Published online on January 2021
Mehrshad Ketabdar, Hamed Yazarlou, Doug Moon
Abstract: The vulnerability and evaluation of masonry arch bridges used in transportation networks has recently become a very important task for transportation engineers because of the key role they play in the transportation network. Most of the current research on masonry arch bridges focuses only on the behavior under service loads and the seismic vulnerability of these structures has received less attention in the literature. The presence of many historical masonry arch bridges located in seismically active regions only heightens the need for increased research on the topic. In this paper, unreinforced masonry arch bridges are modeled, using Nonlinear Finite Element Method (N.F.E.M). Cracking and crushing of masonry materials are considered in the model. The ductility of masonry arch bridges is evaluated by use of push over analysis. The main goal of this research is to estimate the ductility of masonry arch bridges in longitudinal direction.
International Journal of Bridge Engineering, Vol. 8, No. 3, 2020: pp. 1-9
Abstract: This paper pertains to the case study on a skewed Reinforced Cement Concrete deck Slab Bridge constructed at km 5.300 on Gotogali Goyar major district road in Karwar Taluka of Uttar Kannada District in India. The work pertains to the Karnataka Public Works, Ports and Inland Water Department. The author was working as an Assistant Engineer in the same department in design section. The author designed this bridge and had issued the design details along with working design drawings to the field engineers for execution. The location of the bridge is in a thick forest area under wildlife protection zone. In the design of a bridge, it is always preferred to fix the alignment of the bridge in such a way that it should make a right angle to the river flow which helps in easy flow of water and gives clear vision for traffic movement. But sometimes due to restrictions at site and other local obstructions, it may not be possible to fix the alignment of the bridge at right angles to the flow of the river. In such cases, the bridge has to be designed as a skewed bridge. The inclination of the centre line of traffic (road) to the normal to the centre line of the river in case of a river bridge or other corresponding obstruction is called the skew angle.[Fig-1]. In the instant case as per the wildlife zonal regulations, there was an obstruction from the forest department to fix the alignment of the said bridge at right angles to the flow of the river by acquiring forest land. So the author designed the said bridge with 30o skew angle as per the detailed survey and the design details and drawings were issued to the field engineers for execution. Unfortunately, the bridge executed by the field engineers is in the opposite direction of the actual skew. This was observed by the concerned higher authorities during their inspection and brought to the notice of the designer (author) who was retired, asking him for the remedial measures for the safety of the bridge. By the time designer inspected the bridge the major portion of the bridge was already executed and the only choice left with the designer was to suggest the remedial and protection measures against the hydrodynamic effects of eddies on substructures and foundation. The designer suggested some protection measures after inspecting and studying technical aspects. So the author has taken it as an opportunity to have a case study on the said skewed bridge to throw light on the protection measures taken up and to analyse the performance of the bridge.
International Journal of Bridge Engineering, Vol. 8, No. 3, 2020: pp. 11-26
Osama Mohammed Elmardi Suleiman Khayal
Abstract: Ergonomics is the study of people while they use equipment in specific environments to perform certain tasks. Ergonomics seeks to minimize adverse effects of the environment upon people and thus to enable each person to maximize his or her contribution to a given job. This industry guide applied to bridge engineering explains generally how measurements of human traits can be used to further workplace safety, health, comfort and productivity, discusses how to enhance worker safety by combining principles that govern the action of forces with knowledge of the human body, analyzes properties of illumination and explains how proper illumination makes for a safer workplace by reducing worker fatigue, shows how hand tools can be designed to reduce injuries to employees and to lessen trauma to their body members, illustrates ways to recognize proper sitting positions and to construct seating arrangements to minimize stress to the lumbar region, demonstrates how workspaces can be designed to decrease psychological stress and to increase employee motivation, directs attention to the benefits of proper selection and strategic arrangement of controls and displays for the machinery operation, offers general information about ways to reduce back injuries that result from manual lifting and offers more specialized guidelines for evaluating physical stresses imposed by lifting, refines the concept of the worker with a disability and suggests ways of meeting the special needs of people with disabilities, and stimulates new thinking about problems such as those from the sustained operation of computers brought about by technological advancements. This industry guide to bridge engineering demonstrates how benefits are derived from applying the principles of ergonomics to workplace safety and health. It gives the reader a solid starting point from which to seek new solutions to occupational safety and health problems.
International Journal of Bridge Engineering, Vol. 8, No. 3, 2020: pp. 27-58
Aminu Muhammed., Oluwatobi Olufemi Akin, Jibrin Muhammed Kaura, Olugbemga Samuel Abejide
Abstract: In this study, finite element analysis was conducted to evaluate the structural effectiveness of reinforced concrete bridge deck subjected to vehicular vibration. Series of numerical tests using the finite element method as coded in ANSYS Software were carried out. Load case analysis type was selected for this study, which includes modal analysis, transient and vibration analysis. For the various analyses, the load which was used was 24.11kN (2460 kilogram) which is the average weight of a Large Truck as an extreme load condition case. The model results from simulation were compared with the maximum allowable span deflection of a bridge based on the relevant design codes such as BS 5400-3:2000, AASHTO LRFD and Australian Bridge Design Code. The results indicate a maximum span deflection of 2.8974mm which is less than the maximum allowable deflection of the bridge span, 22.5mm by about 676%. The modal analysis result shows the failure mode of the bridge with respect to dynamic movement of the vehicle, that is, the action of the force of the vehicle with respect to the natural frequency of the bridge and also shows the modes of failure due to ground movement and wind force under severe conditions. The former and later had a maximum deflection of 26.354mm and 21.624mm respectively. The result obtained herein shows that the reinforced concrete bridge of span length 18000mm, 220mm thick deck, reinforced with T16/200 of steel is effective to sustain the design load and vehicular vibrations during its design life with little deformation.
International Journal of Bridge Engineering, Vol. 8, No. 3, 2020: pp. 59-73
Fathelrahman M. Adam, A.E. Mohamed, Osama M. Elmardi Suleiman
Abstract: This paper adopted a four-node degenerated shell element. A reduced integration point's scheme has been used as a remedy for the shear lock problem. The element was subjected to the patch test and passed all tests except the pure bending test. Different shell thicknesses have been adopted to find different ratios between thicknesses and the lengths of the elements for each mesh size. Some numerical examples have been applied, including curved and flat shells. Accordingly, different plots have been obtained by plotting the maximum displacements versus the ratios between the thicknesses and the lengths obtained of the elements for the different mesh sizes. The plots showed that the solution diverged after a certain value of the ratio which has been found equal to 0.23 for the curved shell and equal to 0.9 for the flat plate shell. These values were verified by using examples of known exact maximum displacement.
International Journal of Bridge Engineering, Vol. 8, No. 3, 2020: pp. 75-86