• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2005.10a
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• pp.303-319
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• 2005

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 1994.03a
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• pp.75-80
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• 1994

지반의 진동은 크게 지진과 같은 자연적인 진동과 발파, 항타(piling) 및 중장비의 가동 등에 따른 건설진동 등 인공진동으로 나눌 수 있는데 이들 지반진동은 지상 구조물의 안전도에 큰 영향을 미친다. 특히 양생(養生)중인 모르타르 및 콘크리트의 강도 및 물리적 성질에 큰 영향을 미치기 때문에 선진국에서는 엄격히 제한하고 있다. (중략)

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 1995.03a
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• pp.48-55
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• 1995

주입공법은 지하공간을 개발할 때 굴착면의 붕괴와 지하수의 유입으로 인한 지하 공동의 불안정성을 방지하고 지반 침하를 최소화하여 지상 구조물에 미치는 피해를 줄이는 목적에 사용되고 있다. 또한 주입공법은 설비가 간단하고 소규모이기 때문에 협소한 장소나 공간에서도 시공할 수 있고 진동 및 소음에 대한 영향이 적기 때문에 공사현장에서 요긴하게 사용되는 공법이다. $^{(1)}$ (중략)

• Journal of Korean Tunnelling and Underground Space Association
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• v.9 no.3
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• pp.275-286
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• 2007

In construction of a structure in underground space, in-situ stress in rock mass has great effect on the stability of the structure. Especially, the direction and magnitude of rock stress have influence on the excavation method, the choice of support and reinforcement method for establishing the stability of tunnel. Therefore, it is very important to consider the characteristics of in-situ stress in rock mass for tunnel stability analysis. In this study, a reasonable design method for underground structure was reviewed through the case study for tunnel design considering in-situ rock stress. For this purpose, the estimation for SRF (Stress Reduction Factor) as input parameter in rock classification using Q-System and the assesment for tunnel support were studied. Also, considering the characteristics of in-situ rock stress such as the magnitude of K and the direction of principal stress, the parameter studies for tunnel stability analysis were carried out. An improved method was proposed for obtaining the better results in the tunnel stability analysis.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 1995.03a
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• pp.92-100
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• 1995

최근 지하 공간의 활용이 증대되는 추세에 이와 관련되어 지하 구조물의 시공전 또는 시공 중에 있어 시공 전략 수립, 장비 결정, 안정성 및 경제성 등을 위해 암반 내의 파쇄대나 균열대의 발달 및 분포에 대한 탐사는 필수적으로 선행되어야 한다. 이러한 탐사에는 분해능이 매우 높은 탐사 기술이 요구되며, 일반적으로 시추공이나 지하 갱도를 이용한 탄성파 탐사나 지오레이다(georadar) 탐사를 많이 사용하고, 자료해석을 위한 역산 기법으로는 지오토모그래피(geotomography)가 필수적인 기법으로 인식되고 있다. (중략)

• Journal of the Korean Geotechnical Society
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• v.16 no.5
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• pp.63-74
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• 2000

지하구조물 걸설시 발파에 의한 암반의 굴착공법이 일반적으로 사용된다. 그러나 발파에 의한 암반의 굴착은 잔존암반의 손상과 진동을 유발하는 문제점을 가지고 있다. 현재까지는 이러한 암반의 손상과 진동문제를 해결하기 위해 현장계측을 기초로한 경험적인 방법이 이용되어 왔으나 여러 가지 한계점을 지니고 있는 것이 현실이다. 따라서 수치해석에 의한 터널 발파의 모델링을 이용하면 이러한 한계점을 보완할수 있을 것이다. 본 논문에서는 발파에 의한 발파공 주위 암반의 거동을 유한요소해석을 이용하여 규명하고, 토로터널의 표준발파패턴을 기초로 하여 외과공 발파와 외곽공에 인접한 주변공 발파에 의한 암방의 손상의 손상을 비교하여 발파패턴의 적절성을 평가하고자 하였으며, 이를 근거응 발파에 의한 암반의 손상을 최소하기 위한 발파패턴의 최적화를 도모하였다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.16 no.4
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• pp.369-376
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• 2003

In this paper, a nonlinear structural analysis for the composite structure composed of the spent nuclear fuel disposal canister and the 50㎝ thick bentonite buffer is carried out to predict the collapse of the canister while the horizontal symmetric sudden rock movement of 10㎝ is applied on the composite structure. This sudden rock movement is anticipated by the earthquake etc. at a deep underground. Elastoplastic material model is adopted. Drucket-Prager yield criterion is used for the material yield prediction of the bentonite buffer and von-Mises yield criterion is used for the material yield prediction of the canister(cast iron, copper). Analysis results show that even though very large deformations occur beyond the yield point in the bentonite buffet, the canister structure still endures elastic small strains and stresses below the yield strength. Hence, the 50㎝ thick bentonite buffet can protect the canister safely against the 10㎝ sudden rock movement by earthquake etc.. Analysis results also show that bending deformations occur in the canister structure due to the shear deformation of the bentonite buffer.

• Tunnel and Underground Space
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• v.19 no.1
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• pp.1-10
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• 2009

Site characterization for structural stability in rock masses mainly involves the collection of joint property data, and in the current practice, much of this data is collected by hand directly at exposed slopes and outcrops. There are many issues with the collection of this data in the field, including issues of safety, slope access, field time, lack of data quantity, reusability of data and human bias. It is shown that information on joint orientation, spacing and roughness in rock masses, can be automatically extracted from LIDAR (light detection and ranging) point floods using the currently available Split-FX point cloud processing software, thereby reducing processing time, safety and human bias issues.

• Tunnel and Underground Space
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• v.9 no.2
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• pp.149-157
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• 1999

A powerful numerical method that can be used for that purpose is the Discontinuous Deformation Analysis (DDA) method developed by Shi in 1988. In this method, rock masses are treated as systems of finite and deformable blocks. Large rock mass deformations and block movements are allowed. Although various extensions of the DDA method have been proposed in the literature, the method is not capable of modeling water-block interaction that is needed when modeling surface or underground excavation in fractured rock. This paper presents a new extension to the DDA method. The extension consists of hydro-mechanical coupling between rock blocks and water flow in fractures. A example of application of the DDA method with the new extension is presented. The results of the present study indicate that fracture flow could have a destabilizing effect on the tunnel stability.

• Explosives and Blasting
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• v.38 no.3
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• pp.15-29
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• 2020

In this paper the Hoek-Brown (HB) failure criterion is integrated into the Holmquist-Johnson-Cook (HJC) concrete material model to reflect the inherent characteristics of field rock masses in LS-DYNA blast modeling. This is intended to emphasize the distinctive characteristics of field rock masses that usually have many geological discontinuities. The replacement is made only for the static strength part of the HJC material model by using a statistical curve fitting technique, and its procedure is described in detail. An example is also given to illustrate the use of the obtained HJC material model. Computation is performed for a plane strain model of a single-hole blasting on a field limestone by using the combination of the fluid-structure interaction (FSI) technique and the multi-material arbitrary Lagrangian Eulerian (MMALE) method in LS-DYNA.