一种新型钢—混凝土组合节点及其组成的框架结构性能研究

发布时间：2018-06-19 08:09

本文选题：组合节点 + 框架结构　；参考：《华南理工大学》2014年博士论文

【摘要】：汶川地震震害调查表明，框架结构的破坏基本上是柱端破坏或节点破坏，鲜见梁端破坏现象，未能实现规范规定的“强柱弱梁”屈服机制，造成大量建筑物倒塌。此外，常规钢筋混凝土框架结构破坏后，即使能够加固再利用，往往难以修复原结构的残余变形，加固钢筋及新浇混凝土存在应力滞后问题，加固难度大，，成本高。我国的普通钢筋混凝土框架结构抗震能力有待提高。本文发明一种“钢－混凝土组合节点”，该组合节点由钢板、钢管混凝土及柱纵筋组成，钢管混凝土与钢板之间可产生摩擦滑移以实现耗能。设计一种新型框架结构，框架柱的两端为钢－混凝土组合节点，在框架内对角双向设置预应力拉杆。本文以试验为主要手段，辅以理论计算及数值分析，对柱端为钢－混凝土组合节点的长柱、短柱及框架结构进行分析研究，并对试验破坏后的新型柱及新型框架进行修复试验。结果表明，新型柱及新型框架具有显著的变形能力及抗震性能，并具有良好的可修复性。为检验钢－混凝土组合节点的性能，本文进行3个新型长柱及3个新型短柱试验研究，同时设置1个普通长柱和2个普通短柱作对比试验。结果表明，钢－混凝土组合节点能显著提高柱的弯曲变形能力，当组合节点产生滑移，还能明显提高柱的剪切变形能力。所有新型长柱破坏局限于组合节点处，表现为组合节点钢筋屈服、断裂，组合节点以外的柱身混凝土无任何损坏；而普通柱一旦混凝土被压碎，就无法维持轴力稳定，并很快失去承载能力。新型长柱的变形能力约是普通长柱的2～5倍以上，新型短柱的变形能力约是普通短柱的1.6～2.0倍以上。实测数据及数值分析均表明，新型柱可以产生滑移，实现摩擦耗能的作用。为验证新型框架结构的实际效果，本文进行1个新型框架及1个普通框架对比试验研究。试验结果表明，框架柱（为长柱）的破坏区域位于柱端组合节点处，柱身混凝土无开裂，轴力始终能维持稳定；拉杆破坏后，框架仍能继续工作，直至组合节点钢筋断裂。普通框架破坏区域也集中于柱端处，柱端混凝土被压碎，箍筋向外崩脱，纵向钢筋屈曲外鼓，达到峰值承载力后，轴力不能维持稳定，水平力下降迅速。新型框架的屈服位移、峰值位移分别是普通框架的2.71、2.0倍；峰值位移角大于1/50，是规范要求的1.49倍；屈服承载力及峰值承载力是普通框架的3.0倍以上，弹性转角刚度是普通框架的1.55倍；在相同加载制度下，新型框架的加载循环次数远大于普通框架，耗能能力显著优越于普通框架，具有优越的抗震性能。为了解新型结构的可修复性，本文对试验破坏后的新型框架及1个新型柱进行修复，然后采用相同的试验设备、按相同的加载制度重新进行试验。结果表明，新型框架结构及新型柱的修复工作简单，成本低，速度快，修复后即可投入使用，可消除原破坏造成的大部分残余变形；与原结构相比，各项性能指标相差不大，表明新型结构具有优越的可修复性能。本文采用数值分析方法研究不同组合节点参数对新型柱的力学性能影响；推导了柱端为钢－混凝土组合节点的框架柱及预应力拉杆的刚度方程，解决了新型结构整体分析问题；推导了钢－混凝土组合节点的压弯承载力设计计算方法；推导了钢－混凝土组合节点产生摩擦滑移耗能的力学条件。为新型结构推广应用提供理论支撑。钢－混凝土组合节点具有显著的变形能力，保护了柱身混凝土，相当于实现规范要求的“强柱弱梁”的效果；只要组合节点的钢管混凝土不破坏，新型结构就可始终维持轴力稳定，柱端抗剪能力可维持不变，这对实现“大震不倒”具有重要意义；新型结构修复简单，造价低，速度快，不需要技术间隙时间，适合于震后快速抢修，同样具有实际意义。
[Abstract]:The earthquake damage investigation in Wenchuan shows that the destruction of the frame structure is basically the failure of the column end or the joint failure. It is rare to see the Liang Duan failure phenomenon, and the failure to realize the "strong column and weak beam" yield mechanism stipulated by the standard, resulting in the collapse of a large number of buildings. In addition, it is difficult to repair the conventional reinforced concrete frame structure even if it can be reused and reused. The residual deformation of the original structure, the reinforcing bar and the newly poured concrete have the problem of stress lag, which is difficult to reinforce, and the cost is high. The earthquake resistance of the common reinforced concrete frame structure in China needs to be improved.
In this paper, a "steel concrete composite joint" is invented, which consists of steel plate, concrete filled steel tube and column longitudinal reinforcement. The friction and slip between steel tube concrete and steel plate can be produced to energy consumption. A new frame structure is designed. The two ends of the frame column are steel concrete composite joints, and the prestress in the diagonal of the frame is set in the frame. In this paper, with the test as the main means, with the theoretical calculation and the numerical analysis, the long column, short column and frame structure of the column end of steel concrete composite joint are analyzed and studied, and the new column and new frame after the test are repaired. The results show that the new type column and the new frame have significant deformation ability and resistance. Seismic performance and good repairability.
In order to test the performance of steel-concrete composite joints, 3 new long columns and 3 new short columns were tested in this paper. At the same time, 1 ordinary long columns and 2 ordinary short columns were set up. The results showed that the steel concrete composite joints could significantly improve the flexural deformation capacity of the columns. When the joint node slips, it can obviously improve the column. All new long column failure is limited to the combination node, which shows that the steel bar of the combined joint is yielded and broken, and the column concrete outside the combination node has no damage, and the ordinary column can not maintain the axial force stability and quickly lose the bearing capacity once the concrete is crushed, and the deformation ability of the new long column is about ordinary. More than 2~5 times of the long column, the deformation ability of the new short column is about 1.6 to 2 times more than that of the ordinary short column. The measured data and numerical analysis all show that the new column can produce sliding and realize the effect of friction energy dissipation.
In order to verify the actual effect of the new frame structure, 1 new frames and 1 common frame comparison tests are carried out in this paper. The experimental results show that the failure area of the frame column (for the long column) is located at the joint of the column end. The column concrete has no cracking and the axial force is always stable. After the failure of the rod, the frame can continue to work until the combination. The common frame failure area is also concentrated at the end of the column. The concrete is crushed in the column end, the stirrup is broken outward and the longitudinal steel bar flexes the outer drum. After reaching the peak bearing capacity, the axial force is not stable and the horizontal force drops rapidly. The yield displacement of the new frame is 2.71,2.0 times of the common frame, and the peak displacement angle is respectively. More than 1/50 is 1.49 times that of the standard. The yield bearing capacity and the peak load bearing capacity are more than 3 times more than the ordinary frame. The elastic angle stiffness is 1.55 times that of the ordinary frame. Under the same loading system, the load cycle of the new frame is much larger than the ordinary frame, and the energy dissipation capacity is superior to the ordinary frame, and has superior seismic performance.
In order to understand the repairability of the new structure, the new frame and 1 new columns after the test are repaired, and the same test equipment is used to re test the new type of columns. The results show that the repair work of the new frame structure and new type column is simple, the cost is low, the speed is fast, and the repair can be put into use after repair. It eliminates most of the residual deformation caused by the original damage. Compared with the original structure, the performance index has little difference, indicating that the new structure has excellent repairability.
In this paper, the numerical analysis method is used to study the influence of the parameters of different combination nodes on the mechanical properties of the new type column, and the stiffness equation of the frame column and the prestressed pull rod is derived. The whole analysis problem of the new structure is solved, and the design calculation formula of the bending bearing capacity of the steel concrete composite joint is derived. The mechanical conditions of friction and slip energy dissipation of steel-concrete composite joints are derived, which provides theoretical support for the popularization and application of new structures.
The steel-concrete composite joint has significant deformation ability, which protects the column concrete, which is equivalent to the effect of "strong column and weak beam", which is required by the standard. As long as the concrete filled steel tube of the composite node does not destroy, the new structure can always maintain the stability of the axial force and the shear ability of the column can remain unchanged. The new structure has the advantages of simple repair, low cost, fast speed, no need for technical gap time, and is suitable for quick repair after the earthquake.
【学位授予单位】：华南理工大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU398.9

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