RC空心板抗弯承载性能与振动频率的关系  

Research on the Relationship Between Flexural Bearing Performance and Vibration Frequency of RC Voided Slabs

作　　者：徐略勤[1,2] 李修君 王佩 陈叙先 张洪[1,2] 周建庭[1,2] XU Lueqin;LI Xiujun;WANG Pei;CHEN Xuxian;ZHANG Hong;ZHOU Jianting(School of Civil Engineering,Chongqing Jiaotong University Chongqing,400074,China;State Key Laboratory of Mountain Bridge and Tunnel Engineering,Chongqing Jiaotong University Chongqing,400074,China;Chongqing Jiaoda Construction Engineering Quality Test Center Co.,Ltd.Chongqing,400074,China)

机构地区：[1]重庆交通大学土木工程学院,重庆400074 [2]重庆交通大学省部共建山区桥梁及隧道工程国家重点实验室,重庆400074 [3]重庆交大建设工程质量检测中心有限公司,重庆400074

出　　处：《振动.测试与诊断》2025年第2期301-308,412,共9页Journal of Vibration,Measurement & Diagnosis

基　　金：国家重点研发计划资助项目(2018YFB1600300,2018YFB1600301);重庆市教委科学技术研究资助项目(KJQN201900737);重庆市杰出青年科学基金资助项目(cstc2020jcyj-jqX0006);重庆英才计划资助项目(cstc2022ycjh-bgzxm0133)。

摘　　要：为了揭示钢筋混凝土(reinforced concrete,简称RC)空心板抗弯承载性能与其振动频率之间的关系,从实桥上拆取了3片服役27年、全长为11.20 m的RC空心板,通过实桥原位试验和室内分级加载静、动力试验,获取了空心板的抗弯承载性能参数和前3阶振动频率,并分析了空心板荷载、挠度、刚度与竖弯频率间的关系,拟合得到了1阶频率比-荷载比、1阶频率比-割线刚度比的函数表达式。研究表明:3片板的荷载-挠度曲线具有明显的双折线特征,在不同加载状态下前3阶振动模态始终为1阶竖弯(对称)、2阶竖弯(反对称)和3阶竖弯(对称),与半波正弦曲线吻合;3片板的前3阶振动频率均随荷载、挠度和裂缝宽度的增大而下降,其中1阶频率在屈服前分别下降4.52%,9.50%和11.46%,屈服后分别下降27.81%,21.62%和23.27%,1阶频率在敏感性和规律性方面都更好;3片板的1阶频率理论解与室内实测和原位实测结果均非常接近,以室内实测结果为准,误差分别为7.90%,8.16%和1.94%,但高阶频率的理论解则明显偏大;1阶频率比-荷载比和1阶频率比-割线刚度比这2个拟合函数理论上可用于近似评估外加荷载是否超过RC空心板的屈服荷载,并预测RC空心板割线刚度的退化情况。To reveal the relationship between the flexural bearing performance of reinforced concrete(RC) voided slab and its vibration frequencies,three 27-year-old RC voided slabs with a total length of 11.20 m are removed from a real bridge,and the flexural bearing performance parameters and the first three vibration frequencies of the voided slabs are obtained through in-situ tests and monotonic static and dynamic tests in laboratory.The relationships between the vertical bending frequencies and the load,deflection as well as stiffness of voided slabs are analyzed,respectively.In addition,the function expressions of first-order frequency ratio to load ratio,first-order frequency ratio to secant stiffness ratio are obtained through nonlinear fitting.The results show that the load-deflection curves of the three slabs exhibit obvious bilinear characteristics.Under different loading states,the first three vibration modes are always first-order vertical bending(symmetric),second-order vertical bending(antisymmetric) and third-order symmetric vertical bending(symmetric),which are consistent with the half-wave sinusoidal curves.The first three vibration frequencies of the three slabs decrease with the increase of load,deflection and crack width,among which the first-order frequency decreases by 4.52%,9.50% and 11.46% respectively before the yielding of slabs,and 27.81%,21.62% and 23.27% respectively after the yielding of slabs.The first-order frequency is a better evaluation indicator in terms of sensitivity and consistency.The theoretical solution of the first-order frequency is very close to measured results,with the errors of 7.90%,8.16% and 1.94% respectively as compared with results measured in laboratory.However,theoretical solutions of higher-order frequencies obviously overestimate the measured results.In theory,fitted functions of first-order frequency ratio to load ratio,first-order frequency ratio to secant stiffness ratio can be used to evaluate whether the applied load exceeds the yield load of RC voided slab,and

关 键 词：钢筋混凝土空心板 抗弯性能 振动频率 受迫振动试验 弯曲试验 

分 类 号：TU375.1[建筑科学—结构工程]