• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.4-5
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• 2020

Pipe support is a representative structure that supports slab formwork, and it is a representative temporary equipment that has been systematically managed since the 1990s when the domestic temporary equipment performance test system was introduced. Nevertheless, it is also a reality that many of the products in circulation are used products that are reused and do not meet the performance of the initial manufacturing stage. However, if only new products are insisted, it could lead to delays in the process due to an increase in construction costs and difficulties in timely delivery. On the contrary, it is not acceptable for the safety of the construction site to use products of low quality without verification procedures or standards. Therefore, this study attempts to grasp the management system such as safety certification for temporary equipment and the actual condition of quality control to maintain performance, and propose improvement plans.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.23-24
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• 2020

In this study, the concrete compressive strength estimation system Concrete IoT Management System (hereinafter referred to as CIMS) was developed, and CIMS was applied to domestic field structure slabs and wall concrete to check whether CIMS is practically available and to estimate the accuracy of the initial strength estimation of concrete. As a result, it shows a very high correlation when the compressive strength of the specimen for structural management is compared with the estimated strength of CIMS in terms of integrated temperature, and it is expected to be gradually applied to domestic construction sites in the future.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.14-15
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• 2021

Even though the Al. form system, which was developed to replace the Euro-form, has been used as the slab lower formwork for almost all concrete structures based on the light weight and high conversion rate, the low-noise Drop method has been developed and used in order to overcome the limitations of the Al. Form system such as noise pollution and safety accidents caused by free fall during the demolding. However, as the low-noise drop method is still insufficient, Safety Full Drop Al. Form method is expected to be in the spotlight in the construction market based on its excellent advantages compared to the developed methods. In addition, we plan to conduct research to further contribute to securing the quality of the overall structure through continuous improvement and supplementation by introducing an automation system to the very construction method.

• Journal of the Korean Geotechnical Society
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• v.15 no.4
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• pp.235-246
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• 1999

Some of the underground structures such as subway tunnels are constructed by open cut method, in which the ground is excavated, a structure installed, and after that the excavated space is backfilled. In this case, because of their narrow and constrained boundary conditions, the earth pressure induced by self-weight of the backfilled soil acting on the underground structures is different from that of the classical theory. The vertical and horizontal earth pressures acting on upper slab and side wall of the underground structures constructed by open cut method are affected by the backfill geometry. The laboratory model tests were performed in the conditions of a variety of the shapes of backfill geometry and wall friction. And their results were compared with those from theories. As a result, it was observed that the distribution of the earth pressure acting on the underground structure is affected by the shapes of backfill geometry, the width of backfill, the angle of excavation and the wall friction.

• Korean Journal of Construction Engineering and Management
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• v.5 no.3 s.19
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• pp.106-113
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• 2004

Most construction project managers should focus on the reasonable cost-down with same quality and function-enhancement with same cost for the value-added construction project delivery in construction industry. Especially, a building structure construction is one of the most important processes to affect the total cost and schedule in building construction project. It means that the process has the possibility of project cost-down or quality-enhancement among the whole project life-cycle. This research focuses on the importance of underground structure of building project by increasing underground use ratio in the urban building construction projects nowadays. This research adopts VE method for the improvement of cost and time by process and analysis dimension modeling on the underground building structure construction, and verifies it throughout the case study, This research is the basic study on the improvement of underground building works through the value engineering method in construction industry.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.280-285
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• 2012

The 1st assessment (performance test) was applied to assure the floor impact sound performance for developing the dry double- floor with the change of rubber hardness of the upper panel's support and the ceiling structure of the sub-floor. Depends on the change of the rubber hardness in substructure, the heavy-weight sound impact value is improved up to 3 dB, and the light-weight sound impact value is moved up to 21 dB, comparing with the bare-slab. Also, the improved value for the floor impact sound conjugating with the sub-floor's ceiling was 5dB. Based on this result, the 2nd assessment (performance test) was made the state that the rubber hardness of the sub-floor support was ranged between 50 and 70 for considering the stability of walking patients. In addition to this process, the assessment was carried out with a variety of ceiling structure applied to the dry doublefloor structure with the air flow system on the sub-floor's ceiling. The result for the 2nd assessment proved that TYPE-11 had the better sound reduction performance in the heavy-weight impact sound test than other types, and also for the light-weight impact sound TYPE-11 had the 29 dB sound reduction performance overall. Henceforth, based on the result the research for the sound reduction performance from the floor impact sound shall be ongoing process as well as the development of a double-dry floor and a sound reduction ceiling to suitable on the field.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.123-128
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• 2007

Already, core wall construction method for apartment wall structure and general building special areas applied the engineering method's appropriate examination. Also, trial and error depending on slip-form method is a good examination opportunity to consider. In the present paper's slip-form engineering method l)Casting concrete to slab in sliding 2)RC structure + SRC structure (part of segment) 3)Inside segment variation(straight line-diagonal-circle) are together while determining whether it is possible not to carry out actual construction work on the structure. Finally, small problems continuously appear on actual slip-form method application, design and engineering, starting with planning thoroughly the field examination and diagnosing the atmosphere, minimizing cost, secure work safety facilities characterized by good quality, slip-form research extension, development and decision-making.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.5
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• pp.305-311
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• 2019

In this study, we examined the proper spacing between the expansion joints according to the temperature load of the inter-modal terminal platform infrastructure to implement a new inter-modal automated freight transport system, which we intend to introduce in Korea. To review the proper expansion joint spacing of the terminal platforms, we set the maximum expansion joint spacing according to the regional temperature changes using the equation proposed by the Federal Construction Council (FCC) of the United States. Then, the maximum displacement value, which was calculated through the structural analysis program, and the limit of the horizontal displacement of the building structure were compared. The proper expansion joint spacing was selected as the slab length at which the maximum displacement of the structure, due to temperature changes, was below the horizontal displacement limit. Based on the application of maximum expansion joint spacing for each region calculated through the FCC's suggestion, the maximum displacement that could occur within the limit of the lateral displacement of the structure was determined.

• Journal of the Korean Society for Railway
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• v.13 no.2
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• pp.186-193
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• 2010

Track system and periodic live load are characteristics of railway bridges. In the design and construction of railway bridge, periodic live load increases the importance of dynamic behavior. And It is well known that behavior of railway bridge may be affected by track system in real bridge. Through experimental study, static and dynamic behaviors were investigated. Deflection and stress due to bending moment were measured, the location of neutral axis of each section, natural frequency, damping ratio were analyzed for each three track systems - girder only, installed ballast track system and installed concrete slab track system. According to measured values for the each type of track system, concrete track system increases the stiffness of bridge by 50%, and ballast system does by 7%, dynamic responses of structure change linearly with the magnitude of load and location of neutral axis of each sections varies with each track system. Damping ratio is almost equal without and with track. Therefore, the effects of track system on the integral behaviors of railway bridge can not be ignored in the design of bridge, especially in the case of concrete slab track system. So study of the quantitative analysis method for effects of track system must be performed.

• International Journal of Highway Engineering
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• v.5 no.4 s.18
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• pp.1-11
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• 2003

Recently, the new pavement design method considering Korean environment and the specification for improving performance of pavement are being developed in Korea. The Jointed Concrete Pavement Program Applying Load Discretization Algorithm (called HEART-JCP) is one of the results of Korea Pavement Research Project in Korea. HEART-JCP program is developed to analyze various loading condition using the load discretization algorithm without mesh refinement. In addition, it can be modified easily into multi-purpose concrete pavement nidyses program because of the modularized structure characteristic of HEART-JCP. The program consists of basic program part and load discretization part. In basic program part, the displacement and stress are computed in the concrete slab, sub-layer, and dowel bar, which are modeled with plate/shell element, spring element and beam element. In load discretization program part, load discretization algorithm that was used for the continuum solid element is modified to analyze the model with plate and shell element. The program can analyze the distributed load, concentrated load, thermal load and body load using load discretization algorithm. From the result of verification and sensitivity study, it was known that the loading position, the magnitude of load, and the thickness of slab were the major factors of concrete pavement behavior as expected. Since the result of the model developed is similar to the results of Westergaard solution and ILLISLAB, the program can be used to estimate the behavior of jointed concrete pavement reasonably.