Korea Building Code Research Articles

An Investigation on Base Metal Block Shear Strength of Ferritic Stainless Steel Welded Connection

This study develops a finite element analysis model to predict the ultimate strength of the base metal block shear fracture based on previous experimental results and compares the experimental results with the analysis results to verify the effectiveness of the analysis model. This study also analyzed additional variables of the welding direction and weld length on the applied load to investigate the structural behaviors and fracture conditions. In addition, predicted strength according to the analysis results were compared with those by the current design equations, and the equations proposed by previous researchers. As a result, the design formula by the current design equations, such as Korea Building Code (KBC)/American Institute of Steel Construction (AISC) and European Code (EC3), and the equations proposed by Oosterhof and Driver underestimated the base metal block shear strength of ferritic stainless steel by up to 42%. Equations suggested by Topkaya and Lee et al. for carbon steel and austenitic stainless steel welded connections provided more accurate strength predictions, while they did not reflect the difference of material properties. Therefore, this study proposed a modified strength equation for ferritic stainless steel welded connection with base metal block shear fracture considering the stress triaxiality effect of the welded connection and the material properties of ferritic stainless steel.

Loss assessment of building and contents damage from the potential earthquake risk in Seoul, South Korea

Abstract. After the 2016 Gyeongju earthquake and the 2017 Pohang earthquake struck the Korean peninsula, securing financial stability regarding earthquake risks has become an important issue in South Korea. Many domestic researchers are currently studying potential earthquake risk. However, empirical analyses and statistical approaches are ambiguous in the case of South Korea because no major earthquake has ever occurred on the Korean peninsula since the Korean Meteorological Agency started monitoring earthquakes in 1978. This study focuses on evaluating possible losses due to earthquake risk in Seoul, the capital of South Korea, by using a catastrophe model methodology integrated with GIS (Geographic Information Systems). Building information, such as structure and location, is taken from the building registration database and the replacement cost for buildings is obtained from insurance information. As the seismic design code in the KBC (Korea Building Code) is similar to the seismic design code of the UBC (Uniform Building Code), the damage functions provided by HAZUS-Multi-hazard (HAZUS-MH) are used to assess the damage state of each building in event of an earthquake. A total of 12 earthquake scenarios are evaluated by considering the distribution and characteristics of active fault zones on the Korean peninsula and damages, with total loss amounts are calculated for each of the scenarios. The results of this study show that loss amounts due to potential earthquakes are significantly lower than those of previous studies. The challenge of this study is to implement an earthquake response spectrum and to reflect the actual asset value of buildings in Seoul.

Visual language approach to representing KBimCode-based Korea building code sentences for automated rule checking

Abstract The Building Information Modeling (BIM) and its applications enable an automatic building permit process based on 3D building models and their associated information. A crucial part of the building permit process is the interpretation and transformation of natural language-based building regulation into a computer-readable and executable format. As other countries and their projects have developed a certain type of rule-translation methods, KBimCode, part of the KBim application series, has been developed and supported by the Korean government to ignite an automatic, BIM-based building permit system on top of the current e-submission system, which is called Seumter. The rule translation process usually employs a computer hard-coded approach because of its ease of implementation, and there have been advances in making the computer understand the natural language-based building regulations using parametric input tables and script languages. This project includes a step for developing a logic rule-based approach for translating natural language into computer-executable code. However, the main contribution of this study is the introduction of an approach to represent such text-based regulations using visual language for novice programmers, architects, and rule reviewers. This paper describes a KBimCode visual language that is easy-to-write and intuitive because it uses visual symbols instead of textual coding. Highlights KBVL is an approach to computer-readable building code in visual form. KBVL supports easy-to-make rules for complicated building design rules. This paper demonstrates KBVL using KBimCode for Korean Building permit requirements.

서술부의 함수체계화를 통한 인허가관련 건축법규의 자동검토 응용방안

As building information modeling (BIM) is expanding its influence in various fields of architecture, engineering, construction and facility management (AEC-FM) industry, BIM-based automated code compliance checking has become possible prospects. For the automated code compliance checking, requirements in building code need to be processed into explicit representation that enables automated reasoning. This paper aims to develop high-level methods that translate verb phrases into explicit representation. The high-level methods represent conditions, properties, and related actions of the building objects and clarify the core content of the constraints. The authors analyze building permit requirements in Korea Building Code and establish a standardized process of deriving the high-level methods. As a result, 60 kinds of the highlevel methods were derived. In addition, method classification, analysis, and application are introduced. This study will contribute to the representation of explicit building code sentences and establishment of the automated building permit system of Korea.

내진설계를 위한 공동주택의 고유주기 측정에 관한 연구

최근 공동주택은 여러 가지 원인에 의해 그 형태가 변화되고 있으며, 구조물도 벽식 형태의 구조물에서 보-기둥 형태의 구조물로 선호도가 바뀌고 있다. 따라서, 계획된 공간을 효율적으로 이용하기 위하여 구조물은 점점 더 고층화 되어가는 경향이 있다. 한국건축구조기준(KBC)에서는 이러한 고층 공동주택의 경우 내진설계 시 지진하중을 산정할 때, 구조물의 진동특성은 매우 신중하고 정밀하게 측정해야 하며, 특히 동적주기는 동적 주기는 이에 상응하는 정적 해석 시 매우 중요하므로 정밀하게 측정해야 한다. 본 연구의 주 목적은 상시 미진동 실험으로부터 얻어진 기타골조식과 전단벽식을 고려하는 경우 고층빌딩의 고유주기를 한국건축구조기준의 값과 비교하여 안전계수를 산정하고 내진성능을 평가하여, 보다 경제적인 내진설계방안을 제시하는 것이다. 또한, 연구결과 기타 골조 식은 매우 보수적으로 주기를 산정하는 것으로 나타나므로 내진설계 시 이러한 사항도 고려해야 할 것으로 사료된다. Recently, apartment designs are tend to be changed from the standard pattern by many causes and the beam-column structures are getting popular instead of wall structure system. Therefore, for the effective use of planed space the heights of apartment are tend to be higher and higher. According to Korea Building Code, earthquake resistance designs or seismic design for those high rise apartments must be more attentive and accurate, especially, dynamic periods of structures must be exactly measured, because those are very important for equivalent static analysis. The important subject of this study is to investigate the safety factors and seismic performance for natural period of high rise buildings by comparing the natural periods getting from ambient vibration method with those of Korea Building Code.

Guideline for Bridge Design Wind Speed in Coastal Region

Estimation of wind load on bridges is one of the most important aspects in designing bridges in coastal region. Various design codes and researches have suggested the procedure to estimate design wind speed; however, they do not match one another due to many reasons such as incomplete data set, ignorance of wind environment and so on. For this reason, the necessity of guideline for estimation procedure of basic wind speed which reflect the roughness of surface and the topographical effect have been increasing. In this study, we have analysed limitations of the basic wind speed of nationwide suggested by Korea Building code(AIK, 2009) and Highway bridge design code(MOLTMA, 2010). In additional, we set forth guidelines considering the roughness of land surface and the topographical effect. Using the procedure, the basic wind speed were estimated for 15 coastal regions in Korea and compared with those listed in the existing codes.

Bearing Strength of Glass Fiber Reinforced Glulam Bolted Connection

To study the bearing characteristics of glass fiber reinforced glulam for structural design, bearing strength tests were performed. Bearing loads were applied in the direction parallel to the grains, and the holes were prepared in such a way that the bolts would bear and support all the layers. The yield bearing strengths of the glass fiber reinforced glulam were found to be similar to those of the non-reinforced glulam, and were almost constant regardless of increases in bolt diameter. The ratio of the experimental yield bearing strength to the estimated bearing strength according to the suggested equation of the Korea Building Code and National Design Specification was 0.91~1.03. For the non-reinforced glulam and the sheet glass fiber reinforced plastic glulam, the maximum bearing load was measured according to the splitting fracture of specimens under bolt. The textile glass fiber reinforced glulam underwent only an embedding failure caused by the bearing load. The failure mode of reinforced glulam according to bearing load will influence the failure behavior of bolted connection, and estimating the shear yield strength of the bolted connection of the reinforced glulam is necessary, not only by using the bearing strength characteristics but also using the fracture toughness of the reinforced glulam.

표준학교건물의 3차원 비탄성거동에 대한 이력모델의 영향

Abstract The three dimensional inelastic response characteristics of the standard school buildings depending on hysteresis models are reviewed. Three artificial earthquake records in accordance with KBC(Korea Building Code) areused and the inelastic response characteristics such as story shear force, story drift ratio, story displacement, hinge distribution state are reviewed with four hysteresis models. As results, story shear force is increased by maximum 27% and story drift ratio is increased by maximum 30% according to hysteresis models. Modified Takeda Model shows maximum story shear and story drift raio in longitudinal and short direction, expecting higher safety. Storyshear shows minimum value with Clough Model in both directions and story drift ratio shows minimum with Takedamodel in longitudinal and with Clough model in short direction, so these models are expected to decrease the safetyratio. Key Words : 3-Dimensional, Hysteresis Model, Inelastic Behavior, Time History Analysis, Standard School Building

Sensitivity analysis of offshore wind turbine tower caused by the external force

Generally, faster wind speeds are observed in coastal areas than in inland areas. Therefore, for the development of offshore wind energy, more electricity is expected to be generated using wind turbines. This also solves environmental obstacles such as the selection and acquisition of land for a site and the need to protect surrounding sites from noise problems. In this paper, a numerical analysis on the external forces that affects a wind turbine tower is performed, when the wind turbine is installed in a coastal area. To calculate the extreme wind and wave forces, the maximum wind speed is assumed to be 55 m/s, which is observed 10 minutes as the mean maximum wind speed of typhoon Maemi in 2003. During the calculation procedure, the wind force is calculated according to the Korea Building Code 2009. The significant wave height and period are estimated by using the Sverdrup-Munk-Bretschneider (SMB) method. The result data obtained using the SMB method are applied to Morison’s equation to compute the wave force. The blade of the wind turbine is designed based on the Blade Element Momentum Theory, and the thrust force of the blade is computed. The diameters of the wind turbine tower are assumed to be 3 m, 4.5 m, and 6 m. The results of this numerical analysis show that wave force acting on the wind turbine tower is increased according to the diameter of the tower and the wind speed.

Proposal for Directions of Korea Building Code in the Era of Sustainability

Proposal for Directions of Korea Building Code in the Era of Sustainability

Axial capacity of circular hollow section T-joints using grade HSB 600 steel

Because of their structural efficiency and aesthetic appeal, steel circular hollow sections have been used in the construction of a wide range of structures. As more high-rise and long span buildings are built, there has been an increase in demand for high strength steel with sufficient ductility. Steel of grade HSB (High performance Steel for Bridge) 600, with a minimum tensile yield stress (Fy) of 480 N/mm2 for all thicknesses, was introduced in the Korea Building Code (KBC 2009, 2009). However, current design standards may not be applicable to circular hollow sections with steel of grade HSB 600 since the current provisions were established based on tests of steels with a yield strength of up to 355 MPa and a yield ratio of up to 0.8. For joints with large deformation, the yield strength can be increased up to 460 MPa with a resistance factor of 0.9. This paper investigates the strength limits and various possible failure modes. Eight full scale circular hollow section T-joints were tested and analyzed to investigate the applicability of current design standards. Two test series depending on the grade of steel, i.e., SHB600 and SS400, with specimens in each series were tested with variations in the ratio of diameter to wall thickness of chord member (D/t) and vertical member (Dt/bt). All chord members were 3,000mm and vertical members were 1,950 mm in length. For chord members, 750 mm diameter with 12 mm and 26 mm wall thicknesses were used for the tests. For vertical members, 650 mm diameter with 12 mm and 40 mm wall thicknesses were used. The effects of the experimental parameters were evaluated for their applicability to current standards based on the limited test and analysis results of the circular hollow section T-joint.

Experiment and analysis of circular hollow section gap K-joints with grade HSB 600 steel

Circular hollow steel sections are examples of members that are becoming increasingly popular. The demand of high strength with sufficient ductility for materials is increasing for design of long-span and high-rise structures. HSB 600 steel, High performance Steel for Bridge with minimum tensile yield strength, fy, of 480 N/mm2 for all thickness, was introduced in the Korea Building Code (KBC 2009, 2009). However, current design standards may not be applicable to circular hollow sections with HSB 600 steel since they have been established based on tests of steels with yield stress up to 355 MPa and a ductility ratio up to 0.8. Six full scale circular hollow section gap K-joints were tested and analyzed to investigate the applicability of current design standards. Two series using SHB600 and SS400 steel grades were tested. Three specimens in each series with various gaps between bracing members were evaluated. All chord members were 2,250 mm and brace members were 1,400 mm in length. All chord and brace members were 350mm in diameter and 12 mm in wall thickness. Based on the limited test and analysis results of this circular hollow section gap K-joint, the applicability to current standards, the possible elastic local buckling and gap effects of the different grades of steel are examined.

고강도 원형강관의 직각방향 거셋플레이트 접합부 실험 및 해석

A connection composed of a circular hollow structural section (HSS) has complicated details, and exhibits a very complex local deformation when it reaches the yield stress. Given these circumstances, proposing a simple design equation considering local deformation is difficult. The design equations of the Korea Building Code (KBC 2009) for HSS joints are simple and are very similar to those of the AISC. These design equations limit the maximum yield stress up to 360MPa and yield ratio (yield strength/tensile strength) up to 0.8. This means that the material with yield strength exceeding 360MPa could be used after verification based on the test or rational analysis for the similar connection. This paper introduces an experimental program and finite element analysis (FEA) for the circular hollow section (CHS) with a transverse gusset plate made of high-strength steel (HSB600) or structural steel (SS400) when the joints are subjected to lateral force. Comparison of the design equations with the results of FEA and test may be used for the modification of the design equations.

반응수정계수와 주기의 영향에 대한 철골모멘트저항골조 건물의 내진성능평가

본 연구는 높은 지진의 위험이 내재된 지역에 위치한 3층, 9층 그리고 20층 철골 모멘트저항골조에 대한 반응수정계수와 주기의 영향을 평가하기 위한 것이다. 각 구조물들은 IBC 2000과 KBC 2005에서 제시하고 있는 8의 반응수정계수로 설계되었고 건물에 기대되는 최소의 성능과 최대의 성능을 평가하기 위해서 상한범위와 하한범위의 설계가 고려되었다. 또한 반응수정계수에 대한 영향을 조사하기 위하여 4개의 다른 반응수정계수들이(9, 10, 11, 12) 각 구조물에 대하여 적용되었고 각 구조물의 고유주기 값 외의 4개의 다른 주기를 추가로 적용하여 구조물의 동적거동시 주기에 대한 영향을 조사하였다. 총 150개의 해석모델들은 50년 동안 2%의 초과확률(재현 주기 2500년)을 가진 20개의 지반운동에 대하여 평가되었다. 구조물의 성능평가를 위하여 정적 Pushover와 비선형 시간이력해석이 수행되었으며 구조물의 연성능력을 평가하기 위해서 변위연성요구가 고려되었다. 3층과 9층 구조물은 변위연성요구 값이 비교적 안정적인 거동을 보인 반면 20층 구조물은 동적 불안정성을 야기하는 요소에 의해 민감하게 나타나는 것으로 조사되었다. This study was performed to evaluate the effect of Response modification factors (R-factor) in 3-, 9- and 20- story steel Moment Resisting Frame (MRF) buildings. Each structure was designed using a R-factor of 8, as tabulated in the 2000 International Building Code provision (IBC 2000) and Korea Building Code (KBC) 2008. In order to evaluate the maximum and minimum performance expected for such structures, an upper bound and lower bound design were adopted for each model. Next, each analytical model was designed using different R-factors (8, 9, 10, 11, 12) and four different structural periods with the original fundamental period. For a detailed case study, a total of 150 analytical models were subjected to 20 ground motions representing a hazard level with a 2% probability of being exceeded in 50 years. In order to evaluate the performance of the structures, static push-over and non-linear time history analysis (NTHA) were performed, and displacement ductility demand was investigated to consider the ductility capacity of the structures. The results show that the dynamic behaviors for the 3- and 9-story buildings are relatively stable and conservative, while the 20-story buildings show a large displacement ductility demand due to dynamic instability factors. (e.g. P-delta effect and high mode effect)