• 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.

• 한국지반공학회논문집
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• 제19권5호
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• pp.15-26
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• 2003

도심지에서 깊은굴착 및 근접굴착과 관련하여 흙막이 구조물의 설계와 시공에 있어서 주변지반 및 인접구조물의 안전성 확보를 위하여 신뢰할 만한 예측기술이 요구되고 있다. 깊은 굴착 및 근접굴착에서 흙막이 구조물의 지지체에 대한 사전재하의 적용이 연구되었고, 경제적인 효과가 있음은 알려져 왔으나 많은 연구자들에 의하여 완전히 이해되거나 인정될 만한 연구는 미흡한 실정이다. 따라서 본 연구에서는 흙막이 벽체의 수평변위를 억제하여 지반침하를 감소시키는 사전재하 적용의 효과에 대하여 연구를 수행하였고, 사질토지반에서 굴착주변지반의 변위 및 구조물의 손상을 예측하는 모형실험을 수행하였다. 본 연구의 수행결과는 사전재하하중 50%, 70%를 적용하였을 때, 20%의 벽체수평변위가 감소하였고, 지반침하 및 지중변위는 30%내지 40% 감소하였다. 또한 각 단계별 굴착시 사전재하하중에 따른 심도별 지중침하율 및 벽체에 작용하는 토압분포를 제시하였다.

• Geomechanics and Engineering
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• 제31권1호
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• pp.1-14
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• 2022

Urban deep excavation will affect greatly on the deformation of adjacent existing buildings, especially those with shallow foundations. Isolation piles has been widely used in engineering to control the deformation of buildings adjacent to the excavation, but its applicability is still controversial. Based on a typical engineering, numerical calculation models were established and verified through monitoring data to study the influence characteristics of isolation piles on the deformation of existing shallow foundation buildings. Results reveal that adjacent buildings will increase building settlement δ_v and the deformation of diaphragm walls δ_h, while the isolation piles can effectively decrease these. The surface settlement curve is changed from "groove" type to "double groove" type. Sufficiently long isolation pile can effectively decrease δ_v, while short isolation piles will lead to a negative effect. When the building is within the range of the maximum settlement location P, maximum building rotation θ_m will increase with the pile length L and the relative position between isolation pile and building d/D increase (d is the distance between piles and diaphragm walls, D is the distance between buildings and diaphragm walls), instead, θ_m will decrease for buildings outside the location P, and the optimum was obtained when d/D=0.7.

• 한국지반공학회논문집
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• 제16권4호
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• pp.43-50
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• 2000

본 논문에서는 도심지 깊은 굴축현장에서 수집한 계측자료를 토대로 분석한 흙막이벽체의 거동에 관한 내용을 다루었다. 총 57개 현장에 시공된 H-pile+흙막이판 벽체와 현장타설 주열식 말뚝 벽체, 그리고 지하연속벽체 등 다양한 종류의 흙막이 벽체를 고려하였으며, 굴착으로 인한 벽체의 거동 및 겉보기토압을 집중적으로 분석하였다. 수집된 계측자료를 토대로 벽체 및 지지구조의 형식 등 흙막이벽체의 다양한 구성요소가 벽체의 거동 및 겉보기 토압에 미치는 영향을 분석.고찰하였으며, 그 결과를 현재 적용하고 있는 설계/해석법과 비교하는 한편 다양한 차트의 형식으로 제시하였다. 또한 계측자료를 토대로 흙막이벽체의 최대수평변위를 평가하는 경험식을 제안하였다.

• 국제초고층학회논문집
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• 제4권4호
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• pp.261-270
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• 2015

Hong Kong is a renowned small city with densely placed skyscrapers. It is no surprise that heavy duty or even mega foundations are built over the years to support these structures. To cope with the fast construction pace, several heavy deep foundation types have been widely adopted with some prescribed design rules. This Paper has selected two commonly adopted but distinctive foundation types, namely large diameter bored piles and percussive steel H-piles to illustrate the special design and construction considerations related to these pile types in related to local context. The supervision requirement in related to foundation works for which again may be unique in Hong Kong will also be highlighted. A case history is also discussed in the later part of the Paper to illustrate the application of one of these foundations and to highlight the importance of considering foundation design and basement excavation method in a holistic manner.

• 한국지반공학회논문집
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• 제21권10호
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• pp.99-112
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• 2005

도심지에서의 지반굴착은 배면지반의 변위와 그에 따르는 건물의 손상을 유발시킨다. 굴착에 의한 지반변위의 예측과 굴착면 주변에 위치한 건물의 손상 위험도 평가는 설계단계에서 필수적인 요소이다. 본 논문에서는 기존의 굴착에 의한 지반변위 예측기법인 Peck의 방법과 Bowles의 방법을 조합하여 지보굴착에 따르는 배면지반 변위예측방법을 제안하였다. 또한, 배면지반의 Green-field 뒤틈각과 수평변형률을 이용한 인접건물 손상위험도 평가기법을 제안하였다. 이 기법은 싱가폴에서 시공중인 대규모 지반굴착공사의 설계에 성공적으로 적용되었다.

• 한국지반환경공학회 논문집
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• 제12권9호
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• pp.5-11
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• 2011

최근 들어 대규모 및 대심도 지반굴착공사가 증가하고 있으며, 굴착으로 인한 인접구조물들의 붕괴사례는 건설수요와 더불어 꾸준히 증가하고 있고, 특히 도심지 개발 및 불량한 조건에서의 지하철 구조물과 인접하여 진행되는 굴착으로 인해 발생될 수 있는 문제점이 많아지고 있는 실정이다. 이에 본 논문에서는 서울시 내에서 수행된 16개 현장에 대한 사례연구를 통해 적용된 지하굴착공법과 보강공법의 현황을 고찰하였다. 또한 대표 현장을 선택하여 안정성 분석을 실시하였고, 적용된 굴착공법 및 보강방안에 대해 검토하고 이에 따른 공법의 적정성에 대해 검토하였다. 그 결과 16개 현장의 지층 분포상태는 모두 상부로부터 매립층, 그 하부는 퇴적층, 풍화토, 풍화암, 연암층의 순으로 분포하고 있었다. 또한 중요 구조물에 인접하여 굴착공사를 진행할 경우 구조물의 위치 및 지층조건에 매우 큰 영향이 있는 것으로 나타났다. 또한 도심지 특성상 일반 가시설 공법을 적용하여 지하철구조물과 인접하여 굴착이 진행될 경우는 별도의 보강공법의 적용이 필요할 것으로 판단된다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 춘계 학술논문 발표대회
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• pp.19-20
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• 2012

According to develop urban area, the depth and floor area of basement tend to become deeper and larger. Excavation work for basement floor work is very important because its cost take 20% of total construction cost. Therefore, many studies of developing retaining wall system have performed for feasibility and safety in deep excavation work. In this study, new supporting system used high-strength pipe for retaining wall is introduced to reduce the construction cost and improve the safety and constructability by analyzing case study.

• Geomechanics and Engineering
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• 제34권3호
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• pp.251-265
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• 2023

In urban construction projects, it is crucial to evaluate the impacts of excavation-induced ground movements in order to protect surrounding structures. These ground movements resulting in damages to the neighboring structures and facilities (i.e., parking basement) are of main concern for the geotechnical engineers. Even more, the danger exists if the nearby structure is an ancient or masonry brick building. The formations of cracks are indicators of structural damage caused by excavation-induced ground disturbances, which pose issues for excavation-related projects. Although the effects of deep excavations on existing brick masonry walls have been thoroughly researched, the impact of twin excavations on a brick masonry wall is rarely described in the literature. This work presents a 3D parametric analysis using an advanced hypoplastic model to investigate the responses of an existing isolated brick masonry wall to twin perpendicular excavations in dry sand. One after the other, twin perpendicular excavations are simulated. This article also looks at how varying sand relative densities (D_r = 30%, 50%, 70%, and 90%) affect the masonry wall. The cracks at the top of the wall were caused by the hogging deformation profile caused by the twin excavations. By raising the relative density from 30% to 90%, excavation-induced footing settlement is greatly minimized. The crack width at the top of the wall reduces as a result of the second excavation in very loose to loose sand (D_r = 30% and 50%). While the crack width on the top of the wall increases owing to the second excavation in medium to very dense sand (D_r = 70% and 90%).

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.1008-1013
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• 2006

Ground anchor method is widely used in the large scale deep excavation of urban area to support a retained wall. Excavation using the ground anchor as a supporting system near a building have many difficulties due to the limitation of construction space. This method can not be applied to the site with the insufficient space from the retained wall to the boundary line. In this case, soil improvement at the anchor bond zone can be used to secure the frictional resistance of ground anchor within the boundary. Through this method, the bond length of anchor can be shortened considerably. This paper deals with the case study on the ground excavation adjacent to a building. The object field is Yongsan Park Tower Construction Site. In this site, the enlarged anchor with soil improvement was applied to solve the problem due to the limitation of construction space. According to the results of field test and monitoring, the anchor with soil improvement is very effective to secure the frictional resistance at the anchor bond zone.