• Proceedings of the Korean Geotechical Society Conference
• /
• 2010.09a
• /
• pp.553-558
• /
• 2010

The behavior of composite piles composed of steel pipe pile in the upper part and concrete pile in the lower part by a mechanical splicing joint was examined by field lateral load tests and bending tests. A total of 7 piles including two instrumented piles for bending test were installed. The soil profile consists of soft clay with weak silt with shallow groundwater level. Laboratory tests were carried out to determine the basic soil characteristics and the strength parameters. This paper presents the composite pile behavior with various portions of the upper steel pile: 0, 20, 30, and 45% of the pile embedded pile length. Three-point bending tests were performed to investigate the stress-strain relation at the mechanical joint. Based on these test results, the behavior of composite piles with various upper steel pile length are evaluated and the stability of mechanical joints are examined. Through comparisons with results of field load tests, it was found that lateral load carrying capacity of the composite piles increased and deflections of the composite piles decreased with increasing the upper steel piles. The mechanical joint was proved to retain its structural stability against the tested load conditions. Economical benefits of composite pile of this kind can be gained by setting adequately the length of the upper steel pipe piles.

• Structural Engineering and Mechanics
• /
• v.61 no.1
• /
• pp.117-124
• /
• 2017

Load testing is one of the important tests to determine if the structural elements can be used at the intended locations for which they have been designed. It is nothing but gradually applying the loads and measuring the deflections and other parameters. It is usually carried out to determine the behaviour of the system under service/ultimate loads. It helps to identify the maximum load that the structural element can withstand without much deflection/deformation. It will also help find out which part of the element causes failure first. The load-deflection behaviour of the road bridge girder has been studied by carrying out the load test after simulating the field conditions to the extent possible. The actual vertical displacement of the beam at mid span due to the imposed load was compared with the theoretical deflection of the beam. Further, the recovery of deflection at mid span was also observed on removal of the test load. Finally, the beam was checked for any cracks to assert if the beam was capable of carrying the intended live loads and that it could be used with confidence.

• Journal of the Korean Geotechnical Society
• /
• v.23 no.9
• /
• pp.51-63
• /
• 2007

Behavior of rock-socketed drilled shafts subjected to axial load was investigated on the basis of pile load tests. The emphasis was laid on analyzing the shear load transfer characteristics from the shafts to surrounding rock. Field load tests were performed on nine test shafts under various conditions such as weathering of rock mass, borehole roughness, pile diameters, and loading directions. The borehole roughness at each test site was profiled using a laser borehole profiler. In order to evaluate and to propose ultimate shaft resistance($f_{max}$) of drilled shafts in rock of Korean peninsular, also, database of pile load tests was developed by reviewing various literature and technical reports.

• 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.

• Proceedings of the KSME Conference
• /
• 2004.11a
• /
• pp.359-364
• /
• 2004

In this study, experiments were tried on the mixed-mode I+II single overloading model which changes the loading mode of overload and fatigue load. Aspects of deformation field in front of the crack which is formed by mixed-mode I+II single overloading were experimentally studied. Then the shape and size of mixed-mode plastic zone were approximately calculated. The propagation behavior of fatigue crack was examined under the test conditions combined by changing the loading mode. The behavior of fatigue cracks were greatly affected by shapes of plastic deformation field and applying mode of fatigue load. Accuracy of prediction and evaluation for fatigue life may be improved by considering all aspects of deformation and behavior of fatigue cracks.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2002.10a
• /
• pp.350-357
• /
• 2002

The scale effect should be considered to determine the bearing capacity and settlement of footings from Plate-Load Test, because of the size difference between a footing and a loading plate. To analyze characteristics of bearing capacity and settlement according to the difference of loading plate sizes, model tests were peformed with four different sizes of square plate, which is B=10, 15, 20 and 25cm respectively, on five different kinds of subsoil, which is pure sand(100:0), sand-clay mixed soil(75:25, 50:50, 25:75), and pure clay(0:100). Based on the analyzed results, this paper also proposed a method of bearing capacity and settlement determination, where scale effect is considered depending on the mixing ratio of sand and clay. Applying the formular proposed in this research to field problems, it is expected that evaluation of bearing capacity and settlement of footings can be more reliable and more economic construction can be achieved.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.26 no.1A
• /
• pp.35-43
• /
• 2006

In this paper, procedures and research results involved in the development of glass reinforced composite bridge deck of hollow section were presented. Laminate design for the 3 cell deck section was performed. Structural characteristics such as serviceability, strength, failure and stability for DB24 load were analytically studied through the finite element analysis for the composite deck plate girder bridge. Composite deck tube was fabricated with pultrusion and extensive tests such as flexural test, girder-connection test, barrier-connection test, compression fatigue test and flexural fatigue test were carried out to evaluate structural behavior experimentally. Also, field load test was conducted for the demonstration plate girder bridge with composite deck and requirements for the strength and serviceability were reviewed.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.52 no.3
• /
• pp.101-106
• /
• 2003

The high temperature superconductor transformers gain interests from the industries. This paper described construction and test results of 10㎸A HTS transformer Three phase transformer with double pancake windings were constructed. To reduce the leakage magnetic field, secondary coil were placed between the two primary coils. BSCCO-2223 wire. silicon sheet steel core and FRP cryostats were used to construct the transformer. Three coils were stacked in one cryostat. Two double pancake coils were connected in series for the primary coil and one double pancake coil was used for the secondary coil. Total number of turns of the primary winding and the secondary winding were 112turns and 98urns, respectively, The rated voltages of each winding were 440/220V. The rated currents of each winding were 13.1/26.2A. After the tests of basic properties of the three phase HTS transformer using no-load test, short-circuit test and full-load test, continuous operation of 100 hours with pure resistive load has been carried out. Test results proved over-load capability and reliability of the HTS transformer.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.3 no.2
• /
• pp.141-146
• /
• 1999

Recently, many existing bridges has been evaluated for maintenance and protection of collapse. In this study, field measurement according to truck loads tests on the reinforce concrete T beam bridge was carried out. Comparing the results of load test and structural analysis using the moments of inertia of gross section, crack section and effective section, and the moments of inertia of section considering depth of crack, it is conclude that the evaluation of load carrying capacity using the stress modification factor from structural analysis using the moments of inertia of gross section is more rational than using the other moments of inertia of sections.

• Korean Journal of Materials Research
• /
• v.34 no.2
• /
• pp.72-78
• /
• 2024

The lightweight and high strength characteristics of aluminum alloy materials make them have promising prospects in the field of construction engineering. This paper primarily focuses on aluminum alloy materials. Aluminum alloy was combined with concrete, wood and carbon fiber reinforced plastic (CFRP) cloth to create a composite column. The axial compression test was then conducted to understand the mechanical properties of different composite structures. It was found that the pure aluminum tube exhibited poor performance in the axial compression test, with an ultimate load of only 302.56 kN. However, the performance of the various composite columns showed varying degrees of improvement. With the increase of the load, the displacement and strain of each specimen rapidly increased, and after reaching the ultimate load, both load and strain gradually decreased. In comparison, the aluminum alloy-concrete composite column performed better than the aluminum alloy-wood composite column, while the aluminum alloy-wood-CFRP cloth composite column demonstrated superior performance. These results highlight excellent performance potential for aluminum alloy-wood-CFRP composite columns in practical applications.