• Journal of Construction Engineering and Project Management
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• 제2권4호
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• pp.25-31
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• 2012

The growing rate of delays is adversely affecting the timely delivery of construction projects. This study therefore assesses construction stakeholders' perception of the causes of delays and its effects on project delivery in a bid to proffer solution in minimizing the occurrences of delays. Questionnaire was used to elicit responses from construction stakeholders; a total of thirty three causes of delays, seventeen resultant effects of delays and fifteen methods of minimizing construction delays were identified for the study based on literature reviews. The results suggest that client's cash flow related problems are the main causes of delays while time and cost overruns are the major identifiable effects of delays in construction projects. However, adequate project planning and budgeting were suggested as possible ways of minimizing the occurrences of delays.

• Structural Engineering and Mechanics
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• 제45권4호
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• pp.455-470
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• 2013

RC flat plates that have no flexural stiffness by boundary beams may be governed by a serviceability as well as a strength condition. A construction sequence and its impact on the distributions of construction loads among slabs tied by shores are decisive factors influencing immediate and long term performances of flat plate. Over-loading and tensile cracking in early-aged slabs significantly increase the deflection of a flat plate system under construction. A reshoring work may be helpful in reducing slab deflections by controlling the vertical distributions of construction loads in a multi-shored flat plate system. In this study, a change of construction loads by reshoring works and its effects on deflections of flat plate systems under construction are analyzed. The slab construction loads with various reshoring schemes are defined by a simplified method, and the practical calculation of slab deflections with considering construction sequences and concrete cracking effects is applied. From parametric studies, the reshoring works are verified to reduce construction loads and slab deflections.

• The Korean Journal of Ecology
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• 제21권3호
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• pp.251-255
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• 1998

To elucidate the effects of a hydroelectric dam construction on annual ring growth of Pinus densiflora, the annual ring widths of 68 trees collected from 7 sites were closely examined. The result was analyzed to ask three special questions first, whether there are real effects of dam construction on the radial growth second, would the magnitude of the effect be different due to two periods of under-construction and post-construction the last, would it be different among age classes. Annual ring growth has been significantly enhanced by the dam construction. Specially, its effect was marked after the construction was finished and the reservoir was filled up with water. There was, however, no remarkable evidence that pine growth would be reduced while the dam was under construction, even though there was a minor decreasing trend. The magnitude of the effect was different among age groups. That is, the changed condition after the construction enhanced relatively the growth of aged trees monre. According to other meterological research since the dam was constructed, the reasons of enhancing pine growth assumed to be the increase of daily temperature, the decreased of daily temperature difference and the increased of rainy days.

• Journal of Construction Engineering and Project Management
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• 제7권1호
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• pp.13-25
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• 2017

Construction projects have been observed to have problems of project delays and disruptions and the South African construction industry is not an exception. This research identified causes and effects of project delay and disruption through a desktop study. Subsequently, a questionnaire was designed and used to conduct a survey to obtain the views of the three main construction project participants - clients, consultants, and contractors. The questionnaire contains 48 causes and 13 effects of project delay and disruption identified from the desktop study. This research identified sixteen most important causes of project delay and disruption and five most important effects of delay and disruption. Sixteen most important causes were: (1) strikes, (2) rework due to errors during construction, (3) shortage of materials in market, (4) suspension of work by the client, (5) poor communication between the parties, (6) ineffective planning and scheduling of project, (7) delays in issuing working drawings, (8) mistakes and discrepancies in design documents, (9) shortage of labours and equipment, (10) delay in decision making process by the client, (11) unforeseen ground conditions, (12) unclear and inadequate details in drawing, (13) inadequate contractor's experience, (14) delay in approving changes in the scope of works, (15) delay in material delivery and (16) unacceptable quality of materials. The five major effects include: (1) create stress on contractors, (2) cost overrun, (3) time overrun, (4) poor quality of work due to rush, and (5) disputes. Furthermore, the result of this research was compared with the result of previous studies conducted in other regions of Africa in terms of causes and effects of project delay and disruption. The research concludes that numerous causes and effects of delay and disruption are limited to South African construction projects based on the comparison. The causes limited to South African construction projects include: (1) strikes, (2) suspension of work by the client (3) mistakes and discrepancies in design documents (4) delay in approving changes in the scope of works and (5) unacceptable quality of materials, while the two major effects limited to South African construction projects includes: (1) create stress on contractors and (2) poor quality of work. In conclusion, some recommendations were made in order to minimise the causes of delay and disruption identified.

• 한국구조물진단유지관리공학회 논문집
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• 제5권3호
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• pp.213-223
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• 2001

This paper presents an analytical procedure for the time-dependent analysis of the multi-story prestressed concrete structure under the construction stage. To account for the actual structural behavior, the procedure considers the effects due to the construction interval and the time-dependent losses of prestress at every construction step on the entire structural response. A numerical study is performed to demonstrate the general validity of the approach and to quantitatively evaluate the effects resulted from the time-dependent behaviors during construction. Recommendations and conclusions are developed by comparisons with structural responses using the present and conventional methods of analysis. The comparative results show that both effects of sequential construction and time-dependent prestress losses should be considered for the construction stage analysis.

• 한국도로학회논문집
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• 제19권5호
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• pp.153-162
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• 2017

PURPOSES : This study was conducted to analyze the effects arising from extending the duration of nighttime road construction on improving road quality and durability. METHODS : Most previous studies estimating the social cost of various construction conditions did not consider road pavement cooling time as a factor in improving road pavement quality. This study investigated the feasibility of achieving higher road quality and durability by extending the duration of nighttime road construction time extension. For this investigation, the effects of such an extension on traffic conditions were analyzed based on micro-simulation studies and scenario-based cost-benefit analyses, using factors including traffic volume, delay, construction cost, and road pavement cooling time. RESULTS : The results of the traffic simulation studies and cost-benefit analyses indicate that the current road construction method that emphasizes completing nighttime road construction by 6 a.m. reduces pavement life while causing relatively little traffic delay. If the night construction time is instead extended to 2 p.m., road pavement lifetime is increased, reducing road re-construction cost. These savings are greater than the cost of congestion arising from extending the duration of nighttime construction. CONCLUSIONS : The current nighttime construction durations need to be extended in order to efficiently manage roads and reduce road management costs.

• 한국건설관리학회논문집
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• 제12권1호
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• pp.115-124
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• 2011

우리나라는 1989년 기술개발자의 개발의욕을 고취시킴으로써 국내 건설기술의 발전을 도모하고, 국가경쟁력 등을 제고하기 위하여 건설신기술 지정제도를 도입하였다. 국내 건설신기술제도가 1989년 최초 도입되어 2009년 12월 31일까지 총 596건의 건설기술이 신기술로 지정되어 건설현장에 총 3만여회 이상 활용되는 등 양적 성과를 거두었고, 국내 건설산업에 직 간접적인 영향을 미치고 있으나, 건설신기술제도의 도입 효과에 대한 체계적인 분석은 이루어지지 않고 있다. 이에 건설신기술제도 도입 이후 건설현장에 활용되었던 양적 성과 외에 건설산업에 직 간접적으로 영향을 미친 경제적 파급효과를 정량적으로 분석함으로써 동 제도의 운영에 따른 당위성을 확보하고 우수성을 검증하여 동 제도가 향후 지속적으로 발전할 수 있는 기틀을 마련할 필요가 있다. 본 연구는 건설신기술 사용으로 인한 공사비절감액, 공사비절감으로 인한 타 산업 비용절감효과, 취업유발효과, 부가가치 유발효과, 수입대체효과 등 건설신기술의 경제적 파급효과를 정량적으로 분석하였다. 이러한 연구결과는 건설신기술의 경제성과 우수성을 널리 홍보하고, 활용촉진을 도모하는데 활용할 수 있을 것이다.

• 한국건설관리학회논문집
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• 제14권5호
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• pp.103-112
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• 2013

1990년대 이후 국가경제에서 미치는 영향이 감소 추세에 들어선 건설업은 호황과 불황을 넘나들고 있다. 건설업의 경기변동이 심할수록 경기예측은 어려워지며, 불확실한 예측의 피해는 기업과 건설 종사자들이 직접적으로 받게 되므로 건설경기를 예측하는 것은 매우 어려우면서 중요한 일이다. 본 연구에서는 건설경기를 나타내는 지표 중 하나인 건설업생산지수를 GDP와 기온효과를 이용하여 실질소득과 야외활동이 많은 건설업의 특성에 따라 기온효과를 반영한 공급측면에서의 단기 건설 경기예측 모형을 제시하였다. 분석결과, 건설경기는 뚜렷한 기온효과가 있으며 GDP에도 큰 영향을 받는 것으로 나타났다. 이와 같은 과정을 통해 입증된 건설경기 예측모델을 기반으로 GDP예상증가율 3.5%와 2.4%일 때, 두 가지 시나리오로 2013년도 건설업생산지수를 예측하였다. 본 연구결과는 건설업의 경기를 판단하는 지표 중 하나로 활용 가능할 것이며, 향후 기후변화가 건설업에 미치는 영향에 대한 연구의 초석이 될 것이다.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.409-416
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• 2005

This paper presents the possible effects and restrictions that may arise in the field of industrial construction due to compliance with relevant construction codes and regulations, as well as the ways they can be favorably handled in the design of industrial buildings. Designs should be based primarily on human design factors, while considering the human as the centre of the work environment. Design parameters should be described as a function of both the physical and psychosocial attributes of a person as well as the technical and economical aspects on the design of industrial construction. This paper is an examination of the connection that exists between design law (codes and regulations) and industrial construction. The relevant construction laws and regulations are described, including standards and codes of practice that designing and supervising engineers are obliged to observe. Possible solutions and consequences of development in the production, constructional, and ergonomic field of design are also discussed.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 가을 학술논문 발표대회
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• pp.119-120
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• 2022

As the seriousness of the climate crisis is emphasized, movements to solve it are becoming active. In Korea, efforts to reduce environmental impacts across all industries are being strengthened through the Framework Act on Low Carbon Green Growth. The construction industry predicts the environmental impact of buildings during the entire life cycle, but in the construction process, there is a difference in energy usage depending on the amount of input, and it is difficult to predict the environmental impact if data cannot be collected. Therefore, this study evaluated the environmental impact of energy usage in the apartment construction process as part of the study on predicting and reducing the environmental impact of the construction process of the construction site. To this end, the environmental effects of buildings were set as global warming, resource consumption, and ozone layer effects, and the environmental effects of the actual energy use in the case were evaluated. In addition, based on the evaluation results, the characteristics of the input energy usage were compared and analyzed.