• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05a
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• pp.101-104
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• 2010

Development and practical emerging construction technologies has been studied as one of key solution for overcoming these barriers. Many literatures indicated that effective performance evaluation methodologies are demanding for efficient applications of new technologies. This paper presents a performance evaluation methodology using construction simulation technique and introduces studies of two cases where the steel staircase system, as an new technologies was applied and where the conventional method of staircase concrete works. Productivity was measured and calculated by site observation and construction simulations. This results show the quantified influence of new technology to site personnels and assist them to make various decisions for using or not using the technology depending on their own situations.

• Journal of the Korea Institute of Building Construction
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• v.12 no.6
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• pp.636-647
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• 2012

Construction projects have become so large, complicated and incredibly high-tech that process management is currently considered one of the most important issues. Unlike typical manufacturing industries, most major construction activities are performed in the open air and thus are exposed to various environmental factors. Many studies have been conducted with the goal of establishing efficient techniques and tools for overcoming these limitations. Productivity analysis and prediction, one of the related research subjects, must be considered when evaluating approaches to reducing construction duration and costs. The aim of this research is to present a quantified impact analysis of construction delay factors on construction productivity of a steel staircase system, which has been widely applied to high rise building construction. It is also expected to improve the process by managing the factors, ultimately achieving an improvement in construction productivity. To achieve the research objectives, this paper analyzed different delay factors affecting construction duration by means of multiple regression analysis focusing on steel staircase systems, which have critical effects on the preceding and subsequent processes in structure construction. Statistical analysis on the multiple linear regression model indicated that the environment, labor and material delay factors were statistically significant, with 0.293, 0.491, and 0.203 as the respective quantified impacts on productivity.

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

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.8
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• pp.751-757
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• 2016

The aim of this study is to estimate the reliability of fatigue limit of the material used for crank throw components according to the staircase method. The material used for crank throw components is forged S34MnV grade steel, which is heat treated by normalizing and tempering. In this work, to predict the reliability of the design fatigue strength, axially loaded constant amplitude fatigue testing was conducted. The test specimens were loaded with an axial push/pull load with a mean stress of 0 MPa, which corresponds to a stress ratio of R=-1. The fatigue test results were evaluated by Dixon-Mood formulas. The values of mean fatigue strength and standard deviation predicted by the staircase method were 296.3 MPa and 10.6 MPa, respectively. Finally, the reliability of the fatigue limit in some selected probability of failure is predicted. The proposed method can be applied for the determination of fatigue strength for design optimization of the forged steel.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.11
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• pp.2421-2428
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• 2002

In this study, the failure probability of the degraded LP turbine blade steel was performed using the Monte Carlo simulation to apply variation of applied stress and strength. For this purpose, applied stress under the service condition of steady state was obtained by theoretical stress analysis and the maximum Von-Mises stress was 219MPa. The fatigue strength under rotating-bending load was evaluated by the staircase method. Furthermore, 3-parameter Weibull distribution was found to be most appropriate among assumed distributions when the probabilistic distributions of tensile and fatigue strength were determined by the proposed analysis. The failure probability with various loading conditions was derived from the strength-stress interference model and the characteristic factor of safety was also estimated.

• International Journal of High-Rise Buildings
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• v.7 no.4
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• pp.397-408
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• 2018

In a recent tragic fire incident, the Plasco Tower collapsed after an intense outburst of fire lasting for three and a half hours and claiming the lives of 16 firefighters and 6 civilians. This paper will present continuing collaborative work between Hong Kong Polytechnic University and Queen's University in Canada to model the progressive collapse of the tower. The fire started at the 10th floor and was observed to have travelled along the floor horizontally and through the staircase and windows vertically. Plasco Tower was steel structure and all the steel sections were fabricated by welding standard European channel or angle profiles and no fire protection was applied. Four internal columns carried the loads transferred by the primary beams, and box columns were constructed along the perimeter of the building as a braced tube for resisting seismic loading. OpenSees fibre-based sections and displacement-based beam-column elements are used to model the frames, while shell elements are used for the reinforced concrete floor slabs. The thermal properties and elevated temperature mechanical properties are as recommended in the Eurocodes. The results in this preliminarily analysis are based on rough estimations of the structure's configuration. The ongoing work looks at modeling the Plasco Tower based on the most accurate findings from reviewing many photographs and collected data.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 1994.10a
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• pp.31-38
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• 1994

The purpose of paper is to suggest directions of sustainable Architecture for dwelling planning. It deals with foreign example regading recycling Architecture in the point of using natural reources and energy effectively and minimizing environmental wastes. The methods which can be applied to Korean dwelling planning are as follows : 1) To use the underground space of apartments as pubilc energy-saving facility 2) To use conservatory passive solar systems at south-facing balconies of apartments 3) To flow daylight into the staircase of single-family house 4) To construct compactly doors and windows which have high-level insulation with high insulated walls and ventilation systems 5) To recycle materials such as steel, wood and soil 6) To recycle space according to the change of uses 7) To make users participate actively when we plan for dwelling.

• Journal of the Korean housing association
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• v.6 no.2
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• pp.77-86
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• 1995

The purpose of paper is to suggest directions of sustainable Architecture for dwelling planning. It deals with foreign examples regarding recycling Architecture in the point of using natural resources and enerty effectively and minimizing environmental wastes. The methods which can be applied to Korean dwelling planning are as follows : 1) To use the underground space of apartments as public energy-saving facility 2) To use conservatory passive solar systems at south-facing balconies of apartments 3) To flow daylight into the staircase fo single-family house 4) To construct compactly doors and windows which have high-level insulation with high insulated walls and ventilation systems 5) To recycle materials such as steel. wood and soil 6) To recycle space according to the change of uses 7) To make users participate actively when we plan for dwelling.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.191-192
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• 2011

The construction projects contain a lot of variables and risk affecting productivity. The duration of the project must be recognized important as for quality, unit cost and safety. There is need for improving work efficiency by investigating relationship of works to prevent delay. This study focuses on analysing the delay factors of steel staircase system to suggest regression model that enables construction productivity estimation. The position of the observers and construction delay factors were expressed by the independent variable of the regression model and productivity was expressed by a dependent variable. This paper suggests quantitative productivity and it is expected that will be helpful estimating application in construction new technologies.

• Journal of Korean Society of Steel Construction
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• v.27 no.2
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• pp.181-193
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• 2015

High-frequency staircases are widely used nowadays to meet aesthetics and functionality needed in modern architecture. Unfortunately, no design guide is available in domestic practice to predict response or evaluate the vibration performance of high-frequency staircases. SCI-P354 published by the Steel Construction Institute of UK provides the formula for effective impulsive force. However, this formula was shown to overestimate the response of high-frequency staircases excited by fast ascending and descending over 2.2Hz pace frequency because it was developed based on the walking test in a slow pace frequency. This study proposes a semi-analytical formula to predict the response of stiff staircases based on analytical and experimental studies of response acceleration for various walking frequencies covering 1.4~4.5Hz.