• Smart Structures and Systems
• /
• 제17권6호
• /
• pp.859-880
• /
• 2016

This study aims to establish an effective methodology for the detection of instant damages occurred in cable-stayed bridges with the measurements of cable vibration and structural temperatures. A transfer coefficient for the daily temperature variation and another for the long-term temperature variation are firstly determined to eliminate the environmental temperature effects from the cable force variation. Several thresholds corresponding to different levels of exceedance probability are then obtained to decide four upper criteria and four lower criteria for damage detection. With these criteria, the monitoring data for three stay cables of Ai-Lan Bridge are analyzed and compared to verify the proposed damage detection methodology. The simulated results to consider various damage scenarios unambiguously indicate that the damages with cable force changes larger than ${\pm}1%$ can be confidently detected. As for the required time to detect damage, it is found that the cases with ${\pm}2%$ of cable force change can be discovered in no more than 6 hours and those with ${\pm}1.5%$ of cable force change can be identified in at most 9 hours. This methodology is also investigated for more lightly monitored cases where only the air temperature measurement is available. Under such circumstances, the damages with cable force changes larger than ${\pm}1.5%$ can be detected within 12 hours. Even though not exhaustively reflecting the environmental temperature effects on the cable force variation, both the effective temperature and the air temperature can be considered as valid indices to eliminate these effects at high and low monitoring costs.

• 한국건설관리학회논문집
• /
• 제23권1호
• /
• pp.37-45
• /
• 2022

본 연구는 구조물이 하중과 외부요인으로부터 피해를 받을 경우 구조물의 안정성을 판단하기 위해서 발생하는 변위를 측정하는 방법론을 제시하고 실험을 통한 검증을 보여준다. 변위측정은 모아레의 원리를 이용 하였으며 이를 통해 구조물의 미세한 변위를 증폭하여 관찰 할 수 있다. 실험은 실제 현장의 파이프 서포트와 동일한 지름의 파이프를 사용하였으며 파이프가 수평으로 움직인다는 가정하에 파이프의 수평 변위에 따른 모아레 간섭무늬의 수직 변위를 측정하였다. 실험 결과 파이프의 수평 변위와 간섭무늬의 수직 변위의 선형 관계를 확인하고 관계식을 도출하였다. 추가적으로 카메라를 이용한 방법론을 적용하기 위해 수직부재와 카메라 사이의 거리에 따른 간섭무늬 변위의 관계식을 도출하여 카메라의 위치에 상관없이 방법론을 적용할 수 있게 하였다. 결론적으로 본 연구에서 제시한 방법론을 통해 카메라를 이용하여 거리에 상관없이 다수의 수직부재 변위를 동시에 측정하고 구조물의 안전성을 판단하여 붕괴를 감지할 수 있다.

• 디자인융복합연구
• /
• 제12권6호
• /
• pp.159-175
• /
• 2013

최근 들어 원도심 지역의 재활성화에 대한 관심이 급증하고 있다. 인천시에서도 원도심 재생을 위한 여러 가지 계획을 추진 중에 있지만 급속한 도시화와 외곽지역의 개발이 도시공간을 확산을 시켰고, 이는 도심의 중심성을 약화시키고 침체와 쇠퇴를 초래하였다. 이러한 상황에서 세계적으로 창조도시에 대한 관심이 높아지면서 창조도시 프로젝트가 각국에서 이루어져 오고 있다. 국내에서도 이러한 추세에 발맞추어 창조도시를 표방한 도시개발사업이 시행되고 있다. 그러나 경제 논리만을 추구함으로 급성장한 도시는 그 정체성을 잃었다. 따라서 본 연구에서는 주민참여가 이루어지는 창조도시 발전에 중점을 두고자 하였다. 이에 본 연구는 창조도시와 주민참여 관련 문헌 및 이론, 관련 선행 연구를 고찰하고, 주민참여 중심의 창조도시 조성 방안을 도출하기 위해 먼저 주요 요소를 추출하여 분석의 틀을 설정하고, 이를 통해 주민참여 중심의 창조도시 조성 방안을 도출하였다. 나아가, 주민들의 설문조사를 통하여 인천시 원도심 재생을 위한 주민참여 중심의 창조도시 조성방안을 제안하고자 한다.

• Journal of Construction Engineering and Project Management
• /
• 제4권1호
• /
• pp.1-7
• /
• 2014

The Sudanese construction sector is characterized by many small and large projects and high labor intensity, and accounted for 3.2% of the Sudanese country's GDP. The basic problems facing the Sudanese construction projects are the factors that affect on construction project performance. The objectives include identifying the factors affecting the performance of Sudanese construction projects, and to determine the critical factors. The literature review has been done to gather the information about the causes and their factors that affect on the performance of construction projects from the previous researches. The research methodology was conducted to gather the data by questionnaire which was examined to be reliable and valid according to statistical tests. The (34) factors were identified as factors affect on construction projects and the (10) factors were the critical factors which may lead to poor performance of Sudanese construction projects. This study has some conclusions such as the instrument for measuring the critical factors on the performance is reliable and valid, so the project management stage performance is 64.2%.

• 한국디지털건축인테리어학회논문집
• /
• 제12권1호
• /
• pp.61-70
• /
• 2012

A construction project is very costly and takes a long time to make investment and yield profit. For this reason, financial institutions are cautious about financing construction projects. Meanwhile, a construction company needs financing from financial institutions to cover a large expense of a construction project. Thus, there is likely to be a close correlation between financing conditions and business operation of a construction company. To examine the relationship, variables were identified that are related to insolvency of a construction company and changes in financing conditions. The analysis period is between the second quarter of 2001 and the fourth quarter of 2010. Data was retrieved from TS2000 established by Korea Listed Companies Association (KLCA), Statistics Office, and Construction Economy Research Institute of Korea (CERIK). In terms of methodology, VECM (Vector Error Correction Model) was used to analyze dynamic relationship between changes in financing conditions and insolvency of a construction company based on the identified variables. The hypothesis was that changes in financing conditions would significantly affect business of a construction company, but, the analysis did not find a close relation between the two factors. However, it was shown that poor business of a construction company affects financing conditions adversely.

• 한국건설관리학회:학술대회논문집
• /
• 한국건설관리학회 2007년도 정기학술발표대회 논문집
• /
• pp.722-727
• /
• 2007

As the world construction market is rearranged by the level of technological capability, recently the technological capability in construction industry is developing rapidly. The important of measuring and analyzing technological capability in construction industry is gaining more and more emphasis. It enables to grasp the past and present situation of construction industry as well as to foresee changes in the future. However the concept of technological capability cannot be identified easily, as well as it is hard to compare that capability of construction industry among different countries. Although there have been numerous studies conducted on the technological capability of construction industry, most of the studies were in formsof surveys of specialists or industry professionals which lacked objectivity and sound basis for data. This study will be focused on investigating the methodology in exploiting and measuring surface of the earth and developing indicator and process to understand technological capability in construction industry through quantitative and statistical analysis. Then it will verify them through a case study.

• 한국건설관리학회논문집
• /
• 제14권3호
• /
• pp.97-106
• /
• 2013

최근 건설산업은 녹색건설(Green Construction)이라는 새로운 도전에 직면하고 있다. 본 연구에서는 "건설기업으로 하여금 녹색건설을 추진하게 하는 동인(動因)은 무엇인가?"라는 연구 질문(Research Question)을 설정하여 녹색건설을 추진하게 하는 동기유발요인을 도출하고 주요 특징과 시사점을 분석하였다. 연구 범위는 대형 종합건설사로 설정하였으며 정치경제 접근법을 연구방법론으로 채택하였다. 대형 종합건설사는 미래시장인 녹색건설에 대해 높은 관심을 보이고 있는 것으로 나타났으며, 녹색건설시장의 시대적 사회적 흐름에 주목하며 경제적 요인들을 중요시하고 있었다. 특히 동기유발요인 중 내부 경제적 요인이 중요하게 작용하며 최고경영진의 의지가 이를 유발시키는 중요한 동력으로 나타났다.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2008년도 추계학술대회 논문집
• /
• pp.23-29
• /
• 2008

Most VE operation related to construction project is progressed in stage of planing or design phase, especially in case of domestic. It is encouraging fact and if you have VE process in stage of planning and design, you'll have experience a reduction of about 70% of total saving cost in which total construction process may occurred. However, recently the work of construction in overseas increase and almost is only construction-work, except planning and design process. As this reason, VE process for construction-work phase only is demanded in high necessity. VE in construction phase comes to accomplish intensively in the part which the design change does not follow, through know-how, equipment operating method and method of temporary-structure erection at the established construction-site learned, builders will be the possibility of reduction from 3% to 10% in constructive expense. This paper describes VE performing example in OO company's construction-work phase, and propose the methodology of VE performance in the phase of construction. And also it is aimed to extending VE applications into the overseas construction enterprise.

• 국제학술발표논문집
• /
• The 5th International Conference on Construction Engineering and Project Management
• /
• pp.592-595
• /
• 2013

Advent of Wireless Sensor Networks (WSN) has provided potentials to a variety of construction applications. It is well appreciated that WSNs have advantages over traditional wired system, such as ease of installation and maintenance with increased cost savings and efficiencies. However, the obstruction of wireless signal from physical objects in the heterogeneous construction environment often brings challenges to WSN measurement system. This paper analyzed the obstruction characteristic of construction environment where construction materials, equipment, and built structures obstruct the wireless signal yielding negative effect of measurement system. By adopting evaluation criteria, such as packet reception rate, field experiments have been implemented to quantitatively identify the interference of wireless signal from penetration, reflection, and network traffic under the construction environment. The results show that reliable performance of wireless sensor in construction environment depends on the optimal separation distance between a receiver and a transmitter, obstruction types, obstruction thickness, and transmission interval. In addition, the methodology and experimental results of this paper could be used in the practical design of network topology when hundreds of sensor nodes form a mesh network in the large scale construction applications.

• 국제학술발표논문집
• /
• The 5th International Conference on Construction Engineering and Project Management
• /
• pp.1-6
• /
• 2013

Concrete construction requires utilization of many temporary facilities such as formwork, shoring, and scaffolding. Appropriate use of these temporary facilities greatly impacts the quality, cost, schedule, and safety of concrete construction. The current practice in design and planning of temporary facilities is often manual, error-prone, and re-active based on construction site layout, status, and progress in the field. Early design and planning of temporary facilities for concrete construction using Building Information Modeling (BIM) technology offers a potential solution. Although some commercially-available software exists that assists in the generation of temporary facility designs, the construction industry lacks tools that support detailed planning and design of many other temporary facilities. This research presents our early work in automating the design and planning of temporary facilities utilizing BIM. Algorithms were developed to automatically assess geometric conditions of work space to detect required temporary facilities and design them. The proposed methodology was implemented in a test model. By automatically incorporating temporary facilities into BIM, more realistic construction models can be created with less effort and errors. Temporary facilities-loaded models can finally be used for communication, bill of materials, scheduling, etc. and as a benchmark for field installation of temporary formwork, shoring, and scaffolding systems.