• Title/Summary/Keyword: 도로 건설현장

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Developing an Owner's Project Evaluation Framework for Construction Management (프로젝트 관리자로서의 발주자 사업수행평가 프레임워크 개발)

  • Kim, Jonghoon;Lee, Hyun-Soo;Park, Moonseo;Park, Sanghyuk;Lee, Inbeom
    • Korean Journal of Construction Engineering and Management
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    • v.17 no.5
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    • pp.130-137
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    • 2016
  • Owner's participation on a construction project can alter the success of a construction project. In general, success of a construction project is measured by project schedule and cost decrease without considering the role an owner has in a project. As a result, this research developed a framework for the project evaluation form and after extracting a total of 9 project critical success factors (CSF) and 27 sub-CSF. AHP method was utilized to evaluate the importance factor of each CSFs. Setting a goal for each CSFs at the beginning of a project and comparing the values at the completion of the project utilizing the project evaluation form will allow a systematic evaluation and management of a project. Solution Map was introduced and Solution Tool was suggested in order to utlize the evaluation results effectively. In the future studies, various project cases needs to be supplemented for further verification and a solution based on the evaluation result needs to be developed that can be applied to construction projects.

Analysis on Risk Factors of Reactor Containment Building Construction using Analytic Hierarchy Process (계층 분석 방법을 이용한 원자로 격납 건물 시공의 리스크 요인 분석)

  • Shin, Dae-Woong;Shin, Yoonseok;Kim, Gwang-Hee
    • Journal of the Korea Institute of Building Construction
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    • v.15 no.4
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    • pp.425-431
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    • 2015
  • Since the construction of Kori 1 was completed in 1978, the construction projects for nuclear power plant are increasingly expanded into domestic and foreign sites. However, some of construction sites of nuclear power plant have the problems of process delay and cost loss due to lack of ability of risk management. The construction of reactor containment building in nuclear power plant is especially dotted with many risk factors because it needs professional skills and large-scale resources due to long duration compared with different construction phase. Therefore, it needs the study that analyzes risk factors expected in construction of reactor containment building and suggests way of stable performance of projects. So, this study assesses risk factors of construction of reactor containment building. For the objectives, this study uses survey for group of minority specialists of 36 experts. The risks of 24 factors is classified by criterions of process, cost, safety, and quality and the results of assessment is analyzed by analytic hierarchy process. As the results, the importance and priority of risk factors classified by each criterion were calculated and the applicability of analytic hierarchy process was identified to analyze risk factors of nuclear power plant construction. These will be baseline data for risk management in construction phase of reactor containment building.

Efficient Spent Sulfidic Caustic wastewater treatment using Adsorption Photocatalysis System (흡착광산화 시스템을 이용한 효과적인 SSC 페수처리)

  • Kim, Jong Kyu;Lee, Min Hee;Jung, Yong Wook;Joo, Jin Chul
    • Proceedings of the Korea Water Resources Association Conference
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    • 2016.05a
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    • pp.520-520
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    • 2016
  • 석유 화학공장에서 발생하는 spent sulfidic caustic (SSC) 폐수는 액화석유가스(LPG)나 천연가스(NG)의 정제과정에서 발생되는 것으로 고농도의 sulfide와 cresylic, phenolic 그리고 mercaptan 등이 포함된 독성과 냄새를 유발하는 물질이다. 이러한 물질들은 LPG나 NG의 정제과정에서 높은 산도를 가진 휘발성 황화합 물질들을 제거하기 위해 사용된 NaOH가 $H_2S$와 반응하여 발생하는 것이다. 진한 갈색 또는 검은색을 띄는 SSC 폐수는 12 이상의 높은 pH를 가지고 있으며 5~12 wt%의 높은 염분도를 가지고 있다. 또한 강한 부식성과 독성을 가진 황화합물의 농도가 1~4 wt%이며, 방향족 탄화수소 물질 (i.e. methanethiol, benzene, tolune and phenol)들도 다량 함유되어 있다. 따라서 이러한 유해 물질들은 기존의 하수처리 공정으로 방류하기 전에 완벽하게 처리해야만 하수처리 공정의 오염 부하량을 줄일 수 있다. 습식산화공정은 SSC 폐수를 처리하기 위해 흔히 사용되고 있는 물리-화학적 처리 공정이지만 고비용, 고에너지가 필요하며, 고온 및 고압에서만 작동되어 안전상의 문제점을 갖고 있다. 또한 습식산화공정을 거친 폐수는 배출허용기준을 만족하기 위해 생물학적 2차 처리가 반드시 필요하다. 철-과산화수소를 이용하는 펜톤산화 공정, 그리고 sulfide를 sulfate로 전환시키는 생물학적 처리 공정은 황화합물의 완전한 무기물화가 힘들며, 현장 적용 시 기술적 경제적 부담이 크다. 이러한 단점을 극복하고, SSC 폐수를 효과적으로 처리하기 위해 본 연구는, 높은 흡착력과 광산화력을 가진 흡착광산화 반응 시스템(Adsorption Photocatalysis System, APS)을 개발하였다. APS는 SSC 폐수를 시스템 내부로 유입하여 수중의 오염물질을 흡착광산화제로 구성된 반응구조체가 흡착하고, 흡착된 오염물질을 UV에너지와 이산화티타늄 광촉매의 광화학반응에 의해 최종적으로 무해한 물질로 환원시키는 폐수처리시스템이다. APS의 반응구조체는 태양에너지 및 인공에너지원에 의해 활용 가능하며, 난분해성 유기화합물질을 물과 이산화탄소로 분해할 수 있는 친환경적이고 경제적인 소재로서 널리 쓰이고 있는 이산화티타늄 광촉매와 화력발전소의 높은 소성온도에 의해 연소된 후 발생되는 bottom ash를 이산화티타늄의 지지체로 사용하여 높은 흡착력과 광촉매 산화력을 가진 복합물이다. 개발된 APS에 의해 SSC 폐수를 처리한 결과, COD 86.1%, 탁도 98.4%, sulfide 99.9%의 높은 처리효율을 보여주고 있다. 따라서 본 연구를 통해 개발된 APS는 강한 부식성과 독성 그리고 높은 농도를 가지고 있는 SSC 폐수를 효과적으로 처리할 수 있다.

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Evaluation Model for Lateral Flow on Soft Ground Using Commitee and Probabilistic Neural Network Theory (군집신경망과 확률신경망 이론을 이용한 연약지반의 측방유동 평가 모델)

  • Kim, Young-Sang;Joo, No-Ah;Lee, Jeong-Jae
    • Journal of the Korean Geotechnical Society
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    • v.23 no.7
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    • pp.65-76
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    • 2007
  • Recently, there have been many construction projects on soft ground with growth of industry and various construction problems concerning soft soil behavior also have been reported. Especially, foundation piles of abutments and (or) buildings which were constructed on the soft ground have been suffering from a lot of stability problems of inordinary displacement due to lateral flow of soft ground. Although many researches for this phenomena have been carried out, it is still difficult to assess the mechanism of lateral flow on soft ground quantitatively. And reliable design method for judgement of lateral flow occurrence is not established yet. In this study, PNN (probabilistic neural network) and CNN (committee neural network) theories were applied for judgment of lateral flow occurrence based on eat data compiled from Korea and Japan. Predictions of PNN and CNN models for new data which were not used during model development are compared with those predicted by conventional empirical methods. It was found that the developed PNN and CNN models can predict more precise and reliable judgment of lateral flow occurrence than conventional empirical methods.

A Study of Obtaining Reliable Travel Time Information in Downhole Seismic Method (다운홀 기법에서 신뢰성 있는 도달시간 정보 산출 방법에 대한 고찰)

  • Bang, Eun-Seok;Lee, Sei-Hyun;Kim, Jong-Tae;Kim, Dong-Soo
    • Journal of the Korean Geotechnical Society
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    • v.23 no.8
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    • pp.17-33
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    • 2007
  • Downhole seismic method is widely used for obtaining shear wave velocity profile of a site because it is simple and economical. Determining accurate travel time of shear wave is very important to obtain reliable result in downhole seismic method. In this paper, comparison study of various travel time determination methods was performed. Numerical study and model chamber test were performed for effective comparison study. Signal traces were acquired by performing downhole test at each numerical simulation and soil box test. Travel time data for each signal traces were determined by using six different methods and Vs profiles were evaluated. Comparing travel time data and Vs profiles with the reference value, the first arrival picking method proved to be ambiguous and unreliable. Other methods also did not always provide accurate results and the magnitude of error was dependent on the signal to noise ratio. Cross-correlation method proved to be the most adequate method for the field application and it was verified additionally with field data.

Modification of SPT-Uphole Method using Two Component Surface Geophones (2방향 지표면 속도계를 활용한 SPT-업홀 기법 개선 연구)

  • Bang, Eun-Seok;Kim, Jong-Tae;Kim, Dong-Soo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.2C
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    • pp.109-120
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    • 2006
  • SPT-Uphole test is a seismic field test using receivers on ground surface and a SPT (Standard penetration test) source in depth. Even though this method is simple and economic, it makes hesitate to apply in real field that it is difficult to obtain reliable travel time information of shear wave because of the characteristics of SPT impact source. To overcome this shortcoming, in this paper, modified SPT-Uphole method using two component surface geophones was suggested. Numerical analysis was performed using finite element method for understanding the characteristics of surface motion induced by in-depth vertical source, and comparison study of the various methods which determine the travel time information in SPT-Uphole method was performed. In result, it is thought that the most reasonable method is using the first local maximum point of the root mean square value signals of vertical and horizontal component in time domain. Finally, modified SPT-Uphole method using two component surface geophones was performed at the site, and the applicability in field was verified by comparing wave velocity profiles determined by the SPT-Uphole method with the profiles determined by SASW method and SPT-N values.

Case study on frequency bands contributing the single number quantity for heavy-weight impact sound based on assessment method changes (중량충격음 평가방법 변화에 따른 단일수치평가량 기여 주파수 대역 사례 분석)

  • Hye-kyung Shin;Sang Hee Park;Kyoung-woo Kim
    • The Journal of the Acoustical Society of Korea
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    • v.42 no.6
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    • pp.565-571
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    • 2023
  • With the introduction of the post-verification system, the measurement of floor impact noise performance on-site has become mandatory, and the evaluation method has changed. To track the performance changes since the policy implementation, research is needed on how the characteristics of heavyweight impact sound change according to the varied evaluation method. In this study, we analyzed the contribution rate of the frequency band-specific sound pressure level on the single-number quantity for a multi-family housing unit with the same floor plan and floor structure, comprising 59 households, based on the changed impact sources and evaluation indicators. It is difficult to compare simply because the method of calculating contributions by frequency band according to the single-day evaluation is different, but the average contribution rate of 63 Hz was 80.8 % in the evaluation method before the introduction of the post-confirmation system (Tire measurement and evaluated as L'i,Fmax,AW), and the average contribution rate of 125 Hz was 19.2 %. The current evaluation method (rubber ball measurement and evaluation as L'iA,Fmax) shows that the contribution rate has decreased to 33.1 % on average at 50 Hz ~ 80 Hz, 58.7 % on average at 100 Hz ~ 160 Hz, 6.9 % on average at 200 Hz ~ 315 Hz, and 1.3 % on average at 400 Hz ~ 630 Hz. This result is a case analysis for the target apartment house, and it is necessary to analyze measurement data for more diverse apartment houses.

Improvement of Field Installation Method for Asphalt Concrete Pavement Strain Gauge (아스팔트 콘크리트 포장 변형률계 매설 방법 개선에 관한 연구)

  • Lee, Jae-Hoon;Kim, Ji-Won;Kim, Do-Hyung;Lee, Kwang-Ho
    • International Journal of Highway Engineering
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    • v.5 no.3 s.17
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    • pp.31-42
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    • 2003
  • The KHC Test Road project was initiated on 1991 to develop Korean Pavement Design Guide. It was constructed along the Joongbu Inland Expressway line between Yeoju and Gamgok. It is two-lane wide expressway containing fifteen asphalt and twenty-five Portland cement concrete test pavement sections. Various sensors were installed in the Test Road to evaluate the behavior of test pavement sections under the influence of traffic load and environmental change. The most important issues in the sensor installation are the accurate location and long-term survivability. They are directly influenced by the sensor installation methodology. The methodology for asphalt strain gages is mainly discussed in this paper because it is the second important sensors in the KHC Test Road project. In order to find the best methodology, we evaluated existing methodology from prior experience and several conducted test installations. We have tried mound, block out, and trench cuts since 2000. Among three methods, block out was the most effective one in terms of accurate location, long-term survivability, and material homogeneity. However, this method cannot be applied to the wearing coarse so that the mound method was used as an alternative. The block out method was applied to base and intermediate layers while the mound method was used to the wearing coarse. Three hundred seventy-four asphalt strain gauges were installed on asphalt pavement sections from September 3rd to November 18th in 2002. According to the sensor measurement evaluation, 6.3% of sensor demonstrated over ranged readings for mound method installation and 2.5% did for block out method installation. We lost only two sensors during the installation. It is 99.5% survival and it is excellent survival rate according to other experience.

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A Study of Establishment Ratio of Native Tree Transplant (자생수목 이식 성공률에 관한 연구)

  • Lee, Sang-Cheol;Jo, Bu-Yeon;Choi, Song-Hyun
    • Journal of the Korean Institute of Landscape Architecture
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    • v.43 no.2
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    • pp.23-29
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    • 2015
  • To fulfill the need for reuse indigenous tree to mitigate the elimination of nature forests due to road construction, one representative method for this reuse is to transplant them and re-establish in similar conditions. In order to investigate the transplant and establishment of indigenous tree, a correlation and regression analysis was conducted by species and tree size. Data were collected for 6 years(2008~2013) in 7 construction sites in cooperation with the Korea Expressway Corporation. Regarding the transplanted indigenous trees status, the success rate of transplant was 15,519(69%) of 22,521. The tree most transplanted was Pinus densiflora(15,562), followed by Quercus spp.(6,156), Prunus sargentii(235), and P. thunbergii(154). P. densiflora and P. thunbergii belong to the conifer group while Quercus spp., Prunus sargentii belong to the broadleaf group. As a result of a contrast test, the conifer group had a significantly lower success rate of transplant than the broadleaf group. In the relation of root collar diameter and success rate of transplant, there was the tendency that the larger the root collar diameter, the lower the success rate of transplant. This study demonstrated that there is a strong negative correlation between the two factors(r=-0.730, p>0.000). The predicted regression equation of the success rate of transplant was Y= -0.811X+88.627(X: root collar diameter, Y: success rate of transplant) and the $R^2$ value for the linear equation was 0.532.

Pyrite Content using Quantitative X-Ray Diffraction Analysis and Its Application to Prediction of Acid Rock Drainage (정량 X-선회절분석을 이용한 황철석 함량 결정과 산성 암반 배수 발생 평가에의 응용)

  • Chon, Chul-Min;Kim, Jae-Gon;Lee, Gyoo-Ho
    • Journal of the Mineralogical Society of Korea
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    • v.19 no.2 s.48
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    • pp.71-80
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    • 2006
  • We examined the mineralogical composition of pyrite-bearing rocks by quantitative powder X-ray diffraction analysis using the matrix-flushing method and ROCKJOCK (a full pattern fitting computer program). The neutralization potential (NP) and acid generating potential (AP) were calculated on the basis of mineralogical compositions. The mineralogical AP was compared with the conventional AP calculated from bulk sulfur concentration to assess the applicability to the prediction of acid rock drainage(ARD). The pyrite content calculated by matrix-flushing method showed a high positive correlation($r^2$=0.95) with those by ROCKJOCK. The pyrite contents by matrix-flushing method was 1.45 times larger than those by ROCKJOCK. The pyrite content and mineralogical AP obtained by the matrix-flushing method had a better correlation($r^2$=0.98) with those by the total sulfur concentrations in the all samples except KB sample. The mineralogical NPs of YJ sample were 23.0 and 34.0(kg $CaCO_3$ equivalent per tonne) by matrix-flushing method and ROCKJOCK, respectively. The AP calculated by matrix-flushing method and ROCKJOCK program were 47% and 72% of those by the conventional ABA test. We hereby suggested that the quantitative analysis using XRD data can be applied to prediction of ARD. For more reliable calculation of the mineralogical NP and AP, other sulfide and carbonate minerals such as pyrrhotite, dolomite, ankerite, siderite, rhodochrosite which can affact the mineralogical NP and AP should be considered.