• Journal of the Korean Professional Engineers Association
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• v.34 no.1
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• pp.53-58
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• 2001

Value Engineering (VE) is an organized process with an impressive history of improving value and quality. VE can be applied to the construction projects with having good study results. The VE study in construction projects gives identification of opportunities to remove unnecessary costs while assuring quality, performance, reliability, and other factors will meet or exceed the clients needs. VE techniques can save money, reduce time, and improve quality, reliability, maintainability, and performance. VE can also make improving of human factors (altitudes, creativity), and team work. According to the results of VE study in recent USA, 5∼35% reduction in initial costs have been made for the construction projects (ROI ranges : 100∼1000). To have successful work results, if possible, VE study shall be considered at project planning stage or basic design stage later than field work stage with application of VE JOB PLAN, multi-disciplinary approach, and proper techniques in respective study phases (pre-workshop / information gathering / function analysis / creativity / judgement and evaluation / development / presentation and implementation) among the detail techniques in many.

• Korean Journal of Construction Engineering and Management
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• v.14 no.1
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• pp.71-81
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• 2013

Recently, Korean Traditional House is being reconsidered as a alternative and eco-friendly residential housing. With these flows, government and industry actively studies the modernization and industrialization of Korean Traditional House. Apply for BIM as a way of modernization and industrialization of Korean Traditional House, research has been actively conducted. Korean Traditional House is building that is assembled by individual Component Therefore it is very useful for modernization of the Korean Traditional House to design Korean Traditional House With BIM. Which is the management technology that produces and distributes information of the architecture. But compared with the effect, the use of BIM is sluggish in the construction. Therefore, In this study after surveying about lowly using BIM on point of AEC(Architect-Engineer-Contract), the result is analyzed with AHP(Analytic Hierarchy Process). So the aim of this study is to offer the base to find the solution of the Affecting factors about lowly using BIM.

• Korean Journal of Construction Engineering and Management
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• v.13 no.2
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• pp.110-119
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• 2012

The Plan and equipment of vertical lifting are very important in high-rise building construction site, and unmanned lifts usage is increasing for financial and efficient reason. However if lift stop position error occur, It can be accumulated. And the lift can not be available during an engineer fix the problem. So loss of time and cost will occur when lifts have problems. This paper reports an improved lift stop position sensing device for preventing loss of time and cost from lift stop position error. The result of tests showed that the system has a correction function of lift stop position error, and the accuracy of device which was developed in this paper was about 9.75mm better than existing equipment.

• Advances in concrete construction
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• v.2 no.4
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• pp.249-259
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• 2014

Mortar is a masonry product which is matrix of concrete. It consists of binder and fine aggregate and moreover, it is an essential associate in any reinforced structural construction. The strength of mortar is a special concern to the engineer because mortar is responsible to give protection in the outer part of the structure as well as at a brick joint in masonry wall system. The purpose of this research is to investigate the compressive strength and tensile strength of mortar, which are important mechanical properties, by replacing the cement and sand by stone dust. Moreover, to minimize the increasing demand of cement and sand, checking of appropriateness of stone dust as a construction material is necessary to ensure both solid waste minimization and recovery by exchanging stone dust with cement and sand. Stone dust passing by No. 200 sieve, is used as cement replacing material and retained by No. 100 sieve is used for sand replacement. Sand was replaced by stone dust of 15%, 20%, 25%, 30%, 35%, 40%, 45% and 50% by weight of sand while cement was replaced by stone dust of 3%, 5%, and 7% by weight of cement. Test result indicates that, compressive strength of specimen mix with 35% of sand replacing stone dust and 3% of cement replacing stone dust increases 21.33% and 22.76% respectively than the normal mortar specimen at 7 and 28 days while for tensile it increases up to 13.47%. At the end, optimum dose was selected and crack analysis as well as discussion also included.

• Journal of the Korean Professional Engineers Association
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• v.16 no.3
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• pp.5-23
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• 1983

On the Seoul Metropolitan Subway Construction of No. 3, 4 Line, the total length is 57 Km and it is now undergoing almost 55％ progress. The working method is classified into Open Cut of 70% and the rest of 30% tunnelling method in the 48 job site. Above tunnelling method is execute by American Steel Support System and the rest of 10 job site carried out by New Austria Tunnelling Method. This paper describes Blasting Standardizations works on the above Tunnelling ' Open Cut Method under big slogan, first safety, second execution. As a superintendent, I strived standardization of works with Better powder, Better Drills ' Better Pattern. Geological structure of Seoul area is composed by Jurassic Granite and also the above rockgroup are over burden by Alluviums as a Unconformity. First of all, I carried out the standard amount of powder and burden through experimental standard blasting by each powder as following Blasting works in the subway construction is surrounding shop Building, under pass the city river and also under pass highest building basement floor. I made allowable Blasting Vibration Value by West-Germany Vornorm DIN 4150, Teil 3 and should measure each blasting works as fellows all of powder is used basically Low-Gravity and Low Velocity such as Slurry, Ammonium Nitrate ' Finex I, II. for Smooth Blasting Instead of Gelatin Dynamite. Electric Detonation Cap is used basically M/S Delay Cup instead of Electric delay ' Simultaneous cap. I applied following formula V=KW3/4 $D^{-2}$ V=Particle Velocity (Cm/sec) K=Ginh Huh's Value W=Delay Charge (Kg) D=Distance(m) In the Open Cut, within 1m distance from H-pile I made to use the Concrete breaker, as following V=7W/$^{0.5}$V/$^{-1.75}$ On the Concentrate Building area, I advise to use Light class drill ø36m Bit and advance 1.1m per round blasting the three boom jumbo drill over ø45mm used only suburb of city.e Light class drill ø36m Bit and advance 1.1m per round blasting the three boom jumbo drill over ø45mm used only suburb of city.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.6
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• pp.811-823
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• 2019

Slip form method is applied to many cases of a shaft these days because it is safer, more economical and faster than cast-in-place method. Slip-up height of the method is approximately 2.5 to 4.0 m/day. If the temperature of concrete is outside the range of 10 to 30℃, the effects of changes in strength or elastic characteristics are significant. Therefore, it is difficult for slip-up speed to be higher than 3 m/day during winter construction. In addition, concrete has heat caused by hydration, which causes temperature cracking of hardened concrete. Therefore, temperature control of concrete curing is necessary for the continuous slip-up of slip form. In this study, the rebound hardness, time of ultrasonic waves propagation, heat of hydration, and external temperature are measured by developing heating panels and test devices for the continuous slip-up. Based on this, heating slip form is manufactured; this was applied to "Kimpo sites" and "Sinwol sites". The compared slip-up speed samples were 1.9 m/day or 0.200 m/hr on average at Gimpo sites (08:00~17:30) and 2.0 m/day or 0.210 m/hr at Sinwol sites.

• Korean Journal of Construction Engineering and Management
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• v.19 no.6
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• pp.103-114
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• 2018

Public-Private-Partnership(PPP) is becoming a popular form of projects in construction industry worldwide. Normally, the management team of PPP project consists of various experts from different disciplines such as construction engineer, bank financier, contract manager, investors, etc. The diversity of team members causes difficulties in managing the team efficiently and furthermore for the smooth execution of the project itself. One of the solutions to this issue might be the application of citizenship behavior by the team members. This study conducts an empirical investigation of the effect of project citizenship behavior on the project performance. We have collected data by using a questionnaire from those with PPP project experiences in the domestic construction industry. The results show that project citizenship behavior has full mediating effects between PM's leadership and the project performance. This study has an academic significance in that it is the first attempt to apply the concept and to show the effect of citizenship behavior in project management discipline, particularly in construction industry, in Korea. We also expect that the project management teams for PPP projects would benefit from the findings of this study.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.5
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• pp.1147-1156
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• 2015

The result of responsibility supervision system which has been enforced for the last twenty (20) years since January, 1994 is evaluated, and keeps an eye out the process of unification and absorption of the system into the construction management (CM). As a baseline data for this study, the grade framework of construction engineer's ICEC introduced with CM is summarized. In this manuscript, the questionaire survey for CM and ICEC was conducted toward the target group of road field construction engineers and analyzed the outcome of the respondents' answers. 50% of the respondents have answered positively for the question about converting responsibility supervision to CM. 48% of the respondents from construction works field have answered positively for converting responsibility supervision system to CM while 38% of the respondents from engineers of supervision field have answered positively, less positive than the answers from works field engineers. 46% of overall respondents have answered, however, to maintain the present system of 40%, 40% and 20% on the survey to the question asking the opinion on the ways of calculating ICEC to use the rates : 40% of career, 40% of qualification and 20% of academic achievements. However, it appeared that engineers who have comparative advantages with academic achievements and career, and engineers with lower grade qualification demanded higher rate for career.

• Korean Journal of Construction Engineering and Management
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• v.17 no.1
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• pp.119-127
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• 2016

Since May 23, 2014, the Construction Technology Promotion Act has been effect through the entire reform of the Act. Despite the extensive reform, the previous penalty articles remain intact. According to the article 85 (1), especially, if a service provider or an engineer has caused death or injury by violating the duty of good faith and by damaging the principal parts of facilities, the person should be sentenced for lifetime imprisonment or imprisonment for no less than three years. The article has been controversial in its clarity and adequacy. This study is to verify the characteristics and the scope of the article and to suggest the theoretical backgrounds by analyzing the article based on the principle of legality, which enables to set forth the possibility to improve the article. To achieve the goal, the provision has been analyzed in accordance with the basic laws in Korea including the constitutional law and the criminal law, the related cases have been collected, and the comparison of the relevant acts has been executed. The detailed discussion about the articles in laws and acts on construction and the long-term and integrated study are expected to vitalize through this research.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.35-41
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• 2002

This research introduces the development of a project-level cash flow forecasting model in construction stage based on the planned earned value and the cost from a general contractors view on a jobsite. Most previous models have been developed to assist contractors in their pre-tendering or planning stage cash flow forecasts. The critical key to cash flow forecasting at the project level is how to build a cash-out model. The basic concept is to use moving weights of cost categories in a budget over project duration. The cost categories are classified to compile resources with almost the same time lags that are based on contracting payment conditions and credit times given by suppliers or venders. For cash-in, net planned monthly-earned values are simply transferred to the cash-in forecast, to be applied there with billing time and retention money. Validation of the model involves applying data from on-going 4 projects in progress for 12 months. Based on the results of the comparative analyses through the simulation of the proposed model and the existing models, the proposed model is more accurate, flexible and simpler than traditional models to the employee of construction jobsite who is not oriented financial knowledge.