This study is to investigate and analyze the correlation of carbonation according to strength of concrete members for bridge in marine enviroment. Also depth of carbonation according to age for 100 years is estimated by carbonation rate coefficient. As a result of the measurement, it was found that the depth of carbonation decreases with increasing strength. This is because it is considered that water-cement ratio and amount of unit cement are influenced by the concrete mixing. Also, It is anticipated that rebar corrosion due to carbonation will not occur in concrete members.
In recent days, many damages have been detected in superannuated bridges. Especially, the fatigue problems become serious in the maintenance of the bridges. It is important to investigate the load bearing capacity of the girder ends ability when some crack damages have occurred in the steel bridge. In this study, typical crack damages have dealt with analytically; one is the crack which occurred in the vicinity of the welding of the sole plate, the other is the crack which occurred in the vicinity of the gusset section of the web. Based on the analytical results, the relation between the load carrying capacity at the girder end and the crack length/direction is discussed. The crack occurred in the part which a tension field forms with cracks of steel girder on which shearing force acts in analysis in case a crack occurs, it turned out that reduction of ultimate shear strength is large.
We have experienced cracking around column bottom and safety check places on a bridge due to lamp post shaken by traffic and wind. So we need to take a measure to decrease stress on lamp post by suppressing vibration.
In this study, We have tested how much we can reduce the stress by using an anti vibration damper.
본 연구는 전․의경에 대한 체계적이고 효율적인 인적자원 관리를 위한 기초 자료로써의 성격을 갖는다. 우선 전·의 경과 경찰관을 대상으로 방사선 검사 중 단순 X-선검사, CT 검사, MRI 검사를 시행한 환자를 대상으로 분석을 실시 하였다. 질환별 분류에 있어서는 신체부위별로 일반 질환과 근 골격계 질환으로 분류하였다. 근 골격계 질환은 다시 검 사 부위별로 세분화하여 분석하였다. 경찰관과 전 의경의 정량적 비교에 있어서는 단순 X-선검사, 전산화 단층 촬영 술, 자기공명영상검사의 부위별 평균 인원을 비교하였다. 연구 결과 전 의경은 단순 X선 검사, CT 검사, MRI 검사 등 세 검사 모두 Lower extremity 검사가 다른 부위에 비해 가장 많이 차지하고 있으며 Lower extremity 검사 중에서 특히 Knee 검사 비율이 가장 많이 차지하고 있다.