超长混凝土框架梁弹性内力行波效应研究

Research into traveling wave effect of ultralong RC frame beam on internal force

鉴于超长混凝土框架结构行波效应规律尚缺乏系统研究,借助建筑结构通用有限元软件MI-DAS/GEN,采用一致与非一致两种激励方式对165～1100m/s地震波速作用下长度为33～264m的3层钢筋混凝土框架结构进行弹性时程分析。通过对比一致与非一致激励下的梁弯矩、剪力和轴力,详细讨论了其随波速、长度以及不同部位的变化规律。研究表明:波速越慢,模型越长,行波效应越明显。框架梁弯矩的增大作用主要集中在264m模型第1层两端,减小作用表现在各模型第1层中部和第2、3层的梁上;剪力与弯矩有相似的变化规律;梁中存在拉力与压力,中部各梁的拉力和压力较两端的梁要大。

In view of lack of research on traveling wave effect of ultralong RC frame structure,finite element software Midas/Gen for architectural structure and methods of uniform and non-uniform excitation were applied to analyze time-history responses of a three-storey and 33-264m reinforced concrete structures under action of 165~1100m/s earthquake wave.By comparing the data of the bending moments,shear forces and axial forces under condition of uniform and non-uniform excitation,their change with wave speed,beam length and acted position was discussed in detail.Research shows that the slower the seismic velocity or the longer the structure,the more obvious the travelling effect is.The increasing effect mainly concentrates at both ends of the first floor of 264m model,the reducing effect reflects in the middle part of all first floor and all second and third floors;The change rule of shear force is similar to that of bending moment,tension and pressure exist in beams,the tension and the pressure in middle beams are larger than that in end beams.