• 한국지반환경공학회 논문집
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• 제10권3호
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• pp.63-71
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• 2009

대도시에서의 공사는 외부방향이 아닌 상부로 진행되기 때문에 현장의 벽면 움직임은 매우 중요하다. 고층 구조물은 주차장을 위한 여분의 공간 확보뿐 아니라 건물의 잠재적 침하를 줄이기 위하여 일반적으로 깊은 굴착을 수반한다. 이러한 대형 굴착은 깊은 심도에 따른 횡방향 지중압력에 견디기 위한 견고한 브레이싱 시스템을 필요로 한다. 벽체 움직임은 잠재적인 인접 구조물의 침하를 허용하기 때문에 sheetpile 이나 diaphragm wall과 같은 옹벽구조물의 변형을 예측하는 방법은 매우 중요하다. 사례들을 분석하고 측정된 벽체 변형은 경험적 도표로부터 예측된 값들과 비교되었다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.1251-1258
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• 2008

The purpose of this research is to introduce the new temporary earth retaining wall system using landslide stabilizing piles. This system is a self-supported retaining wall(SSR) without installing supports such as tiebacks, struts and rakers. The SSR is a kind of gravity structures consisting of twin parallel lines of piles driven below dredge level, tied together at head of soldier piles and landslide stabilizing piles by beams. There are three types of excavation wall structures: standard method for medium retained heights(<8.0m), internal excavation method and slope excavation method for deep-excavation applications(>8.0m). In the present study, the measured data from seven different sites which the SSR was used for excavation were collected and analyzed to investigate the characteristic behavior lateral wall movements associated with urban excavations in Korea.

• Advances in concrete construction
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• 제5권5호
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• pp.493-512
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• 2017

Blast loads may considerably affect the response of structures. In previous years, before computer analysis programs, the parameters of blast effects were calculated with empirical methods, consequently some researchers had proposed equations to find out the phenomenon. In recent year's computer analysis programs have developed already, so detailed solutions can be made numerically. This paper describes the blasting response of the structures using numerical and empirical methods. For the purpose, a reinforced concrete retaining wall is modelled using ANSYS Workbench software, and the model is imported to ANSYS AUTODYN software to perform explicit analyses. In AUTDYN software, a sum of TNT explosive is defined 5,5 m away from the wall and solution is done. Numerical results are compared with those of obtained from empirical equations. Similar study is also considered for equal explosive which is the 4 m away from the wall. The results are represented by graphics and contour diagrams of such as displacements and pressures. The results showed that distance of explosive away from the wall is highly affected the structural response of it.

• 한국지반신소재학회논문집
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• 제20권1호
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• pp.1-8
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• 2021

도심지에서는 공간 활용을 위해 구조물 하부 깊은 지하까지 구조물을 설치하고 있다. 그래서 구조물 건설 시, 지반에서 발생하는 토압을 방지하기 위해서 흙막이를 활용하고 있다. 굴착공사에 적용되던 흙막이가 건설기술의 발전으로 인해서 성토 공사나 옹벽 설치시에 가시설 낙석이나 산사태와 같은 위험 방지용으로도 이용되고 있다. 일반적으로 성토공사시 가시설 흙막이를 적용하는 경우는 기존에 존재하는 도로나 철도를 확장하는 경우이다. 그러므로 고속철도의 복선화 현장과 같은 성토공사에 적용되는 흙막이에 관한 연구가 필요하다. 본 연구에서는 일반적인 1열 H-pile 흙막이와 지주식 흙막이 2종류에 대해 수치해석을 하였으며, 고속철도의 단선지역에 성토하여 복선화하는 공사에 적용된 흙막이의 안정성을 분석하였다. 지주식 흙막이는 사면안정에 적용되는 억지 말뚝(이하 배면지주)을 흙막이 벽체(이하 전면지주)에 경사지게 결합한 공법이다. 분석결과, 지주식 공법은 동적하중이 적용되는 동안, 전면에만 H-plie이 설치된 타입에 비해 수평변위가 최대 19.0%만 발생하였다. 또한, 고속철의 운행속도가 느릴수록 변위가 많이 발생하였으며, 이 결과는 운행속도가 저속인 구간에서의 지반 설계시 더욱 주의가 필요하다는 것을 보여준다.

• 한국지반공학회지:지반
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• 제12권5호
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• pp.5-16
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• 1996

지하수위가 높고 느슨한 사질토지반에서 가설흙막이벽을 설치하여 지하굴착공사를 실시할 경우 굴착저면에서 보일링현상이 발생하여 굴착공사 뿐만 아니라 인접구조물에 상당한 피해를 주게 된다. 따라서 최근에는 흙막이벽 배면지반의 강도를 증대시키면서 동시에 흙막이벽의 차수효과를 높이기 위하여 고압분사주입공법을 실시하여 차수벽을 설치하는 보조공법인 널지 이용되고 있다. 고압분사주입공법에 의해 가설흙막이벽 배면지반에 시공된 지반개량체의 지반보강효과 및 차수효과를 검토하기 위하여 각종 실내시험 및 현장시험을 실시하였다. 시험결과 지반개량체는 지반조건과 시공방법에 따라 약간의 차이는 있으나 충분한 흙막이벽 배면지반의 보강 및 벽체의 강성보강 효과를 얻을 수 있는 것으로 나타났다. 한편 지반개량체의 투수계수는 원지반의 투수 계수보다 10-2~10-3cm/s정도 작아서 흙막이벽의 차수효과를 기대할 수 있는 것으로 나타났다.

• Geomechanics and Engineering
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• 제20권3호
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• pp.255-265
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• 2020

Laboratory tests are conducted to investigate the performance of retaining system with different combinations of long-short piles. Numerical analysis implemented using ABAQUS are verified by comparing numerical results with measured data. By performing numerical studies, the horizontal displacement of piles, heave of excavation bottom and bending moment of pile for various pile system with different pile lengths are investigated. Results show that long piles share higher bending moments than short piles. The increase in the number of short piles leads to a slight increase in the heave at excavation bottom for long-short pile retaining system. Retaining system with different long and short pile combinations have greater effects on the horizontal displacement of pile above the excavation bottom, compared to its counterparts below excavation bottom. For a given length of long pile, the bending moment and displacement of piles increase with the decrease in length of short piles, while the increasing rate of maximum moment of retaining pile system is insignificant. Results highlight that a reliable and economical pile retaining system can be designed by optimizing the number and length of short piles, provided that the working performance of retaining structures above excavation bottom meets the design requirement in practice.

• 농업과학연구
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• 제50권3호
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• pp.469-484
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• 2023

In this study, three types of structures-stepped gabion retaining walls, vertical gabion retaining walls, and parapets-were installed on the dam floor crest to prevent the overflow of deteriorative homogeneous reservoirs. The acceleration response, displacement behavior, and pore water pressure ratio behavior were compared and evaluated using shaking-table model tests. The experimental conditions were set to 0.154 g in consideration of the domestic standard and the seismic acceleration range according to the magnitude of the earthquake, and the input waveform was applied with Pohang, Gongen, and artificial earthquake waves. The acceleration response according to the design ground acceleration increased as the height of the embankment increased, and the observed value were larger in the range of 1.1 to 2.1 times the input acceleration for all structures. The horizontal and vertical displacements exhibited maximum values on the upstream slope, and the embankment was evaluated as stable and included within the allowable range for all waveforms. The settlement ratio considering the similarity law exhibited the least change in the case of the parapet structure. The amplification ratio was 1.1 to 1.5 times in all structures, with the largest observed in the dam crest. The maximum excess pore water pressure ratio was in the range of 0.010 - 0.021, and the liquefaction evaluation standard was within 1.0, which was considered very stable.

• 복합신소재구조학회 논문집
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• 제5권3호
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• pp.23-31
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• 2014

Recently, sewer-pipe constructions replacing deteriorated pipes are currently underway in the downtown area. To resolve many problems in the conventional method of open-cut construction, lining-board system using light-weight GFRP panels is developed. The pultruded GFRP panels can be successfully used for the developed lining-board system as temporary decks and retaining walls in virtue of light weight, high strength and high durability. In this paper, the structural safety and serviceability of the lining-board system are examined through FE analyses and experiments. Further more, a field application of the lining-board system is presented. The field application shows that quality and environment of construction can be significantly improved.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.224-231
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• 2005

The ground excavation causes the deformation of the ground where the neighborhood structure is located. The ground deformation result in the vertical settlement of the neighborhood structure as well as the horizontal displacement of the temporary earth retaining structures. The decreased volume of the soil due to the ground settlement is defined as 'the ground loss quantity' or 'the ground loss'. When excavation is performed nearby existing structures, retaining walls should be designed and constructed to minimize the ground loss. Among various methods for reducing the ground loss, this study introduces the pre-loading method which has been recently developed. The reduction effect of the ground loss by pre-loading has been found to be larger as using a wall with relatively smaller rigidity.

• Earthquakes and Structures
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• 제7권6호
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• pp.909-935
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• 2014

The seismic characteristics of two semi-gravity reinforced concrete cantilever retaining walls are examined via an experimental program using an outdoor shake table (one with and the other without concrete masonry sound wall on top). Both walls are backfilled with compacted soil and supported on flexible foundation in a steel soil container. The primary damages during both tests are associated with significant lateral displacements of the wall caused by lateral earth pressure; however, no collapse occurs during the tests. The pressure distribution behind the walls has a nonlinear trend and conventional methods such as Mononobe-Okabe are insufficient for accurate pressure estimation.