• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.677-686
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• 2016

A thermal power plant is the first CFBC (Circulating Fluidized Bed Combustion) power plant consisting of 2 boilers-1 turbine. The optimal height of a stack needs to be approximately 156 meters in the case of this thermal power plant; however, the thermal power plant sites satisfy a function and reduce the construction cost by using mountains in the sites after cutting the ground and locating an integrated office and chimney at an altitude of 70 meters thereby lowering the height of the stack to 86 meters. In addition, the integrated office, which has a combined stack style with a unique design, is constructed by connecting with 2 stacks and disposing the office and an observatory in the space between them. Therefore, this study examined the design concept that fulfils the structural, functional, and aesthetic factors, harmoniously by joining the integrated office and the stack, which are disparate, and investigated special construction methods (Slip Form, Steel Inner Flue & Lift-up) through which heterogeneous architectures are structurally, functionally, and aesthetically constructed.

• Journal of Korean Society of Transportation
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• v.34 no.6
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• pp.570-579
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• 2016

This study proposes a concept of Stepwise Transfer Coefficient(STC) which implies greater transfer cost with increasing the number of transfers. Thus, the public transport information system provides the choice sets of travel routes by the consideration of not only transportation time but also the optimum number of transfers. However, path choice problems that involve STC are found to include non additive cost, which requires additional route enumeration works. Discussions on route enumeration in actual transportation networks is very complicated, thereby warranting a theoretical examination of route search considering STC. From these points of view, this study results in a probability based transit trip assignment model including STC. This research also uses incoming link based entire route deletion method. The entire route deletion method proposed herein simplifies construction of an aggregation of possible routes by theoretically supporting the process of enumeration of the different routes from origin to destination. Conclusively, the STC reflected route based logit model is proposed as a public transportation transit trip assignment model.

• Geomechanics and Engineering
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• v.18 no.5
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• pp.535-543
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• 2019

Building on/with expansive soils with no treatment brings complications. Compacted expansive soils specifically fall short in satisfying the minimum requirements for transport embankment infrastructures, requiring the adoption of hauled virgin mineral aggregates or a sustainable alternative. Use of hauled aggregates comes at a high carbon and economical cost. On average, every 9m high embankment built with quarried/hauled soils cost $12600MJ.m^{-2}$ Embodied Energy (EE). A prospect of using mixed cutting-arising expansive soils with industrial/domestic wastes can reduce the carbon cost and ease the pressure on landfills. The widespread use of recycled materials has been extensively limited due to concerns over their long-term performance, generally low shear strength and stiffness. In this contribution, hydromechanical properties of a waste tyre sand-sized rubber (a mixture of polybutadiene, polyisoprene, elastomers, and styrene-butadiene) and expansive silt is studied, allowing the short- and long-term behaviour of optimum compacted composites to be better established. The inclusion of tyre shred substantially decreased the swelling potential/pressure and modestly lowered the compression index. Silt-Tyre powder replacement lowered the bulk density, allowing construction of lighter reinforced earth structures. The shear strength and stiffness decreased on addition of tyre powder, yet the contribution of matric suction to the shear strength remained constant for tyre shred contents up to 20%. Reinforced soils adopted a ductile post-peak plastic behaviour with enhanced failure strain, offering the opportunity to build more flexible subgrades as recommended for expansive soils. Residual water content and tyre shred content are directly correlated; tyre-reinforced silt showed a greater capacity of water storage (than natural silts) and hence a sustainable solution to waterlogging and surficial flooding particularly in urban settings. Crushed fine tyre shred mixed with expansive silts/sands at 15 to 20 wt% appear to offer the maximum reduction in swelling-shrinking properties at minimum cracking, strength loss and enhanced compressibility expenses.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.3
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• pp.43-48
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• 2019

Since the revision of the Rationalization of Energy Use Law, the spread of new and renewable energy in buildings has been promoted. In addition, the production of electric power and thermal energy is an important issue in the change of energy paradigm centered on the use of distributed energy. Among them, geothermal energy is attracting attention as a high-performance energy-saving technology capable of coping with heating / cooling and hot water load by utilizing the constant temperature zone of the earth. However, there is a disadvantage that the initial investment cost is high as a method of calculating the capacity of a geothermal facility by calculating the maximum load. The disadvantages of these disadvantages are that the geothermal energy supply is getting stagnant and the design of the geothermal system needs to be supplemented. In this study, optimization design of geothermal system was carried out using optimization tool. As a result of the optimization, the ground heat exchanger decreased by 30.8%, the capacity of the heat pump decreased by 7.7%, and the capacity of the heat storage tank decreased by about 40%. The simulation was performed by applying the optimized value to the program and confirmed that it corresponds to the load of the building. We also confirmed that all of the constraints used in the optimization design were satisfied. The initial investment cost of the optimized geothermal system is about 18.6% lower than the initial investment cost.

• Korean Journal of Construction Engineering and Management
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• v.10 no.5
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• pp.113-122
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• 2009

The domestic construction market started to expand steadily since 1970s. The building market which utilizes a sandwich panel with advantages of economical construction expenses and convenient construction has grown rapidly in recent years. However, the companies which specialize in constructing sandwich panels are relatively small or medium size, compared with other construction companies. As a result, studies on the improvement of productivity have not been conducted sufficiently. In this study, the construction sites of sandwich panel are investigated, and the work processes by each team are analyzed. Additionally, the productivity and the construction cost of each work group are analyzed by constructing a model using the Web-Cyclone. It analyzed sensitivities about change of productivity and work costs following in processing place of the panel which is one of the productivity effect factors, so it assayed the optimized productivity by each work group and work costs. Analysis showed that 30% of productivity has improved compared with the factory processing work group, and analysis of work costs showed that about 15% of work costs was increased. Also sensitivity analysis of opening ratio showed that the work costs optimization will be accomplished when about 20% of opening was processed from the factory.

• Korean Journal of Construction Engineering and Management
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• v.19 no.4
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• pp.12-20
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• 2018

As facilities have become larger, more complex, and advanced, the importance of the facility management in the operation phase of the building is increasing. As a result, the scope of the facility management function is expanding, and the requirements of information are ever-increasing. However, inefficient exchange of information occurs due to duplicated tasks and lack of collaboration among the construction life cycle phases, resulting in cost loss. These low interoperability issues can be complemented by construction information management from a life cycle perspective. Efficient construction information management at each life-cycle stage is derived from the owner's will and is materialized through the construction information handover requirements by the owner. The purpose of this study is to develop an evaluation method of construction information handover requirements for facility management. In order to develop the method, facility management types and business functions are also classified and defined in this paper. Using the methodology proposed by this study, a case-study of evaluating the 'takeover items' submitted by contractors was performed for the purpose of research validation. The results of the case-study found that the most effective areas are in the order of 'legal informations', 'drawings', 'guides', etc. This study can be used as a reference data for deriving handover requirements for construction information at the early stage of the project.

• Journal of the Korean Institute of Landscape Architecture
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• v.26 no.2
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• pp.73-90
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• 1998

The construction and management of the royal garden and landscape were the most significant project in Choson Dynasty. The kind of the royal garden and landscape were the rear garden of the palace, the groves of the royal shrine and orchard, etc. As the important project of the country, these constructions were controlled by the administrative system without division into the fields of engineering, building and landscaping. The purpose of this study is to investigate the administrative system. In particular, this study is focused on the construction and management of the royal garden and landscape in Hanyang from the 18th century to the late 19th century. This study is based on the analysis of historic documents and a survey of the relics. The results were summarized as follows : 1) The administrative system of the construction and management of the royal garden and landscape was composed of the government offices under Industry Board as a permanent organization - Yongjosa, Santaeksa, Chunchonsa, Songonggam, Changwonso - and Togam as a temporary organization. In addition to these organizations, there were Revenue Board, Ceremony Board, Military Board, which served as supporting organizations. The control of the construction and management of the royal garden and landscape was held by decision makers, executors of works and management. 2) The general process of the construction and management of the royal garden and landscape included Sangji and Kyuho다 as the first step; In case of buildings and facilities, according to former examples and drawings, the most of the planning and design was already fixed. In the case of landscape, those things aimed at construction according to the existing lie of the land. The works in the 2nd step; This process was divided into the construction of facilities and planting. In case of construction of facilities, those works were done by Togam and Songonggam. The high cost works were carried out through Togam and normal repairing works were completed by Songonggam. In case of planting, those works were carried out through Chunchonsa and the military. The management in the 3rd step; This process was done by two parts like the process of works. In case of facilities, management was done 효 the officers of Pongshim. In case of groves of newly - planted trees, this management was done by Tongsanbyonlgam and Tongsanjik who served cultivation and harvest of fruit trees as an expert.

• Korean Journal of Construction Engineering and Management
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• v.18 no.2
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• pp.99-107
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• 2017

In recent years, Korean engineering companies are actively entering into the international business. Although international engineering project is known to have lower risk rather that EPC construction project, Korean engineering companies' international sales profit is not as good. Therefore, this study analyzes the risks that are predicted before bid and actually occurred after award. In addition, this study shows the difference of risk depending on lump sum contract and cost reimburse contract. Finally, this study analyzes the difference of risk according to civil engineering and building engineering. This study provides industry to analyze risk more practically and helps academics to focus on risk to be studied more in the future.

• Journal of Korean Society of Steel Construction
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• v.18 no.3
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• pp.395-403
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• 2006

Recently constructed bridges often have long spans and simple structure details considering not only the function but other important factors such as aesthetics, maintenance, construction duration and life cycle cost. Therefore, bridges require high-performance steels like extra-thick plate steels and thermo-mechanical control process (TMCP) steels. TMCP stels are now gaining wide attention due to their weldability improved strength and toughness. Recently, SM570-TMC steel, which is a high-strength TMCP steel with a tensile strength of 600 MPa, has been developed and applied to steel structures. However, using this steel in building steel structures requires the elucidation of not only material characteristics but also the mechanical characteristic of welded joints. In this study, high-temperature tensile properties of SM570-TMC steel were investigated through the elevated temperature welded joints of SM570-TMC steel were studied through the three-dimensional thermal elasticplastic analyses on the basis of mechanical properties at high temperatures obtained from the experiment.

• Explosives and Blasting
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• v.20 no.4
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• pp.5-15
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• 2002

For the noise reduction measures in a construction field where noise sources such as blasting and pile driving works exist, the construction of the sound barrier near the noise source or receiver is often the most economic measure in order to exclude the propagated sound. The dimension of the barrier is decided by the noise and construction design, and the constructive quality of a soundproof panel shall be secured in accordance with KS F4770 to guarantee the safety of sound barriers. In this paper the problems included in the KS F4770-1 that is the regulation for the metallic sound barrier of the absorption type are identified and it is suggested what to be corrected or improved. Through a series of the analyses, conclusion were reached that it is required to improve test methods in KS F4770-1 as well as to break down loads for building more cost-effective sound barrier. In addition, KS F4770-1 was compared with ZTV-Lsw 88 which is the german regulation for sound barrier design. As a result, it was found that the Korean regulation is more conservative than that of Germany.