凝土工作承担系数来指导分配梁的设计。（4）研究了设传力构件的LRCFT柱在轴压﹑纯弯及偏压作用下的共同工作性能。基于《矩形钢管混凝土结构技术规程》（CECS159：2004），得出了设传力构件的矩形钢管混凝土柱轴压﹑纯弯及偏压承载力的设计方法，提出了规程中大偏压承载力设计方法可做适当完善修改的建议，并给出了计算公式。建立了30层的框架模型，研究了传力构件的数量设计。从弹性控制设计和塑性控制设计两个角度，研究了设传力构件的LRCFT柱的共同工作性能。结果表明，应用设传力构件的矩形钢管混凝土柱，过多或过少设分配梁均不能达到最优的分配效果，合适的数量﹑合理的位置能够使矩形钢管混凝土柱表现出较好的共同工作性能。更多还原

【Abstract】 Large rectangular section concrete-filled steel tube column(LRCFT column) has been widely used in complicated super high-rise buildings, and it is very important for the stability of the whole structure. Working together is the basic problem for LRCFT column, which has an important influence on the performance of structure. For the problem of working together of LRCFT column, a new kind of force transmission mechanism has been carried out in this paper, that is force transmission components－distribution beams and inner periphery ribs are arranged at floor node zone to coordinate deformation between steel tube and core concrete, and force steel tube and core concrete to work together. The main contents in this paper are as follows.(1) A new kind of force transmission mechanism was carried out based on the working together performance of LRCFT column, and specific structure and arrangement form of force transmission components were given, meantime mechanical principle of concrete-filled rectangular steel tube(CFRT) column with force transmmssion components was analysed. Under axial compression the working together performance of CFRT columns that consist of force transmission components not being arranged, ring stiffeners being arranged, both ring stiffeners and studs being arranged, and force transmission components being arranged were analysed, which revealed the importance and necessaries for the performance of LRCFT column to arrange force transmission components. The axial compression tests and numerical analysis of CFRT column were analysed, and the test results showed that they were in good agreement by using finite element method(FEM), furthermore verified that bond action was not an accurate way to ensure the performance of LRCFT column, but arranging force transmission components improved the mechanical performance of CFRT column effectively, and ensured working together of LRCFT column fully.(2) Based on mechanical principle for LRCFT column with force transmission components, the theory model of working together that the interaction of distribution beam transfering external load to concrete works as Winkler assumption on elastic foundation beam was carried out. The equations of percentage of load-carrying shared by concrete were established, in which the interaction of distribution beam and concrete was regarded as elastic foundation beam, steel tube provided stiffness, concrete was simplified to elastic foundation, and distribution beam worked as beam. Applying the boundary conditions of CFRT column with distribution beam, the calculation method of percentage of load-carrying shared by concrete can be abtained. Based on mechanical behavior among distribution beam, steel tube and concrete, the stiffnesses solutions of each component of LRCFT column were obtained, which ensured the solution of percentage of load-carrying shared by concrete. By studying mechanical behavior of distribution beam, the design method of distribution beam was determined to guide engineering design. The actual example was analysed, which verified the validity and good practicability of analytical method in this paper.(3) Based on the theory model of working together, the relationships of percentage of load-carrying shared by concrete with stiffnesses of each component of LRCFT column were studied, accordingly the ranges of distribution beam section size were given. Proceedly from governing equations on stiffnesses, coupling between two factors was considered and by using nonlinear regression method, the simplified calculation formulas for each stiffness coefficient were obtained. The error of calculation were discussed, which showed that the simplified calculation formulas were reasonable. Through the simplified calculation formulas the stiffnesses can be calculated quickly, thereby the percentage of load-carrying shared by concrete is given to guide the design of distribution beam.(4) Working together performance of LRCFT column with force transmission components were studied under axial compression, bending and eccentric compression. Based on―Technical specification for structures with concrete-filled rectangular steel tube members‖(CECS159:2004), the design methods of carrying capacity under axial compression, bending and eccentric compression for CFRT column with force transmission components were obtained, and the proposal that design method of carrying capacity under big eccentric compression of specification need to be improved further was proposed and the calculation formula was given. A model of30-stories frame was established and the quantity design of force transmission components was studied. From the standpoints of elastic and plastic design, the working together performance of LRCFT column with force transmission components was studied. It was shown that for CFRT structure, with too much or too little distribution beams the optimal distribution effect can’t be reached, when the quantity is suitable and location is reasonable the performance of CFRT stucture is acceptable.更多还原