• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.69-72
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• 2008

The so-called Pier-Shafts system which consists of the continuous column and shaft is often used to support the highway bridge structure because of advantages in easy construction and low cost. In the earthquake region, the Pier-Shafts system undergoes large displacements and represents a nonlinear behavior under the lateral seismic loading. The soil-pile interaction should be considered for more accurate analysis of the Pier-Shafts system. In this study, a transverse response of a reinforced concrete Pier-Shafts system inside multi-layered soil medium is predicted using a finite element program which adopts an elasto-plastic interface model for the interface behavior between the shaft and the soil. Then, seismic analysis is performed to evaluate the performance of Pier-Shafts system under strong ground motion and their results are verified with experimental data.

• Journal of the Korean Geotechnical Society
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• v.35 no.7
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• pp.5-14
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• 2019

In this study, a prototype abutment was constructed to establish a safety assessment technique of pier and a series of non-destructive tests using impact load. The surcharge load was loaded from 0 tonf to 2.5 tonf on the prototype abutment, and maximum surcharge load was up to 25 tonf. To analyze the behavior of the piers according to the direction of impact, a total of three types of analysis were performed: the direction of the pier, the direction perpendicular to the pier, and the outer direction of the pier. The height of the impact was also tested at each top and bottom. The measuring instrument used an accelerometer to measure the acceleration response when impacted. Based on the series of experimental results, specific values were calculated according to the direction of an impact and the surcharge load using the Fast Fourier Transform (FFT). In addition, the phase difference was used to analyze the pier from the primary 1st mode to the 4th mode.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.337-340
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• 2011

In this study, qualitative and quantitative evaluations are performed using the hydraulic analysis of fiber stone for bridge pier scour protection. We can consider that the effective scour protection should be suggested from the side of hydraulic stability, structure stability, and permissible tractive force. The perfect verification, however, on the fiber stone for bridge pier scour protection is not sufficient because of short literatures and experiments on the field study. The continuous research, therefore, will be needed to establish reliable verification using literatures investigation and the various experiments on the fiber stone for bridge pier scour protection.

• Explosives and Blasting
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• v.25 no.2
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• pp.47-60
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• 2007

The blast demolition technology has been used to demolish various industrial facilities and tall buildings since 1950s in the advanced countries such as USA and U.K. It is now considered as one of safe demolition methods in the above countries. In Korea, several companies have tried to introduce blast demolition technology in the early days of the 1990s. However, this technology is still at the beginning stage and not fully adopted due to situation of avoiding technology transfer by overseas technical tie-up companies, lack of objects to be demolished and low level recognition on blast demolition. This technology shall be considered as a cutting edge technology to be applicable to demolition of skyscrapers, various industrial structures and factory buildings in the near future. Blast demolition of a pier structure was carried out under the site condition where there were already the constructed 2 pier structures of up and down line which had safety problems in an expressway construction project. The pier structures need to be demolished and reconstructed for a short period of time in consideration of the construction work process to be followed.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1993.04a
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• pp.45-52
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• 1993

Evaluation of structural stability of aged wharf structure of pier type is of great importance for both safety and rehabilitation, Series of field dynamic experiments were performed for berthing impact and the results were used to calibrate analysis model. Through dynamic analysis for design, berthing impact safety of old wharf structure were evaluated. In this paper the procedure and results of experiments and analysis are presented.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1994.10a
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• pp.71-78
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• 1994

The main objectives of the study may be stated as follows : \circled1 the acquisition of fundamental updated data for the assessment of aged wharf structures of pier type based on systematic static/dynamic load testing \circled2 the study of techniques and methods for field testing \circled3 realistic safety and load carrying capacity assessment based on practical reliability analysis. In this study field testing of real structure is performed and the results are compared with those of the 2D and 3D linear structural analysis. It may be seen that the practical reliability methods can be applied for the safety and capacity assessment of aged wharf structures of pier type.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.297-302
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• 2001

SRC pier at KTE 6-1 construction area is a very important structure. Precise control of quality is needed. This pier has 3.50m$\times$3.73m section and 38.20m length. So this structure must be treated as mass concrete and thermal crack caused by hydration heat should be controled. In this project belite cement concrete is used to control the thermal crack. As a result of adapting belite cement concrete perfect control is achieved. Finally, hydration heat FEM analysis of horizontal element is executed for Ordinary Portland Cement concrete and belite cement concrete. In comparison of two results, it is confirmed that using low heat portland cement concrete is necessary.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.115-118
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• 2005

In this study, small scale model test was performed to verify the ultimate load capacity of spillway pier structure under static load. The 1/20 scale test specimen was made of specially designed micro-concrete and wire mesh. From the test result, the cracking load of specimen was 10 tonf and the ultimate was 19tonf. From the similarity rule, cracking and ultimate load of prototype pier structure were predicted 4000 tonf, 7600 ton, respectively.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.598-604
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• 2010

The drilled pier foundation is widely used to support transmission line structures due to its simplicity of construction. When this foundation type is used in conjunction with a single shaft or H-frame structure, it is subjected to a high overturning moment, combined with modest vertical and shear loads. Since the length and diameter of drilled piers are often governed by a maximum permissible deflection, many drilled piers being installed today are very conservatively designed. In this study, Nine prototype field-tests (1/8 scale) have been conducted in order to determine the vertical and lateral resistance of drilled pier foundation for single pole structures. These test results reveal the test piers behaved essentially as rigid bodies in soil (6D) and the center of rotation of the pier were typically 0.6~0.4 of the pier depth below ground surface. Test results also show the relationship between the applied load and the deflection at the top of the pier is highly nonlinear.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.1087-1094
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• 2008

The drilled pier foundation is widely used to support transmission line structures due to its simplicity of construction. When this foundation type is used in conjunction with a single shaft or H-frame structure, it is subjected to a high overturning moment, combined with modest vertical and shear loads. Since the length and diameter of drilled piers are often governed by a maximum permissible deflection, many drilled piers being installed today are very conservatively designed. In this study, Five prototype field-tests (1/8 scale) have been conducted in order to determine the lateral resistance of drilled pier foundation for single pole structures. These test results reveal the test piers behaved essentially as rigid bodies in soil (6D) and the center of rotation of the pier were typically 0.6~0.4 of the pier depth below ground surface. Test results also show the relationship between the applied load and the deflection at the top of the pier is highly nonlinear.