• Earthquakes and Structures
• /
• 제21권5호
• /
• pp.505-514
• /
• 2021

A formulation based on structural reliability and cost effectiveness is proposed to provide recommendations to select the best retrofit strategy for schools with reinforced concrete frames and masonry walls, among three proposed alternatives. The cost calculation includes the retrofit cost and the expected costs of failure consequences. Also, the uncertainty of the seismic hazard is considered for each school site. The formulation identifies the potential failure modes, among shear and bending forces for beams, and flexure-compression forces for columns, for each school, and the seismic damages suffered by the schools after the earthquake of September 17, 2017 are taken into account to calibrate the damaged conditions per school. The school safety level is measured through its global failure probability, instead of only the local failure probability. The proposed retrofit alternatives are appraised in terms of the cost/benefit balance under future earthquakes, for the respective site seismic hazard, as opposed to the current practice of just restoring the structure original resistance. The best retrofit is the one that corresponds to the minimum value of the expected life cycle cost. The study, with further developments, may be used to develop general recommendations to retrofit schools located at seismic zones.

• Earthquakes and Structures
• /
• 제22권3호
• /
• pp.263-275
• /
• 2022

Structural collapses can occur as a result of a dynamic amplification of either, the building's seismic response or the ground shaking by local site effects; one of the reasons is a resonance effect due to the proximity of the structural elastic fundamental period TE and the soil fundamental period TS. We evaluate the vulnerability to resonance effects in Guadalajara, México, in a three-step schema: 1) we define structural systems in the building environment of western Guadalajara, in terms of their construction materials and structural components; 2) we estimate TE with different equations, to obtain a representative value in elastic conditions for each structural system; and, 3) we evaluate the resonance vulnerability by the analysis of the ratio between TE and TS. We observe that the larger the soil fundamental period, the higher the resonance vulnerability for buildings with height between 17 and 39 m. For the sites with a low TS, the most vulnerable buildings will be those with a height between 2 and 9 m. These results can be a helpful tool for disaster prevention, by avoiding the construction of buildings with certain heights and structural characteristics that would result in a dangerous proximity between TE and TS.

• 건축역사연구
• /
• 제32권3호
• /
• pp.63-76
• /
• 2023

Homogot Lighthouse is located in Pohang of the easternmost of Korean Peninsula. Homogot has become first known as Cape Clonard in the West through the navigation log by La Perouse, a Frenchman who embarked on a global exploration in 1785. Homogot Lighthouse represents an outstanding accomplishment of modernization that numerous civilized countries scrambled to attain in the early 20^th century. Located where the geographical risk of earthquakes is high, the structure was nonetheless built to be 26.4m high with brick masonry. Structurally safe and aesthetically graceful, it demonstrates neoclassical ideas superbly in terms of style as well. Although the history of Asian lighthouses is shorter than that of European ones. Homogot Lighthouse, which demonstrates the history of a modern lighthouse along with those in Japan and China, is differentiated by the following characteristics. ① The 'living lighthouse heritage' is linked to one of the largest lighthouse museum in the world. ② Where you can see the earliest sunrise at the easternmost of the Eurasian Continent. ③ The completion of a modern-style lighthouse constructed at the easternmost of the Far East after being initiated in Europe. ④ Differentiated historical, architectural, and aesthetic value. ⑤ The heart of the national marine park.

• 국제학술발표논문집
• /
• The 7th International Conference on Construction Engineering and Project Management Summit Forum on Sustainable Construction and Management
• /
• pp.80-88
• /
• 2017

Although hazard identification is one of the most important steps of safety management process, numerous hazards remain unidentified in the construction workplace due to the dynamic environment of the construction site and the lack of available resource for visual inspection. To this end, our previous study proposed the collective sensing approach for safety hazard identification and showed the feasibility of identifying hazards by capturing collective abnormalities in workers' walking patterns. However, workers generally performed different activities during the construction task in the workplace. Thereby, an additional process that can identify the worker's walking activity is necessary to utilize the proposed hazard identification approach in real world settings. In this context, this study investigated the feasibility of identifying walking activities during construction task using Wearable Inertial Measurement Units (WIMU) attached to the worker's ankle. This study simulated the indoor masonry work for data collection and investigated the classification performance with three different machine learning algorithms (i.e., Decision Tree, Neural Network, and Support Vector Machine). The analysis results showed the feasibility of identifying worker's activities including walking activity using an ankle-attached WIMU. Moreover, the finding of this study will help to enhance the performance of activity recognition and hazard identification in construction.

• 한국전산구조공학회논문집
• /
• 제22권1호
• /
• pp.15-23
• /
• 2009

압축력에 강한 석조 홍예아치교의 경우 재료적 음력한계보다는 구조적 형상의 불안정성에 의해서 구조물이 붕괴된다. 이러한 특성을 고려하면, 석조 홍예아치교의 구조적 안정성 평가에는 구조물의 붕괴기구 형상에 초점을 둔 한계상태 해석이 보다 적합하다. 이 연구에서는 한계상태 해석법을 이용하여 건식법(dry construction)으로 축조된 우리나라 석조 홍예아치교의 구조적 거동을 살펴보고, 이 결과를 구조적 안정성 평가시스템 개발에 이용하고자 한다. 이 연구결과는 우리나라 석조 홍예아치교의 구조적 거동을 이해하는데 도움이 되며, 향후 문화재 유지관리 측면에서 공학적 판단기준을 주리라 기대한다.

• 한국건축시공학회지
• /
• 제4권4호
• /
• pp.117-126
• /
• 2004

Construction industry is faced with the problems such as the quickly changeable circumstance and increasing construction companies due to regulation mollification of company registration. In order to overcome these problems, new estimation system based on historical estimation cost is ready to introduce by government step by step. But the time of transition for estimation system causes another problems such as chaos addition to simultaneity of a standard of estimation system and new estimation system, lack of related regulation, accumulation of historical extensive cost data, and adjustment methodology when historical estimation data is applied to next projects. The purpose of this study is to suggest the change factors by activities for estimating historical cost for apartment housing projects. New estimation system is based on historical construction data. For application of this system, the standard adjustment methodology system is necessary. and extensive cost data should be accumulated under an unified construction work classification system. Therefore in this study, according to the construction work classification system, every apartment housing project was classified to 16 work classifications, and 7 major composed items which occupy more than 85% of construction costs are analyzed by detailed activities and by average ratio and maximum ratio each of them. In the result of the study, furniture work, foundation work and masonry work are the works which have big gap of costs between average ration and maximum ratio. In addition to suggestion of change factor by work species, 5 qualified construction specialists are interviewed and change factors in 7 major works are analyzed.

• 화약ㆍ발파
• /
• 제29권2호
• /
• pp.67-80
• /
• 2011

최근 노후화한 구조물 기능의 회복, 도시의 재개발, 부지의 유효이용 등을 배경으로 토목, 건축의 분야에 관계없이 구조물의 해체 요구가 늘어나고 있다. 과거 국내 Shell 구조물은 벽돌로 높이가 낮게 지어졌고, 이와 같은 해체 대상물을 효율적으로 해체한다는 것은 특별한 문제가 되지 않았다. 그러나 최근에는 높이가 높은 철근콘크리트 Shell 구조물이 해체대상이 되는 경우가 많아지고 있어 구조물을 얼마나 효율적인 해체할 것인가, 공사로 인한 진동, 소음 등의 환경에 미치는 영향을 얼마나 저감시킬 것인가라는 주요 관심사가 되고 있다. 이것을 해결하는 방법의 하나로 화약을 이용해 순간에 붕괴, 전도하는 발파해체공법이 있다. 본 논문은 제주특별자치도 제주시 삼양일동 900번지에 있는 제주화력발전소 내 기력 1호기 70m 높이의 연돌을 화약량 13.5kg과 전기뇌관 100개를 사용하여 원하는 방향으로 확실히 전도를 한 사례로 발파해체에 관한 계획에서부터 결과까지의 과정에 대해 기술하고자 한다.

• Structural Engineering and Mechanics
• /
• 제33권2호
• /
• pp.113-136
• /
• 2009

The seismic induced interaction between multistory structures with unequal story heights (inter-story pounding) is studied taking into account the local response of the exterior beam-column joints. Although several parameters that influence the structural pounding have been studied sofar, the role of the joints local inelastic behaviour has not been yet investigated in the literature as key parameter for the pounding problem. Moreover, the influence of the infill panels as an additional parameter for the local damage effect of the joints on the inter-story pounding phenomenon is examined. Thirty six interaction cases between a multistory frame structure and an adjacent shorter and stiffer structure are studied for two different seismic excitations. The results are focused: (a) on the local response of the critical external column of the multistory structure that suffers the hit from the slab of the adjacent shorter structure, and (b) on the local response of the exterior beam-column joints of the multistory structure. Results of this investigation demonstrate that the possible local inelastic response of the exterior joints may be in some cases beneficial for the seismic behaviour of the critical column that suffers the impact. However, in all the examined cases the developing demands for deformation of the exterior joints are substantially increased and severe damages can be observed due to the pounding effect. The presence of the masonry infill panels has also been proved as an important parameter for the response of the exterior beam-column joints and thus for the safety of the building. Nevertheless, in all the examined inter-story pounding cases the presence of the infills was not enough for the total amelioration of the excessive demands for shear and ductility of the column that suffers the impact.

• 한국농촌건축학회논문집
• /
• 제16권3호
• /
• pp.27-36
• /
• 2014

The purpose of this study is to provide necessary information for the establishment of remodeling range needed first to support the future remodeling of rural housing. For this, this study examined landscape characteristics of rural housing such as an outer wall, a roof, a fence, and a gate which are main elements of forming the landscape of a rural village and rural residents' perception for remodeling. The results were as follows. The subject rural housing mostly had a timber structure and a masonry structure. Common roof types were a hip-and-gable roof and a gable roof. Frequent materials were a panel, a tile, and slate and common colors were primary colors such as reddish brown, black, and gray. A fence made of cement blocks and finished by a white paint was often found. A closed gate with iron frames was common. A standup kitchen and a flush toilet inside the house were common. The family members of rural residents were mostly two including a farmer husband and his wife. Elderly people of sixty and over were the most common. For residential environment satisfaction, a half of respondents were not unsatisfied with residential environment mostly due to an old house. Most respondents who were not satisfied with residential environment had high perception for the need of remodeling. The most commonly asked remodeling part was a roof, followed by a toilet, and an outer wall, indicating that the need of exterior remodeling was higher than that of interior remodeling. For a remodeling method, a total improvement was preferred. Although some rural village housing was improved by support of the government, local governments, or social groups, there are still many old houses. As this co-existence of improved houses and old houses hinders the landscape of rural village, it is necessary to give a support. But rural residents' requests should be first actively reflected to establish a guideline of supporting rural house remodeling.

• 한국실내디자인학회논문집
• /
• 제23권6호
• /
• pp.169-177
• /
• 2014

The purpose of this study is to analyze the design characteristics of Hanok hotel. This study was approached by using theoretical investigation and a field survey. The field survey analyzed the current situations by conducting the master plan layout, architecture and interior design of the Hanok hotel. The field survey was tested by examining four different Hanok hotels from February 2014 to July 2014. After all, the results were analyzed based on given categories. The results of this research can be summarized as following. First, the characteristic of the master plan layout in Hanok hotel was appeared as "ㄷ" and "ㅡ" shapes. Those layouts were based on the spatial and the functional aspects of Hanok hotel facilities. Second, three different structural methods such as the korean traditional wooden structure, concrete, and masonry method were used in Hanok hotel construction to deliver the traditional architecture aspects while considering the functionality and convenience of the building. Third, most of Hanok hotels had the limited furniture range. The consideration of using several types of traditional furniture in different rates of the guest rooms help to increase the service quality and customer's satisfaction. Fourth, there were no diversity of using materials and colors in Hanok hotels that only few of them were used to express the traditional look. Fifth, the local characteristics were found in several Hanok hotels. To reflect the local characteristics in Hanok hotel is to construct a suitable environment to fit in nature and also it is easily to convey the local culture to others.