土与一般平面不对称结构地震动力相互作用研究

Seismic behaviors of general asymmetric-plan structures considering soil-structure interaction

为更精确分析结构各层质量中心偏心对结构平移-扭转耦合地震响应影响,提出分析土与一般质量偏心结构地震动力相互作用的基本框架。用极坐标建立双向地震作用下两层一般平面不对称结构(GAS)(六个自由度)动力方程;用五个自由度土阻抗函数表征土与一般平面不对称结构相互作用;建立土与一般平面不对称结构相互作用(SGASI)动力方程。用SGASI系统标准化均方根位移与加速度分析地震动力的相互作用。通过设置不同质量偏心位置,数值研究在双向地震作用下,考虑土与结构相互作用的同轴、非同轴质量偏心对结构平-扭耦合地震响应影响。

In order to more accurately analyze the coupled lateral-torsional seismic responses of a structure whose mass centers at different floors are not located on a single vertical axis, a basic framework for analyzing the seismic interaction between soil and general mass eccentric structure was presented. Polar coordinates were used to develop the dynamic equations of a two-storey general asymmetric-plan structure (GAS) of 6-degree-of-freedom (6DOFs) under bi-directional earthquakes. Then, with resorting to the 5DOF soil impedance functions, the soil-general-asymmetric-plan-structure interaction (SGASI) was characterized. Finally, the dynamic equations of both the GAS and the soil-foudation-superstructure (whole) interaction were integrated. The normalized root-mean-square (RMS) of seismic displacement and acceleration responses of the SGASI system were derived. The effects of the single-axis as well as the non-coaxial mass eccentricities on the coupled lateral-torsional seismic responses were analyzed numerically through setting up different locations of mass centers under bi-directional earthquakes.