• Proceeding of Spring/Autumn Annual Conference of KHA
• /
• 2002.11a
• /
• pp.295-300
• /
• 2002

Since the contents of large-scale repair of a condominium were various, a plan document was not prepared. The owners association of the condominium has given priority to decision-making of price priority over quality. Examination is not performed about the contents of the construction supervision business, which checks whether suitable construction is performed, either. On the other hand, the know-how for builders, such as decision of the process plan under which the repair work lessens influence to the safety and life as much as possible since the place where the resident is living turns into a construction site, and selection of a method of construction, is just going to ask. It is an important subject how the structure of the construction contractor selection, which considered quality, is built. Then, this research focuses on large-scale repair construction of the condominium, and arranges the actual condition of a series of processes from plan document creation to construction supervision. The method of research collects the construction documents of the condominium that carried out Barge-scale repair construction. Next, collection arrangement of the data of construction builder selection is carried out. The method of the construction builder selection of those other than a construction price is examined. The method of quality control of large-scale repair construction is examined.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2005.11a
• /
• pp.587-590
• /
• 2005

This study investigates the efficient construction scheme of the immersed tunnel focusing on the hydration heat. In this respect, some alternatives in curing, temperature condition and removing of the forms are compared together to meet the required criteria. It is addressed that the strict construction stage analysis considering the placing scheme of concrete is one of the key factors to trace the realistic structural behavior for the hydration heat.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2003.11a
• /
• pp.289-292
• /
• 2003

CFRD face slab concrete has a much capability to occur crack due to drying shrinkage and vibrator compaction etc. Because crack of concrete induces structural problem and decrease durability of concrete, it is need to reduce crack of concrete. In the experimental study it was analyzed that the effect of curing of concrete and compaction on CFRD face slab concrete. As a results, it was found that control of construction condition into curing of concrete and compaction improved on construction efficiency of face slab concrete.

• Journal of the Korea Safety Management & Science
• /
• v.2 no.1
• /
• pp.1-17
• /
• 2000

Many Safety training up to now has been done at site varying with their condition without any standardization or fundamental work related technique. In order to prevent any accidents from construction site, now as we all know, we have to approach on it with work based method. The authors have investigated a couple of construction site for collecting the ideas from site Engineers of this. Some of ideas analyzed with the above related data have been shown as conclusions.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2019.05a
• /
• pp.244-245
• /
• 2019

Recently, a variety of window cleaning devices have been developed. There are, however, few cases of anticipated problems and countermeasures that may arise after these devices are installed. Therefore, in this study, the emergency condition was derived and the emergency scenario was derived for the rail-mounted cleaning device. Emergency scenarios and countermeasures derived from this study will be used for continuous improvement and supplementation of cleaning devices through prototyping and testing.

• Journal of the Korean Society of Safety
• /
• v.20 no.4 s.72
• /
• pp.71-77
• /
• 2005

There are insufficient models that find problems and solutions for accident prevention through risk assessment and suggest safe work process and work instruction from foundation works to finish work for accident decrease. This paper presents a quantitative risk assessment model by analysis of risk factors in each process such as foundation, erection, structure, equipment finish and etc based on accident examples and investigation on actual condition in building. In addition, the safety management system was developed to perform risk assessment of construction and use it for effective safety training for labor.

• International conference on construction engineering and project management
• /
• 2015.10a
• /
• pp.109-110
• /
• 2015

This paper presents a computational method that identifies an exact set of optimal overlap rates between critical activities to meet job site specific needs by using rework cost-slope. The procedures to compute the exact solution are provided in peudocode algorithm. The method is coded into Exact Concurrent Construction Scheduling system that allows practitioners to make more informed decision in accordance with the site-specific condition involved in the overlapping of critical activities. Test cases verify the validity of the computational method and the usability of the system.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2000.11a
• /
• pp.561-568
• /
• 2000

본 연구의 목적은 Piezocone 관입시험을 이용한 연약지반의 OCR 평가에 있어 기존의 여러 가지 해석방법들과 최근에 새롭게 제안된 방법들을 실내 모형토조에서 실측된 피에조콘 관입 실험치에 적용하여 각 해석방법들의 차이와 장단점들을 비교 분석하는데 있다. 본 연구의 연구실험방법으로는, Piezocone 관입을 위한 연약 모형지반 조성을 위하여 초대형 Slurry Consolidometer에 Free Stress 상태의 Slurry를 45일간 압밀시킨후 Automatic Computer Control Calibration Chamber (LSU/CALCHAS; Louisiana Slate University Calibration Chamber System)에 옮긴후 다시한번 압밀시키는 Two-Stage Consolidation Method를 사용하였다. 모형지반은 여러 가지 Boundary Condition들과 Stress Condition 그리고 Stress History등을 달리하여 총 5개의 지반을 조성하였다. 관입시험은 총 25개의 Piezocone 관입이 수행되어졌고, 그중 4개는 Standard 10 cm2 Piezocone이고, 나머지 21개는 Miniature Piezocone이 사용되었다. Piezocone 실험치들에 대한 여러 가지 OCR 해석방법 적용결과, Schmertmann방법은 5개 모형지반 모두에서 과다한 OCR평가를 보였으며, $B_{q}$ 방법은 일부모형지반에서 음의 OCR값으로 계산되어졌다. 그러나, Critical-Stale Soil Mechanics 와 Cavity Expansion 이론에 근거하여 Mayne(1991), Kurup(1993), Tumay et al (1995) 들이 제안한 OCR 평가방법들은 실험치와 잘맞는 경향을 보여주었다. 이와같은 이론 모델값들의 차이는 응력조건(Stress Condition)과 경계조건(Boundary Condition)들에 대한 각 해석방법들의 고려정도에 따른 결과로 판단된다.

• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.1752-1759
• /
• 2007

In the new Seoul-Busan high speed railroad construction specially city center passage roadbed establishment is recommended the staibility for the existing subway tunnel segments of Busan subway line No. 1 and No.2. regarding the appearance condition, a quality condition and the durability of the objective facility site exact inspection, and it evaluates the numerical analysis which uses MIDAS GTS it leads and there is the objective of the place where the stability of the objective facility and this tunnel it investigates. To immediacy of the on-the-spot inspection result whole facility it is a condition where the reinforcement which is simple not to be hindrance is necessary, 2nd Line case it is a condition which transfer is good but the general defect and the damage which occur from the tunnel of NATM type were confirmed part. While roadbed establishment constructing that the continuous maintenance is necessary, it is judged. The result of 1st, 2nd Line maximum sinkage, unequal sinkage and the lining stress of numerical analysis are within permission and the damage degree is appearing with the fact that the degree it will can disregard it is slight. But it enforces necessary Pre-grouting in order to minimize an actual tunnel face conduct and when the tunnel is excavated it is judged with the fact that necessary to minimize the outflow possibility.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2008.11a
• /
• pp.349-352
• /
• 2008

Weather condition is the uncontrolled factor to influence the project duration. Determining non-working days due to it incorrectly leads to often change the project duration and increase the total cost as well as causing the dispute among stakeholders. When making decision of non-working days, it is important to consider the expert's experience according to the characteristic of the site and local area. Therefore this paper presented the method to estimate non-working days due to wether condition by using fuzzy numbers reflecting expert's subjective experience.