• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.2
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• pp.51-58
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• 2022

Flat plate slab is cost-efficient structural system widely used in high rise building, apartment and parking garages. But flat plate-column connections are so weak against punching shear failure that it may cause collapse of overall structure. In this study, spiral type shear reinforcement which increases the shear strength and ductility of the plate-column connection and has good workability was proposed. And experimental test was performed to verify the punching shear capacity of spiral type shear reinforcement. The current code does not accurately estimate the punching shear strength of slab-column connection with shear reinforcement because slab is so slender that punching failure may occurred before shear reinforcement reached yield stress. Therefore modified equation of ACI code for punching shear strength was proposed base on finite element analysis using LUSAS program, and data analysis from CEB-FIP database.

• Geotechnical Engineering
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• v.4 no.2
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• pp.5-14
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• 1988

A probabilistic model for the progressive failure in a homogeneous soil slope consisting of strain-softening material is presented. The local safety margin of any slice above failure surface is assumed to follow a normal distribution. Uncertainties of the shear strength along potential failure surface are expressed by one-dimensional random field models. In this paper, only the case where failure initiates at toe and propagates up to the crest is considerd. The joint distribution of the safety margin of any two adjacent slices above the failure surface is assumed to be bivariate normal. The overall probability of the sliding failure is expressed as a product of probabilities of a series of conditional el.eats. Finally, the developed procedure has been applied in a case study to yield the reliability of a cut slope.

• Journal of Korean Society of Steel Construction
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• v.9 no.2 s.31
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• pp.277-285
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• 1997

To investigate the shear strength and hysteretic behavior of SRC column to H steel beam joints, seven cruciform specimens were fabricated and tested. The test specimens showed stable hysteresis behavior with a little pinching. The strength decreased with increase in deflection after the speciemens reached at the maximum strength. The shear strength of panel zones increased with increased in the concrete amount of SRC column sections. The shear strength may conservatively be estimated by the sum of shear yielding strength of steel column web, plastic bending strength of steel column flange and ultimate shear strength of concrete in the panel zone.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.328-331
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• 2011

준정적 횡하중을 재하 받는 철근콘크리트 보-기둥 접합부의 전단강도에 대한 주요 영향요인을 Bayesian parameter estimation의 신뢰성 이론 접목을 통해 검토하였다. 이와 같은 연구 scope의 수행을 위해 철근콘크리트 보-기둥의 실험 database가 구축되었다. 실험 database는 일정한 criteria을 적용하여 구축되었으며, 포함된 시편들은 최종적으로 접합부 내의 전단파괴가 지배하는 경우들이다. 포함된 시편들의 상세는 ACI (American Concrete Institute) 352R-02를 기준으로 평가되어졌다. 보-기둥 접합부의 전단강도에 영향 요인을 편중되지 않게 평가하고자, Bayesian parameter estimation의 신뢰성 이론을 적용하였다. Bayesian parameter estimation의 적용을 통해 전단강도에 영향이 적은 변수 (not informative parameter)를 순차적으로 제거 (stepwise removal process)함으로 주요 영향요인의 우선 순위를 확인할 수 있었다. 검토된 8개의 변수들 중에서, 횡하중을 재하 받는 철근콘크리트 보-기둥의 전단강도는 주로 콘크리트 압축강도, in-plane geometry, 종방향 보의 주철근 그리고 접합부 내의 구속철근 순으로 영향을 줌을 알 수 있었다.

• Journal of the Korean GEO-environmental Society
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• v.13 no.4
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• pp.71-76
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• 2012

Shear strength of soil is power that resists failure and sliding according to any face in soils and one of the most important factors during engineering properties of soil. Shear strength is used for engineering science problems as bearing capacity methods of foundation or piles, slope stability after dam or Cutting Embankment and stability problem analysis of soils as lateral earth pressure of soil structures, ets. This study has analyzed shear strength change of samples classified 2.00mm(10sieve)와 0.85mm(20sieve), 0.475mm(40sieve) using direct shear tester after removing and drying cohesive soil ingredient of Weathered granite soil Therefore, this study would help studies about shear strength properties by particle size.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.241-244
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• 2008

The authors proposed a new rapid-screening method for more reasonably evaluating seismic capacities of medium and low-rise RC buildings controlled by both shear and flexure in Ref. [1]. The method proposed in Ref. [1] was based on relationships between required strengths of each failure system for ductility factors and damage degrees of overall system derived from the view-point of ductility factors. The proposed method was also verified using observed real damage data of low-rise RC buildings caused by past earthquakes. Results indicated that the methodology proposed in Ref. [1] compares well with real damages and is a useful strategy for rapidly identifying low-rise RC buildings having high potential seismic risk. In this study, in order to verify the applicability of the new methodology proposed in Ref. [1] to real RC building systems, seismic capacities of existing eleven low-rise RC buildings in Korea are evaluated based on the new method.

• Composites Research
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• v.23 no.1
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• pp.37-43
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• 2010

In this paper, we present the result of an experimental investigation pertaining to the structural behavior of bolted lap-joint connection of pultruded fiber reinforced plastic structural shapes. In the experimental investigation, in order to find the mechanical property of the material, tension and shear tests on the pultruded structural composite specimen are conducted prior to the investigation on the structural behavior of bolted lap-joint connection of the member. Based on the result, number of bolts, type of placement and location of bolt are determined to be a test variable. Three different types of experimental specimens are prepared. Tensile load is applied through the center of the specimen with lap-joint connection and the structural behavior and failure mode of the test specimens with respect to the tensile load increment are investigated. As a result, it is found that most of the failure mode at the lap-joint connection is shear failure mode. Consequently, it is also found that the data obtained through this experimental program could be used for the structure connection design as a basis.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.4
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• pp.52-59
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• 2012

An analytical model is presented to predict the static behavior of the long-span prestressed concrete bridge deck(the long-span PSC deck). The finite element analysis is performed and the results are compared with that of the previous experimental test. The load-deflection relationship curves by FEM are in good agreement with the results reported in the previous study. The failure mode of all test specimens is predicted by the punching shear in this study. It is also observed in the previous experimental test. The main objective of this paper is presenting supportive method to predict static behavior of the long-span PSC deck slab. It is not simulating the punching shear behavior graphically.

• Journal of the Korea Concrete Institute
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• v.14 no.4
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• pp.492-502
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• 2002

The dapped ends of the Gerber's beam were designed by PCI(Prestressed Concrete Institute) and CPCI(Canadian Prestressed Concrete Institute) methods. The depths of nibs with precast and topping concrete, which were halves of the total beam depth, were 77 cm md 18.2 cm, respectably. Shear tests were performed on four full scale beam ends. All specimens designed by PCI and CPCI methods showed crackings at the re-entrant coner of dap before the 32 ％ of full service design loading, and failed at the load level higher than their design strength but less than their calculated nominal strength. The specimens with increased hanger reinforcement show more effective in development of initial crackings, more ductile in failure with distributed crackings, and failed in higher strength than those of PCI requirement. The tested specimens designed by CPCI method were more ductile in failure than those of the PCI methods.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.241-244
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• 2008

In general, RC flat plate frames have been used as a gravity load resisting system(GLRS) in building. This system should be constructed with lateral force resisting system(LFRS) such as shear walls and brace frames. When lateral loads such as earthquakes occur, LFRS undergo displacement by which connected gravity systems experience lateral displacement. Thus, flat plate system designed as GLRS should be predict unbalanced moments and punching failure due to lateral deformation. This study developed an analytical mode for predicting nonlinear behavior of RC slab column connection for the seismic performance evaluation of RC flat plate frames. For verifying the analytical model, the test results of two flat plate specimens having two continous spans with the difference gravity shear ratio($V_g/{\phi}V_c$) were compared with the results of analysis. The developed model can predict the failure modes and punching failures.