We are designing the Hybrid Post-Tensioned Timber Beams System (HPTTB). HPTTB is a rahmen frame system with high-stiffness, high-strength timber beams, which not only has excellent carbon storage and sustainability, but also is lighter than RC and S structures. As a first step, this study describes the behavior of moment-resisting joints that use a combination of post-tensioned timber beams and steel-plate-penetration screws, based on experimental results. loading post-tensioned increased initial rotational stiffness by approximately 211% and improved the yield strength by approximately 16%.
This study explores UAV-based 3D modeling for bridge damage assessment. UAVs with high- resolution cameras captured images of two bridges at different life cycle stages and locations. These images were processed into detailed 3D models, offering more accurate evaluations than traditional visual inspections (VI). The models provided precise damage localization, geometric data information, and identified areas requiring urgent maintenance, reducing repair costs and time. Despite the advantages, challenges such as model accuracy and flight planning precision were noted. The results showed that larger and more complex bridges require significantly greater resources for 3D modeling, including longer flight and processing times, higher data volumes, and increased detail in the models, as reflected in the differences between the two case studies. Future research should focus on optimizing data acquisition, enhancing algorithms, and integrating augmented reality (AR) to improve collaboration and decision-making in bridge inspections.
Bridges play a key role in the transportation network system and are vulnerable to various natural hazards. For bridges constructed over rivers, scour is one of the major causes of bridge failure. With the growing impacts of climate change, both the intensity and frequency of flood events are increasing, raising significant concerns regarding the safety and maintenance of bridge infrastructure. This study presents a method for remotely monitoring scouring which uses a Fibre Optic scour sensor based on Fibre Bragg Grating, named FOSS. The sensor comprises three sensing elements (fins), which are embedded at different depths. The system operates on the principle that, when erosion occurs, the movement of these fins generates a measurable response, indicating the depth of erosion. This paper presents the sensor’s characteristics and shows preliminary findings from a field deployment on a bridge in the Northern Ireland region.
The Vierendeel bridge L25 crossing the Leuvense Vaart in Mechelen in Belgium, dating from 1935, is a two-track steel Vierendeel arch bridge with riveted connections. Classified as a significant landmark in Mechelen's urban landscape, this historic bridge has become increasingly unique as many similar structures have been dismantled. Despite its historical significance, the bridge has suffered historical damage, including the development of cracks in individual plates between the riveted connections of vertical rigid elements. This study examines the structural impact of these persistent cracks using advanced modelling techniques. Traditional analysis using separate global and detailed models can lose information, especially by ignoring rivets. An integrated model was developed, incorporating detailed plates and spring elements for the riveted connections. This allows for more precise global and local structural analysis under traffic loads. A parametric study showed material properties have negligible global impact. However, modelling rivet joints as springs significantly improves analysis precision. The study cautiously found that cracks have a minimal impact on the global structural behaviour. Yet, local stress distribution around the cracks is affected, warranting further detailed examination. These initial results highlight the importance of integrated modelling for accurate assessment of such structures.
In the context of monumental buildings resting on highly deformable soils, material parameter variability, an intrinsic characteristic of historical constructions, and soil-structure interaction (SSI) should be incorporated into simulations to assess the influence of diverse input parameters on dynamic response. This work explores the potential of sensitivity analyses within a probabilistic setting, utilizing surrogate models of a detailed finite element model (FEM) that accounts for SSI, to identify critical factors influencing the seismic behavior of the Baptistery of San Giovanni in Pisa. The study identifies the natural frequencies most sensitive to variations in masonry properties, which may be easier to detect than those primarily influenced by soil properties. These insights, combined with results obtained from modal analyses, can support the design of an effective structural health monitoring (SHM) system for the monument.
