• Journal of the Korea institute for structural maintenance and inspection
• /
• v.23 no.6
• /
• pp.26-37
• /
• 2019

This paper aims to investigate the seismic characteristics of strip-type damping devices possessing optimized shapes for the moment-resisting mechanism throughout analytical and experimental studies. Predicting equations for initial stiffness and yielding strength were introduced and compared with analytical results obtained from finite element analyses (FEAs) using commercial FEA program ABAQUS. In order for establishing predicting equations, two idealized processes were considered and both predicting equations showed that they could provide enough approximations for seismic applications in building structures. Throughout experimental studies, it was noted that structural uncertainties on mild steels, connection details and structural types linking damping devices with building structures could interrupt predicting structural behavior of the devices. Also, it was observed that shear stress concentrations should be considered if shear yielding type devices are applied into building structures. Nevertheless, it was shown that structural conservatism can be established using the predicting equations and seismic applications of the damping devices can enhance the seismic performance of building structures efficiently in the viewpoint that they have high resistance to low-cycle fatigue failures.

• Proceedings of the Korean Geotechical Society Conference
• /
• 1991.10a
• /
• pp.312-331
• /
• 1991

Top-down Method of basement construction technique has been applied for building of the deep basement car park the close proximity of priceless historic buildings in LONDON. Numerical analysis for the prediction of ground movement of the surrounding buildings was performed in order to compare the field data at the various stages of excavation and support. The predicted results from the elasto-plastic analytical method were compared with the observed data and the agreement is very satisfactory. It may be concluded that the system of diaphragm wall supported by the permanent base slabs (Top-Down Method) was proved to be the most effective technique in terms of reducing any critical damage to the surrounding buildings.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1995.10a
• /
• pp.266-271
• /
• 1995

월성 1호기용 비상운전절차서는 사고별로 세분된 사건대응적 형태의 절차서로 작성되어 있어 발전소 비정상 상태 발생시 운전원이 조치하기 전에 사고진단을 먼저 수행하여야 하며, 또한 다중사고의 경우 적용하는데 난점이 있다. 이러한 결점을 보완하기 위하여 월성 원자력발전소 2호기용 비상운전지침서는 사건 및 징후대응적 판단 방법을 혼합한 형태이며, 운전원 조치사항으로 필수안전변수의 안정화 및 복구를 위한 핵연료 냉각, 열제거원, 원자로건물의 우선순위로 발전소를 안정시키는 방법이 시도되고 있다. 본 논문에서는 현재 월성 원자력발전소 2 호기용 비상 운전지침서에 고려되고 있는 사건들 중 하나인 소형 냉각재상실 및 냉각재계통 누설 사고 비상운전지침서의 특성을 소개하였다.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 2012.04a
• /
• pp.77-80
• /
• 2012

화재 시에는 발생 유독가스와 연기로 인하여 많은 인명 피해가 날 수 있으며, 따라서 주요 건물이나 시설에는 국민의 생명을 보호하기 위한 화재용 긴급대피마스크를 갖추도록 권고하고 있다. 하지만 그 성능에 대한 의혹이 꾸준히 제기되고 있어, 사용자인 국민으로서는 늘 불안한 심정이다. 이에 본 연구에서는 현재 국내 시판되고 있는 화재용 긴급대피마스크 5종에 대하여 KS 주요 시험항목에 의거하여 성능시험을 실시하고, 문제점을 진단하였다. 실험 결과, 일부 제품에서는 성능기준에 미치지 못하는 경우가 발생하였으며, 이는 화재 시 국민의 안전을 크게 위협하는 중차대한 사안이므로, 시급히 부적격 제품의 판매를 제한하고 성능기준에 맞는 제품만이 판매될 수 있도록 법적인 보완이 이루어져야 하는 것으로 나타났다.

• Journal of Korean Society for Geospatial Information Science
• /
• v.3 no.2 s.6
• /
• pp.151-158
• /
• 1995

Change detection, image differencing technique, is the most widely used in a variety of image environments. The digital terrain model and digital images have the same data structure. This study applied digital terrain model and change detection technique for inspecting the deflection of the structure. Authors make digital terrain model from triangular irregular network(TIN) by leveling data and suggest to possibility recognize modification part and volumes by digital terrain model and change detection technique. Authors can reduce testing materials and man power, and displayed his modification part.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.24 no.2
• /
• pp.1-8
• /
• 2020

In the case of power plant facilities, seismic stability of non-structural elements is important. In particular, Cabinet structures to which electrical equipment is attached, should have functional safety against earthquakes. Therefore, in this study the dynamic characteristics of non-structural elements inside existing power plant buildings were identified and the response level generated during dynamic behavior was analyzed. In addition, The steel plate dampers were adopted and adjusted to suit the size of the target equipment. In order to derive the optimal seismic reinforcement, the variables according to the attachment location were set and the responses were analyzed by the seismic movement input before and after reinforcement.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.24 no.4
• /
• pp.10-17
• /
• 2020

The recent earthquake in Korea caused large and small damages to many school building. School building is an important building that is used as a shelter in the event of disaster. Among the seismic retrofit methods, the internal steel braced frame type method is used for its relatively easy construction and excellent performance. In this study, the maximum shear force and displacement were compared and examined by applying the brace frame to existing concrete school buildings. As a result, we verified the adequacy of the analytical model and compared and examined the effect of brace-height ratio on the span of the existing school buildings. The adequacy of the maximum shear force and displacement relationship can be confirmed in the model with a length of 0.3. In addition, seismic frame was applied to the actual non-seismic reinforced concrete school building, and the seismic performance was evaluated by nonlinear static analysis(Push-over analysis) according to the ratio of brace-height. As a result, the increase of the brace-height according to the brace-height ratio has the effect of increasing the maximum shear force and maximum load at the performance point. But the collapse of the braced frame due to the increase in the lateral stiffness occurred, indicating that seismic retrofit according to the proper brace-height is necessary. Therefore, in the seismic retrofit design of brace frame of existing school building, it is necessary to select the proper brace-height after retrofit analysis according to the brace-height ratio.

• Korean Security Journal
• /
• no.60
• /
• pp.175-196
• /
• 2019

The purpose of this study is to examine the role of safety sheriffs and their necessity in order to improve the activation of safety sheriff's professionalism. Seven security sheriffs were finally selected to discuss their activities and discuss ways to improve their effectiveness. We conducted semi - structured interviews and conducted in - depth interviews with limited data and inadequate prior research. The results of this study are as follows. First, the government should get the help of citizens, citizens and residents. If the state wishes to reduce the number of safety accidents and bring positive results to the public, it should not rely solely on the utilization of institutions. Second, in order to be a safe sheriff with a positive response from the local residents, the activities of the sheriff's sheriff are not only aimed at preventing risks in the environmental domain and reducing the number of accidents, Publicity should be provided to the landlord, tenant, and residents to inform them that the activity is preventive of accident prevention. Third, under the current law, it is necessary to disclose public facilities such as roads, airports, and harbors to the private sector in order to make it possible to monitor school facilities and youth training facilities. Fourth, the safety sheriff is expected to put forward the expectations and positive results of prevention through the beginning of the inspection activities, and the role of the Korean people in becoming psychological stable and efforts to be born as safety experts are required. Finally, it is necessary to establish a concrete manual, strategic safety inspection plan.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.7 no.4
• /
• pp.181-189
• /
• 2003

Because of the gravitation of population toward large cities, a number of masonry buildings have been constructed since 1960. They have been rapidly deteriorated as time passed by. Therefore the purpose of this paper is to present basic data on timeworn masonry buildings which have been managed by metropolitan government and to analyse their deterioration factors. And then, the results of this paper can be used to establish the policy of managing timeworn masonry buildings. According to this study, the crack of masonry wall is the most effective deterioration factor and timeworn masonry buildings have a problem with foundation. The structure grade have an interrelation with occupancy type more than building age. Also, the longer building age becomes, the sooner deterioration speeds. A timeworn masonry building is in urgent need of reinforcement on a thirty-year period of building age.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.27 no.2
• /
• pp.67-76
• /
• 2023

In this study, in order to enhance the joint capacity between the existing reinforced concrete (R/C) frame and the reinforcement member, we proposed a novel concept of Internal Composite Seismic Strengthening Method (CSSM) for seismic retrofit of existing domestic medium-to-low-rise R/C buildings. The Internal CSSM rehabilitation system is a type of strength-enhancing reinforcement systems, to easily increase the ultimate horizontal shear capacity of R/C structures without seismic details in Korea, which show shear collapse mechanism. Two test specimens of full-size two-story R/C frame were fabricated based on an existing domestic R/C building without seismic details, and then retrofitted by using the proposed CSSM seismic system; therefore, one control test specimen and one test specimen reinforced with the CSSM system were used. Pseudo-dynamic testing was carried out to evaluate seismic strengthening effects, and the seismic response characteristics of the proposed system, in terms of the maximum shear force, response story drift, and seismic damage degree compared with the control specimen (R/C bare frame). Experiment results indicated that the proposed CSSM reinforcement system, internally installed to the existing R/C frame, effectively enhanced the horizontal shear force, resulting in reduced story drift of R/C buildings even under a massive earthquake.