• 월간 기계설비
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• no.3 s.212
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• pp.50-55
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• 2008

롯데건설(주)은 1959년 창립해 도로, 교량, 항만 등의 대규모 토목공사와 첨단 인텔리전트 빌딩, 호텔, 쇼핑센 터 및 고급 아파트 등의 건축공사를 통해 국가산업 발전과 주거문화 향상에 기여하고 있다. 롯데건설(주)은 잠실 롯데월드를 비롯해 전국에 롯데호텔 · 백화점을 건설하며 테마파크, 관광, 유통시설 건설에 남다른 기술과 노하우를 축적하고 현재 서울, 부산에 100층 이상의 초고층 건물인 제2롯데월드 건설 추진등 수익 다각화를 위해 끝없이 노력하고 있다. 또한 중세 유럽성의 긍정적인 이미지를 아파트 브랜드에 적용, 주택시장의 고급화, 차별화를 선도해왔다. 이런 노력의 결과 롯데건설(주)은 2007년 매출 3조1,608억원, 수주 6억원을 달성했고 올해 매출 3조8,000억원, 수주 8조원을 목표로 정진하고 있다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5A
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• pp.673-683
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• 2008

This study improved the existing method of using the longitudinal strain and concept of influence line to develop Bridge Weigh-in-Motion system without axle detector using the dynamic strain of the bridge girders and concrete slab. This paper first describes the considered algorithms of extracting passing vehicle information from the dynamic strain signal measured at the bridge slab, girders, and cross beams. Two different analysis methods of 1) influence line method, and 2) neural network method are considered, and parameter study of measurement locations is also performed. Then the procedures and the results of field tests are described. The field tests are performed to acquire training sets and test sets for neural networks, and also to verify and compare performances of the considered algorithms. Finally, comparison between the results of different algorithms and discussions are followed. For a PSC I-girder bridge, vehicle weight can be calculated within a reasonable error range using the dynamic strain gauge installed on the girders. The passing lane and passing speed of the vehicle can be accurately estimated using the strain signal from the concrete slab. The passing speed and peak duration were added to the input variables to reflect the influence of the dynamic interaction between the bridge and vehicles, and impact of the distance between axles, respectively; thus improving the accuracy of the weight calculation.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.195-196
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• 2010

The objective of this experiments is to investigate chloride diffusivity of high performance concrete based binary cimentitious materials such as ordinary portland cement and ground granulated blast furnace slag. The results from the study will be utilized as the basic data and guideline in making standard mixproportions and the manufacture, construction work and quality control of HPC.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5A
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• pp.631-639
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• 2008

This paper reports the mode shapes of Seohae cable-stayed bridge extracted by TDD technique. In order to record total 72 acceleration points in the vertical direction of the bridge deck, a custom made data acquisition system with LAN communication has been especially developed and a set of ambient vibration tests has been conducted. For the measured acceleration responses, total twenty four mode shapes up to 2Hz has been extracted by TDD technique. The extracted mode shapes include many new modes that have not been identified in the current on-line health monitoring system installed in the bridge. It is confirmed that TDD technique is the most effective in extracting the high resolution mode shapes on a particularly long span bridge.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.158-158
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• 2011

통상 교량구조물은 차도부와 보도부 및 그 부속시설로서 난간 및 연석부 등으로 구성되는데, 자동차 전용도로의 경우 보도부가 설치되지 않게 되고, 국내의 국도 및 지방도상의 많은 교량이 차도부와 보도부의 별도의 구분이 없이 보행자가 연석부 위로 통행하거나 여의치 않을 경우 난간에 기대어 통행하는 경우가 일반적이어서 안전사고의 위험에 직접 노출되는 경우가 많다. 이에 국토해양부에서는 최근 "도로의 구조 및 시설기준에 관한 규칙"을 개정하여 국내의 보행자 관련 교통사고로 인한 사망자가 전체 교통사고 사망자의 약 절반을 차지하는 실정을 고려하여 보행자의 안전한 통행로 확보를 통해 보행공간의 근본적인 개선이 불가피한 실정임을 시사 하였다. 이에 국내에서는 교량 보도부의 확장에 대한 관심이 높은 실정이며, 현재 보도부 확장에 대한 시공이 활발하게 이뤄지고 있다. 그러나 기존 교량에 보도부를 신설 혹은 확장함에 있어서 보도부 부재의 설치 간격 및 필요한 앵커볼트의 수량 및 부재의 성능 평가에 대한 기준이 명확하게 이뤄지지 않은 상태에서 설치되어져 왔었다. 기존에 시공되던 H-형강의 브라켓 단면의 경우 브라켓 단면의 중량이 커서 안정성 및 시공성이 떨어지며 과다한 앵커볼트의 체결 및 브라켓 단면의 과다설계로 인한 공사기간 및 비용의 증대를 가져오는 문제점이 있었다. 이에 본 연구에서는 교량 보도부의 확장 및 신설에 있어서 보도부 부재의 설치간격의 적정성 및 브라켓의 최적화를 위한 브라켓의 성능평가 시험을 수행하였다. 브라켓의 성능평가 시험은 1차 2차 3차 시험으로 나누어 진행되었으며, 1차시험은 H-형강의 브라켓단면을 원형강관으로서의 대체 가능성을 확인하였고, 2차 시험에서는 원형강관의 브라켓 단면의 앵커볼트수량의 최적화에 대한 시험을 수행하였으며, 3차 시험은 최적화된 브라켓 단면에 프리스트레싱의 도입으로 반력 및 인발력의 감소효과를 확인하는 연구를 수행하였다. 본 연구의 수행결과 기존의 설계 및 시공방법이 과다 설계가 이뤄졌음을 판단하였고, 브라켓 단면의 최적화를 통하여 기존 시공방법에 비해 시공성, 안전성, 경제성을 높일수 있을 것으로 판단된다.

• Journal of Korean Society of Transportation
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• v.17 no.3
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• pp.117-130
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• 1999

Earthquakes damage roadway bridges and structures, resulting in significant impacts on transportation system Performance and regional economy. Seismic risk analysis (SRA) procedures establish retrofit priorities for vulnerable highway bridges. SRA procedures use average daily traffic volumes to determine the relative importance of a bridge. This research develops a cost-effective transportation network analysis (TAN) procedure for evaluating numerous traffic flow analyses in terms of the additional system cost due to failure. An important feature of the TNA Procedure is the use of an associative memory (AM) approach in the artificial intelligence held. A simple seven-zone network is developed and used to evaluate the TNA procedure. A subset of link failure system states is randomly selected to simulate synthetic post-earthquake network flows. The performance of different AM model is evaluated. Results from numerous link-failure scenarios demonstrate the applicability of the AM models to traffic flow estimation.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.4
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• pp.255-262
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• 2021

In this study, a jointless bridge that integrates the superstructure and abutment without installing an expansion joint was analyzed. An example of a jointless bridge that has been introduced in Korea since 2009. Owing to the short period of use and lack of experience in design, construction, and maintenance, there is insufficient information regarding the long-term behavior of jointless bridges. When analyzing numerous bridges, the numerical analysis model must maintain the numerical values used and ensure the convenience of model construction. In this study, sensitivity analysis was performed to select a numerical model for various types of jointless bridges using commercial finite element programs, MIDAS Civil and ABAQUS 2018. According to a solid element-based model, we analyzed the mean and maximum relative errors between structural models. Consequently, it was found that the beam element-based model exhibits a significantly small relative error in comparison to the shell element, where a relatively large error was recorded. Therefore, the optimal numerical analysis model, a practical model that maintains the similarity and precision of the displacement shape cause by relative error, was judged to be the most suitable for jointless bridges based on the shell element.

• Korean Journal of Construction Engineering and Management
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• v.17 no.4
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• pp.57-65
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• 2016

This study found a proper parametric life distribution based on maintenance history data of each bridge member under the jurisdiction of the Korea Expressway Corporation for the past 10 years by introducing the concept of reliability and suggested a measure to calculate the mean life and reliability of each bridge member using the parameter obtained with the maximum-likelihood classification. As a result of analyzing the exponential distribution, weibull distribution and log normal distribution being utilized frequently in order to find the parametric life distribution type which well described the life data of each bridge member, it was found that the log normal distribution and weibull distribution described the characteristics of the relevant life data the best. As a result of calculating the mean life of each bridge member based on the estimated parameter, the average life of the steel bridge coating was 18.51 years which was the longest, followed by the bridge deck as 17.56 years. The mean life of the drainage facility and the bridge bearing were 12.27 years and 12.57 years respectively, showing the shortest life.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.6A
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• pp.597-605
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• 2009

The safety of expressway bridges was estimated by checking the external condition rank based on the nondestructive inspection and material test and by measuring load carrying capacity based on the result of load test. Although the load carrying capacity of the bridges was clearly low compared to the design standard, it was examined that many of the bridges have good external condition rank relatively. Also, it can be assured that load carrying capacity shows a considerable difference according to various condition even though the bridges have similar construction year and a structural type. Therefore, this study showed various problems of the current safety measurement of expressway bridges by considering the status of the expressway bridges, external condition rank, and method of safety diagnosis and repair, rehabilitation for maintenance. Based on the existing data of over 400 expressway bridges, the load carrying capacity was analyzed quantitatively considering bridge type, serviced life, design live load, external condition rank and traffic count as variables. The result of this study will be expected to provide the basic information for a reasonable safety assessment of expressway bridge.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.895-898
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• 2008

This research paper intends to investigate and review the new technology of patent registration trend for the most recent domestic retaining wall and bridge abutment, and to apply the technology appropriately to the actual retaining wall and bridge abutment construction. Investigated new technological patents for retaining wall include pre-fabricated PC retaining wall construction method that reduces section force with prestressed PS steel bars, pre-fabricated Coupler-Tension retaining wall, clay reinforced retaining wall block for road, earth reinforced retaining wall block that induces uniform settlement, and etc. Investigated new technologies for abutment are abutment construction method that uses sheet pile, monolithic bridge with complex abutments, construction method for abutment bridge, earth reinforced abutment structure and etc.