• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.6
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• pp.129-137
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• 2020

In performing the structural analysis, the foundation is considered to be a fixed end as a plastic hinge model. In this study, the displacements of the foundation, pier, and shoe were compared when the foundation modeled as a fixed end, a shallow foundation constructed on bedrock of 2m depth, and a pile foundation constructed in the 10m to 20m depth of bedrock. The shear force was also compared, and the probability of damage was calculated and compared for the critical condition. When calculated as a fixed end, the displacement of the foundation converged to 0mm, but the shallow foundation built on the bedrock with a depth of 2m caused relatively displacement, and the pile foundation constructed to contact the bedrock with a depth of 18m caused a larger displacement. In addition, it was analyzed that the displacement of the foundation, which is the lower structure, affects the displacement of the super structure, but the difference in shear force applied to the foundation was insignificant in the three cases. There was no difference between the shallow foundation and the pile foundation in the influence on the displacement of the top of the pier, but there was a big difference from the analysis assuming as a fixed end.

• Journal of the Semiconductor & Display Technology
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• v.18 no.4
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• pp.143-148
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• 2019

Numerous pipe lines can be found on various plant-based industrial sites. These pipelines should be periodically checked for defects. Most of these pipelines are internally inaccessible and difficult to visually inspect. Therefore, the inspection is being carried out with the help of non-contact inspection equipment such as ultrasonic flaw detection equipment. The use of ultrasonic flaw detection equipment can raise time and efficiency issues. In order to solve this problem, we will study the basic technology necessary for the development of automated inspection system equipped with ultrasonic measuring equipment and verify the validity through the fabrication of the demonstration device.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.2
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• pp.137-144
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• 2010

Up to now, common studies of top base have concentrated upon bearing capacity and settlement by in-situ loading test in Japan and Korea. But most of all preceding study for top base must analyze how to deliver overburden loading on bottom of foundation. Therefore, in this study, the stress delivery mechanism of Top-Base Foundation developed in Japan and Floating Top Base developed in Korea is investigated through numerical analysis and laboratory model test. Analyzing the load delivery mechanism of top base, it was found that the division rate of load reduction of top base for overburden load was largest in peripheral skin friction between the top base and the crushed stone. Further, total stress dispersion angle of Top-Base Foundation including internal stress dispersion effect of top base was $41.8^{\circ}$ and total stress dispersion angle of Floating Top Base was $44.5^{\circ}$.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.2
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• pp.83-89
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• 2018

In this study, the settlement of concrete rectangular pyramid foundation on soft ground is investigated based on a finite element analysis. considering the grounding load and the grounding area of square pyramid foundation, we compensate the insufficient design bearing capacity and investigated the effect of settlement by load. Based on this study, it is found that the rectangular pyramid foundation shows the smallest settlement of three different type of foundations. As a result of this study, it was resulted that the square pyramid foundations were more effective than the crushed stone foundations by 18%. These results show that the ground pressures of the square pyramid bases are divided into horizontal and vertical stresses, so it is analyzed that the horizontal stress builds up the rigid ground on the foundation of the structure and distributes the load widely to increase the resistance to the overhead load.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.45 no.4
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• pp.70-78
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• 2022

Recently, elevator inspection and self-examination were strengthened through the revision of the Elevator Safety Management Act, but there have been no significant reduction in serious accidents and major failures. Therefore, the government intends to lay the foundation for reflecting the safety quality rating system, which adjusts the elevator inspection cycle, as a policy to induce safety management of preemptive and active management entities. This study systematically reviewed and classified the safety quality rating system for elevator inspection cycle adjustment in previous studies, collected expert opinions, and reconstructed the key items into realistic evaluation items, and evaluated and scored the relative importance of each factor through the AHP technique.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.4
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• pp.168-178
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• 2008

The hybrid simulation test method is a versatile technique for evaluating the seismic performance of structures by seamlessly integrating both physical and numerical simulations of substructures into a single test mode. In this paper, a software framework that integrates computational and experimental simulation has been developed to simulate and test a bridge structural system under earthquake loading. Using hybrid simulation, the seismic response of complex bridge structural systems partitioned into multiple large-scale experimental and computational substructures at networked distributed experimental and computational facilities can be evaluated. In this paper, the examples of application are presented in terms of a bridge model with soil-foundation-structure interaction.

• Proceedings of the Korean Geotechical Society Conference
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• 1998.10a
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• pp.121-128
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• 1998

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.1 s.53
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• pp.125-134
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• 2009

This paper deals with the free vibrations of circular strip foundations which have uniform solid rectangular cross-section. The ground which supports circular strips was modeled as the two parameter elastic foundation. Differential equations governing the flexural-torsional free vibrations of circular strips supported by such foundation were derived, and solved numerically for obtaining the natural frequencies and mode shapes. Boundary condition of free-free ends was considered for numerical examples. Four lowest natural frequencies according to the variations of five system parameters i.e. subtended angle, depth ratio, contact ratio, elasticity ratio and soil parameter are reported in the non-dimensional forms. Also, typical mode shapes of both deformations and stress resultants are presented in the figures. Experiment was conducted for validating the theory developed in this study.

• Journal of the Society of Disaster Information
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• v.8 no.2
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• pp.138-147
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• 2012

In this paper, the various parametric study of collisions between a offshore wind tower and vessels were performed to estimate the ultimate behaviors of the bucket foundation and the tower. Additionally, the stability of the foundation and the energy dissipation capacities of the tower were analyzed. The results shows that the collision energy of the vessel was mainly dissipated by the plastic deformation energy of the tower and the foundation system shown enough bearing capacity against to this severe loading condition.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.2
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• pp.83-93
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• 2013

Generally the capacities of electric power transmission tower's members are improved by increasing their stiffness nature through injection of grout or attachment of other structural stiffeners. Those are for upgrading their axial strength by fulfillment of proper materials into pipe members, increment of member dimension by addition of section, or a combination of the two. However the use of innovative and unusual procedures would be positively recommended for getting more stable state. It is that buckled members are replaced with lengthened and strengthened members. In providing the structural restoration procedures for the existing electric power transform tower whose main members have been damaged due to unequal foundation settlement, structural damage inspection works and numerical analyses for the damaged one and the restored one were done in detail at first. secondarily member-exchanging works using a newly-generated jacking system and strengthened members were achieved. This figures are to point clearly to inherent advantages attending the management of the towers.