• Geotechnical Engineering
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• v.1 no.1
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• pp.21-30
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• 1985

The reasonable static and dynamic earth pressure equations were developed by applying the Dubrova's theory and Chang's method to the following cases of wall movements; (1) Active case rotating about the top (2) Active case rotating about the bottom (3) Passive case rotating about the top (4) Passive case rotating about the bottom The equations are presented in accordance with particular wall displacements for the sand and cohesive back-fill, respectively. The results computed by the proposed equations are compared with the conventional theoretical values.

• Journal of the Korean Geotechnical Society
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• v.16 no.5
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• pp.179-191
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• 2000

본 연구에서는 화강토 지반상의 자립식 diaphragm wall의 거동을 연구하기 위하여 벽체의 근입깊이비, 지하수위 및 굴착조건(연속 및 단계굴착)을 변화시키면서 원심모형시럼을 수행하였다. 원심모형실험시 지반굴착은 흙과 동일한 밀도로 혼합된 zine chloride 용액이 배수되도록 밸브를 조작하여 실시하였으며, 굴착에 의해 발생되는 지반의 변형괴 벽체의 변위 및 휨모멘트를 시간경과에 따라 측정하였다. 실험결과, 벽체의 근입깊이비가 증가함에 따라 벽체의 휨모멘트는 증가하는 반면, 굴착과정동안 배면측에서의 간극수압 감소속도는 감소하였다. 최종 굴착단계에서 굴착후 시간경과에 따른 침하량은 굴착과정중의 침하？에 비해 5~7% 정도를 나타내었다. 최대표면침하량과 벽체변위를 굴착깊이로 정규화한 결과 최대 침하량은 벽체 변위량의 0.8~1.2배9평균0.91배)사이에 분포하였다. 굴착깊이로 전규화한 벽체변위와 근입깊이와의 관계는 지수함수식으로 제안하였다. 파괴면은 직선적인 형태로 파괴면내의 배면측 지반은 벽체를 향하여 하향의 변위를 일으키면서 벽체의 회전에 의해 파괴되었으며, 퐈괴면의 각도는 66~72.5$^{\circ}$정도로 이론적인 파괴면의 각도보다 크게 평가되었다.

• Journal of the Korean Geotechnical Society
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• v.15 no.5
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• pp.259-279
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• 1999

Model tests on propped retaining walls were performed for the investigation of wall displacement, distribution of earth pressure, surface settlement and underground movement at various excavation stage in sand. The result of model tests on the trough of surface settlement showed considerable difference depending on the characteristic of wall stiffness, wall friction and soil condition. The location of maximum underground movement were found to be at range of 0.15H to 0. 1H(H: Final excavation depth). Effect of arching by the redistribution of earth pressure were closely related to the stiffness of wall as well as the soil condition. The wall displacement and earth pressure distribution were simulated by elasto - plastic beam analysis program and finite element method with GDHM model respectively. The result of elasto-plastic analysis showed some discrepancy on the wall displacement and earth pressure, but result of underground movement by FEM with various wall stiffness were in good agreement with the model tests.

• Korean Journal of Construction Engineering and Management
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• v.24 no.2
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• pp.70-78
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• 2023

Inclinometer has several problems of 1)difficulty installing inclinometer casing, 2) measuring 2D local lateral displacement of retaining wall, 3) measurement by manpower. To solve such problems, a 2D LiDAR sensor-based retaining wall displacement measurement system was developed in previous studies. The purpose of this study is to select a displacement analysis algorithm to be applied in the retaining wall displacement measurement system. As a result of the displacement analysis algorithm selection, the M3C2 (Multiple Model to Model Cloud Comparison) algorithm with a displacement estimation error of 2mm was selected as the displacement analysis algorithm. If the M3C2 algorithm is applied in the system and the reliability of the displacement analysis result is secured through several field experiments. Convenient management of the displacement for the retaining wall is possible in comparison with the current measurement management.

• Journal of the Korean Geotechnical Society
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• v.15 no.6
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• pp.187-200
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• 1999

An extensive investigation is performed to analyze the behavior of tieback anchored wall. Finite element method is used and several case histories are collected to investigate the relationship of wall deflection, anchor unbonded length, and anchor load. The finite element method can calculate wall deflection with changing the anchor unbonded length and the anchor load. Wall deflection normalized by excavation height can be related to anchor location so that it may produce a zone chart. It is found that a different chart showing the relation of the wall deflection, the anchor load, and anchor unbonded length can be constructed. It is necessary to collect more case histories considering soil conditions and to perform FE analysis extensively with changing bonded length to extend the capability of this relation chart into practice.

• Journal of the Korean Geotechnical Society
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• v.16 no.5
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• pp.83-92
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• 2000

벽체의 수평변위 중 토체의 침하 및 앵커체 자체의 움직임 등으로 인해 발생하는 mass movement가 타이백 앵커토류벽의 거동에 미치는 영향을 조사하였다. 시공사례에 대한 유한요소 해석을 실시하여 벽체의 변위, 겉보기토압, mass movement 및 앵커 자유장 내에서의 하중 변화를 투적하였다. 유한요소해석법을 이용해 mass movement를 계산, 예측할 수 있었으며, 시공 순서에 따흔 앵커 자유장 내의 하중변화를 예측할수 있었다. 현장계측결과와 유한요소해석결과로부터 벽체변위, 겉보기토압 및 앵커의 하중 변화에 미치는 mass movement의 영향이 매우 큼을 확인 할 수 있었다.

• Geotechnical Engineering
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• v.5 no.1
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• pp.47-60
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• 1989

Lateral earth Pressure distributions due to the ,randy soil backfill behind the rigid vertical walls for three different wall movement modes are obtained by the elasto-plastic finite element analys of soil deformation, and these earth pressures are compared with both Rankine's and Dubrova's active earth pressures. Thereby, the effects of the magnitude and the mode of wall displacement on the earth pressure distribution are investigated. Three different modes of wall movement considered in this study are the rotation about bottom, the rotation about top and the translation. For the case of the wall rotation about top, the earth pressure distribution is shown as a reverse S-curve-shaped distribution due to the arching effect. Consequently, the point of application of the lateral thrust is much higher than one-third of the wall height from the base. And, comparing the other modes of wall movement, the magnitude and the point of appliestion of the lateral thrust for the wall rotation about top are larger and higher, respectively. The wedge-shaped plastic zone in the backfill at active failure is developed only for the mode of wall rotation about bottom. The lateral earth pressure distributions on the walls with inclined backfill of several different slopes are shown for the mode of wall rotation about bottom.

• Journal of the Korean Geosynthetics Society
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• v.14 no.4
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• pp.23-33
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• 2015

Together with the wall stiffness, a berm has the role of deciding the stability of a temporary retaining wall before structure installation after excavation. Especially in case of loose or soft soil excavated ground, the role of berm is very important. In this study, the measurement data obtained from the temporary retaining wall in the bermed excavation site in urban and numerical analysis are used to investigate the effects of berm's dimension (width and slope), excavation depth and ground property on the maximum horizontal displacement of the temporary retaining wall. The measurement data indicated that the wall displacement varied to the berm's width. That is, as the berm width decreased, the wall displacement increased. As a result of numerical analyses, the maximum wall displacement increased as slope increased and berm width decreased. This means that the berm is effectively restrained to the wall displacement. As excavation depth increased, the effect of berm's slope and width increased. In case of the same berm condition, the wall displacement restrained as ground property increased.

• Journal of the Korean Geosynthetics Society
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• v.17 no.3
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• pp.33-46
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• 2018

This study presents the experimental results on the performance of deep excavation by using image processing technique particle image velocimetry (PIV). The purpose of present study is to be checked the application of PIV for the successive ground deformation during deep excavation. To meet the objectives of concern study, a series of reduce scale model test box experiments were performed by considering the wall stiffness, ground water table effect and ground relative density. The results were presented in form of contours and vector plot and further based on PIV analysis wall and ground displacement profile were drawn. The results of present study, indicate that, the PIV technique is useful to demonstrate the ground deformation zone during the successive ground excavation.

• Journal of the Korean Society of Hazard Mitigation
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• v.5 no.4 s.19
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• pp.49-57
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• 2005

The purpose of this study is to closely examine the influence of the surcharge load applied to the retaining wall through some model tests, in which wall stiffness in each stage of excavation, horizontal displacement of the retaining wall and surface displacement of the backfill according to wall stiffness and ground conditions, and change and distribution of the earth pressure applied to it were measured and their values were produced, then these values were mutually compared with their theoretical values and their values after analysis of the data obtained at the field, and they were analytically studied, in order to closely examine the influence of the surcharge load applied to the retaining wall. Findings from this study are as follows: The shape of ground surface settlement curve on the model ground under surcharge load, different from the distribution curve of regular probabilities which is of a shape of ground surface settlement under no surcharge load, appears in that settlement in an arching shape shows where the center part of surcharge load shows the maximum settlement. In examining the maximum horizontal displacement with the surcharge load applied to each stage of excavation, it occured at the point of 0.8H(excavation depth) when finally excavated. Regarding the range in which the displacement of the retaining wall increases according to application of surcharge load, the increment of displacement showed till the point of depth which is of two times of the distance of load from the upper part of the wall. Also since each displacement of the foundation plate caused by the ground surface settlement according to each stage of excavation occured most significantly at the final stage. Also since regarding wall stiffness, the wall of its thickness of 4mm(flexible coefficient $p:480m^3/t$), produced maximum 3 times of wall stiffness than its thickness of 9mm(flexible coefficient $p: 40m^3/t$), it was found out that influence of wall stiffness is so significant.