• Proceedings of the Korean Geotechical Society Conference
• /
• 2003.03a
• /
• pp.431-438
• /
• 2003

The domestic design method for the shaft resistance of drilled shafts into a bedrock Is based on the empirical method, where the uniaxial compressive strength of rock specimen is utilized for calculation of the shaft resistance. This method has uncertainties in prediction of capacity of drilled shafts and result in uneconomic engineering design. Recently a new improved design method was suggested, which reflects important factors that affect the strength of pile sockets. Socket roughness is one of significant factors influencing the shaft resistance of drilled shaft socketed into rock In this paper roughness information for the shaft resistance design of socket pile was suggested on the basis of statistical analysis of data measured from wall surface In the bore holes of drilled shafts.

• The Journal of Engineering Geology
• /
• v.32 no.4
• /
• pp.671-684
• /
• 2022

This study verified the stability of a high-strength combined buried pile retaining wall and its applicability in the field. A cast-in-place (C.I.P) retaining wall and the high-strength combined embedded pile retaining wall were compared and analyzed numerically. The numerical analysis assessed the ground behavior and stability (and thus field applicability) of a high-strength combined buried pile retaining wall using data measured in the field. The experimental results showed that the cross-sectional force and displacement of the high-strength bonded pile retaining wall were reduced by 13.6~19.7%, the shear force increased by 0.7~4.7%, and the bending moment increased by 4.5~8.8% relative to the values for the C.I.P retaining wall. Examination of the amount of subsidence in the ground around the excavation showed that the maximum settlement of the C.I.P retaining wall was 46.89 mm and that at the high-strength combined buried pile retaining wall was 39.37 mm. Overall, designing a high-strength combined embedded pile retaining wall by applying the maximum bending moment and shear force calculated using the elastic beam method to the site ground was shown to achieve the safety of all members, as member forces were generated within the elastic region.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.5 no.4
• /
• pp.23-30
• /
• 1985

Dynamic pile-driving formulas are widely used in predicting the load capacity of piles in cohesionless soils. However, the accuracy of the formulas has been questioned for a long time due to their oversimplified assumptions and empirical parameters involved in the formulas. The allowable pile capacities calculated by 6 different dynamic pile-driving formulas are compared statistically with the capacities measured in the field, in this paper, to find out the correlations between the calculated capacities and the measured values. The statistical data are then used to evaluate and to adjust the formulas to improve their accuracy. For the greatest accuracy and simplicity of use, it is recommended that the adjusted form of Gates formula be used. When the result of this recommended formula is compared with that of the existing Olson's modified formula, the former is found to be conservative by more than 10 percents.

• Earthquakes and Structures
• /
• v.12 no.6
• /
• pp.629-641
• /
• 2017

Foundation plays a significant role in safe and efficient turbo machinery operation. Turbo machineries generate harmonic load on the foundation due to their high speed rotating motion which causes vibration in the machinery, foundation and soil beneath the foundation. The problems caused by vibration get multiplied if the soil is poor. An improperly designed machine foundation increases the vibration and reduces machinery health leading to frequent maintenance. Hence it is very important to study the soil structure interaction and effect of machine vibration on the foundation during turbo machinery operation in the design stage itself. The present work studies the effect of harmonic load due to machine operation along with earthquake loading on the frame foundation for poor soil conditions. Various alternative foundations like rafts, barrette, batter pile and combinations of barrettes with batter pile are analyzed to study the improvements in the vibration patterns. Detailed computational analysis was carried out in SAP 2000 software; the numerical model was analyzed and compared with the shaking table experiment results. The numerical results are found to be closely matching with the experimental data which confirms the accuracy of the numerical model predictions. Both shake table and SAP 2000 results reveal that combination of barrette and batter piles with raft are best suitable for poor soil conditions because it reduces the displacement at top deck, bending moment and horizontal displacement of pile and thereby making the foundation more stable under seismic loading.

• Journal of the Korean Geophysical Society
• /
• v.7 no.4
• /
• pp.305-311
• /
• 2004

Several sensor systems are used to estimate the reinforceing effect of pile in hihg cut slopes, and to find a failure zone in slopes effectively. Inclinometer, extensometer and V/W sensor have shown a great potentiality to serve real time health monitoring of the slope structures. They were embedded or attached to the structures, we conducted field tests and test results have shown great solutions for sensor systems of Civil Engineering Smart Structures. This research is to seek for the relationships among the slope movement and the reinforceing effect of pile, and the strain distribution in a active zone by analyzing the data from the in-situ measurement so that the possible failure zone should be well defined based on the relationships. Also, the relationships between temperature and reinforceing effect of pile, and the strain distribution are estimated in this paper.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2005.03a
• /
• pp.677-686
• /
• 2005

The allowable bearing capacity of a pile, the most important factor in stability estimation, is determined by applying safety factor to the ultimate load or yield load. There are several but contradictory methods available in current design codes to estimate the allowable bearing capacity and the safety factor. This paper analyzes load-settlement curves obtained from 19 static load tests measured from 11 sites. At all tests, the load is applied until apparent failure is observed. The validity of the ultimate and yield load estimation method and load caculated from the settlement criterion is investigated through comparison with the measured data. In addition, a new procedure to estimate allowable load and safety factor is proposed. Additional data from field static load tests, such as those incorporated in this study, are needed to more reliably apply the proposed method in design practice.

• Geotechnical Engineering
• /
• v.11 no.2
• /
• pp.19-28
• /
• 1995

Based on the various test data acquired in the field, the large pressure chamber and the small pressure chamber, uplift behaviors and method of determining the ultimate uplift capacity of pile driven in small pressure chamber were studied. After uplift pile experienced 2 or 3 sudden slip due to increase of uplift load, complete pullout failure was occurred. Thus, it appears that the ultimate uplift capacity could be identified as the load at displacement where first slip occurs. The ultimate uplift capacity might be determined in every test and the disturbance after first uplift test could be recovered by adding one blow of the drop hammer, which had to depend on the model pile capacity.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.8 no.3
• /
• pp.33-42
• /
• 2005

The bearing methods using pile of steel itself or reinforced concrete has been applying which in excavated depth was not deep. Also, the retaining wall as resisting structure to lateral force has taken weakness that the cure periods of concreted is long. Recently, with the material cost of steel, the application of cement is more increasing trend. In this study, the design methods of earth retaining and retention wall within the pre-casted concrete pile, PHC(Pretentioned spun High strength Concrete piles), was proposed which in the ground condition of excavated depth was not deep. The typical ground conditions, cohesive and non-cohesive soil, was considered as follows; soil strength as internal friction angle and UU(Undrained Unconsolidation triaxial test) strength, soil reaction and stabilization of structures. The application of design methods could be confirmed through the comparing and analyzing between measured data and utility software for the design.

• Korean Journal of Construction Engineering and Management
• /
• v.23 no.2
• /
• pp.45-53
• /
• 2022

The purpose of this study is to present a model for analyzing construction errors of reinforced concrete pile foundations using drones. First, a drone is used to obtain an aerial image of the construction site, and an orthomosaic image is generated based on those images. Then, the circular pile foundation is automatically recognized from the orthomosaic image by using the Hough transform circle detection method. Finally, the distance is calculated based on the the center point of the reinforced concrete pile foundation in the overlapped data. As a case study, the proposed concrete concrete pile foundation construction quality control model was applied to the real construction site in Incheon to evaluate the proposed model.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2002.03a
• /
• pp.413-420
• /
• 2002

Recent experimental research results of connection method between steel pipe pile and concrete footing are provided based on various experimental observations. It gives a shedding light toward developing better and concrete connection method for steel pipe pile at the field application. In this study, the newly developed method is tested for compressive, pull put and combination load including moment with carefully designed monitoring system. The measured data show that new method have at least equivalent or better load resistant capacities compared with those of specified method in Korea Highway Corporation design code. It is also tried to define and investigate the load transfer mechanism for new method.