后浇整体式预制混凝土框架结构抗连续性倒塌性能及控制方法研究

Comparing to cast-in-situ reinforced concrete (RC) frames, the mechanisms of pre-cast concrete (PC) frames with cast-in-situ monolithic joints are more complex and variety. In addition, it may have much higher progressive collapse risks comparing to RC frames due to its lower integrity. To improve the progressive collapse performance of PC frames, a series of experimental, analytical, and numerical analysis will be carried out and the reasonable design strategies will be discussed. The main contains are: 1) several sets of PC beam-column substructures will be conducted subjected to static or dynamic loading regimes. The experimental studies will investigate the progressive collapse performance of such PC frames subjected to the scenario of a sudden loss of an interior column completely. The tests will also help researchers and design engineers to deeper understand the effects of the location of column missing and design details of connections on their performance and load resisting mechanisms in resisting progressive collapse. Analytical models will be given for predicting the key load resisting mechanism of PC frames; 2) load resisting function of PC connections subjected to the loss of an interior column scenario will be determined. A special beam-column joint element will be generated for simulation of the progressive collapse behavior of PC connections reasonably; 3) simplified analytical tools with above special joint elements will also be developed for quick evaluation of the progressive collapse resilience of PC frames without conducting a detailed finite element analysis. Based on the simplified analytical tools, a series of parametric studies will be carried out to identify the key parameters, which will control the failure modes of PC frames. The most dangerous failure mode of the PC frame suffered column removal scenario will also be identified; 4) With the aids of above experimental, numerical, and analytical analysis, design details, which could improve the progressive collapse performance of PC significantly, will be suggested. For design PC frames to resist progressive collapse quantitatively, a dual controlling index based on “ultimate displacement” and “ultimate load resisting capacity” will be proposed.

针对后浇整体式预制混凝土框架结构的力学机理的复杂性和多样性以及相对较差的整体性，可能具有比现浇结构更大的倒塌风险，拟采用试验研究、理论分析和数值模拟相结合的方法对其抗连续倒塌性能及控制方法进行研究。主要研究内容包括：1) 通过开展拟静力和动力试验，系统研究其抗连续倒塌的破坏模式，探讨失柱位置与节点处钢筋连接方式对其抗倒塌的抗力机制（压拱效应和悬索效应）的影响规律；2) 建立后浇整体式预制混凝土框架结构抗连续倒塌的关键抗力机制的理论计算模型，提出节点抗连续倒塌的恢复力模型及适应后浇整体式预制混凝土框架结构连续倒塌模拟的新型节点单元；3) 开展大规模高精度非线性模拟，确定影响该结构体系抗连续倒塌性能的控制因素及最不利失效模式；4) 定性地给出后浇整体式预制混凝土框架结构抗连续倒塌的有效构造措施，提供用于定量控制后浇整体式预制混凝土框架结构抗连续性倒塌的“极限位移”和“极限承载力”的双参数指标。

针对后浇整体式预制混凝土框架结构的力学机理的复杂性和多样性以及相对较差的整体性，可能具有比现浇结构更大的倒塌风险，本项目采用试验研究、理论分析和数值模拟相结合的方法对其抗连续倒塌性能及控制方法进行研究。主要研究内容包括：1) 通过开展拟静力和动力试验，系统研究其抗连续倒塌的破坏模式，探讨失柱位置与节点处钢筋连接方式对其抗倒塌的抗力机制（压拱效应和悬索效应）的影响规律；2) 建立后浇整体式预制混凝土框架结构抗连续倒塌的关键抗力机制的理论计算模型，提出节点抗连续倒塌的恢复力模型及适应后浇整体式预制混凝土框架结构连续倒塌模拟的新型组合节点单元；3) 开展大规模高精度非线性模拟，确定影响该结构体系抗连续倒塌性能的最不利失效模式；4) 定性地给出后浇整体式预制混凝土框架结构抗连续倒塌的有效构造措施，提供用于定量控制后浇整体式预制混凝土框架结构抗连续性倒塌的“极限位移”和“极限承载力”的双参数指标。