在连续梁桥活动墩上设置限位装置后,活动墩处将包含活动支座的摩擦及限位装置的接触碰撞两种非线性,综合摩擦单元及接触单元的特性,分别考虑接触单元的弹性及弹塑性情况,提出了接触摩擦单元的有限元模型,给出了接触摩擦单元的滞回曲线,针对卸载曲线的不同状态,分别推导出了其卸载刚度;利用接触摩擦单元对设置有分散抗震挡块及活动摩擦支座的连续梁桥进行了非线性地震反应分析,对挡块在降低连续梁桥固定墩地震反应上的分散抗震作用进行了研究,该接触摩擦单元可用于设置有防落梁装置及活动支座桥梁的较为细致的抗震分析模型。
For continuous girder bridges, once the restrainer is installed at the movable pier, the seismic analysis model would be characterized by the friction nonlinearity at the movable support and conctact-and-collision nonlinearity of the restrainer. Based on the characteristics of the friction element and the contact element, finite contact-and-friction element models are presented, with the contact element being elastic and elasto-plastic, respectively. The hysteresis curve for the contact-and-friction element is given and the stiffness under unloading is derived according to various curves. The contact-and-friction element models were applied to the nonlinear time-history analysis of continuous girder bridges which contain friction-type movable supports and restrainers. The seismic dissipating effect of the restrainers on the seismic responses of the fixed pier is analyzed and it is shown that the contact-and-friction element can be used in the detailed aseismic model of continuous girder bridges which contain both restrainers and movable supports.