Tuned Liquid Damper (TLD) utilizing the motion of shallow liquid for absorbing anddissipating the vibrational energy is studied with emphasis on liquid motion. Amathematical model based on the nonlinear shallow water wave theory is presented todescribe the liquid motion in a rectangular tank. Liquid damping is evaluated semi-analytically and is included in the formulation. Mechanical properties of: TLD are alsoexperimentally investigated using the shaking table. It is found that the liquid motion inTLD is strongly nonlinear and reveals a hardening-spring property even under smallexcitation, Good agreements between the simulation and the experimental results areshown when no breaking wave occurs. The model presented in this study is expected toserve as a tool for TLD design.

In this paper, a method based on the artificial neural network technology, which is used to iden-tify two moving vehicles load on a simply supported bridge, is discussed. A multi-step identification procedure, which can be used effectively to identify multiple vehicle parameters such as loadlocation, load magnitude, andmoving speed, is proposed. The sensitivity of various input variables to the output and the effect of variation ofsample number to the identification result are investigated. The example data for training and verification aregenerated by theoretical simulation. The identification simulation shows that the proposed ANN method andprocedure can identify the moving vehicle load problem with acceptable accuracies. The ANN can also identifythe vehicle loads withclosed spacing and high moving speed, for which a conventional TDM or FTDM does notgive good identification results.

This paper presents the most recent development in the research, implementation andissues for future studies of structural health monitoring systems for large span bridges in China. Aftera brief review on the large span bridge projects in recent years and main deterioration and defectsproblems of existing bridges, this paper puts the focus on the review of the following three aspects: theimplementation of structural health monitoring system for large span bridges, the advanced sensing,transmission, and system integration technologies, and the novel signal processing and conditionassessment techniques. Through the review, a discussion on the issues for the future implementationof structural health monitoring system is offered.

The pushover analysis is becoming popular as a simple method for seismic performance evaluation ofstructures. This paper presented a pushover analysis model, which can take account of soil-pile-structureinteraction. As load pattern for pushover analysis, monotonic increasing inertial forces was applied to asuperstructure and shear deformation was applied to soil respectively. A bridge pier-pile-soil system wasanalyzed by using the presented model, and the results were compared with those of nonlinear dynamictime history analysis, it was showed that the improved pushover method and its parameters determinationwere proper for providing a reasonable estimate of the structural maximum response. In order to embodythe nonlinearity of soil, nonlinear soil springs contacting piles and soil should be adopted in the modelinstead of equivalent linear ones. A static experiment of multi-pile foundation in a shear deformation soilbox was carried out to study the effect of soil movement on a multi-pile foundation, the relationship ofsoil-pile interaction force and relative deformation, and the determination method of the nonlinearinteraction spring.

Donghai bridge is a linkage connecting Luchao Port in Shanghai and Yangshan Island deep Water Port. The linkage is about 32km long and consists of 2 cable stayed bridges and a large number of spans of eontinuous and simply supported bridges. It crosses East China Sea and lies on soft clay so the durability gainst ocean environment and the un-uniform settlement of foundations are concerned. The bridges are under construction and are planed to open to traffics around the end of 2005. A structural health monitoring system designed and is being installed to the bridge. This paper reported the conceptual design and the key issues thpse have been studed on the structural health momtonng system of the bridge.