基于BRB的铁路双柱式超高墩连续梁桥横向减震研究  

Transverse seismic mitigation of railway continuous girder bridge with double-column ultra-high piers based on BRBs

作　　者：漆启明 邵长江[1] 黄辉 王应良 戴晓春[3] 韦旺 QI Qiming;SHAO Changjiang;HUANG Hui;WANG Yingliang;DAI Xiaochun;WEI Wang(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;China Railway International Group,Co.,Ltd.,Beijing 100039,China;China Railway Eryuan Engineering Group Co.,Ltd.,Chengdu 610031,China)

机构地区：[1]西南交通大学土木工程学院,成都610031 [2]中铁国际集团有限公司,北京100039 [3]中铁二院工程集团有限责任公司,成都610031

出　　处：《振动与冲击》2022年第7期182-192,共11页Journal of Vibration and Shock

基　　金：国家自然科学基金(51978583,51178395);四川省应用基础研究重点项目(2017JY0059)。

摘　　要：为提升双柱式超高墩桥梁的横向抗震性能,可将屈曲约束支撑(buckling restrained brace,BRB)用于双肢墩身。通过某铁路超高墩大跨连续钢桁梁桥非线性时程分析,研究了罕遇(PGA=0.227g)和极罕遇(PGA=0.640g)地震下BRB的参数影响规律、作用机理及减震效果,探讨了高阶振型对BRB墩身地震响应的影响。结果表明:BRB能够改变墩身传力路径,在一定参数范围内可将原有墩身部分弯矩转化为支撑点的轴力和剪力;罕遇地震下BRB未充分发挥耗能作用,地震响应随芯材面积A;增加而不断接近X撑方案;极罕遇地震下设置BRB可明显减小墩顶位移和墩身轴力响应;BRB会适当增加墩身弯矩响应,但截面PM滞回并未超过等效屈服包络;由于高阶振型效应,BRB墩身中部的剪力、弯矩响应包络图凹凸交替变化;随着墩高的降低,高阶振型的影响减弱,墩身剪力、弯矩包络图近似双折线;采用BRB可有效抑制超高墩的高阶振型,同时提升极罕遇地震下桥墩的耗能能力、增强横桥向抗震性能。Here,to improve lateral aseismic performance of double-column ultra-high pier bridge,buckling restrained braces(BRBs) were used as lateral connections of double-column.Based on the nonlinear time history analysis of a certain railway ultra-high pier long-span continuous steel truss girder bridge,influence laws,action mechanism and seismic mitigation effect of BRB parameters under rare(PGA = 0.227g) and extremely rare(PGA = 0.640g) earthquakes were studied,and effects of high-order vibration modes on seismic responses of BRB pier body were explored.The results showed that BRB can change the force transmission path of pier body,and can convert part of bending moment of the original pier body into axial force and shear force at support points within a certain parameter ranges;under rare earthquakes,BRB does not give full play to its energy dissipation ability,and its seismic response continues to approach the X-brace scheme with increase in core material area Ae;under extremely rare earthquakes,setting BRB can obviously reduce pier top displacement and pier body axial force response;BRB can appropriately increase pier body bending moment response,but its cross-section PM hysteresis does not exceed the equivalent yield envelope;due to high-order mode effect,response envelope diagrams of shear force and bending moment in the middle of BRB pier body change with concave-convex alternating;with decrease in pier height,effects of high-order vibration mode weaken,and envelope diagrams of BRB pier body shear force and bending moment are approximately bilinear line;BRB can effectively suppress high-order vibration modes of ultra-high pier,improve its energy dissipation capacity under extremely rare earthquake and enhance its aseismic performance in transverse direction of bridge.

关 键 词：连续梁桥 双柱式超高墩 屈曲约束支撑(BRB) 高阶振型 减震性能 

分 类 号：U448[建筑科学—桥梁与隧道工程]