• Steel and Composite Structures
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• v.51 no.6
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• pp.647-659
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• 2024

Given the increased interest in enhancing structural sustainability, the current study sought to apply multiobjective optimization to a footbridge with a steel-concrete composite I-girder structure. It was considered as objectives minimizing the cost for building the structure, the environmental impact assessed by CO2 emissions, and the vertical accelerations created by human-induced vibrations, with the goal of ensuring pedestrian comfort. Spans ranging from 15 to 25 meters were investigated. The resistance of the slab's concrete, the thickness of the slab, the dimensions of the welded steel I-profile, and the composite beam interaction degree were all evaluated as design variables. The optimization problem was handled using the Multiobjective Harmony Search (MOHS) metaheuristic algorithm. The optimization results were used to generate a Pareto front for each span, allowing us to assess the correlations between different objectives. By evaluating the values of design variables in relation to different levels of pedestrian comfort, it was identified optimal values that can be employed as a starting point in predimensioning of the type of structure analyzed. Based on the findings analysis, it is possible to highlight the relationship between the structure's cost and CO2 emission objectives, indicating that cost-effective solutions are also environmentally efficient. Pedestrian comfort improvement is especially feasible in smaller spans and from a medium to a maximum level of comfort, but it becomes expensive for larger spans or for increasing comfort from minimum to medium level.

• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.6
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• pp.115-125
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• 2009

The Picturesque Style of the $18{\sim}19th$ Century Romantic landscape gardening had features of both irregularity and variety. These features were applied to $19{\sim}20th$ Century urbanism, which was called 'Urban Picturesque'. Preceding research has found that pedestrians take more interest in streets modeled after 'Urban Picturesque' principles mainly focused on physical appearance. further development of this research was undertaken through an experiment focused on pedestrian activity as well as physical factors through a case study of the Duksugung-gil, Insadong-gil and Myoungdong-gil. The results of the research are as follows. Although the physical conditions of the street in Duksugung are fitted more on Urban Picturesque principles than the other two case studies, the degree of pedestrian interest was highest for the street in Insadong due to excellence both in physical appearance and the diversity of cultural activities available in it. In conclusion, it can be said that to achieve the fdl effect of a Picturesque urban scene, a diversity of place-appropriate activities related to socio-cultural programs should be combined with an excellent physical appearance.