• Journal of the Korean Institute of Rural Architecture
• /
• v.17 no.1
• /
• pp.73-81
• /
• 2015

The purpose of this study is to analyze the approach characteristics, relation to other facilities, and current status focusing on 28 total of exhibition-culture facilities in Gangneung. The results are following as. First, 19 facilities are located in urban area and nine are located in country side. With locational characteristics of Gangneung which is mountains in west and sea to east, three are located in high hill side and four are in sea shore among nine facilities. Facilities in urban area converge to Gungpodae and Ojukhuk which are symbol space in Gangneung. Those facilities started to have been increased from 1990s and rapidly increased from 2000s. The reason is that people have been interested in culture and art in society in general. In building structure, buildings related with traditional contents were constructed with wooden structure while buildings have been mainly constructed with modern ways such as steel and reinforced concrete structure. Second, the 28 facilities are classified into three types by function of other space or facilities within same a site or a building. The three types are themselves usage only, multi-function, and park type. The multi-function type is re-classified into two; public type and commercial type. Those functions have changed according to changes of society and times. Finally, for approaching to the exhibition-culture facilities with general transportation, the mean distance from the closest bus stop to those facilities each is 280m and 27 facilities are located within 670m from the closest bus stop. For approaching way using by car creates movement along road-building site-parking space-main entrance of building. When based on main entrance by the movement, parking space located in front side of main entrance is the largest, next is in the side, and the least is in back side. Various factors such as approaching form from road to parking space and space size between main entrance and parking space influence to approaching ways of exhibition-culture facilities in Gangneung.

• Journal of the Korean Geosynthetics Society
• /
• v.17 no.2
• /
• pp.33-40
• /
• 2018

Characteristics of interface friction between cohesionless soils and geotechnical structure surfaces play an important role in the analysis of earth load and resistance on the structure. In general, geotechnical structures are mainly composed of either steel or concrete, and their surface roughnesses with respect to soil particle sizes influence the interface characteristics between soils and the structures. Accurate assessment of the interface friction characteristics between soils and structures is important to ensure the safety of geotechnical structures, such as mechanically stabilized earth walls reinforced with inextensible reinforcements, piles embedded into soils, retaining wall backfilled with soils. In this study, based on the database of high quality interface friction tests between frictional soils and solid surfaces from literature, equation representing peak interface friction angle is proposed. The influential factors of the peak interface friction angle are relative roughness between soil and solid surface, relative density of frictional soil, and residual (constant volume) interface friction angle. Futhermore, for the developed equation of the interface friction angle, its uncertainty was assessed statistically based on Goodness-of-fit test results.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.7 no.4
• /
• pp.191-199
• /
• 2003

The inelastic response of many structural steel and reinforced concrete structures subject to extreme loadings can be characterized by elastoplastic behaviors. Although excursion beyond the elastic range is usually not permitted under normal conditions of service, the extent of permanent damage a structure may sustain when subjected to extreme conditions, such as severe blast or earthquake loading, is frequently of interest to the engineer. A blast is usually the result of an explosion defined as a "sudden expansion". This paper discusses the basic concept that defines blast loadings on structures and corresponding elastoplastic structural response (displacement, velocity, and acceleration) and try to explain a crack propagation of concrete in sudden expansion. According to nonlinear finite element analysis, the crack forms of static and dynamic states displayed different in RC structural members. This paper also provides useful data for the dynamic fracture analysis of RC frame structures.

• Structural Engineering and Mechanics
• /
• v.77 no.4
• /
• pp.441-461
• /
• 2021

Reinforced concrete (RC) columns are crucial in building structures and they are of higher vulnerability to terrorist threat than any other structural elements. Thus it is of great interest and necessity to achieve a comprehensive understanding of the possible responses of RC columns when exposed to high intensive blast loads. The primary objective of this study is to derive analytical formulas to assess vulnerability of RC columns using an advanced numerical modelling approach. This investigation is necessary as the effect of blast loads would be minimal to the RC structure if the explosive charge is located at the safe standoff distance from the main columns in the building and therefore minimizes the chance of disastrous collapse of the RC columns. In the current research, finite element model is developed for RC columns using LS-DYNA program that includes a comprehensive discussion of the material models, element formulation, boundary condition and loading methods. Numerical model is validated to aid in the study of RC column testing against the explosion field test results. Residual capacity of RC column is selected as damage criteria. Intensive investigations using Arbitrary Lagrangian Eulerian (ALE) methodology are then implemented to evaluate the influence of scaled distance, column dimension, concrete and steel reinforcement properties and axial load index on the vulnerability of RC columns. The generated empirical formulae can be used by the designers to predict a damage degree of new column design when consider explosive loads. With an extensive knowledge on the vulnerability assessment of RC structures under blast explosion, advancement to the convention design of structural elements can be achieved to improve the column survivability, while reducing the lethality of explosive attack and in turn providing a safer environment for the public.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.11
• /
• pp.259-272
• /
• 2019

Steel-concrete single-leaf blast-resistant doors are protective structures consisting of a steel box and reinforced concrete slab. By the domestic blast-resistant doors, the structure is not designed efficiently because few studies have examined the effects of variables, such as the blast pressure, rebar ratio, and steel plate thickness on the structural behavior. In this study, the structural behavior of the doors was analyzed using the FE method, and the support rotation and ductility ratio used to classify the structural performance were reviewed. The results showed that the deflection changes more significantly when the plate thickness increases than when the rebar spacing is a variable. This is because the strain energy absorbed by the door is reduced considerably when the plate thickness increases, and as a result, the maximum deflection becomes smaller. According to a comparison of the calculated values of the support rotation and the ductility ratio, the structural performance of the doors could be classified based on the support rotation of one degree and ductility ratio of three. On the other hand, more explosion tests and analytical studies will be needed to classify the damage level.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.17 no.6
• /
• pp.21-30
• /
• 2013

As increasing number of large-size earthquake, the social interest of seismic retrofitting of RC structure is growing. Especially, the RC columns that are not reflected seismic design can not resist lateral loads by the earthquake. The brittle fracture of Non-seismic designed columns lead to full collapse of the building. Thus, the emergency columns reinforcement method is needed. That have a fast construction time, do not cause damage to the column. In the past, cross-sectional expansion method, a steel plate reinforcing method is applied mainly, but in recent years, carbon fiber sheet taking advantage of FRP (Fiber Reinforced Polymer) is widely used. In this study, retrofitting effect of seismic performance of FRP seismic reinforcement, which is possible to emergency construction, was examined. Reinforced concrete specimens were constructed to experimental study. The seismic performence of specimes retrifitted with FRP seismic reinforcement were evaluated. As a result, the seismic performance of specimen reinforced with FRP seismic reinforcement has been improved.

• Land and Housing Review
• /
• v.6 no.3
• /
• pp.129-138
• /
• 2015

The building structure in Korea is planned to maximize the use of space in recent. The hybrid OCB(Optimized Composite Beam) beam is developed to take advantage of using the space. The OCB beam is composed of the steel H-beam section reinforced by open strands in negative moment zone and the pretensioned PSC concrete section in positive zone. Flexural behavior of typical architectural hybrid OCB beam section was investigated by F.E.M. The 15m, 20m, 30m OCB models were tested on nonlinear material and geometry under static loading system. Following results are obtained from the analysis; 1)The OCB beam develop initial flexural cracking over full service loading. 2)Overall deflections of OCB beam under the service loads are less than those of the allowable limits in KCI Code(2012). 3)The ultimate load capacity get over the nominal strength of the OCB main section. The OCB beam is verified of structural reliability from the finite element analysis.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.15 no.1
• /
• pp.1-11
• /
• 2013

Steel fiber-reinforced concrete (SFRC) is widely used for tunnel lining structure such as shot-crete in NATM tunnel and segment in TBM tunnel. In tunnel fire accidents, structural performance of a lining is very important because the lining is the structure that directly exposed to fire. In this study, the effects of high temperatures, mix ratios and types on failure pattern, DPT tensile strength and coefficient of variation were investigated through Double Punch Tests (DPT) of SFRC subjected to high temperatures. In the results, it is confirmed that the residual DPT tensile strength increases as for SFRC and this is more in SFRC with higher mix ratio. But, the equation for evaluation of DPT tensile strength does not involve the number of failure surfaces SFRC specimens subjected to high temperatures, therefore, it is required to investigate more fracture energy in DPT tests.

• Steel and Composite Structures
• /
• v.28 no.4
• /
• pp.439-447
• /
• 2018

The structural behaviors of cylindrical barns as a specific engineering structure have been considered as a complicated computing process. The structure design against the earthquake load, to protect by using the code, is an urgency avoiding unexpected damages. The situation has been subjected to the applied design method if there would be no failure across the construction procedures. The purpose of the current study is to clarify the behaviors of cylindrical reinforced concrete barns through the analytic methods across the mass and Lagrangian approaches through the whole outcomes comparison indicating that the isoparametric element obtained from the Lagrangian approach has been successfully applied in the barns earthquake analysis when the slosh effects have been discarded. The form of stress distributions is equal with $s_z$ closed distributions to one another.

• Journal of the Korea Concrete Institute
• /
• v.26 no.2
• /
• pp.211-218
• /
• 2014

In the design of reinforced rectangular concrete beam structure, the minimum amount of flexural reinforcement is required to avoid brittle failure. KCI code is based on concept of ultimate strength and usually used as a model code. But bridge design code enacted by Ministry of land, transportation and maritime affairs in 2012 is based on concept of limit state and similar to Euro code EN 1992-2. This means that the minimum reinforcement presented in both design codes has different origination and safety margin. When rectangular concrete beams with minimum reinforcement are designed according to EN and KCI codes, the amount of minimum reinforcement specified in EN code is only 76% of that in KCI code. This makes the design engineers to be confused. In this study, flexural tests were conducted on nine beams with the two different minimum reinforcement specified in KCI and EN design codes. In results, the measured ratios of nominal strength to crack strength from the test were about 25% greater than those evaluated from the equations presented in KCI and EN codes. The EN beams having only 76% of the minimum reinforcement for the KCI beams were fractured by rupture of steel reinforcement but in ductile manner. It is confirmed that the minimum reinforcement concrete beams designed according to both codes have enough safety margin in flexural capacity and moreover in ductility.