强震下钢板混凝土联肢墙双重抗震防线机制与性能控制

Steel plate reinforced composite shear wall is suitable for super high-rise building structures due to its high axial load carrying capacity. The compression-flexure failure of such composite wall type can be induced under strong earthquakes. In addition, seismic damages are concentrated at plastic hinge of bottom wall region due to its single energy dissipation mechanism, which is adverse to the damaged wall post-quake rehabilitation. Based on the fact that the core wall of super high-rise building typically needs large area openings, an innovative type of steel plate reinforced composite coupled wall system is proposed to make use of its coupling beam-wall pier dual energy dissipation mechanism, which can lead to enhanced load carrying capacity, lateral stiffness, energy dissipation capacity and improved post-quake rehabilitation capacity compared with the single pier wall counterparts. Steel plate or steel shape reinforced composite coupling beams are adopted and connected to the composite wall pier using welded or bolted endplate connection details. The load transfer mechanism, deformation and energy dissipation capacity of the composite coupling beam as well as its connection to composite wall pier are experimentally and numerically investigated. Testing setup for further examining the overall performance of coupling beam-composite wall pier subassembly is developed and applied to investigate the internal force transfer mechanism between coupling beam and wall pier, plastic damage distribution, stiffness and load carrying capacity degradation and energy dissipation capacity. Nonlinear finite element parametric analysis is conducted in conjunction of experimental study to develop performance-based seismic design methodology of steel plate reinforced composite wall system aiming to realize the quantitatively determined coupling beam-wall pier dual seismic force resisting mechanism.

钢板混凝土组合剪力墙轴向承载力高，适用于底部楼层轴压大的超高层建筑，但强震时易发生压弯破坏，且底部塑性铰区的单一耗能机制导致局部墙体损伤集中，不利于灾后修复加固。根据超高层建筑核心筒需要较大面积开洞的建筑形式，提出钢板混凝土联肢组合剪力墙新型结构体系，利用其连梁-墙肢双重抗震防线机制，强震下的承载力、侧向刚度、耗能机制和灾后可修复性等均优于其单肢实体形式。采用内藏钢板或钢骨的钢-混凝土组合连梁，考虑焊接和端板螺栓连接两种方式连接连梁和组合墙肢，验证组合连梁及其与墙肢的连接作为第一道抗震防线的受力、变形与耗能能力。自主研发能反映连梁-墙肢整体受力和变形特征的试验加载装置，进一步考察钢板混凝土组合墙肢作为第二道抗震防线性能的连梁-墙肢内力传递机制、损伤分布、刚度与承载力退化以及耗能能力等。结合非线性有限元参数分析，提出合理量化双重抗震防线机制为目标的钢板混凝土联肢墙的性能化抗震设计理论方法。

钢板混凝土组合剪力墙轴向承载力高，适用于底部楼层轴压大的高层建筑，但强震时易发生压弯破坏，底部塑性铰区的单一耗能机制导致局部墙体损伤集中，不利于灾后修复加固。本项目提出钢板混凝土联肢组合剪力墙新型结构体系，通过引入耦合机制，将地震引起的结构损伤均匀分散到结构全高，通过钢连梁的塑性耗能能力，降低剪力墙的承载力和变形能力的需求。考虑焊接和螺栓连接方式，设计并制作了五个连梁-组合墙肢连接节点的试件，通过试验证明了该连接的可靠性；考虑了钢板直接与钢框架焊接以及钢板间螺栓连接两种构造形式，分别设计、制作了1:4的缩尺试件进行了低周往复加载试验研究。结果表明，提出的组合钢板联肢剪力墙能够实现先连梁后剪力墙的预定屈服耗能机制,且剪力墙屈服后,钢连梁仍然具备足够的塑性变形能力，通过钢连梁的剪切变形和墙肢底部的塑性铰变形来耗散能量，达到连梁-墙肢双重抗震防线机制的目的。采用ABAQUS软件建立数值分析模型，基于试验实测数据，验证了数值模型和分析方法的可靠性。为了弥补试验数量的不足，利用已获验证的数值分析模型，考虑剪力墙轴压比、截面配钢率和钢连梁弯剪比等进行了参数分析，结果表明:轴压比对承载力、刚度和耗能能力影响不明显,但延性却先增加后减小；配钢率提高对承载力和耗能能力提升作用明显,但需避免发生脆性破坏；钢连梁的剪切塑性变形的延性和耗能能力优于弯曲塑性变形,钢连梁的设计应符合“剪切弱于弯曲”要求,同时保证钢连梁充分发挥剪切塑性变形能力。最后针对组合联肢剪力墙的抗震设计方法，首先解决耦联比这一参数在初设阶段难以应用的困难，以连梁跨高比和墙肢高宽比为关键参数，遵循中心复合设计的CCF方案准则并严格按照中国现行规范设计建立结构模型，提出了钢筋混凝土联肢剪力墙的优化设计方法。引入基于能量原理的塑性设计理论，提出了混合联肢剪力墙和联肢钢板组合剪力墙的抗震设计方法，并通过数值分析手段，验证了所提出设计方法的有效性与合理性。

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