• Explosives and Blasting
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• v.27 no.2
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• pp.42-47
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• 2009

Ground vibrations caused by pile driving or explosive blasting can affect the stability of power line tower and its foundation. Because the characteristics of ground vibrations generally depend on the distances from the blast, the ground vibrations should be controlled by taking the distance into account. In this study, ground vibration levels were measured at the foundation of a power line tower and on ground surface adjacent to the tower. The relationships between the dominant frequencies of the ground vibrations that were measured at both locations were comparatively investigated.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.4
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• pp.393-401
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• 2003

Automatic control technologies for the marine pile driving provides accurate and rapid intruding into the planned positions of the pile with planned slope and direction, so that the construction maintenance and management are more efficient and the quality of the construction is more promising. Therefore, in this study, the application scheme of RTK GPS to the automatic control of the pile driving presented. It is expected that the presented scheme using the precise RTK GPS technique assures the efficient and economic 3D positioning accuracy for the precise marine construction management like the precise foundation of marine structures made of piles and the dredging work. It is found that the suggested scheme decrease 60% of the construction error compared with specifications reference because marine position accuracy is measured within 4cm in real time. In addition, the automatic position control system using GPS reduced the construction period and cost compared with existing methods about 30% and 35%, respectively.

• Journal of the Korean Geosynthetics Society
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• v.16 no.4
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• pp.1-11
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• 2017

In this study, 1/6 small-scale model tests of helical piles were conducted to evaluate their installation time and ultimate capacities. Model sand layers were constructed using sand pluviating method to produce uniform soil relative density. For installation of different helical piles varying locations (vertical center-to-center spacings of 50 mm and 150 mm) of helix plates, two different rotation speeds of 15 rpm and 30 rpm were implemented. Cone penetration equipment was installed within the hallow section of the helical pile to increase ultimate capacity of helical pile and to evaluate soil properties of plugged soils and soils below pile tip after installation of the piles. Based on the test results, the most fasted installation was possible under the condition of "rotation speed of 30 rpm and center-to-center spacing of 50 mm", and the highest ultimate capacity was mobilized under the condition of "rotation speed of 30 rpm and center-to-center spacing of 150 mm with cone penetration implementation."

• Journal of Digital Convergence
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• v.18 no.10
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• pp.219-224
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• 2020

The purpose of this study is to develop a device to replace the pre-boring method, which is generally constructed, to prevent pile damage caused by tension cracks that reason from tension waves generated during PHC pile construction on soft ground. Tension cracks are caused by tension waves from the hammer striking during the PHC pile hitting on the soft ground, which in turn leads to faulty construction. In order to prevent the occurrence of tension waves generated during driving, apply separate driving force increasing device to prevent the generation of tension waves, and pile damage as well. Also, it is an eco-friendly construction method that reduces smoke and noise by improving construction speed, reducing construction costs, and able to small equipment when developing equipment. This development equipment is a piece of effective equipment that can pioneer the Saemangeum reclamation area, the South-east Asian construction market, where the Deep soft ground is distributed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.1
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• pp.211-217
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• 2019

Oil extraction from oil sands, a non-traditional crude oil resource, is attracting attention as the oil price fluctuates due to recent economical and political issues. Many oil sands sites are mainly located in the polar regions. For plant construction to extract crude oil from oil sands in harsh environment of the polar regions, fast and simple installation of plant foundation is necessary. However, typically-used conventional foundations such as drilled shafts and driven piles are not suitable to construct under cold temperature and organic surface layers. In this study, helical piles enabling rapid and simple constructions using small rotary equipment without driving or excavation was considered. The helical pile consists of steel shaft and several helices attached to the steel shaft; therefore, the behavior of the helical pile depends on the number and shape of the helices. The effect of the helices' configuration (number and diameter of helices) on helical pile behavior was analyzed based on the numerical analysis results.

• Journal of the Korean Geotechnical Society
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• v.39 no.5
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• pp.27-40
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• 2023

A pile is a structural element that is used to transfer external loads from superstructures and has been widely utilized in construction fields all over the world. The method of installing a pile into the ground should be selected based on geotechnical conditions, location, site status, environmental factors, and construction costs, among others. It can be divided into two types: direct hammering and preboring. The direct hammering method installs a pile into the bearing layer, such as rock, using a few types of hammer, generating a considerable amount of pile driving-induced vibration. The vibration from pile driving influences adjacent structures and the ground; therefore, quantitatively investigating the effects of vibration is inevitably required. In this study, two-dimensional dynamic numerical modeling and analysis are performed using the finite difference method to investigate the influence on the adjacent slope, including temporary supporting system. Time-dependent loading induced by pile driving is estimated and used in the numerical analysis. Consequently, large surface displacement is estimated due to surface waves and less wave deflection, and refraction at the surface. The total displacement decreases with the increase of the distance from the source. However, lateral displacement at the top of the slope shows a larger value than vertical displacement, and the overall displacement tends to be concentrated near the face of the slope.

• Journal of the Korean Geosynthetics Society
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• v.17 no.4
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• pp.29-40
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• 2018

Oil sands, which are largely distributed in Canada and Venezuela, are a mixture of crude oil and sandy soils. In order to extract crude oil from oil sands, construction of massive oil sand plants is required. Generally, the typically-used foundation types of the oil sand plant are driven piles and cast-in-place piles. Most of the oil sand plants are located in cold and remote regions. Installation of driven piles in frozen or organic surface soils is difficult due to high resistance and installation equipment accessability, while the cast-in-place pile has concrete curing problem due to cold temperature. Helical pile can be installed quickly and easily using rotation with a little help of vertical load. As the installation of helical pile is available using a small and light-weight installation equipment, accessibility of installation equipment is improved. The helical pile has an advantage of easy removal by rotation in reverse direction compared with that of installation. Furthermore, reuse of removed helical piles is possible when the piles are structurally safe. In this study, the behavior of helical piles varying helix pitch was analyzed based on the numerical analysis results. Numerical model was calibrated based on the results of model helical pile tests in laboratory. The ultimate helical pile loads, the displacement of each helix attached to the shaft of the helical pile, and the load sharing ratio of each helix were analyzed.

• The Journal of the Korea Contents Association
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• v.20 no.11
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• pp.669-675
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• 2020

This research has focused on comparing the capacity predicted by the theoretical formula with the one measured by field load tests to examine characteristics of the bearing capacity of a helical pile. The helical pile is featured by a central shaft with one or more helical-shaped bearing plates. Being established by a small rotary attached to an excavator that applies toque, the helical piles can be readily constructed at narrow sites, especially in an urban area with relatively less noise than the others requiring driving and excavation. Although many cases of the helical pile constructions can be recently found, the bearing capacity of the pile has been limitedly studied. To this end, this contribution analyzes and presents comprehensive results of the ten field loading tests with an application of different parameters depending on joint condition and specification of the helical piles, and types of tests and grouting.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.344-348
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• 2008

During the last few years, the use of Pre-tensioned spun High strength Concrete(PHC) pile has been gradually increased in many construction sites such as super high-rise and large building construction. there is almost no specific code and/or standard described in the specifications to check verticality for Pre-tensioned Spun High Strength Concrete pile installation process. The most commonly used method for the vortical PHC pile installation is a naked-eye measurement or water level measurement conducted by assistant crew in the construction sites. And recent analysis results of the pile cutting work revealed that it frequently makes a lot of cracks which significantly reduce the strength of the pile and is very labor intensive work, thus requiring a large amount of additional time, costs, and efforts. The main objective of the research is to analize problems and to improvement. measure of PHC Pile Construction. The improvement measure present to the main problem with survey and discussion.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.244-247
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• 2002

The pile foundations have been chosen more frequently as the comprehensive development of the country progressed, especially where the ground conditions are not suitable for the construction and the dimension and the length of the piles utilized becomes larger and longer. The purpose of this study suggests the improvement method of construction management for PHC pile in an apartment house. To do This, We analyzed about current process and provided improved Process with IDEF method. And, The objectives of this research is to propose the means to solve the current problems and management factors from the results of the investigation.