框架-核心筒结构的框架内力调整方法对比研究

在框架-核心筒结构的抗震设计中，作为二道防线的外框架部分，需要对其内力进行调整，但我国相关标准在调整方法和调整要求上存在差别，使得设计具有一定程度的不确定性。基于对我国JGJ 3-2010、CECS 230:2008和美国IBC 2000等标准规定的分析和解读，分别从适用范围、调整对象、双重抗侧力体系划分、框架合理刚度、内力重分布等5个方面，对比分析基于基底剪力或最大框架楼层剪力调整方法和基于楼层剪力调整方法的不同。以一实际结构为例，通过弹塑性分析和振动台试验研究了不同调整方法对各部分设计的影响。结果表明：可采用外框架和核心筒承担的剪力比例或者整体刚度分析方法来界定其是否为双重抗侧力体系；外框架与核心筒互为二道防线，在设计时，需对其承载力和刚度协调匹配，对承载力可采用基于楼层剪力的调整方法，调整对象除剪力和弯矩外也应包括轴力，两者的最小分担比例之和为100%，框架最小和最大分担比例分别为20%和80%，对于两者间的刚度匹配关系，可采用广义刚度特征值和刚度比参数来评价，其合理取值范围分别为1~3和0.2~0.9。

Contrastive study on adjustment method of internal force of frame in frame-core wall structure

Internal force of exterior frame needs to be adjusted in order to realize the second fortification line in seismic design of frame-core wall structure, but many differences among various specifications exist in China, which lead to uncertainties of design. Based on investigations and interpretations of relative specifications provision of China(JGJ 3—2010,CECS 230:2008) and USA(IBC), two adjustment methods, i.e. the method based on base shear force or maximum frame story shear force and the method based on story shear force, are compared in terms of scope of application, adjustment objects, definition of dual system, reasonable stiffness of frame and redistribution of internal force. Then an actual structure is utilized to check the influence of adjustment methods on the design by elasto-plastic analysis and shaking table test. Several suggestions are given as follows: dual system can be defined by shear force percentage carried by exterior frame (or core walls) or whole stiffness analysis method; exterior frame and core walls act as each other’s second fortification line, the design of capacity and stiffness should be consistent, the method based on story shear force is reasonable for capacity design, the adjustment objects also should include axial force except shear force and moment, the sum of their minimum percentages is 100%, the minimum and maximum percentage carried by frame are 20% and 80% respectively, the generalized stiffness characteristic value and stiffness ratio parameters can be used to express the stiffness relationship between frame and core walls as for stiffness design, whose reasonable scope are 1~3 and 0.2~0.9 respectively.