• Explosives and Blasting
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• v.34 no.3
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• pp.17-20
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• 2016

This paper introduce a multistage parallel non-vibration electronic tunnel blasting cases which adapts Electronic Blasting System(EBS) and the center-cut blasting method to excavating a single line railway tunnel close to residential area. As a result, it was revealed that the vibration and noise showed a reduction of 23.5% and 75% of compared with the allowable standard. We successfully completed the tunnel excavation with decreasing construction time and construction cost and without civil compliant.

• Magazine of the Korean Society of Agricultural Engineers
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• v.12 no.2
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• pp.1960-1964
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• 1970

Underdrainage has been studied by using PVC suction pipes in the low and wet Paddy field: Fist, three test plot and three control plots were set and drainage methods and Soil tempratures in the test plots have been examined. The experiment was conducted making use of the 'NONG-RIM No, 4'(Wheat) 'DOWON' (rice barley), a recommended variety. Test period was from September, to December, 1969. The experimental methodsand results obtained through this experimontation are as follows: 1) Ground water level in the test plot goes down by 34 cm. 2) In sprouting, control plot is earlier than test plot by three days. 3) The rate of sprouting is equal.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.12
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• pp.7364-7371
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• 2014

Construction post-evaluation (CPE) boosts the efficiency of public construction projects by assessing the performance results of public construction projects and using the results to pursue similar projects. This evaluation comprehensively analyzes and assesses the planning of construction work, the estimated and actual construction costs, the construction period, the demand for construction projects, and the effects of construction projects after the construction work to ensure efficiency. The data was used to prevent lax project execution and enhance the quality and efficiency of similar construction projects. On the other hand, CPE results information must be managed systematically to refer to and use CPE data in similar construction projects. Therefore, in this study, the CPE system was developed as a measure of the systematic and comprehensive management and use of the CPE results information of individual ordering agencies. Therefore, the groundwork was laid for the assurance of quality enhancement and efficient project execution in public construction projects. This system is expected to serve as a useful tool for comprehensively analyzing and assessing construction works.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.653-659
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• 2018

The accurate prediction of construction cost is a key factor in a project's success. However, it is hard to predict the construction costs in the planning stages rapidly and precisely when drawings, specifications, construction cost calculation statements are incomplete, among other factors. Accurate construction-cost prediction in the planning stage of a project is also important for project feasibility studies and successful completion. Therefore, various techniques have been applied to accurately predict construction costs at an early stage when project information is limited. There are many factors that affect the construction cost prediction. This paper presents a construction-cost prediction method as multiple regression model with seven construction factors as independent variables. The method was used to predict the construction cost of a local housing union project, and the error rate was 4.87%. It is not possible to compare the cost of the project at the planning stage of the local housing union project, but it has high prediction accuracy compared to the unit price of an existing unit area. It is likely to be applied in construction-cost calculation work and to contribute to the establishment of the budget for the local housing union project.

• The Journal of Engineering Geology
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• v.19 no.3
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• pp.417-422
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• 2009

Tunnels that have recently been constructed are characterized by longer length than ever before and furthermore they frequently go through the ground area with poor conditions such as fractured zones. If ground strength is weak, plastic deformation of tunnel occurs, and occasionally a big fall may be brought about. Up to now, the construction work of tunneling has been executed as a sequential method placing the lining concrete after completion of excavation. Such a method requires a long time and much money to complete the tunnel. It is hard to ensure the stability of tunnel if tunnel is left undone for a long time after excavation in fracture zones or plastic grounds. For this reason, we tried to take simultaneous construction of tunnel excavation and lining concrete in order to not only shorten construction schedule but also stabilize the tunnel at the highly fractures zone as soon as possible. As preliminary consideration for simultaneous construction, in-situ tests are performed to calculate the isolation distance over which blasting vibration does not influence the strength of lining concrete. Improvement of ling form, placing method of concrete, ventilation using a dust collector, together with equipment arrangement, was made to assure the simultaneous construction work.

• Korean Journal of Construction Engineering and Management
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• v.22 no.1
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• pp.36-46
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• 2021

With an increasing trend toward high-rise modular construction, the simultaneous use of tower cranes at a modular construction site has recently been observed. Tower crane layout planning (TCLP) has a significant effect on cost, duration, safety and productivity of a project. In a modular construction project, particularly, poor decision about the layout of tower cranes is likely to have negative effects like additional employment of cranes and redesign, which will lead to additional costs and possible delays. It is, therefore, crucial to conduct thorough inspection of field conditions, lifting materials, tower crane capacity to make decisions on the layout of tower cranes. However, several challenges exist in planning for a multi-crane construction site in terms of safety and collaboration, which makes planning with experience and intuition complicated. This paper suggests a multi-objective optimization model for selection of the number of tower cranes, their models and locations, which minimizes cost and conflict. The proposed model contributes to the body of knowledge by showing the feasibility of using multi-objective optimization for TCLP decision-making process with consideration of trade-offs between cost and conflict.

• Korean Journal of Construction Engineering and Management
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• v.24 no.1
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• pp.3-11
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• 2023

According to the post evaluation scheme in Korea of a public construction project which is more than 30 Billion KRW, project performance is evaluated by investigating outcomes and effects of the construction after the completion of the project. The current post evaluation results can be used for planning and estimating a construction project in the future. However, it is not easy to utilized for an on-going project because the system does not provide the phase-based performance of a project. Although project planning performance is important for project initiation, few attempt has been made to evaluate planning performance in Korea. The purpose of this study is to provide a conceptual performance evaluation of planning performance using preliminary feasibility study conducted by Korea Development Institute. This study developed a planning performance database using data extracted from preliminary feasibility study reports of the completed 354 road construction projects. This study analyzed the performance of the planning stage of road projects by developing absolute metrics such as standard construction cost and standard construction schedule based on a Lane-Km. Using the standard construction cost and schedule metrics, the planning performance was analyzed by project characteristics. The results of this study can be used for phase-based performance evaluation from planning phase to construction phase.

• Journal of Wetlands Research
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• v.16 no.4
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• pp.371-378
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• 2014

The subject of this study is the Gongchon-cheon which is one of the largest streams in Incheon and is closely related to lives of citizen. Comparative analysis is made on the changes of the environment and the ecological condition of Gongchon-cheon after the stream naturalization construction which is completed in July 2009. From the results of the survey, 32 species in 2004, 22 species in 2009 and 46 species in 2010 have been recorded. The number of the species decreased from 2004 to 2009 due to the disturbance of the river environment, and it increased in a short time from 2009 to 2010 because of the recovery of the environment. It demonstrates the stream naturalization construction providing enough environments (dikes and rapids) for the benthic macro invertebrates. The result of the present study is similar with the river's biology index, ESB index, and KSI index, and also it is similar with the pattern of the appearance, which illustrates that the species decreased during the naturalization construction, and increased after the stabilization since the finish of the naturalization construction, and it has been confirmed that the naturalization construction provides the better environment for the inhabitation of organisms.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.3
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• pp.475-488
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• 2017

Wear prediction of TBM disc cutters is a very important issue for hard rock TBMs as number of cutter head intervention. In this regard, some model such as NTNU, Gehring model, CSM models have been used to predict disc cutter wear and intervention interval. There are some deficiencies in these models. This paper developed a new test method for wear prediction for TBM disc cutter and proposed a new abrasion index. In this regard, different abrasivity indices along with their testing methods are explained. A comparative study is performed to develop the predictability of different cutter life evaluation methods and index. The evaluation of the new methods proposed in this paper shows a very good agreement with the actual cutter life and intervention interval length. The proposed tester and index can be easily used to predict the intervention interval length and cutter wear evaluation in both planning and construction stages of a TBM tunneling project.

• Magazine of the Korean Society of Agricultural Engineers
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• v.34 no.1
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• pp.10-19
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• 1992

서해안 시대를 맞이하여 21세기를 열어나갈 새萬金 千拓綜合開發事業 기공식이 지난해 11월 28일 전북 부안군 변산면 대항리 현장에서 盧泰愚대통령, 曺京植농림수산부장관, 金榮鎭農漁村振興公私社長, 국회농림수산위원회 위원장, 전북도지사, 地域出身國會議員등 내외 귀빈과 지역 주민 2,400여명이 참석한 가운데 열려 사상 최대의 간척사업으로서 첫발을 내딛었다. 이날 盧泰愚대통령은 치사를 통해 "자손만대에 물려줄 웅대한 국토확장의 첫삽을 뜨게 되어 깊은 감회를 느낀다"면서 "만경, 김제의 넓은 벌이 우리나라의 곡창으로 겨레의 삶을 보장해온 터전이었듯이 새만금의 광활한 간척지를 21세기 번영을 기약하는 땅이 되도록 하자"고 당부하였다. 새만금사업의 공사기간은 '91년부터 98년까지 외곽방조제를 완공하고 2004년까지 내부개발을 완료할 예정이고, 총 사업비 1조 3천억원을 투입하게된다. 사업지역은 1도 3군 1시 19읍면동 (전북 옥구군, 부안군, 김제군, 군산시)에 걸쳐서 40,100ha를 개발하게 된다. 주요시설로는 부안군 변산면 대항리에서 可力島, 新侍島, 夜味島, 및 飛鷹島를 연결하는 세계 최장의 방조제 33km를 축조하고 방조제 위에는 4차선 도로를 설치하고 장항선이 군산하구둑을 경유, 이 방조제를 거쳐 고군산군도까지 갈 수 있도록 하는 철도부지도 건설된다. 이와 함께 새만금국제항을 개설, 연간 5,000만톤의 하역능력을 갖게 되고 고군산군도를 잇는 관광휴양지가 형성된다.