• Journal of the Korean Geotechnical Society
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• v.17 no.4
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• pp.269-278
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• 2001

국내 30개의 교대측방이동 사례현장에 대하여 교대기초말뚝의 사면안정효과와 교대의 실측측방변위를 고려한 사면안정해석을 실시하였다. 해석결과 사면안전율은 말뚝의 효과를 무시한 경우 1.5이상, 말뚤의 효과를 고려한 경우 1.8이상 되어야 안전함을 알 수 있다. 그리고, 교대의 실측측방변위와 사면안전율과의 상관관계로부터 교대의 허용측방변위 설계기준은 5cm보다 1.5cm로 함이 더 합리적임을 알 수 있다. 사면안정해석결과와 교대의 실측측방변위를 토대로 기존에 제안된 교대측방이동 판정기준의 국내 적용여부를 검토한다. 이를 위하여 교대의 사면안정해석결과 및 실측측방변위와 교대측방이동 관련지수와의 상관관계를 조사한다. 그 결과 실측된 교대의 측방변위와 이를 고려한 사면안전율은 교대의 측방유동지수, 측방이동판정지수 및 지반의 안정계수와 무관한 경우도 많이 존재하는 것으로 나타났다. 이는 결국 이들 경험적인 지수만으로 교대측방이동을 판정하는 것은 불충분함을 의미한다. 따라서, 교대측방이동을 판정할 경우에는 반드시 교대의 측방변위를 고려한 사면안정해석이 실시되어야 한다.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1178-1189
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• 2010

낙동강 하구지역 연직배수공법이 적용된 연약지반에서 성토시 발생할 수 있는 지반의 측방변형에 대해 3개소 현장 35개 지점에서 수행한 현장 계측데이터를 분석하였다. 성토과정에서 측방변형 패턴 및 변형량을 파악하는데 가장 우선적으로 파악해야 할 계측항목이 지중경사계이며 지반특성별 측방변형 패턴(최대 측방변위발생 지점, 전단변위 발생지점, 지층에 따른 변위발생 형태 등)의 정밀 분석을 위해서는 지중경사계가 설치된 지점의 지층구성을 파악하는 것이 가장 중요하다는 것을 알 수 있었다. 최대 측방변위량과 성토체 중앙부 침하량과의 관계에서는 Tavenas et al.(1979)이 제안한 ${\Delta}_y=(0.18+0.09){\Delta}_s$이하로 관측되었다. 또한 측방변형 억제 및 인접지반의 동반침하를 차단하기 위해 보강된 D.C.M., C.I.P.구간에서는 Tavenas et al.(1979)이 제안한 ${\Delta}_y=(0.18-0.09){\Delta}_s$이하로 관측되었다. 최대 측방변위량과 성토속도와의 관계에서는 과잉간극수압 소산에 필요한 충분한 시간과 원활한 배수가 될 수 있도록 시공관리(성토속도조절, 배수관리 철저)하는 것이 무엇보다도 중요하다는 사실을 다시 한 번 확인 할 수 있었다. 마지막으로 편재하중 재하에 따른 인접 지반 및 구조물의 침하 및 기울기 변화는 측방유동에 의한 거동과 함께 압밀침하에 의한 제체의 체적감소로 인한 인접지반의 동반침하가 상당기간 동안 발생하고 있는 것으로 관측되었다.

• Journal of the Korean Geotechnical Society
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• v.17 no.4
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• pp.199-208
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• 2001

본 연구의 목적은 교대가 설치된 지반의 사면안전율과 교대측방변위의 관계를 분석하여 교대의 측방이동 판정기준을 마련하고자 함에 있다. 이를 위하여 국내의 연약지반에 설치된 30개 교대의 측방이동사례를 조사하고, SLOPILE (Ver 2.0)프로그램을 이용하여 교대의 측방변위와 교대기초말뚝의 사면안정효과를 고려한 사면안정해석을 실시한다. 해석결과 교대기초말뚝의 실측측방변위를 고려할 경우 1.8이상 되어야 한다. 또한, 교대기초말뚝의 허용측방변위량에 따른 사면안정 해석결과, 교대의 허용측방변위가 작게 규정될수록 사면안정성에 기여하는 말뚝의 효과는 감소하고 있음을 알 수 있다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.5
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• pp.423-427
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• 2005

In this paper, the lateral displacement of soft soil was measured in pier structure. The result was compared and investigated with the result of numerical analysis. The lateral displacement of soft soil was affected by lateral flow of soft soil due to embankment rather than settlement, and rapidly occurred at the embankment and preloading phases. The measurement and the numerical analysis showed very similar trend of lateral displacement but the magnitude was larger in numerical analysis than in measurement.

• Journal of the Korean GEO-environmental Society
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• v.5 no.2
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• pp.63-69
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• 2004

During and after the construction of embankment on soft ground, consolidation settlements and lateral displacements develop. But generally it's very difficult to predict the magnitude of lateral deformations and the correct distribution of lateral displacements with depth under the toe of embankment because the consolidation and the shear deformations of soft ground occur simultaneously. This study shows that later displacements of ground surface arise by embankment loading act on soft clay hight water contents in laboratory model testing. The results of model test are observed settlement of embankment, amount of maximum rising and displacement of ground surface with loading velocity. The formula were proposed to predict lateral movement by test series.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.6C
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• pp.239-247
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• 2012

Some methods were proposed to predict lateral flow due to embankments for road constructions on soft grounds, in which vertical drains were placed. In order to investigate the prediction methods of lateral flow, 200 field monitoring data for embankments in thirteen road construction sites at western and southern coastal areas of the Korean Peninsula were analyzed. For analyzing the relationship between the safety factor of embankment slope and the horizontal displacement in soft grounds where horizontal drain mats were placed, it was reliable to apply the maximum horizontal displacement in soft ground instead of the horizontal displacement at ground surface. The maximum horizontal displacement was developed less than 50mm in fields where the safety factor of slope was more than 1.4, while the one was developed more than 100mm in fields where the safety factor of slope was less than 1.2. In safe fields where the maximum horizontal displacement were developed within 50mm, lateral flow would not happen since shear deformation was not appeared. On the other hand, shear failure would happen in the fields where the maximum horizontal displacement were developed more than 100mm. In such fields, embankments might be continued after some appropriate countermeasures should be prepared. Safe embankments can be performed on soft grounds, in which the stability number is less than 3.0 and the safety factor for bearing is more than 1.7. However, if the stability number is more than 4.3 and the safety factor for bearing is less than 1.2, shear deformation would begin and even shear failure would happen.

• The Journal of Engineering Geology
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• v.11 no.2
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• pp.175-190
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• 2001

This study investigates the existing theoretical backgrounds in order to examine the behavior of lateral flow according to the plasticity of soils when unsymmetrical surcharge is worked on polluted soft soils by comparing and analyzing the results measured through model tests. Model tests are canied out as follows soil tank, bearing frame and bearing plate are made. By increasing unsymmetrical surcharge to the ground soils with the consistent water content and with gradually increased polluted materials at intervals, the amounts of settlement, lateral displacement and upheaval were respectively observed. In conclusion, the value of critical surcharge was expressed as q$_{cr}$=2.78$_{cu}$ which was similar to those Tschebotarioff(q$_{cr}$=3.0$_{cu}$) and Meyerhof(q$_{cr}$=(B/2H+$\pi$/2)$_{cu}$) had been proposed. The value of ultimate capacity was expressed as q$_{ult}$=4.84$_{cu}$ which was similar to that of Prandtl. The lateral flow pressure is adeQuately calculated by the eQuation(P$_{max}$=K$_o$ r H) and the maximum value of lateral flow pressure is found near O.3H of layer thickness(H) and is higher to ground surface than the ones in composition pattern, Poulos distribution pattern and softclay soils (CL, CH) which is not polluted. The stability control method used in this research followed the management diagram of Tominaga.Hashimoto, Shibata.Sekiguchi, Matsuo.Kawamura who use the amounts of plasticity displacement by lateral flow. As a result, the ultimate capacity values in the diagram {S$_v$-(Y$_m$/S$_v$)} of Matsuo.Kawamura and in the diagram {(q/Y$_m$)-q} of Shibata. Sekiguchi were smaller than in the ones of load-settlement curve (q-S$_v$).

• Journal of the Korean GEO-environmental Society
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• v.12 no.4
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• pp.33-41
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• 2011

In case of building up port facilities on soft ground, unsymmetrical surcharge of embankment, which make the excess pore water pressure to increase, causes to occur lateral displacement due to plasticity of soil. A study on lateral displacement and settlement of the caisson, which is installed on improved ground, was accomplished. The field measurement data and calculated values obtained from FEM program of Plaxis were compared and analyzed. For numerical analysis, the properties of soils, constructions stage and time were considered. Lateral displacement was measured at the point of inclinometers installed in front of caisson. Settlement was measured at the center of extra embankment behind of caisson. Comparison of measured and calculated for lateral displacement showed that the calculated value was greater than the measured, and increasing trend was different. The calculated value showed step increasing as step extra embankment applied, whereas the measured gradually was increased. For settlement of embankment, the amount of both measured and calculated were similar, but the trend was different like that of lateral movement.

• Journal of the Korean Geosynthetics Society
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• v.19 no.3
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• pp.35-44
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• 2020

This study described the result of laboratory model tests, in order to compare the improvement effect of the DCM column installed on the soft ground according to DCM column type. In the laboratory model test, the non-reinforced type and the 3 types of DCM column were applied, and the behavior (settlement, lateral flow) of soft ground was evaluated under the surcharge load condition for each type. The settlement evaluation result showed that the settlement of soft ground without DCM column occurred rapidly under the low load condition, but the settlement of the soft ground with the DCM column had relatively small settlement. The evaluation result of lateral flow in the soft ground showed that the soft ground with DCM column had lower lateral displacement than the soft ground without DCM column. Especially, the lateral displacement under the same load condition decreased in the order of pile type, wall type, and grid type. Therefore, it confirmed that the improvement effect of soft ground was excellent when the DCM of grid type was applied for settlement and lateral flow.

• Journal of the Korean GEO-environmental Society
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• v.13 no.2
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• pp.27-39
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• 2012

This research is to propose the reinforcing method and design code for the lateral behaviors of the abutment displacement induced from the rainfall infiltration on high landfill slope. First, to make the proper numerical analysis, in-situ soil (weathered granite soil) was taken, and the variance of strength parameters according to water content variance was examined by undrained direct shear test, furthermore, other soil parameters were calculated from the standard penetration test such as elastic modulus and Poisson's ratio etc,. Those parameters were used to calculate the lateral behavior of abutment by finite element method and the member force of pile in high landfill slope according to rainfall infiltration . From the results, the shoe displacement on abutment was calculated as 8.98cm, which is 3 times bigger than the allowable displacement, 3cm. To reinforce it, several reinforcing methods were selected and analyzed such as reinforced retaining wall, soil surcharge, pile reinforcing (5m enlargement, 3-line arrangement, 5m enlargement and 3-line arrangement). In case of 5m enlarged and 3-line arrangement piles, the lateral behavior of shoe showed lower value(2.26 cm) than allowable displacement.