• Proceedings of the Korean Society for Rock Mechanics Conference
• /
• 1996.03a
• /
• pp.25-34
• /
• 1996

터널은 긴 선상구조물로서 사전지질조사에 의해 설계에 필요한 정보를 정밀도 높게 구하는 것이 매우 어렵다. 따라서 터널시공 중 암반 및 지질상황을 관찰하고, 터널주변 지반의 거동을 계측하여 지반에 적합한 지보공을 설계ㆍ시공하는 것이 필수적이다. 이를 위해서 터널시공 중 정량적인 암반분류와 계측(일상관리계측과 대표단면계측)이 주기적으로 실시되고 있지만, 이러한 결과를 어떻게 시공에 반영하느냐는 터널의 합리적인 시공에 있어 매우 어려우면서도 중요한 문제라 할 수 있다. (중략)

• Tunnel and Underground Space
• /
• v.20 no.6
• /
• pp.408-420
• /
• 2010

It is important to forecast the final deformation of a tunnel during construction for evaluating its mechanical stability. In this study, the final deformation of a tunnel is forecasted by fitting tunnel deformations measured while excavating to a displacement function and exterpolating it. The tunnel for the study was built in two stages divided into an upper and a lower part. During the lower part construction of the tunnel, the displacement function forecasts the final incremental displacement well compared to the increment measured after completion of the tunnel. It is because the critical initial displacement occurred on passing the measurement pins can be adequately measured during excavating the lower part, which can not be measured during the upper part excavation of the tunnel.

• Magazine of korean Tunnelling and Underground Space Association
• /
• v.3 no.2
• /
• pp.63-67
• /
• 2001

최근 구조물의 안전과 관련하여 계측기술에 대한 관심이 고조되고 있으며, 시공중 계측 뿐 아니라 시공후 유지관리를 위한 구조물의 계측 사례가 증대되고 있다. 본 고에서는 영구계측을 위하여 고속철도용 터널에 적용된 유지관리 계측시스템을 소개함으로써 추후 터널의 유지관리 계측시스템을 구축하는데에 기초적인 자료를 제시하고자한다.

• Tunnel and Underground Space
• /
• v.17 no.5
• /
• pp.428-434
• /
• 2007

Displacement of tunnel face is important issues for the evaluation of tunnel safety. In this study, conventional convergence and displacement data measured from horizontal inclinometer were analyzed to investigate the trend and characteristics of tunnel deformation during construction. Trend of measured displacement agreed with general understanding of tunnel deformation prior to excavation. It shows that displacement measured from horizontal inclinometer can be used to preestimate the total deformation of tunnel.

• Tunnel and Underground Space
• /
• v.23 no.2
• /
• pp.110-119
• /
• 2013

It is generalized to measure the arch settlement and convergence during tunnel construction for monitoring its mechanical stability. The initial convergence rate a day is defined from the first convergence measurement and the final convergence defined as the convergence measured lastly. The initial and the final tunnel arch settlement are defined like the preceding convergence. In the study, the relations between the initial and final displacements of a shallow tunnel are analyzed. The measurements were performed in the tunnel of subway 906 construction site in Seoul. The overburden is 10-20 m and the tunnel goes through weathered soil/rock. The width and height of the tunnel are about 11.5 m, 10m, respectively. So this is a shallow tunnel in weak rock. The length of tunnel is about 1,820 m and the tunnel was constructed in 2 stages, dividing upper and lower half. The numbers of measurement locations of arch settlement and convergence are 184 and 258, respectively. As a result, the initial displacement rate and the final displacement are comparatively larger in the section of weathered soil.

• Computational Structural Engineering
• /
• v.29 no.2
• /
• pp.12-17
• /
• 2016

본 기사에서 대형 비정형 건축물의 시공 중 자동 모니터링 사례를 소개하였다. 소개한 사례에서는 무선 자동 계측 시스템을 이용하여 변형률계, 경사계, 변위계 등이 총 88개 설치되어 약 13개월 동안 장기 모니터링이 수행되었다. 무선 자동 계측시스템은 장기간의 데이터를 확보하고 데이터 간의 상관성 및 이력분석을 용이하게 하였다. 이를 통해 대상 구조물의 시공 중 안전성 및 안정성을 확보하고, 정밀 시공을 구현하는데 기여할 수 있었다.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.32 no.6A
• /
• pp.389-398
• /
• 2012

In this study, structural strain responses of the jacket-type Uldolmok tidal current power plant structure under severe tidal environments were measured and analyzed using long-term measurement system during construction and also operation. It was observed that there were significant changes in strain responses at the steps of jacket lifting, block loading, pile ejection and insertion. Strains due to dead loads and tidal loads were analyzed before and after removal of a jacket leg, and it was also found that the strains due to dead load were much significantly changed after jacket leg removal. From the measurement data during operation, it was found that strain responses were fluctuated with M2 and M4 tidal periods and also relatively short period of about 10 min due to the peculiar tidal characteristics in the Uldolmok strait. Finally, the neural network-based non-parametric estimation models were investigated to build up the signal-based structural damage monitoring system.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.29 no.3
• /
• pp.219-227
• /
• 2016

In this study, we have proposed a method of monitoring of bridges under construction in view of the long-term behavior of the prestress concrete bridge of which the Free Cantilever Method is applied. As a method to confirm the ability of the long-term behavior of the concrete box girder, temperature sensors and strain gauges were installed, and the measured data was used to calculate creep coefficient. Moreover, we have measured the stress of the concrete box girder during construction which was applied with creep coefficient and compared with the changes in temperature to analyze the vertical displacement along the segment. In conclusion, monitoring of the FCM bridge during construction in consideration of the long-term behavior can be analyzed efficiently by suing temperature and displacement data without the use of laser displacement meter or laser delfectometer.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.27 no.6
• /
• pp.573-580
• /
• 2014

In this paper, axial strains and lateral displacements of columns in a 58-story reinforced concrete building were measured using vibrating wire gauge and laser scanner, respectively, and compared with predicted values. Predictions were obtained using ASAP, which is a 3D construction stage analysis program developed based on PCA report. Comparisons indicated that columns in the middle of floor plan showed good correlation with predictions. However, the columns in the corners showed some deviations. Lateral displacement of columns between measurement and estimation showed similar trends but considerable deviations, which are seemingly caused by construction error of column faces, and inaccuracy in differential vertical displacement prediction.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.9 no.2
• /
• pp.103-112
• /
• 2005

This study examines the stability of Sungsu bridge which was issued nine years ago because of its collapse accident and now is on the progress of extension work in each construction stage by construction monitoring system. From this study, the measured value in each construction stage of anchorage truss and suspended truss shows the agreement with the analytical values up to 60~110 percents, and the elements' stresses emanating from the pre-loading stage, are also similar to the analytical value. Regarding these results, it is expected that each member has enough stiffness and the construction condition is satisfactory. In addition, it is expected that the transverse members and sway bracing bolts integrate completely the existing truss and new attached truss as a one body from the result of the vibration test to find out the integration rates.