文档介绍：
基于频率法的体外预应力桥梁有效预应力
测试方法#
谭国金,刘寒冰,王龙林*
5
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(吉林大学交通学院)
摘要:以工程实际为例,对频率法在体外预应力桥梁有效预应力测试的应用进行了分析。通
过求解张拉索的动力微分方程,分析了边界条件对体外预应力筋固有频率的影响。分析结果
表明,固支边界条件下预应力筋的一阶频率比铰支边界大,二者的相对差随着预应力筋的张
拉力的增大而减小。而在张拉力相同的情况下,二者的相对差则随着索长的减小呈现非线性
增大的趋势。在实际测试当中,利用实测的预应力筋频率,仅能得到有效预应力的上、下限
值,实际有效预应力值介于二者之间。对于体外预应力筋这种长度较短的张紧索,利用频率
法测试其有效预应力还存在一定的误差。
关键词:桥涵工程;体外预应力;自振频率;有效预应力;边界条件
中图分类号:
Effective Prestressing Force Testing Method of External
Prestressed
Bridge Based on Frequency Method
TAN Guojin, LIU Hanbing, WANG Longlin
(College of Transportation ,Jilin University)
Abstract: A practical project is taken for the example to analyze the application of frequency
method in the effective prestress test of external prestressed bridge. In the process of solving the
dynamic differential equation of tension cable, the effects of boundary conditions on the natural
frequencies of external prestressed tendons are analyzed. The analysis results show that the
fundamental frequency of the prestressed tendons under fixed boundary condition is higher than
that under hinged-support support boundary condition, and the relative variance decreases with the
increase of tensioning force. With the same tensioning force, the relative variance decreases with
the increase of cable length. In the practical test, only the upper and lower bound limits can be
obtained according to the