• Geotechnical Engineering
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• v.13 no.4
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• pp.13-24
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• 1997

A predicting method for ultimate vertical and horizontal bearing capacity by means of PAR(Pile Analysis Routines) was suggested. Based on the static pile load test data, case studies by means of PAR were performed. Ultimate pile capacity predicted by PAR was within 15% error range of that determined by stairs pile load tests. Also, the results of static pile load test, statnamic tests and PDA data performed on pipe piles were compared and, by using PAR, ultimate pile capacity was determined. Distributions of atrial pile load could be predicted and load transfer analysis could be done approximately by those distributions.

• Journal of the Korean Geotechnical Society
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• v.33 no.6
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• pp.27-36
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• 2017

Gravel compaction pile method has been widely used to improve the soft ground on the land or sea as one of the soft ground improvement technique. The ultimate bearing capacity of the ground reinforced by gravel compaction piles is affected by the soil strength, the replacement ratio of pile, construction conditions, and so on, and various prediction equations have been proposed to predict this. However, the prediction of the ultimate bearing capacity using the existing models has a very large error and variation, and it is not suitable for practical design. In this study, multiple regression analysis was performed using field loading test results to predict the ultimate bearing capacity of ground reinforced by gravel compaction pile, and the most efficient input variables are selected through evaluation of error by leave one out cross validation, and a multiple regression equation for the prediction of ultimate bearing capacity was proposed. In addition, the prediction error was evaluated by applying artificial neural network using the selected input variables, and the results were compared with those of the existing model.

• Journal of the Korean GEO-environmental Society
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• v.6 no.3
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• pp.47-54
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• 2005

In many practical cases, design methods of pile have been used mainly semi empirical bearing capacity equations. It can be done that confirmation of pile bearing capacities through using of dynamic and static tests during constructing or after constructions. If a prediction of layered point pile bearing capacity could be done through simple tests during field investigation, it could be done that more reliable design of pile than a prediction of using semi empirical equations or static formulations. This paper suggests a method to estimated point bearing capacity during in-situ investigation by using the dynamic rod model pile and verifies the point bearing capacity compare with results of static pile load tests. From test results, the unit ultimate point bearing capacities are relatively similar through a dynamic rod model pile tests and static pile load tests. The unit ultimate point bearing capacity by using N value is shown about 50 % value of measured unit ultimate point bearing capacity from field test result and the prediction of the unit ultimate point bearing capacity by using N value is shown very conservative, illogical and uneconomical pile designs.

• Journal of the Korean Society of Safety
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• v.18 no.1
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• pp.81-88
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• 2003

Recently, pile foundations were constructed in rough or soft ground than ground of well condition thus it is important that prediction of ultimate bearing capacity and calculation of proper safety factor applied pile foundation design. This study were performed to dynamic loading tests for the thirty two piles at four different construction sites and selected pile at three site were performed to static loading tests and then compare with measured value and value of static and dynamic loading tests. The load-settlement curve form the dynamic loading tests by CAPWAP was very similar to the results obtained from the static load tests. Based on dynamic and static loading tests, the reliability of pile-driving formula were analyzed and then suggested with proper safety factor for prediction of allowable bearing capacity in this paper.

• Journal of the Korean Geotechnical Society
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• v.34 no.6
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• pp.37-47
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• 2018

In this study, 34 laboratory load test data were collected, and analyzed to propose the equations for predicting ultimate bearing capacity of sand compaction pile (SCP) and gravel compaction pile (GCP) reinforced clay. The collected data were compared with the ultimate bearing capacity estimated by existing theoretical equations, and the prediction accuracy of the existing theoretical equations was identified. Also, multiple regression analysis was performed to predict the ultimate bearing capacity, and the most efficient number and type of input variables were selected through error evaluation by leave-one-out cross validation. Finally, the multiple regression equations for estimating the ultimate bearing capacity of laboratory load test for SCP and GCP were proposed, and their performance was evaluated.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.4C
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• pp.145-151
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• 2009

In general, a drilled shaft embedded in weathered rock has a large load bearing capacity. Therefore, most of the load tests are performed only up to the load level that confirms the pile design load capacity, and stopped much before the ultimate load of the pile is attained. If a reliable ultimate load value can be extracted from the premature load test data, it will be possible to greatly improve economic efficiency as well as pile design quality. The main purpose of this study is to propose a method for judging the reliability of the ultimate load of piles that is obtained from extrapolated load test data. To this aim, ten static load test data of load-displacement curves were obtained from testing of piles to their failures from 3 different field sites. For each load-displacement curve, loading was assumed as 25%, 50%, 60%, 70%, 80%, and 90% of the actual pile bearing capacity. The limited known data were then extrapolated using the hyperbolic function, and the ultimate capacity was re-determined for each extrapolated data by the Davisson method (1972). Statistical analysis was performed on the reliability of the re-evaluated ultimate loads. The results showed that if the ratio of the maximum-available displacement to the predicted displacement exceeds 0.6, the extrapolated ultimate load may be regarded as reliable, having less than a conservative 20% error on average. The applicability of the proposed method of judgment was also verified with static load test data of driven piles.

• Journal of the Korean Geotechnical Society
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• v.15 no.2
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• pp.73-80
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• 1999

Analytical studies on piles so far have been directed toward prediction of bearing capacity under vertical loads. Various static and dynamic formulas have been used in predicting the ultimate bearing capacity of a pile. Further, the reliability of these formulas has been verified by comparing the predicted values with the pile load test measurements. Accordingly, by means of the ultimate load from the data measured by the actual field load tests of PHC piles, safety factors were compared and analyzed static and dynamic formula methods applying to 4 different sites. As a result, the safety factor by Meyerhof formula method indicates 3.0 and the safety factor by Hiley formula method indicates 5.0.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.744-747
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• 2008

In this study, to analyze the rotation point of piles, the laboratory lateral load test was performed. The lateral load bearing capacity is one of the important factor related with structure failure directly. Analyzing rotation point in different soil condition, relative density and stress condition, leads more accurate ultimate lateral bearing capacity. Also, reliability was analyzed about established 예측식 as applying to tapered pile. As a result, the established prediction was suitable to cylider pile, but not to tapered pile.

• Journal of the Korean Geotechnical Society
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• v.19 no.4
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• pp.95-105
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• 2003

The existing design criteria f3r the estimation of ultimate bearing capacity of drilled shaft socketed into rock masses are mainly obtained from the ultimate pile load capacities, which are determined by inconsistent failure criteria. Therefore, these design criteria generally produce difffrent predictions even for drilled shaft in the same condition. In this paper, the accuracies of the existing design criteria are investigated to develop an optimized design process for drilled shaft socketed into rock masses. Reasonable and consistent ultimate capacities of drilled shafts socked into rock masses, necessary far the check of accuracies of predictions, are determined by applying a specific failure criterion to a total of 11 pile load test results. A comparison between the predicted and the measured load capacities shows that ultimate base load capacities calculated from Zhang and Einstein's equation and NAVFAC are close to the measured values. Rosenberg and Journeaux's equation produces satisfactory prediction f3r ultimate side load capacity.

• Geomechanics and Engineering
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• v.11 no.2
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• pp.235-252
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• 2016

This paper presents a new numerical solution of the ultimate lateral capacity of rectangular piles in clay. The two-dimensional plane strain finite element was employed to determine the limit load of this problem. A rectangular pile is subjected to purely lateral loading along either its major or minor axes. Complete parametric studies were performed for two dimensionless variables including: (1) the aspect ratios of rectangular piles were studied in the full range from plates to square piles loaded along either their major or minor axes; and (2) the adhesion factors between the soil-pile interface were studied in the complete range from smooth surfaces to rough surfaces. It was found that the dimensionless load factor of rectangular piles showed a highly non-linear function with the aspect ratio of piles and a slightly non-linear function with the adhesion factor at the soil-pile interface. In addition, the dimensionless load factor of rectangular piles loaded along the major axis was significantly higher than that loaded along the minor axis until it converged to the same value at square piles. The solutions of finite element analyses were verified with the finite element limit analysis for selected cases. The empirical equation of the dimensionless load factor of rectangular piles was also proposed based on the data of finite element analysis. Because of the plane strain condition of the top view section, results can be only applied to the full-flow failure mechanism around the pile for the prediction of limiting pressure at the deeper length of a very long pile with full tension interface that does not allow any separation at soil-pile interfaces.