地震作用下装配整体式混凝土楼盖受力性能和设计方法研究

The topped precast concrete floor slab is one of the most commonly used floors in concrete structures because it has the advantage of good quality and easy construction. However, the connections between the precast concrete slab are the weakness of the precast concrete floor slab. Current seismic design specifications have not fully considered this point. This project proposes a ductile connection for the topped precast concrete floor slab. We will conduct test on connections of the topped precast concrete floor slab subjected to the combination of tesion, compression and shear. The purpose is to investigate the failure mechanism of the diaphragm subjected to the seismic load and to propose the design methodology for the diaphragm action. We will also test the beam-column connections and the frame structures with topped precast concrete floor slab to study the influence of the composite action on the stiffness, load bearing capacity and ductility of the structure. We will propose the hysteretic rules for the connections that can be incorporated in the finite element model using the efficient layered-shell-beam element. Then we will conduct seismic tests on structures with topped precast concrete slab based on the nonlinear dynamic analysis of the finite element model.The purposes of the structure test are not only to study the spatial action of the topped precast concrete slab under seismic load but also to verify the finite element model. Based on the results of the test and the analysis, an in-depth study will be conducted on the seismic behavior and the reliability of the topped precast concrete floor slabs. The seismic design index will be defined to support the performance-based seismic design methodology of the topped precast concrete floor slab.

装配整体式楼盖是混凝土结构常用的水平承重体系之一，在施工工艺及构件质量控制等方面具有显著优势。但震害表明，楼板拼缝节点是装配式混凝土楼盖体系的薄弱环节，目前抗震设计规范对此考虑还不充分。本项目将构造装配整体式楼盖延性拼缝连接件，进行装配式混凝土楼盖拼缝节点的拉压-剪复杂受力试验，探索拼缝节点在地震作用下面内受力的破坏机理。通过含装配整体式楼盖梁柱节点的抗震试验，研究装配整体式楼盖面外组合作用对结构刚度、承载力及滞回性能的影响。将试验得到的拼缝和节点滞回模型嵌入高效率的分层壳-杆系整体分析模型。在非线性动力模拟的基础上进行含装配整体式楼盖的结构抗震试验，研究地震作用下楼盖的空间受力特点，并校准非线性分析模型。以此为基础，对装配整体式混凝土楼盖的抗震性能和可靠度进行深入分析，构造该类型楼盖的抗震性能指标，为装配整体式混凝土楼盖基于性能的抗震设计提供理论支持和技术支持。

本项目研究成果主要包括以下5方面内容：.（1）完成了2榀1/2比例的两层两跨现浇柱预制梁框架的低周反复荷载试验。试验结果表明：装配整体式式框架结构具有稳定的滞回性能及良好的延性；梁端钢筋的套管很好地发挥了作用，套管将接缝处钢筋应变平均到套管中，增强了钢筋的变形能力，能够满足在地震设防区应用的要求。.（2）完成了5榀足尺含外墙挂板的混凝土框架结构低周往复荷载试验。试验结果表明：外墙挂板与框架脱开后，对结构承载力的影响可以忽略；外墙挂板对结构的初始刚度存在显著影响，并且外墙挂板与框架梁柱均相连时远大于外墙挂板仅与框架梁相连时对结构刚度的提高效果；考虑三明治保温夹芯外墙挂板后，结构的刚度提高25%，结构的屈服荷载提高19%。大震下结构发生大变形时外墙挂板与主体结构的连接能够满足抗震设计要求。.（3）完成了5组钢筋半套筒灌浆连接试件进行了静力拉伸试验。研究发现：试件发生了钢筋拉断、钢筋刮犁式拔出和套筒滑丝三类破坏；当破坏形态为钢筋拉断时，钢筋是否偏位对试件的承载力几乎没有影响。并提出了防止试件发生钢筋刮犁式拔出和套筒滑丝破坏的设计方法。.（4）进行了装配整体式楼板精细有限元分析，并对装配整体式楼板框架剪力墙结构进行弹塑性动力时程分析，研究了混凝土强度、楼板现浇层厚度、支座负筋直径、强度和穿孔钢筋直径、强度等参数对装配整体式楼板的面内受力性能以及装配整体式楼板框剪结构的抗震性能。.（5）研究了楼板面内弹性变形和非弹性变形对结构抗震性能的影响，并确定区分刚性楼板和弹性楼板的量化指标。对24个装配式结构模型进行弹性及弹塑性动力时程分析，每个模型的楼板都分别考虑刚性楼板、弹性楼板和非弹性楼板三种情况。通过回归分析得到了评估楼板变形对装配式结构内力影响的简化公式。并建议了区分刚性楼板和弹性楼板的量化标准，为考虑楼板变形的装配式结构抗震设计提供参考。