大跨度缆索支承桥梁基础冲刷动力识别方法
|
摘要
为快速评估运营阶段桥梁基础冲刷状态,提出一种基于实测模态与模型更新的冲刷动力识别方法,并在杭州湾大桥桥塔冲刷检测中进行应用.分别于2013年、2016年对杭州湾大桥上部结构进行了两次环境振动下的加速度数据采集工作,并进行模态分析,得到两次测试所对应的结构自振频率与振型.同时利用有限元分析软件采用鱼骨模型进行上部结构数值建模,采用土弹簧进行下部结构桩土效应的模拟.首先利用冲刷非敏感模态的实测自振频率对数值模型中的桩侧等效弹簧刚度进行模型更新,直至得到与实际相符的桩土边界条件.进而利用冲刷敏感模态自振频率的实测变化值,对有限元模型中的基础冲刷深度进行模型更新,直至数值模拟变化值与实测变化值相一致,从而定量识别出3 a内基础冲刷深度的发展.最后,利用水下地形测量数据完成对该冲刷识别方法准确性的验证.研究结果表明:该方法利用桥梁上部结构实测模态变化进行下部结构基础冲刷模型的更新是可行的,基础冲刷深度的识别是准确的,可解决长期以来需要水下作业才能完成桥梁基础冲刷检测的技术难题.
In order to quickly assess bridge scour during operation period, a dynamic-based identification method was proposed based on the measured vibration modes and model updating technique, and was applied to the pylon scour detection of the Hangzhou Bay Bridge. Two field measurements were conducted in 2013 and 2016 respectively to record the acceleration data of the superstructure of the Hangzhou Bay Bridge under ambient vibration. A modal analysis was carried out to obtain the natural frequencies and modes of vibration for each measurement. The superstructure was numerically simulated by a fish-bone finite element model and the pile-soil effect of the substructure was simulated by soil springs. The stiffness of equivalent springs around piles in the simulation model was firstly updated based on the measured natural frequencies of the scour-insensitive modes. Until the simulated natural frequencies corresponded to the measurement, the stiffness of the springs in the simulation could be seen as the identification of the real pile-soil effect of the bridge. Then, the scour depth in the simulation model was updated based on the variation of the measured natural frequencies of the scour-sensitive modes. Until the simulated and the measured variations of the natural frequencies were the same, the scour depth in the simulation model could be regarded as the identification of the real situation of the foundation during the three years. The identification accuracy was finally verified by the results of underwater terrain map around the foundation of the bridge. Results show that it is feasible to update the foundation scour by tracing the measured modal variation of the superstructure to identify a correct scour depth. This method can resolve the long-term difficulty of the traditional scour detection because it does not need underwater operation.
In order to quickly assess bridge scour during operation period, a dynamic-based identification method was proposed based on the measured vibration modes and model updating technique, and was applied to the pylon scour detection of the Hangzhou Bay Bridge. Two field measurements were conducted in 2013 and 2016 respectively to record the acceleration data of the superstructure of the Hangzhou Bay Bridge under ambient vibration. A modal analysis was carried out to obtain the natural frequencies and modes of vibration for each measurement. The superstructure was numerically simulated by a fish-bone finite element model and the pile-soil effect of the substructure was simulated by soil springs. The stiffness of equivalent springs around piles in the simulation model was firstly updated based on the measured natural frequencies of the scour-insensitive modes. Until the simulated natural frequencies corresponded to the measurement, the stiffness of the springs in the simulation could be seen as the identification of the real pile-soil effect of the bridge. Then, the scour depth in the simulation model was updated based on the variation of the measured natural frequencies of the scour-sensitive modes. Until the simulated and the measured variations of the natural frequencies were the same, the scour depth in the simulation model could be regarded as the identification of the real situation of the foundation during the three years. The identification accuracy was finally verified by the results of underwater terrain map around the foundation of the bridge. Results show that it is feasible to update the foundation scour by tracing the measured modal variation of the superstructure to identify a correct scour depth. This method can resolve the long-term difficulty of the traditional scour detection because it does not need underwater operation.
引文
[1] RICHARDSON E V, DAVIS S. Evaluating scour at bridges[R]. Washington DC: ASCE, 2001
[2] DENG L, CAI C. Bridge scour: prediction, modeling, monitoring, and countermeasures—review[J]. Practice Periodical on Structural Design and Construction, 2009, 15(2): 125
[3] PRENDERGAST L J, GAVIN K. A review of bridge scour monitoring techniques[J]. Journal of Rock Mechanics and Geotechnical Engineering, 2014, 6(2): 138
[4] XIONG W, TANG P B, KONG B, et al. Computational simulation of live-bed bridge scour considering suspended sediment loads[J]. Journal of Computing in Civil Engineering, ASCE, 2017, 31(5): 04017040
[5] XIONG W, CAI C S, KONG X. Instrumentation design for bridge scour monitoring using fiber Bragg grating sensors[J]. Applied Optics, 2012, 51(5): 547
[6] LIN Y B, LAI J S, CHANG K C, et al. Using MEMS sensors in the bridge scour monitoring system[J]. Journal of the Chinese Institute of Engineers, 2010, 33(1): 25
[7] WANG C Y, WANG H L, HO C C. A piezoelectric film type scour monitoring system for bridge pier[J]. Advances in Structural Engineering, 2012, 15(6): 897
[8] WU B, CHEN W L, LI H. Real-time monitoring of bridge scouring using ultrasonic sensing technology[C]//Proceeding of SPIE Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems. San Diego, California: The International Society for Optical Engineering, 2012
[9] RADCHENKO A, POMMERENKE D, CHEN G D, et al. Real time bridge scour monitoring with magneto-inductive field coupling[C]//Proceeding of SPIE Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems. San Diego, California: The International Society for Optical Engineering, 2013
[10]YU X B, YU X. Development and evaluation of an automation algorithm for a time-domain reflectometry bridge scour monitoring system[J]. Canadian Geotechnical Journal, 2011, 48(1): 26
[11]MILLARD S G, BUNGEY J H, THOMAS C, et al. Assessing bridge pier scour by radar[J]. NDT International, 1998, 31(4), 251
[12]FALCO F D, MELE R. The monitoring of bridges for scour by sonar and sediment[J]. NDT International, 2002, 35(2): 117
[13]熊文, 董夏鑫, 唐平波, 等. 基于动力指纹的斜拉桥桥塔冲刷深度识别方法[J]. 湖南大学学报(自然科学版), 2017, 44(11): 1 XIONG Wen, DONG Xiaxin, TANG Pingbo, et al. Identification method for pylon scour depth of cable-stayed bridges by tracing dynamic index[J]. Journal of Hunan University (Natural Science), 2017, 44(11): 1
[14]熊文, 邹晨, 叶见曙. 基于动力特性识别的桥墩冲刷状态分析理论[J]. 中国公路学报, 2017, 30(5): 89 XIONG Wen, ZOU Chen, YE Jianshu. Condition assessment of bridge scour by tracing dynamic performance of bridges[J]. China Journal of Highway and Transport, 2017, 30(5): 89
[15]李泽新. 公路双柱式桥墩健康状态动力评估方法研究[D]. 北京: 北京交通大学, 2013 LI Zexin. Study on dynamic assessment method for highway bridge double-column piers[D]. Beijing: Beijing Jiaotong University, 2013
[16]FISHER M, ATAMTURKTUR S, KHAN A A. A novel vibration-based monitoring technique for bridge pier and abutment scour[J]. Structural Health Monitoring, 2013, 12(2): 114
[17]API. Recommended practice for planning, designing and constructing fixed offshore platforms-working stress design: RP 2A-WSD[S]. Washington DC: API Publishing Services, 2007
[2] DENG L, CAI C. Bridge scour: prediction, modeling, monitoring, and countermeasures—review[J]. Practice Periodical on Structural Design and Construction, 2009, 15(2): 125
[3] PRENDERGAST L J, GAVIN K. A review of bridge scour monitoring techniques[J]. Journal of Rock Mechanics and Geotechnical Engineering, 2014, 6(2): 138
[4] XIONG W, TANG P B, KONG B, et al. Computational simulation of live-bed bridge scour considering suspended sediment loads[J]. Journal of Computing in Civil Engineering, ASCE, 2017, 31(5): 04017040
[5] XIONG W, CAI C S, KONG X. Instrumentation design for bridge scour monitoring using fiber Bragg grating sensors[J]. Applied Optics, 2012, 51(5): 547
[6] LIN Y B, LAI J S, CHANG K C, et al. Using MEMS sensors in the bridge scour monitoring system[J]. Journal of the Chinese Institute of Engineers, 2010, 33(1): 25
[7] WANG C Y, WANG H L, HO C C. A piezoelectric film type scour monitoring system for bridge pier[J]. Advances in Structural Engineering, 2012, 15(6): 897
[8] WU B, CHEN W L, LI H. Real-time monitoring of bridge scouring using ultrasonic sensing technology[C]//Proceeding of SPIE Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems. San Diego, California: The International Society for Optical Engineering, 2012
[9] RADCHENKO A, POMMERENKE D, CHEN G D, et al. Real time bridge scour monitoring with magneto-inductive field coupling[C]//Proceeding of SPIE Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems. San Diego, California: The International Society for Optical Engineering, 2013
[10]YU X B, YU X. Development and evaluation of an automation algorithm for a time-domain reflectometry bridge scour monitoring system[J]. Canadian Geotechnical Journal, 2011, 48(1): 26
[11]MILLARD S G, BUNGEY J H, THOMAS C, et al. Assessing bridge pier scour by radar[J]. NDT International, 1998, 31(4), 251
[12]FALCO F D, MELE R. The monitoring of bridges for scour by sonar and sediment[J]. NDT International, 2002, 35(2): 117
[13]熊文, 董夏鑫, 唐平波, 等. 基于动力指纹的斜拉桥桥塔冲刷深度识别方法[J]. 湖南大学学报(自然科学版), 2017, 44(11): 1 XIONG Wen, DONG Xiaxin, TANG Pingbo, et al. Identification method for pylon scour depth of cable-stayed bridges by tracing dynamic index[J]. Journal of Hunan University (Natural Science), 2017, 44(11): 1
[14]熊文, 邹晨, 叶见曙. 基于动力特性识别的桥墩冲刷状态分析理论[J]. 中国公路学报, 2017, 30(5): 89 XIONG Wen, ZOU Chen, YE Jianshu. Condition assessment of bridge scour by tracing dynamic performance of bridges[J]. China Journal of Highway and Transport, 2017, 30(5): 89
[15]李泽新. 公路双柱式桥墩健康状态动力评估方法研究[D]. 北京: 北京交通大学, 2013 LI Zexin. Study on dynamic assessment method for highway bridge double-column piers[D]. Beijing: Beijing Jiaotong University, 2013
[16]FISHER M, ATAMTURKTUR S, KHAN A A. A novel vibration-based monitoring technique for bridge pier and abutment scour[J]. Structural Health Monitoring, 2013, 12(2): 114
[17]API. Recommended practice for planning, designing and constructing fixed offshore platforms-working stress design: RP 2A-WSD[S]. Washington DC: API Publishing Services, 2007