• Earthquakes and Structures
• /
• 제19권5호
• /
• pp.379-393
• /
• 2020

The purpose of this study is to first evaluate the seismic behavior of ageing arch bridges by using the Intensity Measure - based demand and DCFD format, which is referred to as the fragility-hazard format. Then, an investigation is performed for their seismic vulnerability. Analytical models are created for bridges concerning different features and these models are subjected to Incremental Dynamic Analysis (IDA) analysis using a set of 22 earthquake records. The hazard curve and results of IDA analysis are employed to evaluate the return period of exceeding the limit states in the IM-based probabilistic performance-based context. Subsequently, the fragility-hazard format is used to assess factored demand, factored capacity, and the ratio of the factored demand to the factored capacity of the models with respect to different performance objectives. Finally, the vulnerability curves are obtained for the investigated bridges in terms of the loss ratio. The results revealed that decreasing the span length of the unreinforced arch bridges leads to the increase in the return period of exceeding various limit states and factored capacity and decrease in the displacement demand, the probability of failure, the factored demand, as well as the factored demand to factored capacity ratios, loss ratio, and seismic vulnerability. Finally, it is derived that the probability of the need for rehabilitation increases by an increase in the span length of the models.

• Computers and Concrete
• /
• 제21권4호
• /
• pp.441-449
• /
• 2018

FE models for complex or large-scaled structures that need detailed modeling of structural components are usually constructed using commercial analysis softwares. Updating of such FE model by conventional sensitivity-based methods is difficult since repeated computation for perturbed parameters and manual calculations are needed to obtain sensitivity matrix in each iteration. In this study, an FE model updating procedure avoiding such difficulties by using response surface (RS) method and a Pareto-based multiobjective optimization (MOO) was formulated and applied to FE models constructed with a commercial analysis package. The test building is a low-rise reinforced concrete building that has been seismically retrofitted. Dynamic properties of the building were extracted from vibration tests performed before and after the seismic retrofits, respectively. The elastic modulus of concrete and masonry, and spring constants for the expansion joint were updated. Two RS functions representing the errors in the natural frequencies and mode shape, respectively, were obtained and used as the objective functions for MOO. Among the Pareto solutions, the best compromise solution was determined using the TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) procedure. A similar task was performed for retrofitted building by taking the updating parameters as the stiffness of modified or added members. Obtained parameters of the existing building were reasonably comparable with the current code provisions. However, the stiffness of added concrete shear walls and steel section jacketed members were considerably lower than expectation. Such low values are seemingly because the bond between new and existing concrete was not as good as the monolithically casted members, even though they were connected by the anchoring bars.

• Computers and Concrete
• /
• 제22권5호
• /
• pp.439-447
• /
• 2018

One of the important factors is the infill walls in the change of the structural rigidity, ductility, dynamic and static characteristics of the structures. The infill walls are not generally included in numerical analysis of reinforced concrete (RC) structural system due to lack of suitable theory and the difficulty of calculating the recommended models. In seismic regions worldwide, the residential structures are generally RC buildings with infill wall. Therefore, understanding the contribution of the infill walls to seismic performance of buildings may have a vital importance. This paper investigates the effects of infill walls on seismic performance of the existing RC residential buildings by considering requirements of the Turkish Earthquake Code (TEC). Seismic performance levels of residential RC buildings with and without walls in high-hazard zones were determined according to the nonlinear procedure given in the code. Pushover curves were obtained by considering the effect of masonry infill walls on seismic performance of RC buildings. The analysis results showed that the infill walls beneficially effected to the rigidity, roof displacements and seismic performance of the building.

• Earthquakes and Structures
• /
• 제18권4호
• /
• pp.437-449
• /
• 2020

It is quite apparent that engineering concerns related to the influence of masonry infills on seismic behavior of reinforced concrete (RC) structures is likely to remain relevant in the long term, as infill walls maintain their functionalities in construction practice. Within this framework, the present paper mainly deals with the issue in terms of modal expansion of effective earthquake forces and the resultant modal responses. An adequate determination of spatial distribution of effective earthquake forces over the height of the building is highly essential for both seismic analysis and design. The possible influence of infill walls is investigated by means of modal analyses of two-, three-, and four-bay RC frames with a number of stories ranging from 3 to 8. Both uniformly and non-uniformly infilled frames are considered in numerical analyses, where infill walls are simulated by adopting the model of equivalent compression strut. Consequently, spatial distribution of effective earthquake forces, modal static base shear force response of frames, modal responses of story shears from external excitation vector and lateral floor displacements are obtained. It is found that, infill walls and their arrangement over the height of the frame structure affect the spatial distribution of modal inertia forces, as well as the considered response quantities. Moreover, the amount of influence varies in stories, but is not very dependent to bay number of frames.

• Architectural research
• /
• 제4권1호
• /
• pp.25-31
• /
• 2002

For more than a hundred years, art and architectural historians, architects, and engineers interested in structure have attempted to interpret Gothic architecture, one of the most technologically complex and sophisticated structural systems in history. Indigenous Gothic, however, such as non-vaulted Gothic in the Lower Languedoc region of southern France, has been largely ignored. This study intends to analyze the Gothic non-vaulted nef unique (aisleless) structures of Lower Languedoc which have never been scientifically tested, and to provide as comprehensive an explanation as possible of the way in which these non-vaulted buildings work. In order to achieve this goal, this paper is to examine, by means of finite element computer analysis, a selected example of an existing building. The church of Notre-Dame de Lamourguier, the earliest surviving example of a Gothic nef unique with wide-span diaphragm arches in Lower Languedoc, is selected. Thus, hypothetical models of diaphragm arch buildings and an existing building as a complete structural system were scientifically analyzed in order to provide a comprehensive explanation of how the non-vaulted nef unique system works. The result of the analysis, allows us better to understand the structural behavior of this type of masonry arcuated system and the processes involved in the design and construction of medieval buildings.

• 한국농촌건축학회논문집
• /
• 제16권1호
• /
• pp.63-70
• /
• 2014

This study is aimed to represent the streetscape in 1960s' focused on Seong-An street of Cheong-ju through the existing business types and buildings, literature, photo details, and interview of the longest-term householders. Results of this study are as follows : Firstly, the types of 1st-floor shops were diverse with general merchandise, apparel, medical, bank, restaurant, and etc in 1960s'. The present shops of them are 'Dong-kwang lasa', 'Jung-geum dang', 'Cheong-ju pharmacy' including the existing 'the Korea development', 'Korea first', and 'Woori' bank. Secondly, the streetscape around post office looks just as it did in the old 1960s'. In the other section the present typical buildings are 'Namseon pharmacy ', 'Kukje department', 'Samyang shop', 'Daeyang shop', 'Park shop', and etc. These old 3-4story buildings are reinforced concrete in contrasted with the former wooden and masonry in structure, and converted in use and appearance. Thirdly, the streetscape of Seong-An is ultimately represented by presuming the other buildings and equipments through aerial and street photograph in the old 1960s'.

• 한국지열·수열에너지학회논문집
• /
• 제7권2호
• /
• pp.51-59
• /
• 2011

Storage and transfer heat in soils are governed by the soil thermal properties and these properties are therefore needed in many engineering applications, including horizontal ground heat exchanger for ground-coupled heat pumps. This paper presents the measured results of the thermal diffusivity of soils(silica, quartzite, limestone, sandstone, and masonry soils) used for the trench backfilling materials of the horizontal ground heat exchanger. To assess this thermal property, we (i) measure the soil thermal conductivities and volumetric heat capacities using dual-probe method and (ii) compare the estimates from the de Vries method of summing the heat capacities of the soil constituents. The results show that the thermal diffusivity tends to increase as dry soil begins to wet, but it approaches a constant value or even decreases as the soil continues to wet. Measurements made by using the dual-probe method agreed well with independent estimates obtained using the single-probe method.

• 한국태양에너지학회 논문집
• /
• 제27권4호
• /
• pp.59-65
• /
• 2007

This study is to propose the basic data for deciding remodeling of wornout educational facilities. In order of it, the indoor environmental standard, the actual conditions of thermal environment and sound insulation of walls were examined through field measurement in the subjected open elementary school(J school) and modernization model of elementary school(Y school) which they are located in Seoul. As the result, standard for indoor environmental factors of educational facilities which is established by Ministry of Education is not subdivided into indoor environmental performances considering usages and characteristics of classrooms for comfortable indoor environment. The vertical temperature difference in general classroom and in open classroom showed to be $11.2^{\circ}C$ and $12.1^{\circ}C$ respectively, while indoor temperature of special classroon was, on the whole, higher than that of any other classroom due to its specific heat flux of wall materials. The sound insulation performance of the masonry brick wall of classroom satisfied the minimum standard of AIJ, Architectural Institute of Japan, in the open elementary school and the modernization model of elementary school. That is to say, the movable partition wall between the classroom and the corridor disturbed students in their class in the open school.

• 건축역사연구
• /
• 제1권1호
• /
• pp.117-128
• /
• 1992

The purpose of this paper is to clarify the introduction of foreigner's architectural engineering such as building materials techniques engineers, focused on the Late Yi-dynasty. Such all kind of building materials as timber brick tile cement lime glass window furniture and so on was imported from the foreign company in opening period of ports in Cho-son. The timer of these materials was imported from Japan, the brick tile from China, and others directly from Western counteries indirectly from Japan China. As it was active in an inflow of building materials and machines about 1890's, the modern building techniques were introduced and elementarily mastered such as timber sewing, manufacturing baking of brick glass, and masonry, The above modern techniques became the direct background in the formation of Korean modern architecture. Building engineers can be divided into three classes : architect engineer apprentice. But It could be apparently not divided the relation between architect and engineer at that time. They could be classified into job-architects who were engaged by the Korean government and leaded an active life in their settlement, and missonaries, They introduced the construction and style of modern architecture in our country, And so many skilled laborers and laborers participated in the construction of their settlement.

• 한국공간구조학회논문집
• /
• 제18권3호
• /
• pp.45-55
• /
• 2018

The arched stone bridge has been continuously deteriorated and damaged by the weathering and corrosion over time, and also natural disaster such as earthquake has added the damage. However, masonry stone bridge has the behavior characteristics as discontinuum structure and is very vulnerable to lateral load such as earthquake. So, it is necessary to analyze the dynamic behavior characteristics according to various design variables of arched stone bridge under seismic loads. To this end, the arched stone bridge can be classified according to arch types, and then the discrete element method is applied for the structural modelling and analysis. In addition, seismic loads according to return periods are generated and the dynamic analysis considering the discontinuity characteristics is carried out. Finally, the dynamic behavior characteristics are evaluated through the structural safety estimation for slip condition.