• The Journal of Engineering Geology
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• v.23 no.1
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• pp.47-55
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• 2013

To analyze lateral displacement of excavation walls exposed during the construction of Subway Line 1 in the Daegu region, inclinometer measurement data for sites D4, D5, and Y6 are investigated from the perspective of engineering geology. The study area, in the Banyawol Formation, Hayang Group, Gyeongsang Supergroup, is in the lower part of bedrock of andesitic volcanics, calcareous shale, sandstone, hornfels, and felsite dykes that are unconformably overlain by soil. The rock mass around the D4 site is classified as RMR-V grade and the maximum lateral displacement of 101.39 mm, toward N34W, was measured at a bedding-parallel fault, at a depth of 12 m. The rock mass around the D5 site is classified as RMR-IV grade and the maximum lateral displacement of 55.17 mm, toward the south, was measured at a lithologic contact between shale and felsite, at a depth of 14 m. The rock mass around the Y6 site is classified as RMR-III grade and the maximum lateral displacement of 12.65 mm, toward S52W, was measured at an unconformity between the soil and underlying bedrocks, at a depth of 7 m. The directions of lateral displacement in the excavation walls are vector sums of the directions perpendicular to the excavation wall and horizontally parallel to the excavation wall. Lateral displacement graphs according to depth in the soil profile show curvilinear trajectories, whereas those in bedrock show straight and rapid-displacement trajectories.

• 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.

• Tunnel and Underground Space
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• v.17 no.5
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• pp.428-434
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• 2007

Displacement of tunnel face is important issues for the evaluation of tunnel safety. In this study, conventional convergence and displacement data measured from horizontal inclinometer were analyzed to investigate the trend and characteristics of tunnel deformation during construction. Trend of measured displacement agreed with general understanding of tunnel deformation prior to excavation. It shows that displacement measured from horizontal inclinometer can be used to preestimate the total deformation of tunnel.

• The Journal of Engineering Geology
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• v.27 no.1
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• pp.81-90
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• 2017

Preceding displacements in tunnel are difficult to predict since the measurements of displacements after excavation can not be performed immediately. In the present study, The longitudinal displacements which can be measured immediately after excavation are used to predict the crown settlements occurring before excavation only if fault is located at the tunnel crown. Three-dimensional finite element analysis was conducted using 28 numerical models with various fault attitudes to analyze the correlation between the longitudinal displacements on tunnel face and preceding crown settlements. The results, $L_{face}/C$ ratio show 2~12% in the drives with dip models and 2~13% in the drives against dip models individually. In addition, each model has a certain $L_{face}/C$ ratio. The result of the regression analysis show that the coefficient of determination is over 0.8 in most models. Therefore, crown settlements occurring before excavation can be predicted by analyzing the longitudinal displacements occurring on tunnel faces.

• Journal of the Korean Geotechnical Society
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• v.33 no.2
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• pp.17-26
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• 2017

Pile foundations that support offshore structures or transmission towers are dominantly subjected to cyclic lateral loads due to wind and waves, causing permanent displacement which can severely affect stability of the structures. In this study, a series of cyclic lateral load tests were conducted on a pre-installed aluminum flexible pile in sandy soil with three different relative densities (40%, 70% and 90%) in order to evaluate the permanent displacement of a cyclic laterally loaded pile. Test results showed that the cyclic lateral loads accumulated the irreversible lateral displacement, so-called permanent displacement. As the number of cyclic lateral load increased, accumulated permanent displacement increased, but the permanent displacement due to one loading cycle gradually decreased. In addition, the permanent displacement of a pile increased with decrement of relative density and decreased by soil saturation. From the test results, the normalized permanent displacement defined as the cumulative permanent displacement to the initial permanent displacement ratio was investigated, and empirical equations for predicting the normalized permanent displacement was developed in terms of relative density of the soil and the number of cyclic lateral load.

• Journal of the Korean GEO-environmental Society
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• v.11 no.11
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• pp.37-45
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• 2010

In this study, the value of numerical analysis was compared to the measured value of horizontal displacement during construction. And also, the value was reviewed by comparing with numbers calculated by SUNEX program and EXCAV program. When comparing to suggested values of the maximum horizontal displacement in clayey layer, the displacement caused by the IPS system is larger than one by the Strut girder type system. When comparing the result of SUNEX program to that of EXCAV program, the SUNEX program interprets larger value. It could be concluded the result of SUNEX program is closer to the suggested value, 0.5%H, in clayey layer. The result also shows that the internal friction angle(${\Phi}$) is the key factor of developing horizontal displacement rather than type of supporting systems or materials. That means small horizontal displacement occurs in sandy layer having large value of the internal friction angle, whereas vice versa in clayey layer having small value of the internal friction angle. Therefore, the result of EXCAV program is larger in sandy layer and vice versa in clayey layer. When comparing the measured result during construction to the value of 0.5%H, the measured result is 1.4 times greater than the value of 0.5%H. In contrast, the result of SUNEX program is only 78.1% of the value of 0.5%H and the one of EXCAV program is just 18.1% of that. This result shows the calculated value by SUNEX or EXCAV program is smaller than the observed value by measuring during construction. In result, more careful attention is needed to determine the behavior of the ground. To better analyze the behavior of the ground, more precise finite element method is required.

• Journal of the Korean GEO-environmental Society
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• v.9 no.7
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• pp.13-23
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• 2008

In this study, the centrifuge tests and numerical analyses were performed to investigate the lateral flow behavior and stability of abutment when high filling was applied on the soft ground improved by SCP. The centrifuge model tests and numerical analyses were fulfilled in the case of the back of abutment filled by EPS (case 1) and soil (case 2), and the potentiometer was installed on the abutment and fill to measure the vertical and horizontal displacement at the top of abutment. As a result of the centrifugal tests, the horizontal displacement of abutment in the case 1 was 1.4cm that is almost coincide with the results of numerical and satisfy the allowable standard. On the other hand, the horizontal displacement of abutment in the case 2 was 12 cm that is 18% greater than that of numerical analysis and exceed the allowable standard. As a result of analysis, the maximum horizontal displacement of pile was 1.26 cm in case 1 that satisfies the criterion of allowable horizontal displacement (1.5 cm). In contrast, the maximum horizontal displacement of pile was 1.005 m in case 2 that greatly exceeds the allowable horizontal displacement.

• Journal of the Korean GEO-environmental Society
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• v.13 no.8
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• pp.57-64
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• 2012

The lateral behavior characteristics of concrete group pile under the lateral load were examined by the laboratory model tests in this study. Piles were socketed 1D(D : pile diameter) in the concrete block, and model tests were executed on $2{\times}3$ group piles, of which the length were 11D, 15D and 20D. All results of loading tests under each condition was presented by the lateral load-displacement curves, and the displacements in the ground under the lateral loads were measured. As a results of model tests, as the ratio of pile length/diameter(L/D) was decreased, the yielding load and the lateral displacement at that load were increased. The yielding load was evaluated as the load at lateral displacement of 15 mm. The yielding loads at the pile length of 11D, 15D and 20D were 11.7, 6.2kN and 3.4kN. The lateral displacements of pile in the ground under each condition were measured linearly and the failure occurred at the location where the piles were socketed in concrete block.

• The Journal of Engineering Geology
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• v.26 no.3
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• pp.403-411
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• 2016

A three-dimensional finite element analysis was conducted to analyze the predictable distances of a fault zone by using longitudinal displacement on tunnel face, trend line, L/C ratio, and C/C₀ ratio at tunnel crown. The analysis used 28 numerical models with various fault attitudes. As a result, those faults that have drives with dip could be predicted earliest in L/C and C/C₀ ratio analysis. And those faults that have drives against dip could be predicted earliest in L/C ratio and longitudinal displacement analysis. In addition, the fault zone ahead of tunnel was predicted in most models by using longitudinal displacement, trend line, L/C ratio, and C/C₀ ratio. However, the longitudinal displacement among these methods may be most usefully predict a fault zone since it is displacements can be measured immediately after tunnel excavation.

• The Journal of Engineering Geology
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• v.18 no.4
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• pp.493-499
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• 2008

In order to evaluate the lateral behavior characteristics of single drilled shaft embedded in granite gneiss, a lateral load test was conducted in field. Horizontal displacement according to lateral load were measured along with the depth by an inclinometer installed in the shaft. In this study, We have evaluated horizontal displacement characteristics comparing the measurement values with calculating results by theoretical formula. Based on the comparison, the Chang's method was similar with the measurement values even though it was slightly underestimated. However, the finite analysis method and p-y method was overestimated, especially on the upper part of the ground.