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结构实际承受的地震作用通常都会远大于其设计荷载。根据抗震规范设计荷载的减小值是通过响应修正系数来完成的。在中度至重度的地震作用下,结构通常表现为非弹性,因此设计时应做非弹性分析。非弹性动力分析耗费大量时间并需要较高的专业水平对结果进行解释分析。然而,近年来被广泛应用的推倒分析法能够更简单地评估结构的非弹性响应。尽管传统的推倒分析法(CPA)并不能对高振型影响和构件的刚度变化作出解释,但自适应推倒分析法(APA)解决了这些弊端。研究通过APA和CPA所获得的能力曲线对一些抗震需求参数进行推导和比较,如延性折减系数R_μ、超强系数Ω、响应修正系数R。对来自SAC钢结构工程中分别为3层、9层、20层的3个钢抗弯框架进行分析。在各个框架的推倒分析中,使用8种不同的常数和自适应侧向荷载模式。通过传统推倒分析法和自适应推倒分析法结论得出的响应修正系数的最大相对差约为16%。
The actual earthquakes the structure is usually subjected to will be much larger than its design load. Decreasing the design load according to the seismic code is done by responding to the correction factor. Under moderate to severe earthquakes, the structure usually behaves inelastic and should be designed inelasticly. Inelastic dynamic analysis takes a lot of time and requires a high level of expertise to interpret the results. However, the tumble analysis, which has been widely used in recent years, makes it easier to evaluate the structural inelastic response. Although traditional overturning analysis (CPA) does not explain the effects of high-vibrational modes and structural stiffness, adaptive pushback analysis (APA) solves these drawbacks. Some seismic demand parameters are deduced and compared through the ability curves obtained by APA and CPA, such as the ductility reduction coefficient R_μ, the super-coefficient Ω, and the response correction factor R. Three steel bending frames from 3, 9 and 20 stories in SAC steel structure project were analyzed. In each frame’s down analysis, 8 different constants and adaptive lateral load patterns were used. The maximum relative difference of the response coefficients obtained by the traditional method of tipping analysis and adaptive tipping analysis is about 16%.