Offshore design and construction is much more difficult than land-based design and construction, particularly due to hoisting operations. Real-time monitoring of the orientation and movement of a hoisted structure is thus required for operators' safety. In recent years, rapid development of the smart-phone commercial market has offered the possibility that everyone can carry a mini personal com...

This paper presents a modelling approach that can be used by contractors to plan elevated highway reconstruction projects. The proposed model estimates the project duration, productivity rate of the operation, and visualizes the output using 4D modelling. In this paper, the focus is on the demolition and construction of a box girder elevated highways as part of an interchange reconstruction pro...

Fiber Reinforcement Polymer(FRP) has been widely accepted as an innovative material for renovation and strengthening of existing infrastructures. Among the FRP materials, the Poly-p-phenylene benzobisoxazole (PBO) fiber sheets attracted great attention in recent years because of the high strength, high Young modulus and high energy absorption capability. In this study, a PBO Prestressing Upgrad...

The segmental prestressed concrete box girder of Koror-Babeldaob (KB) Bridge in Palau, which had the record span of 241 m (791 ft.), presents a striking paradigm of serviceability loss due to excessive multi-decade deflections. The data required for analysis have recently been released and are here exploited to show how the analysis and design could be improved. Erected segmentally in 1977, thi...

This research focuses on the analysis of measurements from distributed sensing of structures. The premise is that ambient temperature variations, and hence the temperature distribution across the structure, have a strong correlation with structural response and that this relationship could be exploited for anomaly detection. Specifically, this research first investigates whether support vector ...

The LCLS x-ray FEL has recently achieved its 1.5Angstrom lasing and saturation goals upon first trial. This was achieved as a result of a thorough pre-beam checkout, both traditional and beam-based component alignment techniques, and high electron beam brightness. The x-ray FEL process demands very tight tolerances on the straightness of the electron beam trajectory (<5 μm) through the LCLS und...

Despite numerous studies on chemical and thermal stability of metal-organic frameworks (MOFs), mechanical stability remains largely undeveloped. To date, no strategy exists to control the mechanical deformation of MOFs under ultrahigh pressure. Here, we show that the mechanically unstable MOF-520 can be retrofitted by precise placement of a rigid 4,4'-biphenyldicarboxylate (BPDC) linker as a "g...

This paper deals with the effect of drying as a moisture diffusion process in a segment of a typical box-girder bridge. Pore relative humidity distributions throughout the cross sections of the plates of the girder are calculated from the diffusion equation, taking its nonlinearity and aging into account. The effect of creep with aging on the stresses produced by drying shrinkage is taken into ...

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Acoustic emission (AE) testing was deployed on details of two large steel Interstate Highway bridges: one cantilever through-truss and one trapezoidal box girder bridge. Quantitative measurements of activity levels at known and suspected crack locations were made by monitoring AE under normal service loads (e.g., live traffic and wind). AE indications were used to direct application of radiogra...