• Korean Journal of Construction Engineering and Management
• /
• v.21 no.4
• /
• pp.21-29
• /
• 2020

This study analyzed problems of operating performance bond for public works and derived some suggestions for improvement. The Contract Law for Government Owner requires to submit performance bond which guarantees performing the construction contractor pays back compensation money when the obligation is not executed. Currently, first bid eligibility for participation is exactly required for executing company of performance bond obligation, not considering volume, technical level, and special type of remaining works. In collaboration contract, if guarantee accident occurs, it is obliged for remaining collaboration contractors to be qualified to fulfill the whole contract. This study proposes following improvement plan to solve problems of current performance bone in public works. Firstly, qualification criteria must be deregulated exceptionally for selecting proper contractor, which executing performance bond obligation, considering progress and characteristics of remaining works. Secondly, In collaboration contract, the prerequisite of remaining contractors' should be deregulated as 'implementation requirement of the remaining works'from'implementation requirement of the whole work'. Finally, defect responsibility should be included in liabilities of performance bond by specifying that owner or guarantee agency bear them.

• 월간 기계설비
• /
• no.12 s.221
• /
• pp.62-64
• /
• 2008

현장에서는 주공정과 예산관리를 중심으로 공사진행을 하고, 공정이 90% 이상 달성되었거나 또는 잔여공기가 9개윌 정도 남아 있으면 모든 공정을 재검토하기 바란다. 우선 하청시로부터 잔여 공사에 대한 공정표를 받아, 잔여공시 1개월 전에 준공될 수 있는지 검토한다. 9개월 정도 앞서 준공기일을 검토하는 것은, 자재납기가 장기간(7개월 정도) 소요되는(플랜트 Control Panel 등) 자재의 발주여부를 검토하고, 잔여공기 내에 정상 작업으로 공기 내 준공이 불가하다고 예측될 경우, 3개월 또는 6개월 돌관작업 계획을 세우기 위함이다. 잔여공기가 3개월 정도 남아 있을 때, 시설물을 인계(Hand Over) 하기 위해 본격적인 준비를 한다. 준공이란 "계약적으로 발주자가 실제적으로 계약서에 의도된 목적으로 사용할 수 있는 상태(표준계악일반조건 48. 1)"를 말하므로, 이 점에 착안하여 발주자가 시설물을 제때에 사용하지 못함으로써 발생되는 지체보상금(Liquidated Damage)을 물지 않도록 작전을 세운다.

• Korean Journal of Construction Engineering and Management
• /
• v.3 no.1 s.9
• /
• pp.107-114
• /
• 2002

Recently, a few major construction companies in Korea have a growing interests to the risk management system, and they are trying to apply it to their construction projects. However, the existing methodologies to be applied to the foreign public projects are not proper to the construction environments due to its adaptabilities, that has one time process and heavily depends on personal judgement. The purpose of this paper is to propose a risk response process in consideration of the residual risks, which would be more adaptable and practical in the construction environment, overcoming the current obstacles to be mentioned above. This process has systematic repeat process until the residual risks go down to the risk thresholds based on the efficiency of specific response strategy.

• Proceedings of the Korean Society of Disaster Information Conference
• /
• 2023.11a
• /
• pp.93-94
• /
• 2023

해체공사는 작업의 특성상 단기간에 이루어지며, 해체공사 현장에 투입되는 근로자는 일용직 근로자가 대부분으로 안전사고의 비율이 높다. 사업장 위험성 평가에 관한 지침에는 위험성 평가시 근로자를 참여토록 하고 있으나 해체현장의 특성상 근로자가 참여한다고 하여도 위험요소를 파악할 역량이 부족할 따름이다. 또한 기존의 해체공사 안전관리 매뉴얼은 구조안전성 확보를 위한 매뉴얼로 해체 근로자의 안전을 위한 매뉴얼은 없는 실정으로, 근로자의 안전을 확보하기 위한 위험성 평가 매뉴얼이 요구되고 있다. 이에 본 연구에서는 건설공사 안전관리 종합정보망(CSI)의 해체 및 철거공사의 사고사례를 분석하였으며, 해체 및 철거 사고시 발생한 주요 위험요소를 도출하여 작업 공종별로 유해·위험요인의 파악을 손 쉽게 할 수 있도록 하였다. 또한 해체 현장 규모에 따라 대규모 현장은 빈도·강도법, 중·소규모 현장은 체크리스트법을 활용하여 위험성을 결정하고 감소대책을 수립할 수 있도록 매뉴얼을 구성하였다. 잔여 위험에 대해서는 관리카드를 만들어 해체공사 완료시까지 관리하도록 하였다.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.8 no.2
• /
• pp.307-312
• /
• 2013

The compensation system for residual land in our country is largely composed of the three sub-systems, that is, the purchasing compensation, depreciated compensation and construction expenses compensation. Among those, the purchasing compensation system mainly has problems in eligibility for compensation of the land, meanwhile, there is almost no problem in construction expenses compensation system. This study aims to examine the current depreciated compensation system for the residual land and its accompanying problems, and also review and compare those systems in USA and Japan with that of our country, and thereby discover the ways for the alternative solution for the compensation system in the viewpoint of policy.

• Proceedings of the Korean Society for Rock Mechanics Conference
• /
• 2004.10a
• /
• pp.13-22
• /
• 2004

본 연구에서는 도심지 지하철 터널을 대상으로 지반공학적 위험요소가 공사비 및 공기에 미치는 영향을 정량적으로 평가하기 위하여 잔여 리스크 개념을 이용하여 조사개소의 증가에 따른 공사비 및 공기의 신뢰도를 분석하였다. 신뢰도 분석결과, 지반조사 개소가 증가함에 따라 공사비 및 공기에 대한 위험도가 축소됨을 확인하였으며, 이러한 결과를 통하여 도심지 지하철 터널에서의 지반공학적 위험도 분석의 유용성을 확인하였다.

• Korean Journal of Construction Engineering and Management
• /
• v.6 no.6 s.28
• /
• pp.181-192
• /
• 2005

Labor work information can be converted into the useful construction information in an effort to analyze project status, measure performance, and design a new similar project plan. The labor work information can also be used to make productivity data, which can be used to analyze the relationship between 'as planned' and 'as built' in scheduling management of a project, and to calculate 'percent completion' as well as analyzing delay cause. It is require to effectively collect the labor work information base on the activities. In general, current project management heavily depends on the experience and judgment of project managers, according to the work progress. However, relying on the oかy experience and judgment of the project managers might deteriorate the transparency or reliability of the collected labor work information. The purpose of this research is thus to develop a computer-based system for monitoring the work information generated by labors input in activities using PDA and Barcode technologies, and to propose a application method of the productivity data for effective project management.

• Membrane Journal
• /
• v.2 no.1
• /
• pp.67-73
• /
• 1992

The effects of after-treatment condition on the permeability of polysulfone hollow fiber membranes were investigated. It was well known that the permeability of and the rejection of hollow fiber membranes prepared by dry-wet spinning technique was highly affected by spinning conditions such as composition of spinning solution, inner and outer coagulant and spinning height. But these are also governed by after-treatment condition such as drying, hot water treatment and glycerine treatment. Since it was difficult to remove DMAc and NMP in membranes by washing with in cold water and even traces of such solvent affected the reproducibility of the membrane characteristics, the hot water-treatment should be required.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.3A
• /
• pp.341-347
• /
• 2008

Among coating systems used for steel bridge coatings on highway such as red lead-pigmented alkyd, chlorinated rubber, waterborne inorganic zinc, inorganic zinc/epoxy/urethane and inorganic zinc/epoxy/fluororesin, evaluation of deterioration degree and prediction of lifetime through regression analysis were carried out for coating systems widely used and grossly degraded. For evaluation of deterioration degree, 75 bridges on highway were selected, and evaluations were carried out according to point offering method regulated by Guideline of maintenance coating for steel bridges used in Korea Expressway Corporation. Lifetime prediction results showed 13.0~13.3 years for the whole nation, 11.8 years for urban and industrial region in the metropolitan area, 13.2 years for rural region except the metropolitan area, 13.5~13.7 years for chlorinated rubber coating systems, and 12.86 years for red lead-pigmented alkyd systems. For prediction of the rest life of coating, we tried to execute parallel translations of standard deterioration curve to current life and deterioration degree for both x and y axes, and it was thought that parallel translation for x axis corresponded to deterioration aspects in actual environment. Maximum and minimum equations were derived from standard deterioration equation by adding and subtracting error values deduced in regression analysis to/from each coefficient in order to establish maintenance coating criteria for overall steel bridges on highway. Whole domain was divided into 8 parts in order to predict the rest life of coating and optimum time of maintenance coating, and maintenance coating criteria for each 8 domains were presented.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2004.11a
• /
• pp.224-227
• /
• 2004

As a project progresses, it is well known that construction manager has to define the contingency for the expected project cost, which is used as a buffer for uncertainty. In this study, we mention uncertainty as the amount of likelihood that is difficult or impossible to predict project cost. From the completed work package, we obtain the true cost value, and this information is technically good data for estimating the realistic contingency of work packages to be accomplished. Based upon this historical information, construction manager recomputes the contingency for the remaining works. Conditional probability theory is often useful for re-estimating one of the remaining project progress as the true cost of the completed works can be different from the planned cost. As a project is progressing, true value is really important to predict the realistic project budget and to decrease the uncertainty. In this study, we gave applied conditional probability theory to estimating project contingency supposing a project that consists of fire work packages, provide the fundamental framework for setting and controlling project contingency.