箱梁竖向预应力精轧螺纹筋张拉力检测模型  

Tensile Force Test Model of Vertical Prestressing Finishing Rolling Rebar in Box Girder

作　　者：徐向锋[1] 张峰[2] 佘勤聪[3] 

机构地区：[1]山东交通学院土木工程学院,山东济南250023 [2]山东大学岩土与结构工程研究中心,山东济南250061 [3]长沙理工大学土木与建筑学院,湖南长沙410014

出　　处：《应用基础与工程科学学报》2013年第6期1136-1144,共9页Journal of Basic Science and Engineering

基　　金：国家自然科学基金(E080505);湖南省自然科学基金资助项目(11JJ5031);长沙理工大学桥梁工程湖南省普通高校实验室开放基金(10KA16)

摘　　要：精轧螺纹钢筋作为竖向预应力筋在混凝土箱梁中得到广泛使用,但其锚固应力的损失几乎得不到有效控制,损失如果过大,会引起箱梁腹板斜裂缝.基于动力学,选取合适的振动形状函数求解结构频率,避免了常规Rayleigh法中的微分运算,提高了计算精度,建立了外露段频率随钢筋外露段长度和有效张拉力的三参数模型.同时采用有限元数值模拟,验证了三参数模型的有效性.基于室内模型试验,设计制作竖向预应力钢筋张拉受力的箱梁腹板模型,在钢筋外露段的顶端安装高频加速度传感器获得竖向预应力筋外露段的固有频率,采用穿心式压力传感器测试有效的竖向预应力,依托试验测试数据建立精扎螺纹钢筋张拉力与外露段频率的非线性关系模型.本文所提无损检测方法能够快捷、有效测得竖向预应力张拉力.Finishing twisted steel as vertical prestressing tendons is widely used in the concrete box girder,but it is hard to effectively control the loss of anchor stress,with excessive loss it may cause box girder webs to crack.Based on the dynamic,selecting the vibration shape functions for obtaining the structural frequency,without using the differential operation of the conventional Rayleigh law which improved the calculation accuracy,the three-parameter model was built which include the frequency of the exposed segment.Segment length of the exposed steel reinforcements and effective tensile force.Meanwhile the validity of the three-parameter model was verified using finite element numerical simulation.The vertical pre-tensioning force of the box girder webs model was designed at laboratory.The natural frequency of vertical prestressing tendons exposed section was obtained through the high-frequency acceleration sensor which was set up at the top of the exposed reinforcement steel segment.Relying on experimental test data,the model which had the nonlinear relationship between fine bundle the rebar tensile force and the exposed segment frequency was established using feedthrough pressure sensor to test the vertical prestressing effectively.The NDT methods are able to measure the vertical prestressing tension quickly and effectively.

关 键 词：箱梁 精轧螺纹钢筋 竖向预应力 Rayleigh法 模型试验 频率 

分 类 号：U446[建筑科学—桥梁与隧道工程]