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以三跨连续独柱墩曲线梁桥作为基本结构,针对不同桥型布置形式建立有限元模型,利用非线性分析与接触理论考察倾覆过程中结构位移、转角及支座反力的时程变化规律。进而计算抗倾覆稳定安全系数,分析不同桥型布置下的独柱墩梁桥抗倾覆能力及倾覆力学特征,改变桥型布置以对独柱墩倾覆力学行为进行参数分析,并将规范法计算结果与有限元法计算结果进行对比。数值仿真表明:随偏载不断增大,边墩内侧支座反力首先减小直至脱空;反力重新分配后,边墩外侧支座反力增速减缓,中墩单支座反力持续增大,最终达到极限状态。通过参数分析可进一步看出:不同桥型布置形式对这一倾覆过程影响明显,边中跨比越小的独柱墩梁桥,其抗倾覆安全性能越低;如果同时曲线半径较大,则采用规范方法验算时会大大高估其抗倾覆能力,从而降低结构设计的安全性。
Taking the three-span continuous single-column curved girder bridge as the basic structure, the finite element model was established for different bridge-type layouts, and the time-history of structure displacement, rotation angle and bearing reaction force were investigated by nonlinear analysis and contact theory . Then the safety coefficient of anti-overturning is calculated, the anti-capsulation and overturning mechanics characteristics of single-column pier with different bridge layouts are analyzed, the bridge layout is changed to analyze the parameters of overturning mechanics behavior of single-column pier, and the results of canonical calculation Compared with the results of finite element method. The numerical simulation shows that with the increase of partial loads, the reaction force of the inner support of the side pier first decreases until the cavity is vacated. After the reaction force is redistributed, the reaction force of the outer side abutment slows down. Increase, eventually reaching the limit state. Through parameter analysis, it can be further seen that different layout forms of bridge have obvious influence on this overturning process, and the safety performance of anti-overturning of single-column girder bridge with lower cross-span ratio is lower. If the radius of the curve is large at the same time, When using the standard method of checking, it greatly overestimates the anti-overturning ability, thus reducing the structural design safety.