双向叠合楼板拼缝处受力机理试验研究与数值模拟

发布时间：2018-06-07 03:02

本文选题：双向叠合楼板 + 叠合楼板拼缝　；参考：《合肥工业大学》2014年博士论文

【摘要】：为适应国家十二五规划及未来对住宅产业化发展的需求,对在装配式结构中占比重较大的钢筋混凝土叠合楼板开展研究。现有叠合楼板主要是单向受力形式,拼缝处受力性能较弱,综合造价较高,这些都降低了叠合楼板的推广速度,影响住宅产业进程。国内外专家学者对叠合底板形式和双向叠合楼板板拼缝处理做了一些研究,并提出一些新的叠合底板形式和拼缝处理构造,但都存在一定的局限性,课题组从拼缝处的受力机理来研究叠合楼板的拼缝处承载能力,考虑施工易操作性,通过构造来解决叠合楼板的拼缝传力问题。文中首先研究了叠合楼板叠合面的抗剪和抗拉粘结性能,分析了拼缝处截面受力状态、拼缝处钢筋锚固受力状态和叠合面的受弯状态；分析了常用的格构钢筋对叠合楼板的刚度和承载的影响,采用子结构理论建立刚度计算公式；对现有的粘结滑移曲线进行比较分析,在此基础上,提出改进的粘结滑移曲线,并用数值模拟进行验证；通过12块叠合楼板的试验和有限元数值模拟,研究不同拼缝连接形式叠合板的受力性能；文中最后提出了一种新型增强拼缝连接形式,并用试验验证了其受力性能。论文研究的主要成果如下： (1)通过对叠合结构叠合面抗剪、抗拉试验统计分析发现,当混凝土强度大于C20时,叠合面试验抗剪强度与混凝土立方体抗压强度表现出了较强的相关性,回归方程显著；对叠合面抗拉强度与后浇混凝土的轴拉强度表现出较强的相关性,回归结果可信度较高。 (2)推导出了拼缝处钢筋锚固承载力受叠合面影响系数,通过分析得出对于设置格构钢筋的叠合楼板,拼缝处可以满足受拉钢筋锚固要求；从叠合楼板拼缝处叠合面受弯状态推导出带拼缝叠合楼板的叠合面破坏时极限弯矩。 (3)通过我国规范的短期刚度计算公式的推导过程,分析了应用于板的刚度计算时存在的局限性；对比分析了不同刚度计算公式,得出了一些有益的结论；采用子结构理论,对格构钢筋进行了刚度等效,推导出等效计算公式,以便分析格构钢筋对叠合板的刚度贡献。 (4)提出了改进的粘结滑移曲线本构模型,并进行了数值模拟,模拟曲线和试验曲线符合较好,验证了模型的可靠性。 (5)通过12块叠合楼板的试验和有限元分析结果表明：对拼缝处未设附加约束的叠合楼板具有一定的承载能力,但搭接纵筋超过屈服荷载后,会产生脆性断裂破坏；当设置格构钢筋约束时,无论是端拼缝和侧拼缝(格构钢筋横向设置和竖向设置),都能够保证拼缝处钢筋的有效传力,实现“等承载力连接”。 (6)数值计算结果和试验结果吻合较好,表明文中的数值模拟方法的可靠性；数值分析结果表明,模型中添加粘结弹簧单元对承载力和刚度影响不大,但对于裂缝开展有很明显的影响。 (7)文中提出了一种新型增强型整体式拼缝连接形式,试验研究结果表明：采用该种连接形式的叠合板在拼缝处刚度得到加强,受弯承载力得到不同程度地提高,拼缝处最大应力得到转移,裂缝较迟出现,可以实现拼缝处的等同现浇。
[Abstract]:In order to meet the needs of the national planning and future development of housing industrialization in the 12th Five-Year, the reinforced concrete overlapped slab which occupies a large proportion in the assembly structure is studied. The existing laminated slab is mainly one way of unidirectional force, weak force performance at the joint and high comprehensive cost, which all reduce the spread speed of the laminated floor. The process of the housing industry.
Experts and scholars at home and abroad have done some research on the joint floor form and the joint treatment of double stacked slab plate, and put forward some new overlapped floor form and joint treatment structure, but there are some limitations. Over structure is used to solve the problem of splicing force of composite floor.
In this paper, the shear and tensile bond properties of overlapped floor overlapped surfaces are studied. The stress state of the cross section, the stress state of the reinforcing bar anchorage at the joint and the bending state of the overlapped surface are analyzed, and the influence of the commonly used lattice bars on the stiffness and bearing of the laminated floor is analyzed, and the stiffness calculation formula is established by the substructure theory. The existing bond slip curve is compared and analyzed. On this basis, the improved bond slip curve is proposed and verified by numerical simulation. Through the test of 12 laminated slab and finite element numerical simulation, the stress performance of the laminated plate with different joint forms is studied. Finally, a new type of reinforced joint joint shape is proposed. The main results of the study are as follows:
(1) through the statistical analysis of the shear resistance and tensile test of superimposed overlapped surface, it is found that when the strength of concrete is greater than C20, the shear strength of the composite surface test has a strong correlation with the compressive strength of the concrete cube, and the regression equation is significant, and the tensile strength of the overlapped surface has a strong correlation with the axial tensile strength of the post poured concrete. The reliability of the regression results was high.
(2) the influence coefficient of the rebar anchorage bearing capacity of the joint at the joint is deduced. Through the analysis, it is concluded that the joint slab can meet the anchorage requirements of the reinforced bar, and the ultimate bending moment is deduced from the bending state of the overlapped surface at the joint of the laminated slab.
(3) through the derivation of the short term stiffness calculation formula in our country, the limitations of the stiffness calculation applied to the plate are analyzed, the calculation formulas of different stiffness are compared and analyzed, and some useful conclusions are obtained. The equivalent calculation formula is derived for the lattice steel by the substructure theory, so as to analyze the lattice. The contribution of the steel bar to the stiffness of the laminated plate.
(4) an improved bond slip curve constitutive model is proposed, and the numerical simulation is carried out. The simulation curves and test curves are in good agreement, which verifies the reliability of the model.
(5) through the test and finite element analysis of 12 laminated plates, the results of the finite element analysis show that the laminated slab with no additional constraints at the joint has a certain bearing capacity, but when the lap bar exceeds the yield load, it will produce brittle fracture failure. Vertical setting can ensure effective transfer force of reinforcement and achieve "equal bearing capacity connection".
(6) the numerical results are in good agreement with the test results, indicating the reliability of the numerical simulation method in the paper, and the results of numerical analysis show that the addition of the bond spring element has little effect on the bearing capacity and stiffness, but it has a significant effect on the crack development.
(7) a new type of reinforced integral joint form is put forward in this paper. The experimental results show that the stiffness of the joint plate with this type of joint is strengthened, the flexural bearing capacity is improved in varying degrees, the maximum stress at the joint is transferred, the crack joint appears later, and the equivalent cast in place can be realized.
【学位授予单位】：合肥工业大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU375.2

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