-
摘要: 为了将结构的动力参数应用于在役RC梁桥的实际承载能力评估, 根据四片钢筋混凝土简支T梁静、动力损伤试验成果, 应用非线性回归方法, 得到不同配筋率下表征T梁刚度比和频率比关系的曲线族方程, 建立了钢筋混凝土单梁结构动力特性与承载力之间的关系。基于实测基频和裂缝特征将整桥的动力特性分解为单梁的动力特性, 应用钢筋混凝土单梁模型试验研究成果, 对RC梁桥结构性能进行评估。本文建立的动力法评估模型为: 结构基频和裂缝特征→刚度→名义配筋率→单梁抗弯能力。通过对某座实际RC梁桥的动力法评定得到了单梁的变形控制弯矩、裂缝控制弯矩、强度控制弯矩, 评定结果与静载试验结果一致。可见, 以实测基频和裂缝特征可预测出RC简支梁桥的实际承载力, 精度满足实际应用要求。Abstract: Dynamic parameters were used to evaluate the loading capability of existing RC girder bridge. According to the experimental results of damnification test on four pieces of RC simple T-beam and applying nonlinear regression analysis method, some equations expressing the relation of the stiffness ratio and frequency ratio of T-beam were obtained, a relation of the structural dynamic characteristic and bearing capacity of RC single beam was proposed. Based on the measured basic frequency and crack characteristic, the dynamic characteristic of the whole bridge was divided into the dynamic properties of single beams. So the model of dynamic assessment was expressed, structural basic frequency and crack characteristic→rigidity→nominal ratio of reinforcement→resistance to bending of single beam. In the dynamic assessment of a actual RC simple bridge, the deflection-controlling bending moment, crackcontrolling bending moment and intensity-controlling bending moment of single beam are obtained, the evaluation result of vibration method is accurate and accordant to static test result, which indicates that the frequency and crack characteristic can be used to forecast the loading capability of existing RC girder bridge. 3 tabs, 9 figs, 9 refs.
-
Key words:
- bridge engineering /
- RC bridge /
- bearing capacity /
- vibration testing /
- evaluation method
-
表 1 混凝土取芯试件抗压强度
Table 1. Compressive strength of concrete core sample
测点 直径d/mm 长度l/mm d·l-1 抗压力/kN 换算标准抗压强度/MPa 1# 99.4 136.5 0.728 300 39.61 2# 99.5 134.5 0.740 219 29.76 3# 99.5 78.0 1.276 290 34.35 
下载: 导出CSV
表 2 理论与实测基频
Table 2. Theoretical basic frequencies and test basic frequencies
项目 频率/Hz 一阶 二阶 三阶 理论值 5.577 12.699 18.043 实测值 5.860 12.700 20.510
下载: 导出CSV
表 3 动力法预测结果
Table 3. Predictive result by dynamic method
梁号 1#粱 2#梁 3#梁 预测承载力 EIsi/(kN·m2) 1 333 366.695 1 658 686.975 2 043 595.638 μnom 0.046 0.058 0.071 Mδ/(kN·m) 1 947.059 2 542.300 3 305.770 Mf/(kN·m) 1 119.369 1 392.477 1 715.611 Mu(kN·m) 1 689.145 2 188.942 2 818.618 荷载效应 Mr/(kN·m) 53.38 33.67 29.45 Mq/(kN·m) 466.1 413.2 358.5 Mg/(kN·m) 318.7 318.7 318.7 Mj/(kN·m) 1 110.0 1 052.0 925.6 注：Mr、Mq、Mg分别为人群荷载、汽车荷载、恒载在梁跨中引起的弯矩值，Mj为组合后最不利内力值。
下载: 导出CSV
-
[1] 任宝双, 钱稼茹, 聂建国. 在用钢筋混凝土简支梁桥结构综合评估方法[J]. 土木工程学报, 2002, 35(2): 97-102. https://www.cnki.com.cn/Article/CJFDTOTAL-TMGC200202016.htmRen Bao-shuang, Qian Jia-ru, Nie Jian-guo. Synthesized evaluation method for existing simple supported beam type RC bridge structures[J]. China Civil Engineering Journal, 2002, 35(2): 97-102. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-TMGC200202016.htm [2] 范立础, 袁万城, 张启伟. 悬索桥结构基于敏感性分析的动力有限元模型修正[J]. 土木工程学报, 2000, 33(1): 9-14.Fan Li-chu, Yuan Wan-cheng, Zhang Qi-wei. Sensitivity-based FE model updating bf a suspension bridge[J]. China Civil Engineering Journal, 2000, 33(1): 9-14. (in Chinese) [3] Jeong-Tae Kim, Yeon-Sun Ryu, Hyun-Man Cho. Damage identification in beam-type structures: frequency-based method vs mode-shape-based method[J]. Engineering Structures, 2003, 25(1): 57-67. doi: 10.1016/S0141-0296(02)00118-9 [4] Pandy A K, Biswas M, Samman M M. Damage detection from changes in curvature mode shape[J]. Journal of Sound and Vibration, 1991, 145(2): 32l-332. [5] Pandy A K, Biswas M. Damage detection in structures using changes in flexibility[J]. Journal of Sound and Vibration, 1994, 169(1): 3-17. doi: 10.1006/jsvi.1994.1002 [6] 袁万城, 崔飞, 张启伟. 桥梁健康监测与状态评估的研究现状与发展[J]. 同济大学学报: 自然科学版, 1999, 27(2): 184-188. https://www.cnki.com.cn/Article/CJFDTOTAL-TJDZ902.012.htmYuan Wan-cheng, Cui Fei, Zhang Qi-wei. Current research and development of structural health monitoring and condition assessment for bridges[J]. Journal of Tongji University: Natural Science, 1999, 27(2): 184-188. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-TJDZ902.012.htm [7] 贺拴海, 郭琦, 宋一凡, 等. Rc桥梁健康状况及承载能力的动力评估试验[J]. 长安大学学报: 自然科学版, 2003, 23(6): 36-39. https://www.cnki.com.cn/Article/CJFDTOTAL-XAGL200306010.htmHe Shuan-hai, Guo Qi, Song Yi-fan, et al. Health condition and load carrying capacity evaluation of RC beam based on dynamic testing[J]. JournaI of Chang'an University: Natural Science Edition, 2003, 23(6): 36-39. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-XAGL200306010.htm [8] 贺拴海, 宋一凡, 赵小星, 等. 钢筋混凝土梁式结构裂缝特征与损伤评估方法试验研究[J]. 土木工程学报, 2003, 36(2): 6-9. https://www.cnki.com.cn/Article/CJFDTOTAL-TMGC200302001.htmHe Shuan-hai, Song Yi-fan, Zhao Xiao-xing, et al. Experimental study on crack characteristics and damage evaIuation for RC beams[J]. China Civil Engineering Journal, 2003, 36(2): 6-9. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-TMGC200302001.htm [9] 周敉, 贺拴海, 宋一凡. 基于挠度试验的梁式结构评估[J]. 长安大学学报: 自然科学版, 2004, 24(5): 40-42. https://www.cnki.com.cn/Article/CJFDTOTAL-XAGL200405010.htmZhou Mi, He Shuan-hai, Song Yi-fan. Structural evaluation for beams based on deflection testing[J]. Joumal of Chang'an University: Natural Science Edition, 2004, 24(5): 40-42. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-XAGL200405010.htm -
点击查看大图
图(9) / 表(3)
计量
- 文章访问数: 296
- HTML全文浏览量: 122
- PDF下载量: 209
- 被引次数: 0
