Dam risk analysis and assessment, with the state-of the-art technology in developed countries being used. This technology is considered to require a paradigm shift in the national dam safety management. Therefore, this study is developed to utilized the risk-based dam safety management assessment tool.
In this paper, we suggest the new floating type photovoltaic energy generation system, which is improved the structural and economical efficiency, compared with the system developed in the previous research. The structural system in new floating type photovoltaic energy generation system reveals better in structural performance.
In this research, our team developed a semi-active MR damper by designing and producing it, and also evaluated its performance for the control of large structure. It is specially designed to have a flexible capacity to control a range of 10KN-30KN with an input current of 0 - 3A. The evaluation of its performance was carried out; first, to input a 0 - 3A electric current at various frequence range between 0.15Hz and 2Hz, then to measure a consequent power and displacement. By finding that the MR damper secures a control capacity of 10KN-30KN, it was proved that the MR damper is capable to control any large structure.
Nowadays, finger joints have been more popular than rail type joints due to their many merits: easiness to maintain, low noise, etc. However, finger joints have some demerits too. This paper investigates the damage of finger joints installed at a curved PSC box girder bridge. The analytical results show that the damage of finger joints of the curved bridge is caused by thermal expansion and imperfect installation of the joints.
The purpose of this study is to build data base showing new basis about diagnosis equipment through the analysis of diagnosis equipment and establishes a system of classification for efficient management of it. To grasp present state of diagnosis equipment, we collected data by the questionnaire diagnosis company and in order to establish classification system of diagnosis equipment two kinds of classification system are suggested.
Conventionally, the load carrying capacities of bridges have been evaluated from proof loading tests with test trucks by measuring static and dynamic response, such ad deflections or strains under known loading conditions. However, load carrying capacity of bridges was evaluated using the updated finite element (FE) model. To solve these problems, deflections or strains can not represent the bridge's health status as the bridge gets deteriorated. For example, deteriorated boundary condition results in small deflection or strain. The proposed method consists of ambient vibration measurement, experimental modal analysis, correction of the initial FE model based on the identified modal properties, and estimation of the load carrying capacity using the updated FE model. The proposed method has been verified through field tests on a prestressed concrete girder bridge by comparing with the result of the conventional truck loading tests.
The slope adjacent to the road, when it is difficult to observe the shape and if not at the bottom of the upper slopes or steep high due to the presence of the upper slopes of the exact visual inspection is difficult, there is a direct investigation lengthy complaints.
In this study, the disadvantages of having the inspection personnel based complementary and mixed low-cost single global region is the number of slope maintenance and safety can be managed efficiently so that helicopters and hexa mobile survey vehicle was developed. Equipment developed difficulties in spatial or temporal slope Visually inspect efficient investigation to be able to support.
Survey vehicle computer to the Internet environment because it contains Slope check immediately to determine test results sent to the Center, and the efficient maintenance can be performed.
Common feature of displacement-based sensing is that the high-frequency resolution is limited, and often relatively low sampling rates are used. Another problem is that integration of accelerometer data that causes low-frequency noise amplification, and potentially more problematic differentiation of displacement measurements which amplify high-frequency noise. A multi-rate Kalman filtering approach is proposed to solve these problems. This method yields highly accurate motion data.
Vortex shedding occurred at relatively low mean wind velocities between 13m/s and 16m/s in the 2nd Jindo grand bridge. To control the vortex shedding Multiple Tuned Mass Damper(MTMD) was installed in the mid span. The control effects of MTMD was verified by assessing the damping ratio before and after installing MTMD. This paper present the evaluation of damping ratio of a cable- stayed bridge based on measuring data through unified remote monitoring system.
This paper introduces a HGS(Hybrid Grobal Search) method of cable system identification. This method is based on GA(Genetic Algorithms) and LOA(Local Optimization Algorithm) and combines GA and LOA. GA has a advantage of grobal search and LOA has shown a rapid and accurate solution. It is verified the accuracy and effectiveness of the proposed method through a set of numerical test.
In general, to conduct the fatigue evaluation of the steel bridge, the performance test is conducted with the strain gauge where the fatigue crack is generated, or where the geometric influences are made by the structural features. But this test does not consider the actual size of the specific structure and the length of the gauge so that it`s difficult to analyze the result, though the stress analysis is performed. Therefore, this study will be conducted with the strain gauge is installed in the weak range of hot spot stress where the actual fatigue crack is anticipated, will make the regression equation of the strain, and will compare it with the strain equation suggested from IIW .
Concrete is generally accepted to have good fire resistance. It mainly relies on the assumption that concrete has low heat-transfer characteristic and spalling does not occur during the course of a fire. However, the significant numbers of fire accidents have shown in recent years that incidence of spalling has caused sever damages to many structures. This research has investigated a series of catastrophic tunnel fires and tested on the behaviour properties of concrete in association with loading in fire. This paper present that the theoretical consideration and experimental results are used the information of concrete spalling.
This study presents investigation study on the structural health monitoring system for the over-pass bridge connected to the passanger terminal of Inchoen International Airport. The bridge structure designed very conseratively was found to be structurally safe and well-operating based on the measured records over the last 10 years. However, the structural health monitoring system is recommended to be investigated again in a regular basis of every 2~3 years to ensure reliability of measurements.
In this study, a plant safety management system based on IoT(Internet of Things) was developed. The system consists of three parts : smart sensing technology, wireless networking technology and smart plant safety services. The safety management system was constructed in Yeosu Industrial Complex and was validated field applicability in plant. The IoT plant safety management system is appropriate for plant industrial structures.
In this study, a bridge maintenance system is developed to generate performance based maintenance strategy by considering the life cycle cost(LCC). And it is proposed that the concept of generally annual maintenance are practically and easily used to perform LCC analysis. Some of generally annual maintenance data are suggested through existing data analysis due to the proposed concept and LCC analysis of by a real bridge structures is preformed by comparison with a current approach. This paper presents the development of bridge maintenance strategy and can be utilized as an efficient tool to provide the best economical bridge maintenance scenario corresponding to the various constraints and requirements of bridge agency.
In this paper the change of condition ratings are investigated for old highway bridges. The results of condition ratings are selected from those by professional inspector. The bridges are categorized as four types. The inter-relationship of service life, structural elements, condition ratings are investigated to evaluate the deterioration characteristics of bridges
For the safety assessment of the existing bridges on the expressway, the statistical properties of the truck traffic on the expressway needs to be investigated. Also, the reduced uncertainties involved in the assessment and the shorter reference period for the assessment are utilized for the modeling of the live load for evaluation of the existing bridges.
When a floor falls onto the floor below, the impulse transmitted to the lower system results in considerable deformation in the impacted floor. In this paper, a linear static progressive collapse analysis procedure was developed considering the impact of failed members. The impact loads computed from various simplified methods were calibrated with FEM analysis results. The analysis procedure was applied to a moment frame and a braced frame, and the results were compared with those obtained without considering impact load.
This case study is an inspection and improvement case for monitoring system of airside-settlement in incheon international airport, it is to identify the installation and operational issues by investigation for physical, functional defects of running monitoring system and various instruments and it is to determine the safety and damage state of airside facility by the analysis of measured data.
Also, we propose the improved measurement plan to satisfy durability, reliability and efficiency.
The aim of this study is to evaluate performance of snow-resistant for the existing building. For this purpose, it was to propose a way to evaluate whether facilities reach goal performance as performance level separated by immediate occupancy level and collapse prevention level. Preliminary evaluation was developed to conduct by using assessment index of five items of vulnerability and two items of impact for selecting the reinforcement priority of target facilities.