摘要
为考虑土-结构相互作用对输入地震波的影响,基于两步法思想,建立了考虑辐射阻尼效应的等效输入地震波。在该种方法中,将单自由度体系的基础地震反应为上部结构的输入,然后用状态空间法计算考虑土-结构相互作用后体系阻尼比的变换情况,用以修正上部结构的阻尼系数,从而利用刚性基础的反应近似计算土-结构相互作用的影响。对一个单自由度体系和一个5层框架结构进行计算分析,算例分析表明,直接利用自由场的地震波或基岩波作为上部结构的输入,计算误差甚至超过100%,而两步法可使体系的计算误差小于10%,采用修正阻尼系数的两步法,误差将小于5%,满足工程需要。
Taking account of soil-structure interaction on seismic wave input, based on the theory of a two-step method, equivalent seismic wave input considering radiation damping effects is established. Firstly, the base response of single degree of freedom system is considered as the input of superstructure; and then damping ratio of the system is calculated by the state-space method considering soil-structure interaction, which is used to modify the damping coefficients of superstructure; thus the impact of soil-structure interaction is approximately calculated from the response of rigid foundation. Subsequently, a single degree of freedom system and a five-story frame structure are analyzed; numerical examples show that the calculation errors even exceed 100%; while directly taking seismic wave of free field and bedrock as the input of superstructure. However, the calculation errors of the two-step method are less than 10%; furthermore, the calculation errors will be less than 5% adopting the modified damping two-step method, which can satisfy the requirements of engineering. © 2016, Science Press. All right reserved.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2016年第S1期583-590,共8页
Rock and Soil Mechanics
基金
土木工程防灾国家重点实验室开放基金(No.SLDRCE15-01)~~
关键词
辐射阻尼
土-结构相互作用
等效输入
地震反应
Damping
Degrees of freedom (mechanics)
Errors
Radiation
Radiation effects
Rigid structures
Seismic response
Seismic waves
Seismology
Soils
State space methods
Synchrotron radiation
