平转施工桥梁转体角速度及角加速度合理取值分析

Analysis of Reasonable Rotation Angular Speed and Angular Acceleration of Horizontal Rotation Construction Bridges

关于水平转体施工桥梁的转体角速度限值问题存在较大的争议,现有标准提出的0.01~0.02 rad/min的平转角速度限值偏于保守,造成部分转体桥无法在正常的铁路天窗时间内完成转体,而一些工程实际采用的转速大幅超过现有标准,但并未对结构安全造成任何影响。本文对转体角速度和角加速度与结构效应的对应关系进行理论分析,对国内相关研究成果进行归纳总结,并结合襄北编组站大桥的模型试验数据,按照转体悬臂长度提出转体角速度和角加速度合理取值范围。推荐取值为:悬臂长度不大于40 m时,角速度宜控制在0.05 rad/min以下;悬臂长度大于80 m时,角速度宜控制在0.025 rad/min以下;悬臂长度在40~80 m时,转体角速度的上限值可内插取值;转体角加速度宜控制在2.2×10^(-5)~4.2×10^(-5)rad/s^(2)。

There is significant controversy over the limit value of the rotation angular speed for horizontal rotation construction bridges.The existing standard proposes a conservative limit value of 0.01~0.02 rad/min for the rotation angular speed,which results in some rotation bridges being unable to complete the rotation within the normal railway skylight time.In some engineering projects,the rotation angular speed used significantly exceeds the existing standard,but has not had any impact on structural safety.This paper provides a theoretical analysis of the correspondence between rotation angular speed and angular acceleration with structural effects,summarizes relevant domestic research results,and combines model test data of the Xiangbei marshalling yard bridge to propose a reasonable range of values for rotation angular speed and angular acceleration based on the length of the rotational cantilever.The recommended value is when the cantilever length is not more than 40 m,the angular speed should be controlled below 0.05 rad/min.When the cantilever length is greater than 80 m,the angular speed should be controlled below 0.025 rad/min.When the cantilever length is between 40~80 m,the upper limit value of the rotation angular speed can be interpolated.The rotation angular acceleration should be controlled between 2.2×10^(-5)~4.2×10^(-5) rad/s^(2).