• Structural Engineering and Mechanics
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• 제8권5호
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• pp.491-504
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• 1999

The initiation of toppling is explored for a uniform stack of blocks that rotates slowly about its mid-base. As the stack passes through its vertical position ($\theta$=0), it is in free-fall rotation, and a critical inclination angle ${\theta}_c$ is reached at which the toppling stack "fails" or begins to crack or separate. For tall stacks (high aspect ratios), two modes of failure are hypothesized, for which the dynamic failure analyses are shown to correlate with experimental results. These block failure modes are similar to those observed for tall, toppling masonry structures with weak binding material between their brick or stone blocks.

• 한국지반공학회지:지반
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• 제14권2호
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• pp.55-66
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• 1998

본 논문의 목적은 불연속면의 공학적 특성, 사면형상과 하중조건 등을 고려한 암반사면 전도 파괴에 대한 안정해석방법을 개발하고 적용하는테 있다. 암반사면의 전도파괴에 대한 안정은 경사각 $\alpha_s$ 와 H/t비에 주된 영향을 받는다. 설계적용을 위하여 매개변수에 따른 My띠와 $\alpha$서 함수로 표현되는 암반사면 전도파괴에 대한 안정도표를 작성하였다. 안정도표에서 $\alpha_s$와 Hy띠가 작아질수록 안정성이 증가하는 경향을 보인다. 안정도표에서 안정영역은 간극수압변화에 따라 가장 크게 감소한다. 파괴영역의 변화는 지진력과 단계각에 가장 민감하다.

• Geomechanics and Engineering
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• 제27권5호
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• pp.481-495
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• 2021

This article assesses and estimates the progressive failure mechanism of complex pit-rest secondary toppling of slopes that are located within the vicinity of the Gas Flare Site of Refinery No. 4 in South Pars Special Zone (SPSZ), southwest Iran. The finite element numerical procedure based on the Shear Strength Reduction (SSR) technique has been employed for the stability analysis. In this regard, several step modelling stages that were conducted to evaluate the slope stability status revealed that the main instability was situated on the left-hand side (western) slope in the Flare Site. The toppling was related to the rock column-overburden system in relation to the overburden pressure on the rock columns which led to the progressive instability of the slope. This load transfer from the overburden has most probably led to the separation of the rock column and to its rotation downstream of the slope in the form of a complex pit-rest secondary toppling. According to the numerical modelling, it was determined that the Strength Reduction Factor (SRF) decreased substantially from 5.68 to less than 0.320 upon progressive failure. The estimated shear and normal stresses in the block columns ranged from 1.74 MPa to 8.46 MPa, and from 1.47 MPa to 16.8 MPa, respectively. In addition, the normal and shear displacements in the block columns ranged from 0.00609 m to 0.173 m and from 0.0109 m to 0.793 m, respectively.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 가을 학술발표회 논문집
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• pp.511-518
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• 2000

Characteristics of joint orientation, length, spacing and their distribution are very important factors for slope stability, Especially, the effect of joint spacing is an essential factor of slope stability. This study is to analyze the effect of joint spacing in cases of sliding and toppling, which is a typical failure mode. Joint spacing can divided into vertical spacing(spacing) and horizontal spacing(gap). And then, the spacing/length ratio of joint directly affect rock slope failure. When the ratio is below 0.05, the possibility of failure is rapidly increased. In case of toppling, the possibility of failure depends on the ratio of spacing to height of slope ratio slope. As the ratio decreases, the possibility of toppling failure increased. The critical ratio of spacing to height of slope is determined by the dip angle of the slope and the orientation of joint sets.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1997년도 봄 학술발표회 논문집
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• pp.89-96
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• 1997

• 터널과지하공간
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• 제3권1호
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• pp.96-107
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• 1993

This paper deals with the analysis of rock slope stability using the distinct element method. This method consists in analysis of the interaction of discrete block assemblage delimited by elementary joints, which permits to consider the heterogeneous, anisotropic and discontinuous features of the rock mass. In particular, we were able to show that this method, and especially the BRIG3D software, is an outstanding tool which gives informations of greatest interest in order to analyze the toppling mechanisms. We have confirmed the fundamental role of the rock mass structure with different simulations. In the case of toppling phenomena, the essential parameter is the dip of major discontinuities. It has an influence on the intensity and volume of deformations. The anisotropic and heterogeneous features of the rock mass play also an important role. It is proved by insertion of thick rock bars in the structure or varying rock block sizes in the mass. These models modified considerably the stress distribution and the deformation distribution. Finally, we have analyzed the influence of mechanical parameters such as friction angle and tangential stiffness.

• 지질공학
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• 제20권1호
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• pp.13-23
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• 2010

암반사면의 전도파괴는 암반이나 토체가 기존 파괴면을 따라 미끄러지는 다른 파괴형태와는 달리 암주 혹은 암블록의 회전을 동반하는 파괴형태로 정의된다. 이는 사면방향에 대해 역방향으로 발달된 불연속면이 존재하는 구역에서 주로 발생하며, 불연속면의 지질학적 특성뿐 아니라 기하학적인 특성도 사면의 안정성을 판단하는 중요한 요소로 작용된다. 본 연구에서는 역방향 불연속면이 발달된 절토사면에 대해 안정성을 평가하였다. 일반적으로 암반의 파괴거동은 불연속체 특성을 가지고 있으나 최근 연속체 해석에서 불연속면을 모사하는 수치해석방법들이 많이 논의되고 있다. 본 연구에서는 연속체 해석인 유한요소해석에 불연속면을 이질적인 경계특성에 적용되는 계면요소를 이용하여 모사함으로써 불연속면이 고려된 사면의 거동특성을 파악하였다.

• 터널과지하공간
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• 제5권4호
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• pp.308-317
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• 1995

The stability study on the rock slope where have produced failures in Boryung dam site was evaluated using the streonet analysis techniques. SMR(Slope Mass Rating) approach which is suitable for preliminary assessment of slope stability in rock was also carried out for rating rock mass. The 3-4 major discontinuity sets are distributed and all type of failure(plane, wedge and toppling failure) are presented in this slope face. The dip of slope must be lowered to friction angle(26degree), otherwise the possibility of plane and toppling faiue will always exist in this slope.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 추계 학술발표회
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• pp.268-273
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• 2006

Slope failures can be occurred by complex mechanism. In this cases, failures shows characteristics of complex failure mechanism during progressive mass movements. A case is a merged large slide with two sliding events triggered by slip on fault plane. Another case shows extension of failure area by sliding or subsidence at backyards of toppling areas. Generally, areas of progressive failures have wider than them of simple events.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1997년도 사면안정 학술발표회 논문집
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• pp.21-50
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• 1997