• Journal of the Korean Geotechnical Society
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• v.25 no.9
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• pp.19-27
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• 2009

In order to investigate anti-freeze process of precast concrete L-type retaining walls in cold regions, test walls were installed in the campus of Kitami Institute of Technology (KIT, Hokkaido, Japan). The wall consists of following three sections, i) back filled with frost susceptible clay soil, ii) using thermal insulation material, and back filled with frost susceptible soil, iii) back filled with frost-unsusceptible soil. The freezing front distribution and ground temperature within the backfill were observed and deflections of the walls were measured over three freeze-thaw seasons. Some understanding of the mechanisms of the build-up of frost heave pressure was gained, and the effectiveness of replacement method was observed. A simulation was performed to predict the shape of the freezing front in the backfill behind L-type walls with various cross sections. These findings were employed to propose a method for determining the appropriate zone to be replaced with frost unsusceptible backfill material in cold regions.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.2
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• pp.343-355
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• 2017

In this study, an Assembled Earth Retaining Wall (AER wall) is newly proposed. The AER wall combined stabilizing piles names as Back Supporting Beam is developed to improve stability and economics of existing retaining walls. For the verification of the AER wall, the field model tests and 3D numerical analyses were performed. As a result of the field tests, it can be confirmed that the earth pressure is considerably reduced compared with the L-shaped retaining wall. Also, the 3D numerical analyses show that AER wall is at least 29.85% more effective at lateral displacement than general L-shaped retaining wall. In other words, AER wall is expected to raise economical efficiency because of excellent mechanical stability of Back Supporting Beam.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.6
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• pp.134-142
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• 2012

This paper presents a study of system identification on the tilt response of the L-type retaining wall located at Tanhyun 11th ACE Apartment, Ilsan in order to understand mechanism how the structure behaves in operational conditions and to provide a reference tilt values for assessing structural abnormality. The retaining wall was extraordinarily tall (14m) in urban area so the long-term monitoring system had been installed with 3 tilts-meters and 9 temperature sensors operational from Oct 2004 upto Nov 2007. By using 5-months continuous data in which all the 12 channels were up and running, the two prediction models, 1) the linear model, and 2) the state-space equation (SSE) model, have been identified by finding the best fitness model among all possible 511 combinations of input temperatures out of the 9 temperatures. The linear model which was simple in the model structure achieved the validation fittness of 68% due to the fact that the static model wasn't able to represent thermal dynamics. The SSE model achieved the validation fitness of 90% which was quite accurate considering various unexpected noises happening in field measurements.

• Journal of the Korean Geotechnical Society
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• v.33 no.1
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• pp.17-30
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• 2017

There are many limitations for ensuring structural stability of retaining wall. Especially, L-shaped retaining wall and gravity retaining wall need large space, and massive concrete, respectively. Assembled Earth Retailing (AER) wall was developed to overcome the shortcomings. In this paper, stability of AER wall is verified by field model tests and the 3D-numerical analysis. The results show that horizontal displacement of AER wall was reduced by maximum 67.84% for conventional retaining walls, and earth pressure acting on the retaining wall was reduced by maximum 73.19%.

• 발명특허
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• v.31 no.8 s.362
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• pp.64-67
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• 2006

'한강의 기적'이라는 말이 있듯 우리나라의 근대화, 산업화는 그 어느 나라에서도 유래를 찾아볼 수 없을 만큼 눈부신 성장속도를 자랑한다. 그러나 근대화, 산업화라는 명분 아래 우리에게 너무나도 고마운 존재인 자연환경에 대한 외면은 이미 수많은 부작용을 낳고 있다. 그 예로 우리 생활환경에 아주가까운 물인 하천은 심각하게 오염되고 더 이상 오염되어 가는 하천을 그냥 두고 볼 수 만은 없는 일이 되어 버렸다. 이러한 필요에 의해 몇 년 전부터 활발하게 이루어지고 있는 하천의 개보수공사는 석축 쌓기, L형 옹벽 및 돌망태, 견치석 등을 사용하고 있는데, 이는 하천의 생태계를 단절시키는 또 하나의 문제를 야기하고 있다. 또한 이런 과정을 통해 하천이 직선화되면서 홍수가 났을 경우 피해를 가중시키고, 자연석을 고갈시키는 등의 문제점이 대두되고 있다.