• International Journal of High-Rise Buildings
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• v.6 no.1
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• pp.83-89
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• 2017

Due to the time-dependent properties of materials, structures, and loads, accurate time-dependent effects analysis and precise construction controls are very significant for rational analysis and design and saving project cost. Elevation control is an important part of the time-dependent construction control in supertall structures. Since supertall structures have numerous floors, heavy loads, long construction times, demanding processes, and are typically located in the soft coastal soil areas, both the time-dependent features of superstructure and settlement are very obvious. By using the time-dependent coupling effect analysis method, this paper compares Shanghai Tower's vertical deformation calculation and elevation control scheme, considering foundation differential settlement. The results show that the foundation differential settlement cannot be ignored in vertical deformation calculations and elevation control for supertall structures. The impact of foundation differential settlement for elevation compensation and pre-adjustment length can be divided into direct and indirect effects. Meanwhile, in the engineering practice of elevation control for supertall structures, it is recommended to adopt the multi-level elevation control method with relative elevation control and design elevation control, without considering the overall settlement in the construction process.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.278-288
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• 2020

Modular Integrated Construction (MiC) has gained quite momentum as it provides solutions for several problems in the construction sector, particularly in Hong Kong. MiC is converting the building into modules and erecting them easily on site providing various benefits, such as cost and time savings, better quality, lower risk, higher sustainability, less injuries and accidents, etc. The MiC is considered the best alternative to traditional construction approaches in solving the huge housing demand problem in many cities all over the world due to the time-saving privilege. The utilization of MiC is facing a lot of challenges, which are considered obstacles to the wide acceptance of this technique in the construction industry in Hong Kong. This, in turn, has led the interests of the research community to investigate its benefits and challenges aiming at addressing several solutions to harness the benefits of this technique and to tackle these challenges. The present research aims to review the main concept of MiC and to determine the benefits and the challenges of implementing MiC in construction industry. The findings of this research highlight the advantages and limitations of incorporating MiC technique in Hong Kong, which will help the stakeholders to effectively utilize this technique in the construction industry.

• Journal of the Korea Safety Management & Science
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• v.4 no.2
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• pp.23-32
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• 2002

The small-and-medium sized construction sites are in weak state of safety management because of the variable working environments, the lack of safety techniques and the weak economic conditions, and industrial accidents of these sites were occupied 60％ of the total construction accidents. Recently, the safety engineer's number are not to be enough at the small-and-medium sized construction sites. Therefore, the safety engineer's works are addition to more and more. This paper is a development of the integrated program which using composition of construction safety management expenses. It is an management tool which helps to saving time of construction safety engineer. A method of development composition, to used Brain Storming for a place of meeting to construction safety management counselors.

• International conference on construction engineering and project management
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• 2017.10a
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• pp.263-270
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• 2017

The precast concrete (PC) structure has been preferred for reasons of shortening the construction time and securing the quality and, in particular, it has a cost saving effect in case of long span and heavy loaded structure with high floor height. Most engineers take it for granted to install the plant produced PC members. Researchers in several papers have argued that slander PC members such as columns and girders can be cost-effective if in-situ production is possible, while ensuring quality equal to or better than in-plant production. However, this argument is not officially accepted because objective verification has not been done. Therefore, the purpose of this study is to experimentally conduct in-situ production of PC members to verify the above claim. For this study, a storage building with long span and heavy loaded structure with high floor height was selected as a case study site. For the site, most of the PC members were supplied from the plant, and some of the columns were produced in the site for this study. As a result, it has been confirmed that it has a cost saving effect of 20% while having superior quality to plant-produced PC columns.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.503-507
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• 2015

Sustainability continues to gain traction in all industry sectors as people become aware of the advantages of green products. The voluntary use of green products in buildings in the United States continues to grow due to long-term cost saving and the ecological benefit to nature. The voluntary installation of green products is associated with end-users' expectations and perceptions including cost saving, sustainable behavior, and social responsibility. Although involuntary use of green products has similar expectations and perceptions, the installation decision is not based on the goodwill from end-users. This paper surveys college students to capture current experience levels, expectations, and perceptions in regard to green products and/or sustainability and to understand their attitudes about involuntary use of a green product. The installation of low water pressure showerheads in a dormitory provides data to support perception, expectation, and future direction of adoption of green products in public buildings. This information may be used to facilitate sustainable behaviors among involuntary groups regarding to the adoption of green products. The primary objective of this paper is to investigate the college students' perception of a green product, particularly when the students are involuntarily exposed to the green products. As a secondary objective, the paper also attempts to address the college students' general understanding on sustainability and green products. The findings of this study could support the growing importance of sustainable behavior among higher education beyond social responsibility and provide a benchmark against which to improve future change while fostering sustainable behaviors over time among the public.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.4
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• pp.404-407
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• 2008

Because of directly receiving the thing in which a microwave is reflected and comparing the frequency, the microwave sensor with doppler effect completely overcomes the problem of the passive infrared sensor. The microwave sensor with doppler effect well operates about a temperature, the dust, and the peripheral noise because of being dull in the most of ambient conditions. The system developed in this research is the electricity saving detection sensor which it senses the real time action of a man as the microwave sensor and automatically turns on the electric lamp and turns off, minimizes the electrical energy consumption. Since the microwave sensor is not influenced in the light, the dust, and the natural element like the ambient temperature, the effectiveness is considered to be superior to the passive infrared sensor being used currently. There was the energy reduction effect more than about 60% in the performed example which established this system. When this was compared with the construction cost, the cost of establishing payback period was about 1-1.5 year. The microwave sensor with doppler effect developed from this research result is convinced in the future to do enough for the electric energy saving.

• Structural Engineering and Mechanics
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• v.17 no.2
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• pp.245-266
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• 2004

Incremental launching method is one of the highly competitive techniques for construction of concrete bridges. It avoids costly and time consuming form work and centralizes all construction activities in a small casting yard, thus saving in cost and time against conventional bridge construction. From the quality point of view, it eliminates the uncertainty of monolithic behaviour by allowing high repetitiveness and industrial environment. But, from analysis and design point of view, the most characteristic aspect of incrementally launched bridges is that, it has to absorb the stresses associated with the temporary supports that are gradually taken on by the deck during its launch. So, it is necessary to analyse the structure for each step of launching which is a tedious and time consuming process. Effect of support settlements or temperature variation makes the problem more complex. By using transfer matrix method, this problem can be handled efficiently with minimal computational effort. This paper gives insight into method of analysis, formulation for optimization of the structural system, effect of support settlement and temperature gradient, during construction, on the stress state of incrementally launched bridges.

• Korean Journal of Construction Engineering and Management
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• v.12 no.2
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• pp.12-20
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• 2011

Recently, construction site scale has been growing larger along with the growth of national economy. As construction market requires time reduction, cost saving, and improving quality, a cutting-edge technology applied research has been gradually studied for more efficient project management. In particular, the Real Time Location System (RTLS) technology, a real-time location tracking system of construction resources, can be effectively used in safety management. This technology has been studied and applied in various industries including architectural, marine, urban, and other industries. However, although tunnel construction in civil engineering has a narrow space and many safety risks, there are not researched about this content. Therefore, this study proposes an advanced safety management model for tunnel construction using the RTLS technology and a measurement method of the feasibility of this model in the construction site.

• Journal of the Korea Institute of Building Construction
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• v.12 no.4
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• pp.401-414
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• 2012

The adoption of Green Frame is expected to provide economic benefits, since construction costs are reduced by the in-situ production of precast concrete column and beam. The cost reduction can ultimately be realized by saving transportation costs and the overhead and profit of PC plants. The cost structure of Green Frame, which is built up using composite precast concrete members, is similar to that of a bearing-wall structure, but the difference in construction process has resulted in some cost differences for a few items. In particular, production and installation is the principal work involved in Green Frame made by precast concrete members, while form and concrete work is the principal work for a bearing-wall structure. As such, the rental time and fee for a tower crane should be compared through time analysis. To verify reliability, this study focused on developed residential projects to estimate the construction costs. Through this analysis, it was found that the costs of Green Frame were 1.57% lower than the costs of bearing-wall structure. The results of this study will help in the development of a management plan for the structural work of Green Frame.

• Journal of the Korea Institute of Building Construction
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• v.8 no.1
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• pp.49-56
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• 2008

According to the recent trends which are the diversity of customer requests and the multi-function of buildings, A construction company's business has converted from the producer-oriented approach to the consumer-oriented approach. Therefore, each construction company is continuously trying to improve the quality level as a way of corresponding to customer needs in these changing situations. The quality is one of the main management targets which judge the success of a project along with the schedule, the cost and the safety. As construction companies execute the quality management which they aimed at, it should be completed within the optimum schedule and the limit of the budget. Accordingly, the importance of the construction site management to complete a project is continuously increasing. The construction site management is the systematic method to perform the project goals such as the quality improvement, the cost saving and the safety management, which organically operate one another, by procuring the manpower, the material and the machine in the right time. Specially, as the construction industry has based on the construction site, the establish of systematic construction site management, which can effectively correspond sudden changes of the construction business environment, is essential to maximize the construction productivity. On top of that, the necessity of the quality management method is increasing to accommodate customer needs more spontaneously in the construction site. These endeavors could guarantee their competitive power.