• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1998.11a
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• pp.303-308
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• 1998

암반을 대상으로 하는 건설공사는 많은 시간과 비용, 설계, 시공, 안전상에 많은 문제점을 일으키고 있다. 이러한 암반들은 흡수, 풍화 등에 기인하여 안정성이 약화되어 낙석, 산사태, 붕괴 등의 위험을 안고 있으며 이러한 현상은 우기, 해빙기에 두드러지게 나타나고 있다 비균질, 비등방성의 역학적 성질을 지닌 암석은 변형 거동을 완벽하게 예측하지는 못하고 있는 실정으로 이러한 거동은 암석의 종류와 구성 광물, 내부 불연속면의 상태, 응력 조건과 온도, 습도의 함수비등과 같은 다양한 요소에 의해 영향을 받으며, 이러한 경향은 퇴적암의 경우 두드러지게 나타나고 있다. (중략)

• Tunnel and Underground Space
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• v.2 no.2
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• pp.237-250
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• 1992

The cavities formed by the excavation of coal seam cause unstable within rock body, leading to large displacement around adjacent roadway. This displacement brings the closure of roadway and deformation of support. Therefore, it is necessary to understand and predict the deformation characteristics of roadway while coal seam is under excavation. In this study, the observed displacements are compared with the calculated ones through the analysis using Linear Boundary Element Mothod under the elastostatic conditions, in order to determine the virgin stress state and deformation modulus which affect the deformation characteristices.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 1999.03a
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• pp.69-71
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• 1999

이 논문은 대구-포항 간 고속도로 건설공사 지역 중 제 7공구 지역에 대한 지반조사를 목적으로 실시한 지질조사의 결과다. 기존자료는 1대 5만 기계도폭(오인섭과 정국성, 1975)과 이 지역을 포함한 소위 가음단층대의 동부지역에 대한 지질구조를 조사를 연구한 이병주와 황재하(1997)의 논문 등이 있다. 야외에서의 지질조사는 개설될 고속도로를 중심으로 발달하는 노두에서 암상의 특징과 층리, 절리 및 단층 등과 같은 불연속면의 발달 특성을 관찰 기재하였다.(중략)

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2002.05a
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• pp.463-466
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• 2002

건설현장의 특성상 굴착공사는 필수공정이고 비록 말뚝공사가 없다할지라도 암반굴착 등 진동소음 발생여지는 언제나 존재하고 있다고 할 수 있다 이에 대한 국부적인 암반발파, 파쇄에 따른 소음감소 또한 큰 문제를 야기할 수 있다. 건설현장 자체적으로 민원 발생에 대비하여 인접 주택 지점에서 소음 계측을 하고 허용값 초과 여부를 판단하는 실행을 하고 있으나 주민이 느끼는 체감 소음은 조금 다를 수도 있어서 민사소송으로까지 확대되어 현장경영 및 공정에 큰 타격을 가하고 회사 이미지 실추로까지 이어질 수 있고 막대한 보상비 지급이 뒤따를 수도 있는 상태로까지 확대될 수 있다.(중략)

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 1994.03a
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• pp.89-101
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• 1994

기 발표된 보문에서, 정수두압이 작용하는 수갱측벽의 두께 산정과 수갱굴하의 특성을 간략하게 설명하였다. 이 두 부문에 대해서는 계속 다루어 나갈 예정이며, 본 회부터는 수갱굴하의 원론적인 문제도 다루기도 한다. 광산이나 탄광의 수갱은, 심부에 부존하는 광체 또는 탄층에서 채굴된 광물과, 갱도굴진에서 나온 버럭을 권양하고, 작업인원, 제반 자재, 압기동력원이 되는 전기, 급수 등을 공급하여 안전한 갱내작업을 유지하기 위한 통기회로를 형성시키고, 또한 갱내수를 배출하는 다목적의 대동맥과 같은 역할을 하는, 말하자면 광산의 가장 핵심체이다. (중략)

• Tunnel and Underground Space
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• v.10 no.2
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• pp.211-217
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• 2000

In this, study, some laboratory tests and in-situ test were performed for Taegu area. Test blasting was conducted to determine blasting vibration coefficients. The uniaxial strength of rocks vary widely from weathered rock to extremely hard rock. Boasting vibration coefficient, K and n were 114.8, 1.48 for Sungseu site, where rocks show weathered to medium strength.

• Tunnel and Underground Space
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• v.19 no.4
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• pp.318-327
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• 2009

Accelerated weathering tests was executed to understand the physical characteristics of rocks in Dokdo. For the tests rock samples including trachytic andestes, andesite dyke and ash tuff were taken in place. Double soxhlet extractor and peristatic pump were used for accelerating the weathering processes. After the tests for 4 months, the variations of superficial structure, microscopic structure and strength of rock samples were observed.

• The Journal of Engineering Geology
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• v.16 no.3 s.49
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• pp.245-254
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• 2006

Using a natural gradient tracer test, the characteristics of hydrodynamic dispersion according to each depth of a fractured rock were studied, and the effective porosity and longitudinal dispersivity of the fractured rock were estimated. The difference of vertical hydrodynamic dispersion was identified by concentration breakthrough curves linear regression analyses of bromide concentrations according to depths versus time, and hydraulic fracture characteristics at two intervals of the monitoring well. Higher concentration and faster arrival time at GL- 18 m depth (RQD 13%, average joint spacing 2 cm, TCR 100%) than at GL- 25 m depth (RQD 41%, average joint spacing 7 cm, TCR 100%) resulted from shorter distance and more fractures. Tracer was transported through the 1 st fractures until the arrival of its peak concentration and through the 2nd fractures or matrix diffusion after the arrival of its peak concentration. The increase/decrease slopes of bromide concentration versus time were 3.46/-1.57 at GL-18 m depth and 3.l9/-0.47 at GL- 25 m depth of the monitoring well. So the faster bromide transport was confirmed at GL- 18 m depth with more fractures. The concentration increment of bromide was fitted by a Gaussian function and the concentration decrement of bromide was fitted by an exponential function. Effective porosity and longitudinal dispersivity estimated by CATTI code were 10.50% and 0.85 m, respectively.

• The Journal of Engineering Geology
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• v.32 no.1
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• pp.59-72
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• 2022

This study employed a 3-D numerical analysis based on the distinct element method to estimate the strength and deformability of a Cretaceous biotite granitic rock mass at Gijang, Busan, Korea. A workflow was proposed to evaluate the scale effect and the representative elementary volume (REV) of mechanical properties for fractured rock masses. Directional strength and deformability parameters such as block strength, deformation modulus, shear modulus, and bulk modulus were estimated for a discrete fracture network (DFN) in a cubic block the size of the REV. The size of the mechanical REV for fractured rock masses in the study area was determined to be a 15 m cube. The mean block strength and mean deformation modulus of the DFN cube block were found to be 52.8% and 57.7% of the intact rock's strength and Young's modulus, respectively. A constitutive model was derived for the study area that describes the linear-elastic and orthotropic mechanical behavior of the rock mass. The model is expected to help evaluate the stability of tunnels and underground spaces through equivalent continuum analysis.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6C
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• pp.395-406
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• 2006

Drilled shafts are a common foundation solution for large concentrated loads. Such piles are generally constructed by drilling through softer soils into rock and the section of the shaft which is drilled through rock contributes most of the load bearing capacity. Drilled shafts derive their bearing capacity from both shaft and base resistance components. The length and diameter of the rock socket must be sufficient to carry the loads imposed on the pile safely without excessive settlements. The base resistance component can contribute significantly to the ultimate capacity of the pile. However, the shaft resistance is typically mobilized at considerably smaller pile movements than that of the base. In addition, the base response can be adversely affected by any debris that is left in the bottom of the socket. The reliability of base response therefore depends on the use of a construction and inspection technique which leaves the socket free of debris. This may be difficult and costly to achieve, particularly in deep sockets, which are often drilled under water or drilling slurry. As a consequence of these factors, shaft resistance generally dominates pile performance at working loads. The efforts to improve the prediction of drilled shaft performance are therefore primarily concerned with the complex mechanisms of shaft resistance development. The shaft resistance only is concerned in this study. The nature of the interface between the concrete pile shaft and the surrounding rock is critically important to the performance of the pile, and is heavily influenced by the construction practices. In this study, the influences of asperity characteristics such as the heights and angles, the strength characteristics and elastic constants of surrounding rock masses and the depth and length of rock socket, et. al. on the shaft resistance of drilled shafts are investigated from elasto-plastic analyses( FLAC). Through the parametric studies, among the parameters, the vertical stress on the top layer of socket, the height of asperity and cohesion and poison's ratio of rock masses are major influence factors on the unit peak shaft resistance.