• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 가을 학술발표회 논문집
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• pp.279-286
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• 2002

Present all sorts of failure or no failure test methods are done for evaluate structural ability of pavement. It are Plane Plate Test, CBR Test, Benkelman Beam Test, FWD, Dynaflect, etc. but, each method of test not expect compatibility because the result very different by each method of test. Now among pavement's method of evaluation, no failure test gradually use because It quickly and simply obtain pavement's elastic modulus of each layer. But, It accompany expensiveness equipment, and It's degree of trust is lower against expensiveness equipment. Therefore this research practice comparative trustworthy Plane Plate Test, comparative low cost and quick Small FWD Test. And analyzed relation of Plane Plate Test with Small FWD Test.

• 한국농공학회지
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• 제37권2호
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• pp.64-72
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• 1995

A series of cubical triaxial tests with three independent principal stresses was per- formed on Baekma river sand( # 40~100). It was found that the major principal strain at failure remained approximately constant for b values larger than about 0.3 for both the drained and undrained condition, and thereafter increased as b value decreased. The test results showed that the direction of the strain increment at failure form acute angles with the failure surfaces for both the drained and undrained condition. The results were thus not in agreement with the normality condition from classic plasticity theory. Howev- er, it was found that the projections of the plastic strain increment vectors on the octahe- dral plane were perpendicular to the failure surface in that plane. Failure strength in terms of effective stress anlaysis was greatly influenced by the variation of intermediate principal stress and so was failure criterion. The effective stress failure surfaces for both the drained and undrained condition were estimated quite well by use of Lade's failure criterion.

• 한국압력기기공학회 논문집
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• 제18권2호
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• pp.77-86
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• 2022

This study investigates the effect of the diameter and thickness on crack initiation location and orientation of 90° elbows under in-plane mode displacement-controlled cyclic bending loads. Finite element (FE) analysis of cyclic failure test is conducted for elbow specimens under in-plane mode displacement-controlled cyclic bending to identify the parameters affecting crack location and orientation. Furthermore, parametric FE analysis of the pipe elbows with various pipe nominal sizes and Schedules is performed, and the crack location and orientation from the results of FE analysis are determined. It is found that the crack location and orientation in the pipe elbows are determined mianly by the radius to thickness ratio of pipe elbows (R_m/t). It is also found that the presence of internal pressure slightly increases the value of R_m/t at which the failure mode changes.

• Structural Engineering and Mechanics
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• 제6권7호
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• pp.757-772
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• 1998

The objective of the present work is to estimate the strength and failure characteristics of symmetric thin square laminates under negative shear load. Two progressive failure analyses, one using the Hashin criterion and the other using a Tensor polynomial criterion, are used in conjunction with the finite element method. First-order shear-deformation theory along with geometric nonlinearity in the von Karman sense has been incorporated in the finite element modeling. Failure loads, associated maximum transverse displacements, locations and modes of failure including the onset of delamination are discussed in detail; these are found to be quite different from those for the positive sheer load reported in Part I of this study (Singh et al. 1998).

• 터널과지하공간
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• 제22권1호
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• pp.43-53
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• 2012

개착면의 방향성과 규모가 점진적으로 변화되는 개착사면의 안정성을 지반의 암석학적, 구조적 및 역학적 특성을 종합적으로 고려한 횡단면 분석기법을 활용하여 분석하였다. 시추작업을 수행하여 획득한 코어시료를 관찰하여 사면지반의 암석학적 취약성을 조사하였으며, 시추공 내 BIPS 영상을 획득하여 사면 내부의 구조적 특성을 규명하였다. 시추코어 및 코어절리시료를 이용한 암석실험을 통해 사면 지반의 공학적 특성을 분석하였다. 평사투영해석을 수행하여 잠재적인 사면거동 양상과 거동유발 절리들을 분석하였으며, 거동유발 절리들의 트레이스 분포를 개착 형상이 고려된 횡단면상에 도시하였다. 횡단면에 분포된 평면파괴 절리들이 기저면을 형성하는 평면블록들을 절리 트레이스 분포를 고려하여 설정하였다. 횡단면 상에서 심도별 평면블록들의 안정성과 적정 안전율을 유지하기 위하여 요구되는 지보량을 산정하여 최적 사면 설계안 수립에 대한 횡단면 기법의 활용성을 고찰하였다.

• 한국지반공학회논문집
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• 제36권11호
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• pp.51-60
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• 2020

횡방향의 토압에 저항하는 앵커블록, 흙막이 가설벽체, 레이커 지지블록 등에서 수동토압 산정은 중요한 요소이다. 실무에서는 사용의 편의성으로 인하여 파괴면을 직선으로 가정한 Coulomb과 Rankine의 이론을 사용하여 토압을 산정하는 것이 일반적이다. 하지만 실제 발생하는 수동파괴면은 벽면과 지반의 마찰로 인하여 벽체부근에서는 곡면이고 지표부근에서는 평면이 되는 복합파괴면을 형성한다. 흙막이 구조물의 안정검토에서 저항력으로 산정되는 수동토압이 발생되는 변위는 주동토압이 발생되는 주동변위 보다 커 대부분 구조물의 안정성을 초과하는 변위가 발생하여야 수동토압의 저항력이 발휘되므로 수동토압을 설계에 적용하기 위해서는 허용변위 이내의 임의변위에서 발휘되는 수동측토압의 산정이 매우 중요한 요소이다. 본 연구에서는 복합파괴면을 반영한 한계변위 내의 임의 변위에서 발휘되는 수동측토압을 산정할 수 있는 반경험식을 활용하여 벽체의 세 가지 거동조건에 따라 임의 변위에서 발휘되는 수동토압을 분석하였다.

• Earthquakes and Structures
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• 제18권1호
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• pp.83-96
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• 2020

The main structural elements of historical masonry arch bridges are arches, spandrel walls, piers and foundations. The most vulnerable structural elements of masonry arch bridges under transverse seismic loads, particularly in the case of out-of-plane actions, are spandrel wall. The vulnerability of spandrel walls under transverse loads increases with the increasing of their length and height. This paper computationally investigates the out-of-plane nonlinear seismic response of spandrel walls of long-span and high masonry stone arch bridges. The Malabadi Bridge with a main arch span of 40.86m and rise of 23.45m built in 1147 in Diyarbakır, Turkey, is selected as an example. The Concrete Damage Plasticity (CDP) material model adjusted to masonry structures, and cohesive interface interaction between the infill and the spandrel walls and the arch are considered in the 3D finite element model of the selected bridge. Firstly, mode shapes with and without cohesive interfaces are evaluated, and then out-of-plane seismic failure responses of the spandrel walls with and without the cohesive interfaces are determined and compared with respect to the displacements, strains and stresses.

• 한국농공학회지
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• 제45권6호
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• pp.172-182
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• 2003

In this study, the back analysis was performed by means of stereo-net, plane failure and block failure method to collapsed fields among the rock slopes designed by standardized criterion, and the internal frictions from the back analysis were compared with those used to reinforcement design. It was concluded that in the result of the analysis by means of stereo net, plain failure and block failure methods, the internal frictions used to re-design of collapsed slope underestimated 10$^{\circ}$, 5$^{\circ}$ and 10$^{\circ}$ in average. At present, the internal friction on the design is used the experience value according to the state of weathering, but internal friction angle by the back analysis on collapsed slope with various methods were more reliable values than those from the present method. And it was concluded that re-design was made extravagantly because the internal friction used to re-design for reinforcement of the collapsed slope was less than back analysis.

• Earthquakes and Structures
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• 제22권5호
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• pp.475-485
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• 2022

This paper presents a comparative experimental study on structural behavior of the interlocking masonry walls under in-plane cyclic loading. The main purpose of this study is to increase lateral load-bearing capacities of masonry walls by using interlocking units. The interlocking units were designed by considering failure modes of masonry walls and produced using lightweight foamed concrete. To this end, three masonry walls which are hollow, fully grouted, and reinforced were constructed with interlocking units. Also, a traditional masonry brick wall was built for comparison reasons. The walls were tested under in-plane cyclic loading. Then, structural parameters of the walls such as lateral load bearing and total energy dissipation capacities, ductility, stiffness degradation as well as failure modes obtained from the tests were compared with each other. The results have shown that the walls with the interlocking units have better structural performance than traditional masonry brick walls and they may be used in the construction of low-rise masonry structures in rural areas to improve in-plane structural performance.

• Geomechanics and Engineering
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• 제5권5호
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• pp.419-445
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• 2013

This paper presents an experimental study on the influence of principal stress direction and magnitude of intermediate principal stress on the undrained stress-strain-strength behaviors of Bangkok Clay. The results of torsional shear hollow cylinder and advanced triaxial tests with various principal stress directions and magnitudes of intermediate principal stress on undisturbed Bangkok Clay specimens are presented. The analysis of testing results include: (i) stress-strain and pore pressure behaviors, (ii) stiffness characteristics, and (iii) strength characteristics. The results assert clear evidences of anisotropic characteristics of Bangkok Clay at pre-failure and failure conditions. The magnitude of intermediate principal stress for plane-strain condition is also investigated. Both failure surface and plastic potential in deviatoric plane of Bangkok Clay are demonstrated to be isotropic and of circular shape which implies an associated flow rule. It is also observed that the shape of failure surface in deviatoric plane changes its size, while retaining its circular shape, with the change in direction of major principal stress. Concerning the behavior of Bangkok Clay found from this study, the discussions on the effects of employed constitutive modeling approach on the resulting numerical analysis are made.