As a result of the application in accordance with the assessment procedures given in the Detailed Guide (plan) for the precision safety diagnosis of the external tendon in Prestressed Concrete, it was evaluated with reasonable procedures and results.

In this study, the static and dynamic displacement responses due to vehicle loadings were measured by Video Gauge System(VGS) technique. The displacement response data were compared with data obtained from laser displacement sensors(PSM)&electronic distance measurement device(EDM) so that the static and dynamic behavior of the bridge under vehicle loadings was examined. The static and dynamic loading test for an earth-anchored suspension bridge, Nam-hae Bridge&Gwang-an Bridge, was performed using vehicles. The accuracy of the deflection measurement using the VGS in the load of the actual bridge was verified.

The 'Housing Act (‘14.04), which permits the remodeling of old apartment buildings, has been implemented. In particular, vertical remodeling is generally implemented by adding 2~3 floors above the top floor of existing apartments. Technically, it is necessary to reinforce the existing pile due to the increase of vertical, horizontal, seismic load, etc. However, the existing piles are loaded simultaneously and so each pile was constructed at limited base space for application of reinforcement method. The bearing capacity of existing piles decreases due to vertical expansion so the bearing capacity of the piles must be confirmed by the indirect method(laboratory test etc.) in the first safety diagnosis and by the direct method(field test etc.) in the second safety diagnosis.

A fatigue crack occurred in the vicinity of the suspension bridge`s center-stay area is generated. Therefore, the stress and caused of occurrence of each member are analyzed by measurement. When similar cases occur in the future, they shall be utilized as basic data such as research methods and establishment of measures for maintenance.

The safety issue of PSC box Girder Bridge is being brought up to the surface. For countermeasures, we developed an extensive material testing procedures and applied it into our existing bridges. We believe that these set of newly constructed procedures are well within the reasonable mark. With that, we now foresee the necessity in systematic improvement and ample supply of its technology in order to secure the future safety of PSC box girder bridges.

The safety issue of PSC box girder bridge stood out. So, we developed material testing method and procedures and applied them to existing bridge. Consequently, We found that the procedure we developed is very reasonable.

The safety issue of PSC box Girder Bridge is being brought up to the surface. For countermeasures, we developed an extensive material testing procedures and applied it into our existing bridges. We believe that these set of newly constructed procedures are well within the reasonable mark. With that, we now foresee the necessity in systematic improvement and ample supply of its technology in order to secure the future safety of PSC box girder bridges.

This study is the measurement for fatigue cracks at U-Rib in the steel deck bridge. Thus, to analyze the causes and reinforcement methods through the measurement results. So the bridge will preserve the safety & usability and want to enhance the durability.

When estimate Short Lenth External Tendon's tension by Vibration Measurement Method, We Consider Tendon's Boundary. This paper is a case about estimation of short lenth tendon's tension by using practical formula estimation and stiff string with clamped-clamped boundary conditions.

Space took place between two superstructures of which two bridges are adjacent each other. The cause of space between superstructures turn out to be due to several reason such as stratum composition by various ground condition, ground stability after completion of structure, ground stress bulb double, etc.

Recent developments in technology, the use of complex composite section, such as composite truss girder is increasing. These sections, the tensile stress will be generated internal and external constraints caused by other materials. Thus, the effects of the panel point on the concrete slab was studied through the structural analysis.

Autogenous shrinkage isn't currently defined in Korean Highway Bridge Specifications. Accordingly, the structural analysis was carried out to reflect the contents on the autogenous shrinkage of the Eurocode(fib Bulletin 55 : Model code 2010). As a result, we examined the possible initial crack caused by the autogenous shrinkage.

Vibration measurement analysis and In-depth inspection were carried out to understand the cause of defects occurred on joint of bridge. A cause of defects, such as metallic sounds, water leak&corrosion and rubber seal rupture turn out to be due to deterioration and vibrating impact by period so that the bridge is in need of repair and effective maintenance.

In general, the lateral resistant of bearing in a straight bridge is designed for lateral load such as wind or seismic forces. In this study, however, it is found that the cause of damage of bearings in a straight bridge adjacent to the curved road is the centrifugal force or the breaking force of the vehicle. Also, it is suggested that the repair method for the damaged bearings.

In general, the lateral resistant of bearing in a straight bridge is designed for lateral load such as wind or seismic forces. In this study, however, it is found that the cause of damage of bearings in a straight bridge adjacent to the curved road is the centrifugal force or the breaking force of the vehicle. Also, it is suggested that the repair method for the damaged bearings.

Numerical Analysis of corrugated-metal culvert is mainly related with corrugated shape, plate thickness, and load transmission mechanism, and these elements especially should be treated consistently in the analysis of 3-Dimensional analysis of behavior of skewed corrugated-metal culvert. And so, the modelling technic, 3-dimensional equivalent plate modelling, is required to be modified.

The high-strength concrete slab confined by steel members, the possibility of thermal crack due to heat of hydration is high. These thermal cracks, it reduces the serviceability, safety and service life valuation of the structure, it is necessary to review.

Failures of curved bridge have been occurred due to the negative reactions in construction and in survice and this problem has been issued in our society. In this study, the strengthening method of curved bridge which was occured negative reactions was investigated through the structural stability analysis.

In this study, the process for the cause of lateral movement of bridges is suggested. Based on the monitoring of shoe and pier movement, the lateral movement of birdges is studied. As a result, the process is applicable for the small lateral movement of the bridges.