基于动载试验荷载效率的简支梁桥冲击系数研究  

A study on dynamic load allowance of a simply supported girder bridge based on load efficiency of a dynamic load test

作　　者：周勇军[1,2] 赵洋 赵煜[1,2] 曹群 李珍 ZHOU Yongjun;ZHAO Yang;ZHAO Yu;CAO Qun;LI Zhen(School of Highway,Chang’an University,Xi’an 710064,China;Research Center of Highway Large Structure Engineering on Safety,Ministry of Education,Chang’an University,Xi’an 710064,China;Hohhot Municipal Engineering Administration,Huhehaote 010020,China)

机构地区：[1]长安大学公路学院,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,西安710064 [3]呼和浩特市市政工程管理局,呼和浩特010020

出　　处：《振动与冲击》2021年第20期207-216,共10页Journal of Vibration and Shock

基　　金：国家自然科学基金(51978063);陕西省自然科学基金(2019JM-362);中央高校基金(300102210511,300102210512)。

摘　　要：为对中小跨径简支梁桥冲击系数进行评价,建立轻荷载作用与等效设计荷载作用下冲击系数的关系。采用五自由度三轴平面车辆模型,以标准跨径的简支小箱梁桥为研究对象,建立车桥耦合振动方程,采用ANSYS软件二次开发语言APDL进行仿真求解。通过荷载等效原理,将设计荷载的车道荷载还原为等效的多辆重车荷载,进行准设计状态分析;基于动载试验荷载效率研究单辆车作用下各片主梁冲击系数的变化规律,对比分析不同因素对冲击系数的影响规律;最后提出基于动载试验荷载效率的轻荷载冲击系数修正方法。结果表明:现行规范取值的冲击系数偏不安全,但在桥面状况良好和低速行驶时安全性较高;冲击系数随动载试验荷载效率增大而减小,通过轻荷载所得的冲击系数直接与规范值对比没有实际意义;轻荷载的冲击系数经过修正后可还原为准设计状态下冲击系数。研究结论可为中小跨径桥梁设计提供参考,同时为桥梁动载试验的评价方法提供依据。In order to evaluate the impact coefficient of small and medium span simply supported beam bridges,the relationship between the impact coefficient under light load and the impact coefficient under equivalent design load was established.The vehicle-bridge coupling vibration equation was established by using the five-degree-of-freedom three-axis plane model and the standard span simply supported small box girder bridge as the research object,and the simulation solution was carried out by using the secondary development language APDL of ANSYS software.Firstly,through the load equivalent principle,the lane load of the design load was reduced to the equivalent heavy vehicle load,and the quasi-design state analysis was carried out;secondly,based on the dynamic load test load efficiency,the change law of the impact coefficient of each main beam under the action of a single vehicle was studied,and the influence of different factors on the impact coefficient was compared and analyzed.Finally,a light load impact coefficient correction method based on the dynamic load test was proposed.The results show that the impact coefficient of the current code is unsafe,but it is higher when the bridge deck is in good condition and at low speed,and the impact coefficient decreases with the increase of dynamic load test load efficiency.There is no practical significance to compare the impact coefficient obtained by light load directly with the code value,and the impact coefficient of light load can be reduced to the impact coefficient of quasi-design state after correction.The research conclusions can provide reference for the design of small and medium-span bridges and provide a basis for the evaluation method of bridge dynamic load test.

关 键 词：桥梁工程 简支梁桥 冲击系数 动载试验荷载效率 准设计状态 

分 类 号：U441.3[建筑科学—桥梁与隧道工程]