地震行波输入下连续梁桥支承长度的参数分析.pdf

35 10 ( ) V ol. 35 , No . 10 2 0 0 8 1 0 Journal o Hunan U niversity ( N atural Sciences) Oct 2 0 0 8 : 2008) 周光伟 , 李建中, 范立础 ( 1. , 200092) : 根据多跨连续梁桥的主要结构特点, 提出了地震行波 应分析的多跨连续梁桥 分析模型. 采用绝对位移法建立多点输入的运动平衡方程, 并应用非线性时程方法对行波输 入下地震反应的支承长度进行了参数分析. 结果表明: 系统的基本周期大小滑动支座摩阻 系数过渡墩的基本周期以及行波输入延时对地震反应的支承长度有重要影响; 同时考虑 行波 应的多点输入与地震动一致输入的计算结果有较大的差别, 行波 应会使墩梁相对 位移明显增大, 相应地也增大了地震作用下支承长度的需求. : 多跨连续梁桥; 非线性时程方法; 行波 应; 支承长度 : T U279. 72 : A Parametric Study o t he Required Seat ing Length or Continuous Bridges under Longit udinal Excitation o T raveling Seismic Wave ZHOU Guangw ei , L I Jianzhong, FA N L ichu ( College o Civ il Eng ineering, T o ngj i U niv, Shanghai 200092 , China) Abstract: Based on t he key dynamic charact eristics o mult ispan cont inuous bridges, a simpli ied analyt ical model w as adopt ed to st udy the e ect s o traveling w aves . U sing the absolute displacement met hod , the equilib rium equat ion o mot ion was est ablished. T hen , e ects, such as those o the value o nat ural periods, coe icient o riction, the period o t he transitional pier and time lag w ere discussed w ith the nonlinear t imehistory analysis met hod under the longitudinal ex citation o traveling waves. T he results have show n that the relat ive displace ment s bet ween adjacent bridge piers and g irders increase sig ni icant ly, considering t he e ect s o t raveling w aves, and accordingly, t he required seat ing length increases. Key words: m ultispan cont inuous bridges; nonlinear timehisto