Bridges and Structures Division

Hong Kong, Hong Kong

Bridges and Structures Division

Hong Kong, Hong Kong
SEARCH FILTERS
Time filter
Source Type

Xu Y.L.,Hong Kong Polytechnic University | Chen B.,Hong Kong Polytechnic University | Chen B.,Wuhan University of Technology | Ng C.L.,Hong Kong Polytechnic University | And 3 more authors.
Structural Control and Health Monitoring | Year: 2010

The Tsing Ma Bridge in Hong Kong is a long suspension bridge. A wind and structural health monitoring system (WASHMS) has been installed in the bridge and operated by the Hong Kong Highways Department since 1997. The WASHMS is devised to carry out the monitoring of environmental status, traffic loads, bridge features and bridge responses. The environmental status includes temperature environment monitored by temperature sensors, whereas the bridge responses contain displacement responses recorded by displacement transducers, level sensing stations, and global positioning systems (GPS). Bridge displacement responses are, however, induced by a combination of four major types of loadings due to wind, temperature, highway, and railway. This investigation focuses on the temperature environment and the predominating temperature effect on the Tsing Ma Bridge. The main features and the pertinent monitoring system of the Tsing Ma Bridge are first introduced. The data collected from the four types of sensors are pre-processed. The statistics of ambient air temperature, effective temperature and displacement response of the bridge are then figured out based on the measurement data. The statistical relationship between the effective temperature and the displacement of the bridge is finally established. These results are useful for monitoring temperature effects on the Tsing Ma Bridge. Copyright © 2009 John Wiley &Sons, Ltd.


Li Q.,Tongji University | Li Q.,Hong Kong Polytechnic University | Xu Y.,Hong Kong Polytechnic University | Zheng Y.,Hong Kong Polytechnic University | And 3 more authors.
Frontiers of Architecture and Civil Engineering in China | Year: 2011

This paper aims at developing a structural health monitoring (SHM)-based bridge rating method for bridge inspection of long-span cable-supported bridges. The fuzzy based analytic hierarchy approach is employed, and the hierarchical structure for synthetic rating of each structural component of the bridge is proposed. The criticality and vulnerability analyses are performed largely based on the field measurement data from the SHM system installed in the bridge to offer relatively accurate condition evaluation of the bridge and to reduce uncertainties involved in the existing rating method. The procedures for determining relative weighs and fuzzy synthetic ratings for both criticality and vulnerability are then suggested. The fuzzy synthetic decisions for inspection are made in consideration of the synthetic ratings of all structural components. The SHM-based bridge rating method is finally applied to the Tsing Ma suspension bridge in Hong Kong as a case study. The results show that the proposed method is feasible and it can be used in practice for longspan cable-supported bridges with SHM system. © 2011 Higher Education Press and Springer-Verlag Berlin Heidelberg.


Xu Y.L.,Hong Kong Polytechnic University | Zheng Y.,Hong Kong Polytechnic University | Chen Z.W.,Hong Kong Polytechnic University | Xia Y.,Hong Kong Polytechnic University | And 3 more authors.
Bridge Maintenance, Safety, Management and Life-Cycle Optimization - Proceedings of the 5th International Conference on Bridge Maintenance, Safety and Management | Year: 2010

To ensure safety and functionality of long span cable-supported bridges, a bridge rating method is currently used by the Hong Kong bridge management authority as guidance in determining the time intervals for inspection and the actions to be taken in the event of defects being identified. This bridge rating method is based partly on engineering analysis and partly on practical experience. There is insufficient link between the existing bridge rating method and the structural health monitoring system (SHMS). This paper therefore presents a SHMS-based bridge rating method for the Tsing Ma suspension bridge in Hong Kong. The fuzzy based analytic hierarchy approach is employed, and the hierarchical structure for synthetic rating of each structural component of the bridge is proposed. The criticality and vulnerability analyses are performed largely based on the field measurement data from the SHMS installed in the bridge to offer relatively accurate condition evaluation of the bridge and to reduce uncertainties involved in the existing rating method. The procedures for determining relative weighs and fuzzy synthetic ratings for both criticality and vulnerability are suggested. The fuzzy synthetic decisions for inspection are made in consideration of the synthetic ratings of all structural components. The results show that the proposed method is feasible and it can be used in practice for long span cable-supported bridges with SHMS. © 2010 Taylor & Francis Group, London.


Li X.F.,Hong Kong Polytechnic University | Li X.F.,Dalian Maritime University | Ni Y.Q.,Hong Kong Polytechnic University | Chan K.W.Y.,Bridges and Structures Division
Smart Structures and Systems | Year: 2015

The Stonecutters Bridge (SCB) in Hong Kong is the third-longest cable-stayed bridge in the world with a main span stretching 1,018 m between two 298 m high single-leg tapering composite towers. A Wind and Structural Health Monitoring System (WASHMS) is being implemented on SCB by the Highways Department of The Hong Kong SAR Government, and the SCB-WASHMS is composed of more than 1,300 sensors in 15 types. In order to establish a linkage between structural health monitoring and maintenance management, a Structural Health Rating System (SHRS) with relevant rating tools and indices is devised. On the basis of a 3D space frame finite element model (FEM) of SCB and model updating, this paper presents the development of an SHR-oriented 3D multi-scale FEM for the purpose of load-resistance analysis and damage evaluation in structural element level, including modeling, refinement and validation of the multi-scale FEM. The refined 3D structural segments at deck and towers are established in critical segment positions corresponding to maximum cable forces. The components in the critical segment region are modeled as a full 3D FEM and fitted into the 3D space frame FEM. The boundary conditions between beam and shell elements are performed conforming to equivalent stiffness, effective mass and compatibility of deformation. The 3D multi-scale FEM is verified by the in-situ measured dynamic characteristics and static response. A good agreement between the FEM and measurement results indicates that the 3D multi-scale FEM is precise and efficient for WASHMS and SHRS of SCB. In addition, stress distribution and concentration of the critical segments in the 3D multi-scale FEM under temperature loads, static wind loads and equivalent seismic loads are investigated. Stress concentration elements under equivalent seismic loads exist in the anchor zone in steel/concrete beam and the anchor plate edge in steel anchor box of the towers. Copyright © 2015 Techno-Press, Ltd.


Duan Y.F.,Hong Kong Polytechnic University | Duan Y.F.,Zhejiang University | Xu Y.L.,Hong Kong Polytechnic University | Fei Q.G.,Hong Kong Polytechnic University | And 4 more authors.
International Journal of Structural Stability and Dynamics | Year: 2011

The Tsing Ma Bridge is a cable suspension bridge carrying both highway and railway. A bridge health monitoring system called wind and structural health monitoring system (WASHMS) has been installed in the Tsing Ma Bridge and operated since 1997 to monitor the structural performance and its associated loads and environments. However, there exists a possibility that the worst structural conditions may not be directly monitored due to the limited number of sensors and the complexity of structure and loading conditions. Therefore, it is an essential task to establish structural performance relationships between the critical locations/components of the bridge and those instrumented by the WASHMS. Meanwhile, to develop and validate practical and effective structural damage detection techniques and safety evaluation strategies, the conventional modeling for cable-supported bridges by approximating the bridge deck as continuous beams or grids is not applicable for simulation of real damage scenarios. To fulfil these tasks, a detailed full three-dimensional (3D) finite element model of the Tsing Ma Bridge is currently established for direct computation of the stress/strain states for all important bridge components. This paper presents the details of establishing this full 3D finite element model and its calibration. The major structural components are modeled in detail and the connections and boundary conditions are modeled properly, which results in about half million elements for the complete bridge model. The calibration of vibration modes and stresses/strains due to passing trains is carried out, and a good agreement is found between the computed and measured results. © 2011 World Scientific Publishing Company.


Ye X.W.,Hong Kong Polytechnic University | Ni Y.Q.,Hong Kong Polytechnic University | Ko J.M.,Hong Kong Polytechnic University | Wong K.Y.,Bridges and Structures Division
Bridge Maintenance, Safety, Management and Life-Cycle Optimization - Proceedings of the 5th International Conference on Bridge Maintenance, Safety and Management | Year: 2010

This paper aims to seek a method for determining the SCF and its stochastic characteristics for a typical welded steel bridge T-joint. This goal is accomplished by conducting full-scale model experiments of a railway beam section of the suspension Tsing Ma Bridge (TMB). The strain data of the pre-allocated measuring points are acquired and the hot spot strain at the weld toe is determined by a linear regression method. The SCF is then calculated as the ratio between the hot spot strain and the nominal strain which is derived from the measured data from desired strain gauge. To take full account of the effect of predominant factors on the scatter of SCF, the experiments are carried out under different moving load conditions. The statistical properties and probability distribution of SCF are achieved, which reveals that SCF for the welded steel bridge T-joint conforms to a normal distribution. © 2010 Taylor & Francis Group, London.

Loading Bridges and Structures Division collaborators
Loading Bridges and Structures Division collaborators