• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.3-44
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• 1999

This paper discusses the lateral behavior of single and group piles in homogeneous and non-homogeneous(two layered) soil. In the single pile, the model tests were conducted to investigate the effects on ratio of lower layer height to embedded pile length, ratio of soil modules of upper layer to lower layer, boundary rendition of pile head and tip, embedded pile length, pile construction condition, ground condition with saturate and moisture state in Nak-Dong river sand. Also, in the group pile, the model tests were to investigate the effects on spacing-to-diameter ratio of pile, pile array, ratio of pile spacing, boundary condition of pile head and tip, eccentric load and ground condition. The maximum bending moment and deflection induced in active piles were found to be highly dependent on the relative density, pile construction condition, boundary condition of pile head and tip. Based on the results obtained, it was found that the decrease of lateral bearing capacity in saturated sand was in the range of 31% - 53% as compared with the case of dry sand. Also, in the group pile, a spacing-to-diameter of 6.0 seems to be large enough to eliminate the group effect for the case of relative density of 61.8%, and 32.8%, and then each pile in such a case behaves essentially the same as a single pile. In this study, the program is developed by using the modified Chang method which used p - y method and the exact solution of governing equation of pile and it can be used to calculate the deflection, bending moment and soil reaction with FDM in non-homogeneous soil. In comparing the modified Chang method with field test results, the predict results shows better agreement with measured results in field tests.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.1
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• pp.175-183
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• 2014

This study investigates the response of structures to tunnelling-induced ground movements in clay ground, varying tunnel excavation condition (tunnel depth and diameter), tunnel construction condition (ground loss), and tunnel ground condition (soft clay and stiff clay). Four-story block-bearing structures have been used because the structures can easily be characterized of the extent of damages with crack size and distribution. Numerical parametric studies have been used to investigate of the response of structures to varying tunnelling conditions. Numerical analysis has been conducted using Discrete Element Method (DEM) to have real cracks when the shear and tensile stress exceed the maximum shear and tensile strength. The results of structure responses from various parametric studies have been integrated to consider tunnel excavation condition, tunnel construction condition, and tunnel ground condition and provide a relationship chart among them. Using the chart, the response of structures to tunnelling can easily be evaluated in practice in clay ground.

• Journal of the Korea Institute of Building Construction
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• v.18 no.5
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• pp.463-469
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• 2018

A currently used roof green system with multi layers has a low constructability. Therefore a new integrated waterproof & root barrier sheet and roof green box unit system was developed using steel plate fixture and cone type fixture by electromagnetic induction heating method. This study was proceeded to evaluate adhesion performance of two types of fixtures on Engineering PE, TPO, PVC sheet in a normal condition, repeated heating and cooling condition. As a result, adhesion load on Engineering PE sheet showed the highest value. The adhesion loads of steel plate fixture showed higher value as heating temperature was getting higher. However adhesion loads of cone type fixture showed opposite tendency. Regarding to the test conditions, test results of normal condition, repeated heating and cooling condition showed same value. The cone type fixture using butyl tape showed 7 times lower adhesion load than that of cone type fixture using electromagnetic heating and 28% lower adhesion load in a repeated heating and cooling condition than a usual condition.

• Journal of the Korea Institute of Building Construction
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• v.8 no.2
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• pp.121-129
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• 2008

Domestic exoteric construction market by opening of world construction market with recent FTA of rapidly change. On these time, need quality increase of construction to possess government official and international competitiveness of customer satisfaction by offering consumer building of good quality. Therefore, must establish direction to inspects and must advance forward formation government official's present actual conditions for building company's QI. This study is as following if summarize studying result of formation government official to improve quality in construction spot. First, formation's CEO will for QI need side improvement the formation government official enemy by important thing. Second, at checking activity and systematic action that participate of responsible persons cooperation enterprise space-time by complete charge department organization should be achieved. Third, complete charge department for quality control operation large size construction firm substantially formation Organizational well operate, but heavy hydrogen building company was construed by greatly unprepared misgovernment. AHP analysis result complete charge department is serious necessity, and the CEO under direct control organizational structure was construed by thing which can bring excellent effect in operation management side of quality business side and formation. Therefore, heavy hydrogen building company should does to occupy competitive power high position with tissue at active quality complete charge deputy.

• Land and Housing Review
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• v.9 no.1
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• pp.1-9
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• 2018

As the government announced Real Estate Policies on August 02, most areas except for Seoul cities face increasing business risks. Moreover, the government control over financial sectors' loan leads to the highly possible contraction of new distribution markets. The market trend could bring about the reduction of new demand in PF (Private Financing) business that large construction companies mainly concentrate on, and even the business already obtained has a high risk of being distributed, which could result in substantially low profitability. The currently unstable financial structure of most construction companies is caused by the hike of the prime cost of foreign plants except for that of a few construction companies. If PF (Private Financing) business also faces a difficult situation in such a financial condition, even large construction companies come to have the high possibility of a deficiency in credit rating. Accordingly, the major business that large construction companies concentrate on needs the sufficient business review. It is desirable to make a bid for business guaranteeing stability rather than business solely in consideration of profitability, when participating in a competition for a new construction contract.

• Journal of the Korea Safety Management & Science
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• v.16 no.3
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• pp.9-22
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• 2014

Constructions sites are affected by Diversity workplace, complexity of construction, Change of place, Mobility of workers and so on. In a single establishment, Prime contractors and subcontractors have to conduct their work at the same time. There are a lot of unpredictable risks when the construction is running, coordination between contractors is very important to do a risk assessment under the condition. Large Construction companies were investigated by previous studies. Survey research is applied to the risk assessment. In the writing, Risk assessment of the entire lower level. Because of the low level of risk factors to find. Also, There was a limit to investigate accidents. Confirmed that Effort to derive a risk factors were desperately of the risk assessment. Results were obtained through previous studies. The PCM is several experts should be joined. Experts Site Manager, Supervisor, Safety Manager, Director Contractor, Work team leader is required to participate. Construction plans, Process Planning to the risk find beforehand. And Determines how the operations and the control. Also, Made it into the database. and PCRA can be used in the risk assessment was developed.

• Korean Journal of Construction Engineering and Management
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• v.5 no.2 s.18
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• pp.123-135
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• 2004

Construction accident have been increasing in despite of safety management activities and education in construction site. This study surveyed safety organization, education, safety management, scheduling, safety checklist with construction firms in order to grasp the actual condition. A improved method is suggested that safety checklist is supplemented with various safety materials and then stored as database. Furthermore, safety checklists are connected and operated with schedule in ender to more efficiently prevent construction accidents.

• Korean Journal of Construction Engineering and Management
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• v.16 no.1
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• pp.64-73
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• 2015

The theft of construction equipments and materials at construction sites is one of the risk factors that may affect to the productivity as well as the progress of the project. However, managers of the construction site have paid little attention to the security measure, therefore the theft loss at construction sites has been occurred repeatedly every year. In this study the situation analysis has been carried out for the present condition of theft loss of construction equipments and materials as well as its prevention measure based on the questionnaire survey targeting field managers, experienced theft loss at the site, as a part of base study to set up a security measure of construction sites. The main content of this study is analyzing characteristics of theft loss and the degree of impact and risk by it at construction sites, then reviewing the direction of the prevention plan establishment for the future through the analysis of the importance and utilization level of prevention measures. The result of this study would give an opportunity to create an awareness against the theft loss at construction sites as well as can be utilized as a basic survey for the systematic development of concerned prevention measures.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2005.04a
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• pp.167-174
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• 2005

Through time-dependent analyses of RC bridges constructed by a movable scaffolding system (MSS) considering the construction sequence and creep deformation of concrete, structural responses related to the member forces are reviewed. On the basis of the compatibility condition and equilibrium equation at every construction stage, basic equations that can describe the moment variation with time in movable scaffolding construction are derived. By using the introduced relations, the design moment and its variation over time can easily be obtained with only the elastic analysis results and without additional time-dependent analyses considering the construction sequences. In addition, the design moments determined by the introduced equations are compared with the results from a rigorous numerical analysis with the objective of establishing the relative efficiencies of the introduced equations.

• Journal of Industrial Technology
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• v.25 no.B
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• pp.99-106
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• 2005

The planning phase of construction project success or failure of the enterprise decision the 1st dangerous duration which occurs very there is a possibility of making with the phase which is important, of construction project in life cycle most many risk. But the risk management from planning phase well does not become accomplished is the actual condition from existing construction project. Consequently, it classifies the risk event from project initial planning phase of construction project from this study which probably is substantial risk event the possibility of accomplishing from a planning phase successfully in order to be.