钢筋混凝土筒中筒结构拟动力试验研究与理论分析

制作了一个14层的钢筋混凝土筒中筒结构模型,模型比例为1∶10,等效为两自由度体系,进行了6种工况的地震动加速度峰值的拟动力试验,研究了筒中筒结构在地震作用下的动力特性、弹性和弹塑性阶段的地震反应、抗震性能和破坏机理。研究表明,该结构在7度罕遇地震作用下仍处于弹性状态,9度罕遇地震作用下,核心筒除与底板相交处开裂外无其它可见裂缝,而外框筒开裂严重,但结构仍具有较高的承载能力和侧向刚度。实测滞回曲线反映了筒中筒结构具有良好的延性和耗能性能。最后,采用改进了的非线性杆单元模型编写了程序,对筒中筒结构进行了非线性分析。结果表明,位移时程曲线计算值与试验值基本吻合。

Pseudo-dynamic test and theoretical analysis of RC tube in tube structure

For a 14-storied tube in tube structure model on the scale of 1/10,which was equivalent to a two-degree-of-freedom system,the authors executed a pseudo-dynamic test with six cases of earthquake ground motions.The dynamic characteristic,seismic responses in elastic and elasto-plastic stages,seismic behavior and failure mechanism of the model were studied.The test indicates that the model is elastic under seldom seismic intensity of 7 degree and the frame-tube is cracked seriously but the structure behaved with perfect bearing capacity and lateral stiffness under seismic seldom intensity of 9 degree.Hysteric curve of the structure showed superior performance of ductility and energy dissipation.Finally,an FEM program on the basis of the advantaged nonlinear element model is developed in the paper,calculation results of displacement time-history curve being in good agreement with those of the tests.