• Structural Engineering and Mechanics
• /
• v.77 no.1
• /
• pp.89-102
• /
• 2021

Rapid construction of prefabricated bridges requires minimizing the field work of precast members and ensuring structural stability and constructability. In this study, we conducted experimental and analytical investigations of transverse joints of prefabricated T-girder bridge superstructures to verify the flexural performance and serviceability. In addition, we conducted parametric studies to identify the joint parameters. The results showed that both the segmented and continuous specimens satisfied the ultimate flexural strength criterion, and the segmented specimen exhibited unified behavior, with the flexural strength corresponding to that of the continuous specimen. The segmented specimens exhibited elastic behavior under service load conditions, and the maximum crack width satisfied the acceptance criteria. The reliability of the finite element model of the joint was verified, and parametric analysis of the convexity of the joint section and the compressive strength of the filler concrete showed that the minimum deflection and crack width occurred at a specific angle. As the strength of the filler concrete increased, the deflection and crack width decreased. However, we confirmed that the reduction in the crack width was hardly observed above a specific strength. Therefore, a design suitable for prefabricated bridges and accelerated construction can be achieved by improving the joint specifications based on the required criteria.

• Journal of the Korean Geotechnical Society
• /
• v.31 no.5
• /
• pp.23-33
• /
• 2015

In the present study, a ground heat exchanger was installed for each heat source in the system at the site to evaluate ground heat conductivity, constructability, and economic feasibility; the factors considered in the study included ground heat, groundwater, fillers (such as bentonite and pea pebbles) and the shape of the heat exchange pipe (e.g., U and D-U). The aim was to determine the ground heat exchanger appropriate for the geothermal system in the 3rd-phase construction of Incheon International Airport. A comparative cost analysis of the initial costs based on the above information showed that although the initial costs of the regular vertical closed loop-II and modified vertical closed loop were lower than those of the regular vertical closed loop-I, they could not be expected to deliver high economic efficiency from the viewpoint of constructability (filler injection, heat exchange pipe insertion). The initial costs proved to be higher in the case of Geohil.

• Korean Journal of Construction Engineering and Management
• /
• v.14 no.4
• /
• pp.84-96
• /
• 2013

Recently, architectural design has been changing from formal design to freeform design due to the digitalization of construction industry. Especially, the formal design has been accepted as a design trend recently and applied many times as a design concept in the architectural design competitions such as turn-key. However, various deflects such as water leak and cracks have been occurred because the traditional construction methods had been applied without any revision or adaptation of the formal construction method for the freeform building construction. Design and construction of freeform building has been developed as an new method in order to solve the problems and minimize the construction duration and cost for the freeform building. Therefore this research deduced the positive implications for developing freefrom envelope by analyzing the domestic and abroad cases and proposed the considerations during design and construction of the freeform envelope as follows. First, the freeform design should consider the constructability for the freeform envelope. Second, manufacturing technology for the two-way curvature of the unit panel should be developed. Third, exposed concrete form method should be developed for the freeform envelope of concrete. Forth, material characteristics, construction method and facility management should be considered in order to manage precipitation and keep water-proof according to the classification of the freeform envelope area.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.31 no.6A
• /
• pp.417-424
• /
• 2011

This study focused on development of 60 m span PSC girder considering not only structural performance, but also economical efficiency and constructability including from the improvement of cross-section to the tendon profiles in sequence. Bulb-T type cross section was derived from optimization and actual possibilities to design a bridge were assessed through cross section evaluation. Tendons were also arranged efficiently so that the girder could resist the service load effectively. After developed girder was applied to a sample bridge, result of finite element analysis proved all load steps were satisfied with the allowable stress. Furthermore, it seemed that sufficient redundancy will be available to design a bridge safely. Based on these, a full-scale 60 m span girder was fabricated and 4 point bending test was performed. An initial crack occurred over twice of the service load in this experiment, which establishes adequate structural performance. 60 m span Half-Decked PSC girder developed in this study has a lower height for the given span which resulted from cross section improvement and efficient tendon layout. This girder also has not only the structural advantage, but also advantages in economical efficiency and constructability.

• 한국신재생에너지학회:학술대회논문집
• /
• 2010.11a
• /
• pp.59.2-59.2
• /
• 2010

Throughout history, daylight has been a primary source of lighting in buildings, supplemented originally with burned fuels and more recently with electrical energy. Before daylight was supplemented or replaced with electric light in the late 19th-century, consideration of good daylight strategies was essential. As we entered the mid-20th-century, electric light supplanted daylight in buildings in many cases. Fortunately, during the last quarter of the 20th-century and early years of this century, architects and designers have recognized the importance and value of introducing natural light into buildings. There are many simple strategies that can enhance daylighting and reduce the need for electric lights. Good quality daylight is always welcome, but remember that the electric lights must be dimmed or shut off in order for daylighting to save energy. We designed and built mirror systems and vertical daylighting devices to improve daylight condition of office buildings in bad condition because urban density is getting higher. This case study aims to analysis the principles and characteristics of mirror systems and vertical daylighting devices and selected the method that can improve constructability. The results of this study are going to use the back data to set-up the design standards. Hereafter we're going to progress the performance test and product the design manual to improve applicability of daylighting systems at design phase.

• Journal of the Korean housing association
• /
• v.13 no.5
• /
• pp.89-99
• /
• 2002

The multifamily housing has various advantages in construction cost, land-use intensity. KRIHS(1997) recommended the proper scale of th multifamily housing as 800 households in constructability, 1,000 households in facility compactability, 500 households in social aspect. At the early planning stage of project, the size of the multiftmily housing has, until now, been maximizingly considered under the regulation on which has been emphasized at the building volume ratio, land area, etc., except for the expenditure during the maintenance stage. This paper aimed at providing the proper size of multifamily housing in aspect of area and household number with maintenance cost at the early stage of project. For these, it took 곧 average cost function which is made from the 3-rd quardratic form and analyzes the unit increasing rate of the average cost. It surveyed in nationwide focused on the central heating system using diesel and kerosene. The number of samples is 88 and items of management cost is 11. The results are as follows ; first, 3rd-order quadratic function is proper at explaining the cost variation, considering the multicollinearity and statistics. Second, the proper size of multifamily housing is recommended with 83,000 $m^2$ on management area, 820 or over the 2,630 household number in aspect of total management cost.

• Journal of KIBIM
• /
• v.3 no.3
• /
• pp.29-38
• /
• 2013

Domestic construction industry is larger in size, and its shape is more complex. As a result, collaboration and information management tasks are difficult to manage in a way that conventional 2D-based exchange of information. BIM technology was introduced as a solution for this. But BIM only provides a very limited set of features such as Constructability review, clash detection in reality. and duplication of work and a lot of iterations occurs in BIM process. Thus, it takes quite a lot time to work. We studied how to improve the work efficiency by connecting API to business processes. Using the API in the integration process by automating repetitive tasks, reduce a significant amount of work time Using API (Automation, Optimization, Interoperability, Analysis) can solve the task problem that does not solved by the basic features, If we make good use of the combined API will be improved productivity.

• Journal of the Korean Institute of Rural Architecture
• /
• v.16 no.2
• /
• pp.1-8
• /
• 2014

In the past, Korea was classified as a region not affected by earthquakes. However, recent increase of earthquakes has forced to strengthen standards of earthquake resistant designs of structures to minimize seismic damage. In addition, it was thought that masonry infill walls in buildings are only acting as partitions, so these walls are not considered in analyzing building structures. But it was found that when seismic loads are applied to a structure with masonry infill walls, the walls affect the structure. Accordingly, this study conducted nonlinear static analyses for a structure constructed before applying earthquake resistant designs in two cases: when considering masonry walls and when not. The result showed that the seismic performance of the structure is insufficient. Thus, the structural resistance of the structure was also studied in two cases: when reinforcing with steel plate braces and when using carbon fiber braces. In the two cases reinforcing two different stiffeners, it was appeared that the behaviors of the structure were similar, though the cross-section area of a carbon fiber brace used to reinforcing the structure is only 12.6% of a steel plate brace, and its weight is only 2.8%. Thus, the reinforcing effect of the thin, light-weighted carbon fiber brace is much larger than that of the steel plate brace, when considering usability and constructability of both materials.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2009.03a
• /
• pp.30-37
• /
• 2009

In doing the foundation work in the downtown, the popular complaints by means of Noise and vibration have been became heavy burden. Therefore, the noise & vibration-free screw PHC pile method will contribute to the foundation work by removal of the popular complaints and improvement of the constructability. In this paper, the load bearing capacity and displacement characteristics of the noise & vibration-free screw PHC pile were analyzed. The noise & vibration-free screw PHC pile's behavior was better well than the existing PHC pile's one.

• Journal of the Korea Institute of Building Construction
• /
• v.11 no.4
• /
• pp.407-418
• /
• 2011

Recently energy management measures at the political level, for the purpose of reducing energy consumption in the building sector, are being actively introduced. As a practical method, the exterior insulation method, which is proven to effective in reducing the energy loss through walls, has been favored. In this study, detailed implementations are suggested to activate exterior insulation system which can improve the housing insulation performance. The newly designed Gang-form system with hanging scaffolding was suggested to revamp constructability for finishing outer wall. The research results are based on a multifaceted analysis of the current problems of exterior insulation systems, and on recommendations proposed by exterior insulation experts in the Charrette discussion. The study has indicates that the customized TACT schedule considering the site condition has shortened the construction period to 5 months from 7.5 months. Through utilizing the suggestions of this study, the prevalence of exterior insulation systems is expected to become widespread.