• Journal of the Korea Institute of Building Construction
• /
• v.10 no.6
• /
• pp.19-26
• /
• 2010

Advanced construction technologies have been rarely applied to practical construction operations on jobsites due to a lack of quantified evaluation data of the performance of such technologies. The basic objective of this study is to suggest a feasible way for the evaluation of the performance of new technologies based on construction simulation techniques, which have been frequently used in academic research for productivity estimation. Steel staircase systems were selected as the new technology to be investigated. The simulation was implemented in various ways, such as one staircase to six staircases on a floor. The simulation results provided in this study suggest that planners are able to make a fundamental decision on the use of targeted new technology with the estimated performance data (productivity and unit costs). These findings also indicate that a simulation technique could be one of the methods appropriate for use as a planner's decision-making tool.

• Journal of the Korea Institute of Building Construction
• /
• v.23 no.1
• /
• pp.35-43
• /
• 2023

In this study, the mechanical properties of concrete mixed with non-sintered hwangto(NHT) as an alternate material for cement were evaluated, and the compressive strength prediction equation of concrete based on ultrasonic pulse velocity analysis was proposed. Cement replacement rates for mixed NHT were set to 0, 15, and 30%, and design compressive strength was set to 30 and 45MPa to evaluate the effect on the amount of cement and NHT powder. The mechanical properties items analyzed were compressive strength, ultrasonic pulse velocity, and elastic modulus, and were measured on days 1, 3, 7, and 28. As the replacement rate of NHT increased, the mechanical properties tended to decrease. In addition, as a result of analyzing the correlation between compressive strength and ultrasonic pulse velocity, the correlation coefficient(R²) showed a high relationship(R²=0.95) on concrete mixed with NHT.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2010.04a
• /
• pp.758-761
• /
• 2010

본 연구에서는 원전격납구조물과 같이 고품질의 대형 매스콘크리트의 설계, 시공, 품질예측 및 관리에 필요한 구조물 건전성 평가시스템 구축의 일환으로 수화열 예측 프로그램을 개발하였다. 개발된 수화열 예측 프로그램은 국내에서 생산된 시멘트 및 결합재의 화학조성성분, 분말도와 같은 기초정보 및 배합정보를 입력하여 경시변화에 따른 수화발열량을 계산하는 방식으로서 기존의 연구결과를 바탕으로 개발되었다. 개발된 프로그램은 배합환경조건을 고려하여 초기배합온도 3종류(10, 20, $30^{\circ}C$)로 실험한 단열온도상승 실험 결과와 비교해 보았으며, 좋은 상관성을 나타냄을 확인할 수 있었다.

• Journal of Korean Society of Steel Construction
• /
• v.26 no.4
• /
• pp.299-309
• /
• 2014

HSA800 is a new high strength steel (HSS) plate for building structures developed by POSCO and RIST in 2011. It has upper and lower bounds for yield ($F_y$) and tensile ($F_u$) strength as of 650-770MPa and 800-950MPa, respectively, with yield ratio ($F_y/F_u$) limit as of 0.85 which make steel quality more reliable and enhance the seismic resistance of structures. As made by TMCP, it has a good weldability without increasing carbon percentage. The objective of this study is to provide alternative design of mega-structural members of the Lotte World Tower (555m, 123 story), a first super-tall building in Korea, using HSS considering structural safety, constructability, and cost-effectiveness. Steel outrigger trusses, belt-trusses and steel exterior columns were selected and analyzed to evaluate the structural performance between original and alternative designs using HSS. The results show that HSS can be applied to the members which do not affect lateral stiffness of a building and, in this study, approximately 1100tons of steel were saved. It implies that HSS can save overall construction costs - manufacturing, delivery, and erection costs - by reducing mega structural member size. HSA800 was very first applied to the Lotte World Tower based on the results of this study.

• Geotechnical Engineering
• /
• v.11 no.2
• /
• pp.79-98
• /
• 1995

In the present study an analytical modeling was carried out to predict mobilized shear strength at the interface between the nail and surrounding soils by carefully examining the behavior characteristics of nailed boil excavated walls. Based on the developed model of mobilized shear strength, the method of overall stability analysis of nailed -soil walls was also developed using the Morgentern -Price limit -equilibrium slice method. The developed analytical procedure could predict the behaviors of nailed -soil excavated walls during the successive excavation stages, at the final stage of construction and post -construction stages. To verify the validity of the developed model and method of stability analysis, mobilized tensile forces of nails and overal stability estimated by the developed procedure were compared with test measurements from three nailed -soil experimental walls having different soil conditions. The effect of seepage pressures inside the soil mass was considered in the developed procedure.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2012.05a
• /
• pp.251-252
• /
• 2012

The exiting studies on the strength prediction by maturity method is mainly focused on concrete using OPC, meanwhile the study on the concrete mixing blast furnace slag powder (BFSP) is insufficient. The purpose of this study is to investigate the relationships between compressive strength and equivalent age by existing Maturity functions, i.e., Nurse-saul function Arrhenius function. This study also compared and examined the strength prediction of concrete mixing BGSP using ACI model and Logistic Curve prediction equation. Therefore, it is intended that fundamental data are presented for quality management and process management of concrete mixing BFSP.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2012.05a
• /
• pp.201-203
• /
• 2012

The establishment of the technology for evaluating friction resistance and pipe pressure and the relation of the fluid characteristics and pumpability of concrete is essential for the evaluation of concrete pumping performance for high speed construction of super-tall building. So, this study focuses on quantitative evaluation of concrete fluid characteristics and surface friction resistance under the change of concrete mix proportion and pumping condition. In this study, we measured the rheology of concrete and pipe pressure and surface friction characteristics when pumping. And, relations between the rheology characteristics of concrete and pumping performance was investigated by experiment. As the result of the experiment, high regression between the surface friction and pressure gradient was confirmed. And, prediction model to evaluate the friction resistance coefficient and pipe pressure reduction coefficient was suggested.

• Journal of the Korea Institute of Building Construction
• /
• v.17 no.1
• /
• pp.83-90
• /
• 2017

Recently, BIM has been actively adopted in construction projects and industries, and also integrated with Information and Communications Technology(ICT) such as cloud computing technology, sensor technology, 3D scanning and printing technology etc. However, it is very difficult to efficiently utilize BIM services, technologies and collaborate with each other because of differences of usage and requirements of technologies. Every participant in the same construction project has their own needs, requirements and details of the model in each phase. In order to enhance utilization BIM model, BIM services and technologies required in their project have to be clearly defined in the initial stage of the project. In order to support the owner to define the BIM level, BIM service level and application technologies are identified and guidelines how to define the level and technologies for their project purpose are suggested in this study.

• Korean Journal of Construction Engineering and Management
• /
• v.23 no.4
• /
• pp.15-25
• /
• 2022

As the incidence and mortality of serious disasters in the construction industry are the highest, various efforts are being made in Korea to reduce them. Among them, risk assessment is used as data for disaster reduction measures and evaluation of risk factors at the construction stage. However, the existing risk assessment involves the subjectivity of the performer and is vulnerable to the domestic construction site. This study established a DB classification system for risk assessment with the aim of early identification and pre-removal of risks by quantitatively deriving risk factors using BIM in the risk assessment field and presents a methodology for risk assessment using BIM. Through this, prior removal of risks increases the safety of construction workers and reduces additional costs in the field of safety management. In addition, since it can be applied to new construction methods, it improves the understanding of project participants and becomes a tool for communication. This study proposes a framework for deriving quantitative risks based on BIM, and will be used as a base technology in the field of risk assessment using BIM in the future.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2021.05a
• /
• pp.93-94
• /
• 2021

The Korean government has invested a tremendous amount of money in the last 10 years to build large public research infrastructures (LPRI). For efficient operation and maintenance of LPRI built with expensive equipment and professional engineers, reasonable budget needs to be allocated. However, it is difficult to fulfill sustainable operation and maintenance (O&M) because there is no standard on budgeting for efficient LPRI operation, including expensive equipment and manpower allocation. There have been a lot of cost assessment studies regarding O&M of high-demand facilities such as hospitals, hotels and residential buildings, but a very few on sustainable O&M of LPRI. Therefore, mid/long-term budget establishment plans for efficient LPRI O&M are required from the initial planning stage and a cost assessment model to support the plans should be developed. The objective of this paper is to propose a cost assessment model for sustainable operation and maintenance of large public research infrastructures. To do so, actual O&M data of 6 LPRI types in operation are collected, and regression analysis model (RAM) is used for development and evaluation a cost assessment model. The study result will support sustainable operation of LPRI from a business perspective and be used as basic data for continuous development of cost assessment models to establish budgets for LPRI operation from an academic perspective.