设计荷载下中小跨径连续梁桥负弯矩冲击系数计算模式  

Calculation mode for dynamic load allowance of negative bending moment of short and medium-span continuous girder bridge under design load

作　　者：周勇军[1,2] 薛宇欣 杨小刚 范凯翔 焦晨凯 赵煜[1,2] 王业路 ZHOU Yong-jun;XUE Yu-xin;YANG Xiao-gang;FAN Kai-xiang;JIAO Chen-kai;ZHAO Yu;WANG Ye-lu(School of Highway,Chang'an University,Xi'an 710064,Shaanxi,China;Engineering Research Center of Highway Large Structures Safety,Ministry of Education,Chang'an University,Xi'an 710064,Shaanxi,China;China Road and Bridge Corporation(CRBC),Beijing 100007,China;Hubei Communications Planning and Design Institute Co.,Ltd.,Wuhan 430051,Hubei,China;School of Civil Engineering,Qingdao University of Technology,Qingdao 266033,Shandong,China)

机构地区：[1]长安大学公路学院,陕西西安710064 [2]长安大学公路大型结构安全教育部工程研究中心,陕西西安710064 [3]中国路桥工程有限责任公司,北京100007 [4]湖北省交通规划设计院股份有限公司,湖北武汉430051 [5]青岛理工大学土木工程学院,山东青岛266033

出　　处：《交通运输工程学报》2025年第1期263-273,共11页Journal of Traffic and Transportation Engineering

基　　金：国家自然科学基金(52278138,51978063);中央高校基本科研业务费资助项目(300102214301,300102214403,300102214708)。

摘　　要：为明确中小跨径连续梁桥在设计荷载作用下的负弯矩冲击系数,采用理论推导和数值仿真相结合的方法开展了中小跨径连续梁桥负弯矩冲击系数研究。根据欧拉-伯努利梁理论推导了两等跨连续梁在多个移动集中力作用下负弯矩冲击系数的解析表达式,以不同标准跨径连续梁桥为研究对象,选用空间三轴车辆模型,基于负弯矩截面荷载效应相等原理,将设计车道荷载等效为准设计状态的重车荷载谱;采用ANSYS软件建立了车辆-桥梁耦合数值仿真振动分析模型,开展了桥梁频率、桥面不平整度和车辆行驶速度对负弯矩冲击系数影响的显著性分析;通过大量的数值仿真结果进行了统计,以桥梁结构频率为自变量,以桥面不平整度为分项标准,提出了负弯矩冲击系数计算模式及其建议取值,并与国内外规范值展开对比分析。研究结果表明:跨径相同但跨数不同的中小跨径连续梁桥的负弯矩冲击系数最大相差38%;随着桥面不平整度等级的降低,负弯矩冲击系数逐渐增大,B级和C级桥面不平整度的负弯矩冲击系数平均值分别为A级对应平均值的2.07倍和4.15倍;车辆行驶速度对负弯矩冲击系数有较大影响,但并未表现出显著规律;在B级和C级桥面不平整度时,各国规范均不同程度地低估了负弯矩冲击系数,建议中小跨径连续梁桥负弯矩冲击系数设计值取为0.335。To clarify the dynamic load allowance(DLA) of negative bending moment of short and medium-span continuous girder bridges under design load,theoretical derivation and numerical simulation were adopted to conduct the research on the DLA of negative bending moment of short and medium-span continuous girder bridges.Based on the Euler-Bernoulli girder theory,an analytical expression for the DLA of negative bending moment of a two-span continuous girder under multiple moving concentrated forces was derived.Continuous girder bridges with different standard spans were selected as research objects,and a spatial three-axis vehicle model was applied.Based on the principle of equivalent load effect in the negative bending moment section,the design load of lanes was equated to the heavy vehicle load spectrum in a quasi-design state.The vibration analysis model of coupled vehicle and bridge numerical simulation was established by ANSYS software.The significance analysis of the influence of bridge frequency,deck roughness,and vehicle speed on the DLA of negative bending moment was carried out.Plenty of numerical simulation results were counted.With the frequency of bridge structure as the independent variable and the deck roughness as the sub-standard,a calculation mode of DLA of negative bending moment and its suggested value were proposed,and they were compared with the standard values in China and abroad.Research results show that the maximum difference between the DLA of negative bending moment of short and medium-span continuous girder bridges with the same span but different span numbers is 38%.The DLA of negative bending moment gradually increases as the deck roughness class decreases.The average DLA of negative bending moment for deck roughness of Class B and Class C is 2.07 times and 4.15 times the corresponding average value for roughness of Class A,respectively.Vehicle speed has a great influence on the DLA of negative bending moment,but the relationship is not clear.When the deck roughness is Class B and Class C,the

关 键 词：桥梁工程 中小跨径连续梁桥 车-桥耦合振动 负弯矩冲击系数 准设计状态 计算模式 

分 类 号：U446[建筑科学—桥梁与隧道工程]