최근 비탈면의 다양한 붕괴사고, 지반변형 등으로 인하여 비탈면 유지관리에 대한 관심이 증대되고 있는 실정이다. 일반적으로 비탈면에 대한 점검자의 접근성이 양호한 경우는 조치 및 대응이 적기에 취해질 수 있으나, 점검자의 접근성이 곤란한 경우는 장기적인 관점에서 비탈면의 유지관리가 용이하지 않은 것이 현실이다. 본 연구는 점검자의 접근성이 양호하지 않은 비탈면에 대해서 무인체(드론)을 활용하여 비탈면 지반거동의 경시변화를 관찰하고, 이들 결과를 통해서 전반적인 지반 안정성을 사전에 파악하고자 하는 유지관리 사례를 소개하고자 한다.

Using GPR(Ground Penetrating Radar) Precise Inspection, the real lining thickness of the tunnel damage was determined and detailed analysis was performed to provide a more accurate structural safety assessment of the tunnel damage. Through this study, It is presented to provide a guide for the application of the tunnel for inspection and diagnosis.

In this study, digital image processing was used to estimate the tensile forces of the remote hanger cable using image-based back analysis method. A portable digital camcorder was used as a vision-based system considering convenient and economical aspects for use. The ambient vibration test was performed on a suspension bridge to verify the validity of the image-back analysis method of measuring the hanger cable tensile force.

The latest precise inspection for safety and diagnosis has found the clogging of transverse drainage pipes in NATM tunnel, resulting in hydraulic pressure generated on the outside of lining concrete that poses a safety threat to the tunnel structure. Accordingly, this paper aims to conduct a safety analysis on using NATM tunnel that currently suffers the clogging of transverse drainage pipes based on its numerical analysis.

Because of the characteristics of long-span bridges, the cable tension is considered a critical item in their maintenance. In particular, because the evaluation of the cable tension in a suspension bridge is essential for understanding the general status of the structural system, identifying the initial values of this force in the construction of a bridge and then accurately predicting and comparing its estimated values during traffic use are very important tasks for the maintenance of a suspension bridge. In this paper, to verify the algorithm for estimating the cable tension of hanger cables using the back analysis technique, an ambient vibration test was conducted at a suspension bridge.

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.

A fatigue crack occurred in the vicinity of the 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 mesures for maintenance.

During maintenance, we closely examined the reinforced section where concrete has cracked at the time of cable installation. We confirmed that there has not been any sight of new cracks or growth of existing cracks. For the following year of Investigation, we plan to conduct close inspection of the reinforced section.

Improved measurement and structural modeling analysis of result, an improved method is very efficient. The difference of about 10~15% comes out, Improved measurement and structural modeling analysis of result, it is determined that the need for additional research, such as a change of the modeling subdivision, load contions.

In this study, periodical configuration survey is carried out on the subject of the suspension bridge in service. Its reliability and structural modeling validity are performed by comparison and analysis of interpretation value through the structural analysis.

In this study, analyze the proper repair works and after repair works before it, such as via the structural analysis and investigation of various site of damaged of suspension bridge due to the collision of the vehicle is an accident artificial, make sure those good analysis result has been.

Shin Geo-Je Bridge needs new inspection holes to improve the accessibility for various maintenances. This study evaluated the maximum effective stresses of the bottom flange when the inspection holes is made with an ellipse shape. The FEM analysis results show that the inspection installation is possible to the inflection point of the girder.

강교의 정확한 피로균열의 발생원인 또는 교량의 피로안전성을 검토하기 위해서는 적합한 응력이력 측정이 요구된다. 그러나 실제 현장에서의 응력이력 측정은 현장 여건과 경제성, 작업성 등의 이유로 1개소의 스트레인게이지를 설치하여 계측을 실시한다. 이는 특정 구조물의 실제 치수와 게이지 길이 용접부 응력집중 등의 영향을 고려하지 못하고, 구조 모델링을 통한 응력해석에도 많은 어려움이 있다. 그러므로 본 연구에서는 용접단부에 다수의 게이지 설치, 최소 길이 게이지 사용, 설치 위치 등의 개선된 방법을 적용하여 용접단부와 스트레인게이지 설치 거리에 따른 변형률 진폭에 대한 상관식을 도출하고 국제용접협회 (IIW)의 제안식과 비교하였다. 또한 적합한 피로등급 상세범주 선정을 통해 공용중인 교량의 피로손상도 평가 및 잔존수명을 예측하고 분석하였다. 그 결과 피로균열 발생빈도가 높은 부재파악, 용접단부와 게이지 설치 거리에 따른 변형률의 정량적 파악으로 정확한 피로손상도 평가 및 잔존수명 예측이 가능하므로 향후 교량의 응력이력계측 시 개선된 방법을 적용해야 할 것이다.

Shin Geo-Je Bridge needs new inspection holes to improve the accessibility for various maintenances. This study evaluated the maximum von mises stresses(SE) of the bottom flange when the inspection holes is made with an ellipse shape. The FEM analysis results show that the inspection installation is possible to the inflection point of the girder because buckling phenomenon doesn't occur according to the loading.

Steel deck plate is a preferable structure in the long span bridge construction because of the weight decrease and the aesthetic enhancement. But its orthogonal anisotropic structure is connected with various subsidiary materials so that the fatigue transfer is complex. This study will be conducted with the a few strain gauge is installed in the weak range of hot spot stress where the actual fatigue crack is anticipated and will compare it with the fatigue crack range and the allowable fatigue stress category of the steel deck plate in home and abroad

Bridge Deck Waterproof has good constructability and economic efficiency, and it does not have any influence on following processes. But it is uncertain at concrete penetration performance. This paper were investigated pore characteristics in order to examine the performance of the domestic Bridge deck waterproof

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 .