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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. Since the movements of the bridge are often accommodated by the bearings and expansion joints, large forces may develop in the bridge structure if any components of the movement are restrained. These forces sometimes may cause damage to the bridge.Churchward and Sokai [1] instrumented a section of post-stressed concrete bridge for recording of temperature profiles at different instants of time. It was found that the temperature profile could be reasonably predicted using two design variables, namely the maximum differential temperature and the effective temperature. Similar work was carried out by Au et al.[2] and Tong et al.[3] for both composite bridges and steel bridges in tropical region. Moorty and Roeder [4] attempted to relate the movements of a bridge to the temperature environment. Analytical methods were developed to obtain temperature distributions and the maximum bridge temperature ranges. Thermo-elastic analysis was conducted to obtain the temperatureinduced movements and the associated stresses in bridges. A field test was then conducted on the Sutton Creek Bridge in Montana, U.S.A. to verify the analytical models. A comprehensive research program on the Confederation Bridge in Eastern Canada has also been started in the spring of 1997 and will continue over many years to evaluate the effect of temperature on the short-term and long-term behavior of the bridge [5,6].The Tsing Ma Bridge in Hong Kong is a long suspension bridge carrying both highway and railway. A wind and structural health monitoring system (WASHMS) has been installed in the bridge and operated by the Hong Kong Highways Department since 1997 [7]. The WASHMS is de...

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Structural health monitoring works, which measure key structural parameters systematically, provide valuable information in current evaluation of structural integrity, durability and reliability. The application of new structural concept In design and construction of three cable-supported bridges in Tsing Ma Control Area (TMCA) of Hong Kong and complexity and size of cable-supported bridges have called for implementation of such monitoring works to ensure cost optimal maintenance planning and safe bridge operation. A bridge monitoring system has therefore been deployed and implemented in monitormg and evaluating the structural health of these bridges, i.e. Tsing Ma (suspension) Bridge, Kap Shui Mun (cable-stayed) Bridge and Ting Kau (cable-stayed) Bridge. This system is named as Wind And Structural HealthMonitoring System (WASHMS) and is composed of five sub-systems, namely, Sensory Systems, Data Acquisition Systems, Data Processing and Analysis Systems, Computer Systems, and Cabling Network Systems. This paper outlines: (i) objectives and scope of monitoring, (ii) identification of key structural monitoring parameters, (iii) types of sensory systems required, (iv) global layout design ofWASHMS, (v) development ofWASHMS, and (vi) implementation of WASHMS.