The purpose of this study is to provide the damage detection method on shear building structures by the damage index directly induced from dynamic equation. The provided damage index could be estimated from measured mode shape of undamaged structure and frequency difference between undamaged and damaged structure. The damage detection method is applied to numerical analysis model such as MATLAB and MIDAS GENw for the verification. The damage index at damaged story represents (-) sign and 15 times than other undamaged stories.

Severe corrosion damage on the deck surface of a orthotropic bridge deck with bulb rib has been reported in Japan. Therefore, in this study, structural behaviors of a orthotropic bridge deck was numerically examined using FE analysis program MARCment2010. Thus, its deck thickness was decreased according to corrosion damage level of the deck. The deformations and the stress distributions of a orthotropic bridge deck with bulb rib were compared and evaluated.

In this study, shear buckling behaviors of a web panel with local corrosion in a plate girder bridge were numerically examined because severe corrosion damage has been reported in plate girder bridges. The web corroded condition and boundary condition were changed to evaluate the effect of corrosion condition on the shear buckling behaviors of the web panel.

이 논문에서는 기존의 초음파 감쇠량을 측정하는 기법1과 이를 이용하여 콘크리트 내부 공극의 크기 분포를 추정2하는 논문을 요약하고자 한다. 초음파 속도법 등 일반적으로 사용하고 있는 초음파 탐촉자를 이용한 실험에서는, 탐촉자와 시편 사이의 커플링(coupling) 문제로 인해 시편의 감쇠량을 정량적으로 측정하는 데 한계가 있다. 따라서 감쇠량에 대한 신뢰성있는 측정을 위해, Fig. 1과 같은 실험 장치를 고안하여 개발하였다. 가장 중요한 특징으로는 기존의 탐촉자 앞에 얇은 PZT 세라믹을 배치하여 자기보상 주파수 응답함수 기법(self-compensating frequency response function, SC-FRF)를 적용하였다. 이 기법을 이용하여 시편의 고유한 감쇠량을 측정하면, Fig. 2와 같이 주파수에 따른 변화를 측정할 수 있다. 이를 Roney 식과 같은 매질 내 삽입된 입자 분포에 의한 초음파 산란과 비교하면, 시편의 공극에 대한 크기 분포를 Table 1과 같이 정량적으로 추정할 수 있다.

In this study, lateral movement of 78 single-span bridge abutment was investigated. The result showed that the movements were commonly within the range of 10 ~ 30mm. It is recommended that the clearance between the slab and the backwall should be adjusted to accept the movement of the abutment.

In this dissertation, experimental study about the real-time vibration control of the bridge structure was conducted by using the semi-active vibration control method that has been in the spotlight recently. Based on the laboratory-scale bridge model in the form of the cable-stayed bridge, the shear type MR damper and the semi-active vibration control algorithm (Lyapunov and Clipped-optimal) were applied in order to the control the harmful vibration in real time. From the investigation of the test results, the performance of each semi-active control algorithm was evaluated quantitatively.

The main purpose of this study is to develop the advanced structural health monitoring techniques of cable-supported bridges. The research and development about two main topics has been performed as follows: The vision-based cable monitoring technology using cable moving robot and The long-term displacement monitoring technology of bridge structures using Global Navigation Satellite System (GNSS). Therefore, the 100-m-length cable vibration test facility, was selected as the test bed.

The local displacement in the downstream of the embankment dam has been observed since the 2nd precise inspection was investigated. It appears that this displacement is caused by the differential settlement on the different properties of the zone during the construction. Therefore, using the advanced inspection method of the 3D scanning determines whether to proceed with the displacement. In this study, reviewing a field application and analyzing results of the 3D scanning method are drowned a conclusion for improvement in the inspection and maintenance method on the Rock-fill type embankment dam.

In this study, plant pipeline diagnosis system based on IoT(Internet of Things)was developed. The system consists of three parts : sensor system, omnicube system and pipeline safety assessment solutions. The plant pipeline diagnosis system was constructed in plant pipeline and was validated field applicability. Plant pipeline diagnosis system based on IoT is appropriate for plant pipeline safety monitoring.

Safety management means that protect the life and property from natural disaster such as earthquake and abnormal climate etc. And also it is very important as the building structures are higher and more large scale structures. In this paper, various kind of technologies including fiber optic sensor application, image processing for detect the crack width are simply proposed. And also, the schematic system which can be applicable to the safety management of building and large scale structure are suggested. Related research project have performed by KICT since 2011, and this year is 2nd project period. As time goes on, the developing state of the arts will be presented in the future.

Field test was carried out to verify the performance of high-performance Weigh-In-Motion system which was developed to enhance the precision and durability. As a result, the overall measurement error has been distributed in the range of 5 % for total weight and axle weight of vehicle.

To suggest the preliminary data for effective maintenance of RC deck slabs of bridges, the damage characteristics of RC deck slabs are quantitatively analyzed in the present study. Damages of RC deck slab are classified into damage patterns and its details. And, rate of damage possess, cause of damage occurrence and time of damage occurrence are reviewed from this study.

In this paper, analysis on chloride content and carbonation of concrete members in highway bridge is realized. As a result, it is considered that the amount of snowfall, de-icing salt, freeze and thaw affect chloride content, and concrete members with respect to carbonation in highway bridge are safety at least for now

The number of highway bridge has been doubled for last 10 years. It is because many new highway routes has been completed since 2000. As a result, the maintenance cost of highway bridge has been increased as well. Therefore, to predict the long-term maintenance costs, there is a need for a method. To solve this problem, various studies about the life cycle cost analysis was conducted. Maintenance costs for members of the highway bridge is quite different to each other. Therefore, all the elements that are managed by the same proportion is inefficient. In this study, the distribution characteristics of maintenance costs for members of the highway bridge were analyzed using research data and highway bridge maintenance system data.

Structural damping includes material damping, friction effects at bearing and expansion joints, friction at bolted joints and mechanical damping by damper. There is not analytical basis for estimating the damping ratios. Structural damping ratios can be estimated by measuring forced vibration amplitude of a certain mode but it is almost impossible to vibrate the actual bridges to a certain mode by force. Therefore, RD technique utilizing a lot of ambient vibration data can be a practical method to estimate damping ratio. In this study, the damping ratio is estimated by analyzing the ambient vibration data of three steel cable stayed bridges.

Surface of slope have occurred necessarily in regard to constructing road in South Korea which consist of 70% of mountain. Recently, large cut slope's formation increase because of increasing construction of the wide width road. therefore, the importance of maintenance have risen because the bigger scale of slope, the higher risk of collapse and damage increase. Korea Government have designated the large scaled cut slope to manage the slope which have the length of over 200 meters and the height of over 50 meters in accordance with 「Special law regarding facility safety management」. In this study, of the total number of 146's large scaled cut slope which is located at general national road in south korea, the slope dropped safety grade according to time flow was classified as joint, crushing and weak rock slope. moreover, weakness factors which influence the falling down safety grade were analyzed defending on the kind of rocks.

Based on the study of chloride migration coefficient and hydration heat evolution, it was found that the use of ternary blended cement was effective to achieve desired service life and minimum crack index. On the other hand, a high level of compressive strength is required for marine concrete mix design.

In general, protection and reinforcement measures on cut slope are often focused natural slopes to slope design are considered as slopes of safety. In this study, stability analysis is carried out and the differences to the factor were safety based on cases of analyzed erosion and surface collapse on boundary between Cut slope and Upper natural slope.

In this study, the pilot test has been performed to verify effectiveness of constructive method of data dictionary provided by previous study and the results were discussed. To perform pilot test, the construction information of PSC beam bridge at detail design stage was used.

This study evaluates thermal movements of an existing bridge using digital image processing technologies. Digital images are acquired from smart phones. Thermal movements which extracted from bridge bearings' images are compared to the results of conventional displacement transducers. It is concluded that the image-based process for measuring thermal movements of bridges is accurate, practical and cost-effective.