According to the available date sources, 1,814 bridges failures occurred over the past 210 years in the United States. The most frequent cause of bridges failures were attributed to external events such as: floods, collisions, scour, overloading and deterioration. Among these external events, Hydraulic factor caused the maximum number of bridges failures with 54% of the total failures. 20% of hydraulic factor was failed by scour. Thus, base on the result of reviewing design basis and safety assessment practices, criteria for determining safety assessment of bridge foundation scour is proposed.

In order to analyze the accuracy of acceleration measurement by the laser vibrometer, natural frequency measured by the laser vibrometer were compared with that acquired by using conventional accelerometer. The results show that the margin of error is about 2% in the case of the measurement by the low pass filter.

Even though a falling-off in durability and a decrease of safety was caused by environmental factors, there are various cases that it is difficult for structure to diagnose and review exactly because of their working condition. In this study, we show an example which is an inspection of a small waterway culvert having three boxes. It will be used helpfully to evaluate a like structure.

This paper investigated experimentally the feasibility of estimating stress in prestressing strands using induced magnetic field by an external electromagnet and Villari effect that the permeability of ferromagnetic material varies according to its stress or strain.

This study investigated the compressive strength of concrete by using ultrasonic pulse velocity method, and proposed the equation able to predict the compressive strength of concrete.

This study investigated the effect of various buried depth(0.8m, 1.0m, 1.2m) on the stress distribution of gas pipe. Numerical analysis and field tests were carried out with API 5L steel gas pipes. From the results, it can be suggested that field test results including compaction energy can represent the stress distribution of gas pipe more precisely.

When concrete is exposed to extrem fire, its strength and durability degrades. The fire-induced damage in concrete is investigated at microscale and a nondestructive testing for the damaged concrete is presented.

This study was performed to decide weight of an objective evaluation factors so optimized for small reservoirs and reservoirs that operators may survey their status and identify relevant risk factors in a timely way. In this study, evaluation factors were determined based on the expert panel results followed by the brain storming process. The selected evaluation factors were implemented on the formulation of hierarchy and analytic hierarchy process (AHP) technique were used to determine weight factors based on the expert survey results. It is expected that the use of the proposed weight will contribute to the more systematic and efficient safety management of small reservoirs to prevent their failures.

The most commonly used material of construction structures is steel. In this study, Epoxy-based coating materials and Ceramic-based coating materials durability were investigated. Exposed water immersion, chloride immersion, temperature changes, freezing and thawing for severe environments to simulate and environmental conditions are showed degraded in epoxy-based coating materials.

This study analyzes damage estimation technique of earthquake disaster. In order to do this, 1) Proposition of current situation analysis and direction of improvement domestic and foreign-related systems of earthquake disaster response system, 2) Establishment and design of research earthquake disaster damage assesment system 3) Analysis and investigation of domestic and foreign-related soil field on damage estimation, 4) Creation of soil liquefaction risk-map and processes method of soil information. When occurred an earthquake, occurs the system rapidly displays seismic intensity distribution and life, structure, lifeline damage estimations. This enables decision makers to support the earthquake disaster response decisions. Eventually, earthquake disaster damages are expected to be reduced significantly.

Structural dynamic characteristics are obtained by analysing responses of seismic acceleration measuring system obligatorily installed in public structures. Emergency structural safety estimation using these data supports decision making of a structure manager when an earthquake or a strong vibration happens. And proper standards for structural safety are suggested by cumulative statistical analysis. For these reasons, it is necessary that comprehensive analysis and management system indicates analysis results based on GIS(Geographic Information System). This system is developed with comprehensive analysis algorithms and data processing procedures. Various information through the system is served for structural safety management.

In this case, for PSC Box girder bridge of representative bridge types at the Honam high-speed railway section to need in-depth analysis of the dynamic behavior of the structures in high-speed driving and the monitoring system require to check correct behavior of the actual status of high-speed railway bridge, the dynamic behavior of the bridge was analyzed to HEMU-430X load. According to the high-speed driving test, the main behavior was monitored and analyzed.

The goal of this study is to investigate an evaluated aerial work flatform for structure maintenance and repair. This study includes technical components and economic aspect. The investigation is extend and helpful to accomplish successful business according to foreign and domestic business.

This study was conducted to investigate the Structural Health Monitoring(SHM) system built in large-scale structures. Recently large-scale structures such as bridges and high-rise building have installed SHM system and using the SHM system, large-scale structures are monitoring the status of structures. In many practical cases, SHM systems are used sensor, such as strain gauge, inclinometer, accelerometers, seismic, wind anemometer, GPS, to monitor status of structures. This case study foreground potential future research dealing with SHM system using integrated sensor module.

This study suggests Installation methods and a development plan for the installation of the seismic acceleration instrument through the case study of the seismic acceleration instruments installed in the domestic public buildings.

The first time in Korea risk analysis was carried out on dams and risk assessment was carried out by selecting a pilot dam. As a result, the dam risk assessment process was established, and also learned the importance of risk assessment. Dam risk assessment conducted for the first time, but the future through additional research, risk analysis is to develop the system.

Natural frequency changes of an in-service concrete bridge have been monitored to analyze the dynamic characteristic according to temperature and embedded depth changes. 7 acceleration sensors are attached to the bridge, and 11 time impact experiments have been done using the impact hammer. The natural frequency has a trend to drop as the surface temperature of the body goes up. And it also has a trend to decrease as the embedded depth of the bridge foundation increases.

과거에는 생애주기에 기반 유지관리 계획에 대한 인식이 부족하였기 때문에 검측자료의 축적은 이루어졌으나 이러한 검측 자료를 이용한 구성품의 수명예측 및 보수보강 시나리오 선정 등 유지관리 의사결정 지원을 위해 사용되지는 못하였다. 따라서 축적된 검측 데이터로부터 궤도 구성품의 건전도를 평가할 수 있는 방법을 정립하고 잔존수명을 예측하여 효율적 유지관리를 실현할 수 있는 기법 개발의 필요성이 대두되고 있다. 이에 본 연구에서는 검측된 레일 마모데이터를 이용한 불확실성 기반 궤도성능 예측모델 개봘과 관련한 연구를 수행하였다.

This study represented simulation that analyzes extreme load effect based on reasonable probability model reflected actual traffic characteristics on a bridge. Through its simulation, vehicular loads for load carrying capacity assessment were developed by considering traffic characteristics and remaining service life, various structure. According to the analysis results on traffic characteristics through its simulation, extreme load effect tended to increase as the traffic volume and heavy vehicle proportion increase.

It will use the Schmidt hammer law, the Ultrasonic waves velocity law and the composition law in the concrete Korean mandolin lump examination law from the research which it sees consequently and proposal of the usual concrete and existing regarding the high-in-tensity concrete the comparison which will be cool it will analyze and compared to accurately the burglar presumption which is the possibility of buying the compressive strength of the concrete it will be cool and it proposes.