• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.1
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• pp.93-101
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• 2010

When doing underground excavation works for the purpose of constructing large underground structures for a building in the limited space in downtown area, the stability of the adjacent ground must be top priority, and to accomplish this, it is essential to review the retaining wall construction carefully. H-Pile, which has been mainly used as a stress-carrying material in temporary earth-retaining structures, is most likely to be abandoned after completion of the works for the basement exterior wall in relation to contiguous bored piles, so it will result in a waste of material. To improve this situation, Basement Composite Wall where H-Pile and basement wall are compounded, has been developed. This wall is being used most frequently in many local construction sites. In this study, five specimens are made in order to evaluate the shear resistance of the basement composite wall and tested. Test parameter is the composition ratio and wall thickness according to shear connectors. Test result shows that the shear strength is improved when the composite ratio is increased but the magnitude is not much. A formula, which considers the contribution of concrete, web of H-pile as well as flange' effect in calculation of shear strength of composite basement wall, is suggested and used to calculation of the strength of specimens. It is found that there is a good co-relation between test result and the calculated one by the formula.

• Geophysics and Geophysical Exploration
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• v.1 no.1
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• pp.57-63
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• 1998

The electrical resistivity method, one of old and widely used geophysical prospecting methods, has extended its scope to civil & environmental engineering areas. The electrical resistivity imaging technique was performed at the waste disposal site located in Junju to verify the applicability to the environmental engineering area. The dipole-dipole array, with the dipole spacing of 10 m, was applied along eight survey lines. The field data were obtained under the control of automatic acquisition softwares and topographic effects were corrected during processing stage. The processed resistivity images show that very low resistivity develops inside the disposal site and the distribution of low resistivity is exactly in accord with the boundary of the site except the river side. The depth of low resistivity zones is deeper toward the river side, which is interpreted that there is a high possibility for contaminants to be scattered to the river. From resistivity images, it was feasible to deduce the depth of waste disposal as well as the horizontal/vertical distribution of the contaminated zone, which proved the applicability of the electrical resistivity imaging technique to the environmental engineering area.

• Geophysics and Geophysical Exploration
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• v.1 no.1
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• pp.8-18
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• 1998

In exploration seismology, the Kirchhoff hyperbola has been successfully used to migrate reflection seismo-grams. The mathematical basis of Kirchhoff hyperbola has not been clearly defined and understood for the application of prestack or poststack migration. The travel time from the scatterer in the subsurface to the receivers (exploding reflector model) on the surface can be a kinematic approximation of Green's function when the source is excited at position of the scatterer. If we add the travel time from the source to the scatterer in the subsurface to the travel time of exploding reflector model, we can view this travel time as a kinematic approximation of the partial derivative wavefield with respect to the velocity or the density in the subsurface. The summation of reflection seismogram along the Kirchhoff hyperbola can be evaluated as an inner product between the partial derivative wavefield and the field reflection seismogram. In addition to this kinematic interpretation of Kirchhoff hyperbola, when we extend this concept to shallow refraction seismic data, the stacking of refraction data along the straight line can be interpreted as a measurement of an inner product between the first arrival waveform of the partial derivative wavefield and the field refraction data. We evaluated the Kirchhoff hyperbola and the straight line for stacking the refraction data in terms of the first arrival waveform of the partial derivative wavefield with respect to the velocity or the density in the subsurface. This evaluation provides a firm and solid basis for the conventional Kirchhoff migration and the straight line stacking of the refraction data.

• Korean Journal of Heritage: History & Science
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• v.34
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• pp.222-267
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• 2001

The purpose of this document is to explain the revisions of the Protection of Cultural Properties Act and its sub-laws which have been mad from Jan. 1999 to Sep. 2001. The Protection of Cultural Properties Act and its sub-laws have been revised three times from 1999 to 2001, before and after the Office of Cultural Properties was raised to Cultural Properties Administration on May 24, 1999. The main points of the revisions are as follows. First of all, the role of the local autonomous entities has been increased. The governor of the local autonomous entities is entitled to announce administrative orders related to the preservation of State-designated Cultural Properties. Also, the local autonomous entities has the authorities to examine whether the construction work which will be made in the outer boundaries, which is provided by regulations, of the protected area of the cultural properties might have any effect on preservation of cultural properties or not. Second, preventive actions to protect the cultural properties have been strengthened. If the scale of construction work is more than some scale, the preliminary survey of the surface of the earth to confirm the existence of buried cultural properties and their distribution is obligated. One who is promoting the development plan more than some scale must discuss the plan with the Administrator of Cultural Properties Administration in the process of planning. These actions would be effective to prevent the cultural properties from being damaged because of the development. Third, relaxation of the restrictions has been proceeded. On the basis of regulations which specify the actions to affect the preservation of cultural properties, negative system that does not limit the actions which are not specified in the regulations is introduced. The appropriateness of both protected structure and area should be regularly reviewed and adjusted. Also, most of the restrictions which was made only for administrative convenience and over-regulated the people's living have been revised. Finally, the number of cultural properties to be protected has been increased. Besides the State-designated Cultural Properties, the other cultural properties which are worthy to be protected as City-or-Province-designated Cultural Properties can be designated provisionally and protected. The system of registration and maintenance of the buildings and facilities which are not designated as the Modern Cultural Heritages is established. The penalty for damaging and stealing the cultural Properties which are not designated to be protected was strengthened. Even a dead natural monument can be acknowledged as an natural monument and it is limited to make a specimen or stuffing of the dead natural monument. All of these actions are fit to the high level of understanding of the public about the cultural properties and as the result of these actions, the number of cultural properties to be preserved has been increased. To sum up, the directions of revisions of the Protection of Cultural Properties Act and its sub­laws which have been made from Jan. 1999 to Sep. 2001. are the localization of the protection of the cultural properties, the strengthening of protective actions, the relaxation of various regulations and the increasing of the number fo the protected cultural properties. Also, various problems raised in the processes of implementations of the laws have been reviewed and revised.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.1
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• pp.93-113
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• 2019

The behavior of the 3 hinged precast arch structure was investigated by comparing field measurements with numerical analyses performed for precast lining arch structures, which are widely used for the open-cut tunnel. According to the field measurements, the maximum vertical displacement occurred at the crown with upward displacements during the backfilling up to the crown of the arch and downward displacements at the backfill height above the crown. The final crown displacement was 19 mm upward from the original position. The horizontal displacement at the sidewall, which had a maximum horizontal displacement, occurred inward of the arch when compacting the backfill up to the crown and returned to the original position after completing the backfill construction. According to the analysis of displacement measurements, economical design is expected to be possible for precast arch structures compared to rigid concrete structures due to ground-structure interactions. Duncan model gave good results for the estimation of displacements and deformed shape of the tunnel according to the numerical analyses comparing with field measurements. The earth pressure coefficients calculated from the numerical analyses were 0.4 and 0.7 for the left and the right side of the tunnel respectively, which are agreed well with the eccentric load acting on the tunnel due to topographical condition and actual field measurements.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.6
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• pp.120-126
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• 2018

The study conducted an experiment in which residual aggregate and polypropylene fibers are mixed in concrete, and an experiment in which granite and polypropylene fibers are mixed. Two types of experiments, in particular, changed the amount of polypropylene fibers, and examined the mechanical properties of slump, compressive strength, tensile strength and the like. To establish a light and easy-to-use material for landscape construction and packaging material development by comparing two kinds of experimental results, comparing and analyzing residual aggregate as experimental materials and materials using granite soil to prevent partial destruction due to cracks in drying shrinkage. The more the amount of the PP fibers increases in concrete, the more the volume of the PP fibers increases, the less the slump is determined. As a result of the compressive strength, the cast-down earth concrete is measured to be about 59% to 71% of the concrete strength. As the amount of PP fibers mixed in increased, the compression strength showed a relative decrease. As a result of tensile strength, it is found that the granite concrete is about 68-67% of concrete tensile strength. It was found that the compression strength decreased as the amount of PP fibers mixed in concrete or fire-gant concrete was increased. Then, when polypropylene fibers are mixed in the concrete and the concrete, it is found that tensile strength is increased. By analyzing these results, a fixed amount of PP fiber is mixed in the concrete mixed with the granite soil and utilized for various structures in the field of landscape construction or materials related to packaging, the prevention and improvement effect of the structure is determined.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.3
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• pp.55-63
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• 2022

A modular underground arch structure using steel and concrete has been proposed as a structure that has a simple construction process and can effectively resist cross-sectional forces generated during construction and use. Structural behavior of modular underground arch was evaluated about span length less than 15m through 3D structural analysis and test. In general, 2D and 3D structural analysis methods may be applied for structural analysis such as underground arch and tunnels. However, if a 2D or 3D structural analysis method is applied to evaluate the structural safety of a modular underground arch structure, it is difficult to model for structural analysis and it may take an excessively long time to interpret. Therefore, it may not be reasonable as a structural analysis method for considering the structural safety and earth pressure in the design process of a modular underground arch structure. In addition, when a modular underground arch structure is configured for span lengths to which the predetermined cross-section is applicable, it may be reasonable to evaluate only the safety of the structure and cross-section according to the cross-section and load conditions. Therefore, in this study, a structural analysis model using frame elements was proposed for efficient structural safety evaluation. In addition, structural analysis results of the 2D structural analysis model and the simplified analysis model using frame elements were compared, and the structural safety of the modular underground arch structure for a span length of 20m was evaluated with a simplified analysis method.

• Journal of the Korea Institute of Building Construction
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• v.23 no.3
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• pp.295-303
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• 2023

South Korea has recently witnessed an increasing number of seismic events, leading to a surge in studies focusing on seismic earth pressures, as well as the attributes of geological layers and ground where foundations are established. Consequently, earthquake-resistant design has become imperative to ensure the safety of subterranean structures. The slurry wall method, due to its superior wall rigidity, excellent water resistance, and minimal noise and vibration, is often employed in constructing high-rise buildings in urban areas. However, given the separation between panels that constitute the wall, slurry walls possess limited resistance to seismic loads in the longitudinal direction. As a solution, several studies have probed into the possibility of interconnecting slurry wall panels to augment their seismic performance. In this research, we developed and evaluated a method for linking slurry wall panels using mechanical joints, including concrete-confined steel pipes and headed bars, through mock-up tests. We also assessed the constructability of the suggested method and compared it with other analogous methods. Any challenges identified during the mock-up test were discussed to guide future research in resolving them. The results of this study aid in enhancing the seismic performance of slurry walls through the development of an interconnected panel method. Further research can build on these findings to address the identified issues and improve the efficacy and reliability of the proposed method.

• Journal of the Daesoon Academy of Sciences
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• v.23
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• pp.345-383
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• 2014

This article intends to examine the value of the world citizenship in the perspective from the root meaning that is stressed as the behavior style of Daesoon thoughts in relation with 'desirable attitude of life in education of morality. Traditional root meaning of Daesoon thoughts turned out to be proper moral behavior principle such as Yin Yang harmonious virtue, God Humane keeping unity, and conviviality with regrets settlement. Such three principles of Daesoon Thoughts show the characteristic of global code such as respect of life, solidarity unity, and tolerant trust. To revise the phenomenon of duality, and to realize the human awakening in radically changing reality, we need to cultivate world citizenship based on the root meaning of Daesoon thoughts. Daesoon thoughts covering the East and the West, especially the key features of religion, can cultivate the world view of citizenship in the era of plural society based on folk beliefs toward Gucheon Sangje faith as the essence of the multiplism. The world citizenship of human society is necessary to unite the world in the unified construction cooperative spirits. All beings need to be away from antagonistic confrontation with the practice of mutual conviviality. The diameter of acquired joining world citizenship can have the opportunity to realize of Gucheon Sangje's Heaven and earth construction. The root meaning of Daesoon thoughts can contribute to moral practicality with world citizenship by practice of heavenly truth and human truth. First, cultivating heavenly truth by means of insight can develope the profound world citizenship. Secondly, the solidarity of the public and private can cultivate public citizenship. Thirdly, in the crisis of the mankind, this awakening conviviality can be foundation for world citizenship of public communication. Fourthly, the spirit that would not deceive ownself can be contributed to cultivating the world citizenship by means of the process of internalizing Daesoon thoughts. Nowadays in the plural society demanding world citizenship, the public citizenship can deepen the spirit of respect of life, solidarity unity, and tolerant trust in the process of world citizenship cultivation. In the future, the world citizenship can be deepen the alternative of practice in the continuous cultivation of world citizenship. In this process, we can form the culture of coexistence which can contribute to human society as well as korean society by developing the value of living together happiness through the guide of this phonesis.

• The Journal of Engineering Geology
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• v.27 no.3
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• pp.331-343
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• 2017

In this study to improve stability, workability and economics of the H-Pile+Earth plate or H-Pile+Earth plate+Cutoff grouting currently in use, we had developed HCS method belonging to the retaining wall which is consisting of a combination H-Pile, Plastic Sheet Pile and Steel Square Pipe for gap maintenance and reinforcement of flexible plastic Sheet Pile, and the behavior of each member composing HCS method is investigated by three-dimensional finite element analysis. To numerically analyze the behavior of the HCS method, we have performed extensive three-dimentional finite element analysis for three kinds of plastic Sheet Pile size, two kinds of H-Pile size and three kinds of H-Pile installation interval, one kinds of Steel Square Pipe and three kinds of Steel Square Pipe installation interval. After analyzing the numerical results, we found that the combinations of $P.S.P-460{\times}131.5{\times}7t$ (PS7) and H-Pile $250{\times}250{\times}9{\times}14$ (H250), $P.S.P473{\times}133.5{\times}9t$ (PS9) and H-Pile $300{\times}200{\times}9{\times}14$ (H300) is the most economical because these combinations are considered to have a stress ratio (=applied stress/allowable stress) close to that as the stiffness of H-Pile, plastic Sheet Pile and Steel Square Pipe composite increased, the horizontal displacement of the retaining wall and the vertical displacement of the upper ground decreased. Especially, due to the arching effects caused by the difference in stiffness between H-Pile and plastic Sheet Pile, a large part of the earth pressure acting on plastic Sheet Pile caused a stress transfer to H-Pile, and the stress and displacement of plastic Sheet Pile were small. Through this study, we can confirm the behavior of each member constituting the HCS method, and based on the confirmed results of this study, it can be used to apply HCS method in reasonable, stable and economical way in the future.