• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.4
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• pp.197-205
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• 2022

In this paper, a retaining wall system, developed using building Information modeling (BIM), is presented. Based on the information from a literature review, elementary technologies for the system were defined and developed. First, for the elementary technology, BIM libraries were constructed using standards and previous study results to achieve versatility and reusability. Second, methods for determining the quantity take-off (QTO) of a retaining wall were reviewed for an earth-work calculating system. Additionally, inverse distance weighting interpolation was used to generate topography. Finally, four formulas for calculating the QTO were proposed and devised for each element. After its development, the BIM system was analyzed and verified through comparison with a two-dimensional drawing-based QTO. The proposed system is deemed to be practical for determining the QTO of retaining walls and earth works. The contributions and limitations of the research are discussed in this paper.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.401-401
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• 2023

터널이나 폐기물저장소와 같은 지하 구조물 또는 지표에서부터 상당한 깊이로 설계되거나 건설되는 구조물을 계획하거나 건축할 때 구조물의 안전성에 영향을 주는 수많은 요인 중에 간과할 수 없는 것이 바로 지하수이다. 뿐만 아니라 지상 혹은 지하에서 오염이 발생하여 오염물질이 지중환경으로 유입되는 경우, 지하수 거동은 오염물의 이송·확산에 지대한 요인으로 작용한다. 최근에는 지구온난화와 같은 유례없는 기후변화를 경험하고 있고, 따라서 수자원으로써 지하수의 역할이 더욱 중요해지고 있다. 지하수의 저류와 거동은 지하매질의 특성에 지배되고 있지만, 지표 아래 자리잡고 있는 매질의 특성을 정확히 파악하기란 매우 힘들고, 따라서 지하수 거동을 해석함에 항상 불확실성이 존재한다. 전통적으로 지하매질의 특성을 이해하기 위해 다양한 지구물리탐사를 수행하여 왔고, 더욱 직접적인 관찰을 위해 시추를 수행하여, 시료를 수집·관찰하고, 시추공에서의 다양한 현장수리실험을 통해 수리특성을 알고자 하였다. 하지만 그동안의 다양한 노력에도 불구하고, 지하매질 및 지하수 거동에 대한 불확실성은 여전히 줄어들지 않고, 오히려 증가하고 있다. 따라서, 본 연구에서는 지하수 거동을 결정짓는 지하매질의 수리특성에 대한 불확실성을 정량화하기 위한 도구로써, 매개변수 보정법의 하나인 Pilot Point Method(PPM)을 소개하고자 한다. 우물 또는 관측정을 통해 관측되는 지하수의 수위는 지하매질의 특성을 반영하고 있으며, 인간이 가장 쉽게 취득할 수 있는 지하 정보에 해당한다. 지하수 수위를 이용하여 수치모형의 매개변수를 보정하게 되며, 이 때 PPM이 적용된다. Pilot points의 공간적인 분포에 따라 다양한 보정 결과가 산출될 수 있으며, 다양한 결과들을 통해 변동계수를 산정한 후 수리특성의 불확실성이 높은 지역을 나타낼 수 있다. 본 연구를 통해 얻은 결과는 물리탐사 또는 시추 작업을 위한 위치 선정의 기초자료로 활용될 수 있다.

• Korean Journal of Construction Engineering and Management
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• v.24 no.3
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• pp.31-41
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• 2023

This study is a study to develop a configuration management methodology for efficient and systematic management in the event of configuration changes such as deformation, explosion, and remodeling of launch vehicle development test facilities, which are emerging as important national facilities in the era of full-scale space competition. Through the analysis of international standards for configuration management, a configuration management process framework to be applied to launch vehicle development test facilities is extracted, a survey was conducted on experts who performed life cycle engineering of launch vehicle development test facilities, and a configuration management methodology optimized for operation/management of domestic launch vehicle development test facilities was proposed. Identify the configuration for launch vehicle development test facilities, the configuration management manager, configuration management organization, and configuration management board approve/process the configuration changes, and after construction is completed according to design requirements, launch vehicle development test facilities try to manage the configuration in a controlled state.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.1D
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• pp.49-54
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• 2009

The excellent load transfer at transverse joints ensures the high performance of jointed plane concrete pavements(JPCP). Load transfer efficiency(LTE) is affected by dowel-bars, aggregate interlock and types of underlying layers, and these factors have to be modelled adequately for a reasonable analysis of JPCP. Generally, the joint stiffness has been represented by a spring model for the shear transfer by aggregate interlock or dowels. However dowel-bars, aggregate interlock and types of underlying layers have not been considered together in the design of joints. In this study, the joint stiffness that considered those factors was presented by comparing LTE obtained using FWD(Falling Weight Deflectometer) with theoretical results obtained using the finite element analysis. In addition, the effects of temperature and concrete age, on the joint stiffness were investigated.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.1
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• pp.119-126
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• 2024

In building information model (BIM), it is difficult to train an artificial intelligence (AI) model due to the lack of sufficient data about individual projects in an architecture firm. In this paper, we present a methodology to correctly train an AI neural network model based on a large language model (LLM) to predict the steel structure product weight ratios in BIM. The proposed method, with the aid of the LLM, can overcome the inherent problem of limited data availability in BIM and handle a combination of natural language and numerical data. The experimental results showed that the proposed method demonstrated significantly higher accuracy than methods based on a smaller language model. The potential for effectively applying large language models in BIM is confirmed, leading to expectations of preventing building accidents and efficiently managing construction costs.

• Journal of the Korean Geotechnical Society
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• v.40 no.2
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• pp.55-64
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• 2024

While shield tunneling has demonstrated stability in international cases, the new Austrian tunneling method (NATM) encounters challenges in urban environments with shallow cover, weathered ground, and high groundwater levels. This paper introduces two typical collapse scenarios observed in urban areas, specifically within weathered bedrock and uncemented sandy soil layers. The collapses are analyzed using six stability evaluation methods, and the results are synthesized to assess the excavation face stability through a hexagonal diagram. The study finds a consistent agreement between the analysis results of the two collapsed tunnel sites and the evaluation outcomes. The employment of the stability evaluation diagram, a comprehensive method that considers the ground characteristics of the target tunnel, proves crucial for ensuring barrier stability during the tunnel design stage. This method is essential for a holistic evaluation, especially when addressing challenging ground conditions in urban settings.

• Journal of the Society of Disaster Information
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• v.20 no.2
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• pp.284-292
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• 2024

Purpose: Compared to general fires of the same size, underground parking lot fires are more likely to cause human and property damage and are not easy for firefighters to extinguish fire and save lives. This study attempted to find out how to secure the evacuation safety of parking lot users based on changes in the evacuation simulation behavior mode applied to evaluate the evacuation safety of the object. Method: Simulation for each CASE was performed using the Pathfinder program. Result: it was found that the higher the reference value, the higher the evacuation time, and Behavior showed an increase in time in SFPE mode rather than Steering mode. Priority was able to confirm an increase in time in priority designation rather than non-priority designation. Conclusion: The Required Safe Egress Time (RSET) for evaluating the evacuation safety of underground parking lots and the building evacuation design to ensure evacuation safety should be evaluated and reflected separately from Simulation's Behaviour Mode and Priority.

• Fire Science and Engineering
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• v.33 no.6
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• pp.165-172
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• 2019

This study presents the design and manufacture of a self-contained breathing apparatus SCBA wireless communication module with a multipoint simultaneous full-duplex communication system to enable communication between team members wearing the SCBA system. It is necessary for fire-fighters to wear the SCBA system during extinguishing and rescue work at the fire site. Evaluation of the team communication module confirmed the feasibility of communication over more than 500 m in the test condition based on the line of sight. By implementing the Ad-hoc function, it was confirmed that the communication distance could be extended to 128 m by automatic routing up to 3 hoc. The vertical distance inside the building for successful communication was up to the 5th floor in the open staircase and up to the 3rd floor in the partitioned staircase. Furthermore, the performance testing of the communication module assuming a fire situation, confirmed that five team members correctly recognized the standard abbreviation of fire and wireless communication without a separate PTT key operation. In addition, the flame resistance was verified by exposing the module to a flame at 950 ± 50 ℃ for 5 s and then immediately extinguishing the flame.

• Journal of the Korea Institute of Building Construction
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• v.18 no.2
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• pp.125-132
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• 2018

In this study, a direct tensile test was planned to identify the tensile performance of UHPC, and the irregularity of cracks, which is a problem of the direct tensile test, was complemented through the introduction of notches at the center of a specimen. In this regard, a number of specimens divided by batch to reduce the deviation of direct tensile test values were fabricated to present reference data with respect to highly reliable direct tensile strength values. In addition, the mechanical properties and reliability of the specimens were examined under the curing conditions of the specified design strength of 120MPa for the steel fiber reinforced concrete with 1.5% fiber volume fraction, which is most suitable for the field application. As a result, the deviation of averages by batch between compressive strength and direct tensile strength did not show a large difference, and all cracks occurred within 20mm in the direct tensile test. At the 95% confidence interval of the direct tensile strength, the range was considerably small in the mean and the standard deviation, and there was no significant difference depending on the curing conditions. The results confirmed that a stable direct tensile test was performed, and highly reliable results were obtained through the fabrication of specimens by batch and test progress.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.6
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• pp.45-52
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• 2019

As international criteria and standards are required in the fields of design and construction, landscape performance must also be considered not only for the value of the landscape but also for providing quality assurance and sustainability. Given the lack of research on landscape performance, the present research was purposed to analyze the importance of potential assessment categories and items using an analytical network process. A list of assessment items, which is composed of 20 items and 6 categories, was derived through a literature review and a preliminary survey of 11 landscape professionals. An ANP model was established and a survey was conducted among 30 landscape practitioners to determine the weight of priorities considering the criteria. The results of ANP showed that the categories of site selection, preservation and health, and convenience had high priorities while materials had the lowest importance score. For the assessment items, a monitoring plan was the highest importance, followed by cultural/ historic preservation, management cost reduction, and natural ground areas. Despite the difficulties in quantifying landscape achievements, most respondents agreed that there needs to be an evaluation system for landscape performance in order to assure the quality and sustainability of landscape development. More research and discussion are needed to develop an assessment system for landscape performance that is applicable to Korean context.