• Tunnel and Underground Space
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• v.5 no.2
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• pp.104-113
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• 1995

Shear strength of the discontinuity on which the pre-failure of rock slope was occurred during surface excavation was measured through the direct shear test using core samples obtained in-situ. Internal friction angle was increased as the roughness of discontinuity surface(JRC) was increased. Results of the tilt test using core samples of higher JRC also showed very similar trend as those of the direct shear test. When the samples replicated from natural cores were used int he tilt test, results of friction angles showed almost perfect continuation of the residual friction angles from the direct shear test. However, when the gouge material existed in the discontinuity the internal friction angle strongly depended upon the rate of filling thickness to the height of asperity irrespective of the JRC. Based on the results of both direct shear test and tilt test internal friction angle and cohesion of discontinuity, which reflect the in-situ conditions fo pre-sliding failure and also can be used for the optimum design of support system, were assessed. Two kinds of support measures which were expected to increase the stability of rock slope were considered; lowering of slope face angle and installation of rock cable. But, it was found that the first method might lead to more unstable conditions of rock slope when the cohesion of discontinuity plane was negligibly low and in that case the support systems of any kind which could exert actual resisting force were needed to ensure the permanent stability of rock slope.

• Journal of The Geomorphological Association of Korea
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• v.28 no.3
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• pp.63-83
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• 2021

In the southeastern part of the Korean Peninsula, the Yangsan Fault, an active fault zone, has developed. Many earthquakes occur around these faults, and the possibility of earthquakes occurring along the branch faults is being discussed. On the other hand, the Yeongdeok Fault is reported in Yeongdeok-gun, which is the northern part of the Yangsan fault. In this study, goemorphic characteristics of a set faults found on the outcrop of the gentle slope of the coast of Byeonggok-myeon were analyzed and granulometric and geochemical characteristics of sediments and other materials, including fault gouges were analyzed. The outcrop of Byeonggok-myeon is the part of the fault core and can be divided into two parts. Theses fault are formed on the upper part of the Mesozoic bedrock and the tertiary sedimentary layer of red sand-supported clasts are covered in several sedimentary units. The faults were normal fault sets, and a number of vertical cracks were developed, and glossy surfaces were observed in the fault area. It appears that these faults have occurred after alluvial deposition had been formed. In the case of samples from fault gouges, there were differences in particle size and geochemical characteristics from the surrounding area.

• Journal of Korean Ophthalmic Optics Society
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• v.7 no.2
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• pp.169-174
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• 2002

Make Photochromic lens Photochromism estimation method, and gouge photochromic lens and investigated UV light source to apply. UV light source irradiation ago and after wavelength dependence of photo-transmittance (T%) of darkening and fading state by do optical equipment which is consisted of spectrophotometer, light source, power meter and detecter. Use relative ratio value of maximum $T%{\times}{\lambda}$ area and saturated state area in light off. Dependences estimation introduced darkening efficiency $(K_d)=(1-C_1/A_1)/t_{on}$ relationship value course fading efficiency$(K_f)=(C_2/A_2)/t_{on}$ value during Photochromism's irradiation time in Photochromic lens. Wavelength dependence of transmittance (T%) has form of $T_m+T_1{\exp}[-(x_0-t)/a]$ in Darkening course fading state. Can receive each estimation parameter value as result that apply Photochromism's estimation parameter Z, $K_d$, $K_f$ in Photochromic lens.

• The Journal of Engineering Geology
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• v.19 no.3
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• pp.277-285
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• 2009

In order to assess the fault behavior by the geometric analysis of fault slip, the study area between Yangsan city and Shinkwang-myon, Pohang city along the strike of the Yangsan fault is divided into 5 domains($A{\sim}E$ domains) based on the strike change of main fault, the type of fault termination, the cyclic variation of fault zone width, deformation pattern of fault rocks and angular deviation of secondary shears. And, we would apply the relationship between the mode of fault sliding and the resultant deformation texture obtained from previous several experimental studies of simulated fault gouge to the study of the Yangsan fault. To understand sliding behavior of the fault we measured the data of fault attitude and fault slip, and analyzed relationships between the main fault and secondary Riedel shear along the Yangsan fault. The sliding behavioral patterns in each section were analyzed as followings; the straight sections of A, D and E domains were analyzed as the creeping section of stably sliding. In contrast, the curved section of B domain was analyzed as the locked section of stick-slip movement.

• Journal of the Korea Computer Industry Society
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• v.7 no.5
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• pp.583-590
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• 2006

BT technology, medical treatment engineering technology is offering important role and grow by creative technology. Specially, bone fracture treatment can achieve very important role in research of bone, physiology and dynamics of bone is very useful patient's diagnostic and treatment in presence at a sickbed. <중략>Furthermore embedded base of in administration aspect as well as if supersonic waves curer is treatment innocuously and without invasion very efficient tell. If apply supersonic waves in bone fracture treatment, can reduce curer about 40%. Operation frequency through bone fracture treatment supersonic waves curer of embedded base designs and manufactured 1m Hz, 1.2mHz, 1.3mHz, 1.4mHz, supersonic waves origination that have 1.5mHz's tranducer, and embodied protocol in PDA base in this research, and did so that is interfaced to general PC. If is using but supplement research water that see clinically by diagnosis in city, is seen to become convenient medical treatment assistance mounting to bone fracture patient's treatment and courtesy call. Specially, tried to approach basic form after modeling processing if may be applied variously to physiotherapy, orthopaedics patient who gouge late, and study standardization special quality little more.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.107-112
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• 2005

Road is built continuously along with development of industry and cut slope is happened necessarily in road construction. Geoengineers are executing cut slope stability analysis considering various cut slope condition such as topography, geology, hydraulic condition and so on. The Tertiary Jungja Basin is located in the southeastern coastal area of the Korea Peninsula. Jungja Basin area is created by geotectonic movement of the plate after Early Miocene epoch. The northwestern and southwestern boundary of the basin is fault zone. The Basement rock is hornfels (Ulsan Formation). Basin-fills consist of extrusive volcanic rock(Tangsa Andesites), unconsolidated fluviatile conglomerate(Kangdong Formation) and shallow brackish-water sandstone(Sinhyun Formation). The characteristics of cut slopes in this area is different with cut slopes in the other site. Soil layers in this area is unconsolidated sediments and is not formed the weathering and erosion of the rock. So, the depth of soil layer is very thick. Faults of this area are northwest-southeast and northeast-southwest direction. Expandible clay mineral as smectite, chlorite et al. detected from fault gouge using XRD. Therefore, Jungja Basin area must consider the characteristics of the faults and soil layers thickness necessarily cut slopes stability analysis.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.269-274
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• 2008

For fitness-for-service analyses of underground natural gas pipelines, engineering assessment methods against possible defects need to be developed. The assessment methods for high pressure pipeline of KOGAS, was developed using the full size pipe burst tests and the finite element analysis. It included the defect assessment methods for a single and multi-corrosion, corrosion in girth welding part, corrosion in seam welding part, the mechanical damage defects as dent and gouge, crack and large plastic deformation of API 5L X65 pipe. In addition, we developed method to assess pipeline integrity by internal and external load to buried pipeline. Evaluation results were compared with other methods currently being applied to the gas pipeline. The program of Windows environment is made for easily using assessment methods. It provides a consistent user interface, so non-professional technician can easily and friendly use the FFS program from company intranet. Several evaluation programs is easily installed using one installer. Each program constitutes a common input interface and the output configuration program, and evaluation result store and can be recalled at any time. The FFS program based on independent evaluation method is used to evaluate the integrity and safety of KOGAS pipeline, and greatly contribute to safe and efficient operation of pipeline. This paper presents experimental, analytical and numerical investigations to develop the FFS methods for KOGAS pipeline, used as high pressure natural gas transmission pipeline within KOREA. Also, it includes the description of the integrated program for FFS methods.

• Tunnel and Underground Space
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• v.17 no.1 s.66
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• pp.1-8
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• 2007

In Norway, about 30 subsea tunnels have been constructed over the last 20 years. The minimum depth of 17 subsea tunnels is 56 m and rock cover are between 23 and 49 m. As the project areas for subsea tunnel are covered by water, special investigation techniques need to be applied and the investigation results are more uncertain than that of most conventional tunnel projects. The indefinite potential of water inflow and the salinic character of ingress water represent considerable problems for tunnel equipment and rock support materials. The least stable conditions are represented by major faults or weakness zones containing heavily crushed rock and clay gouge. This paper introduces the Oslofjord subsea tunnel project including minimum rock cover requirement, risk of water inflow, investigation costs, construction costs, and traffic & operation costs.

• The Journal of Engineering Geology
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• v.33 no.1
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• pp.121-136
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• 2023

Microstructural characterization, identification of mineral assemblages, and K-Ar age dating of fault gouges from five Quaternary fault sites segmented along the northern Yangsan Fault, SE Korea were performed to understand formation condition and multiple activity of faults. The mean and median sizes of particles of bulk gouges vary among the studied faults: 1.75 ㎛ and 1.43 ㎛ for the Danguri Fault, 1.94 ㎛ and 1.79 ㎛ for the Yukjae Fault, 5.57 ㎛ and 4.16 ㎛ for the Yugye Fault, and 5.55 ㎛ and 2.31 ㎛ for the Bogyeongsa Fault. Fault gouges contain abundant secondary minerals, including smectite, chlorite, illite, kaolinite, laumontite, and mordenite, which are found in association with quartz and feldspar. K-Ar dating of the fault gouges (both bulk samples and separate size fractions) yields ages ranging from 59.1 to 18.8 Ma, with bulk ages of 47.6 Ma for the Yukjae Fault, 59.1 Ma for the Ansim Fault, 39.4 Ma for the Yugye Fault, and 22.6 Ma for the Bogyeongsa Fault. The finer fractions generally have younger K-Ar ages compared with the coarser fractions, and the finest fraction (<0.2 ㎛) is the youngest for each fault. Hydrothermal alteration of the gouges is considered to have occurred under low-temperature (100~200℃) conditions during faulting. Microstructural features and clay mineral assemblages of fault gouges and brecciated rocks should be considered when interpreting fault events and reactivation, in addition to age dating of faulting.

• Korean Journal of Agricultural Science
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• v.49 no.2
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• pp.239-247
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• 2022

The physico-chemical properties of agricultural soil are factors that affect crop productivity and soil fertility. In Korea, agricultural environment change surveys have been conducted every four years since 1999. The purpose of this study is to investigate the status and changes in the physico-chemical properties of agricultural soil in Chungcheongnam-do. Samples were collected from the exact location of the aforementioned environment survey, and environmental variables (land use, type of crop cultivated) were investigated in relation to the samples. Soil collection was conducted using a core sampler and a single gouge auger. The bulk density of the soil generally increased up to a depth of sampling of 40 cm but decreased thereafter to a depth of 60 cm. Additionally, the bulk density was highest in the upland soil case and stood at 1.59 g·cm^-3, while the lowest value of 1.52 g·cm^-3 was obtained from orchard soil samples. Conversely, the porosity and moisture gradually decreased at soil depths of 0 - 40 cm and increased at depths of 40 - 60 cm. Most of the soil chemical properties generally decreased with an increase the soil depth from 0 to 70 cm, but electrical conductivity (EC) increased up to a depth of 40 cm. Therefore, it is judged that it is necessary to lower the bulk density by supplying organic matter for agricultural land in Chungcheongnam-do.