• Title/Summary/Keyword: collapse/failure

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Experimental and numerical study on progressive collapse of composite steel-concrete frames

  • Jing-Xuan Wang;Ya-Jun Shen;Kan Zhou;Yong Yang
    • Steel and Composite Structures
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    • v.50 no.5
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    • pp.531-548
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    • 2024
  • This paper presents an experimental investigation into the progressive collapse behavior of composite steel-concrete frames under various column removal scenarios. This study involves testing two two-bay, two-story composite frames featuring CFST columns and profiled steel decking composite slabs. Two removal scenarios, involving the corner column and middle column, are examined. The paper reports on the overall and local failure modes, vertical force-deformation responses, and strain development observed during testing. Findings indicate that structural failure initiates due to fracture and local buckling of the steel beam. Moreover, the collapse resistance and ductility of the middle column removal scenario surpass those of the corner column removal scenario. Subsequent numerical analysis reveals the significant contribution of the composite slab to collapse resistance and capacity. Additionally, it is found that horizontal boundary conditions notably influence the collapse resistance in the middle column removal scenario only. Finally, the paper proposes a simplified calculation method for collapse resistance, which yields satisfactory predictions.

Model Tests for Deriving Failure Parameter during Levee Overflow (제방 월류시 붕괴매개변수 도출을 위한 모형실험)

  • Kim, Jin-Man;Cho, Won-Beom;Choi, Bong-Hyuck;Oh, Eun-Ho
    • Journal of the Korean Geosynthetics Society
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    • v.14 no.2
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    • pp.11-21
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    • 2015
  • According to the damage investigation in 2002, the failures of river levee were caused by overflow, erosion, and unstable body conditions due to piping, inappropriate embanking materials, and poor compaction. Especially, overflow was identified as a main reason that induces levee failure by 39.5% from the distribution of failure types. The major parameters, such as levee collapsing angle (${\theta}$), levee collapsing rate (k) affect inundation velocity and area size during the analysis of inundation modeling, however, domestic research effort on this area is still insufficient. In this paper authors conducted levee failure experiments of 4 levee height types, 0.20 m, 0.25 m, 0.30 m, and 0.40 m based on theassumption of Froude Similarity (${\lambda}_{Fr}=1$). As a result, the authors suggested a levee failure mechanism according to the levee heights (H), a collapse extension lengthwhich is around, levee collapse angle (${\theta}$), levee collapse rate (k).

Progressive collapse of reinforced concrete structures

  • Yagob, O.;Galal, K.;Naumoski, N.
    • Structural Engineering and Mechanics
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    • v.32 no.6
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    • pp.771-786
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    • 2009
  • In the past few decades, effects of natural hazards, such as earthquakes and wind, on existing structures have attracted the attention of researchers and designers. More recently, however, the phenomenon of progressive collapse is becoming more recognized in the field of structural engineering. In practice, the phenomenon can result from a number of abnormal loading events, such as bomb explosions, car bombs, accidental fires, accidental blast loadings, natural hazards, faulty design and construction practices, and premeditated terrorist acts. Progressive collapse can result not only in disproportionate structural failure, but also disproportionate loss of life and injuries. This paper provides an up-to-date comprehensive review of this phenomenon and its momentousness in structural engineering communities. The literature reveals that although the phenomenon of progressive collapse of buildings is receiving considerable attention in the professional engineering community, more research work is still needed in this field to develop a new methodology for efficient and inexpensive design to better protect buildings against progressive collapse.

A proposal and application of critical rainfall curve for disaster prevention of railway slopes due to rainfall(I) (강우에 의한 철도토공사면 방재를 위한 한계우량식 산출 및 적용(I))

  • 김현기;박영곤;신민호
    • Proceedings of the KSR Conference
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    • 2001.05a
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    • pp.437-442
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    • 2001
  • In Korea, collapse of railway slopes is frequently occurred due to tycoon or heavy rainfall doling rainy season and has been made personal and social damage greatly. In order to evaluate the stability of railway slopes under rainfall, explanatory variables and subordinate variables were selected for multivariate analysis. The sites which failure had occurred due to rainfall were investigated and critical rainfall was defined by the case that had high value of correlation factor after multivariate analyses for 121 cases had been executed. The maximum hourly rainfall during 24 hours before failure caused the collapse of railway embankment and the 0.3 square value of maximum hourly rainfall during 24 hours before failure caused the collapse of railway cut-slope, From the application to collapse examples, it is judged that critical rainfall curve will be used to estimate the stability of slopes.

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Analysis of Influencing Factors on Cavity Collapse and Evaluation of the Existing Cavity Management System (공동 붕괴를 유발하는 영향인자 분석 및 기존 공동관리 시스템 평가)

  • Lee, Kicheol;Park, Jongho;Choi, Byeong-Hyun;Kim, Dongwook
    • Journal of the Korean Geosynthetics Society
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    • v.17 no.1
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    • pp.45-54
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    • 2018
  • In this study, numerical analysis is performed to determine highly influential factors that increase the possibility of asphalt road collapse due to cavity underneath the road. The considered influence factors on road collapse due to underground cavity were the asphalt layer thickness, the cover depth, the cavity width, and the cavity height. The concentrated load and uniform distributed pressure were applied on the top surface of asphalt pavement layers with different shape of cavity and asphalt thickness. For each analysis case of given cavity and asphalt thickness, failure load was analyzed under displacement controlled condition. Based on the analyzed failure loads, the applicability of the cavity management system developed by Seoul city was evaluated. As a result of the analysis, the effect of cavity height on road collapse was not significant while the other factors considerably influenced road collapse. Consequently, degree of road collapse susceptibility should be classified by failure load rather than by the condition of existing cavity.

A Study on the Bending Collapse Analysis and Test of Al Extrusion Members (알루미늄 압출부재의 굽힘붕괴 해석 및 실험에 관한연구)

  • Kang, Shin-You;Seo, Sung-Soo
    • Journal of Industrial Technology
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    • v.17
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    • pp.213-218
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    • 1997
  • This study is concerned with characteristics of bending collapse of aluminum members with multi-cell section. Aluminum is light so it is compatible of being used for vehicle structures members. Bending collpase behaviors of aluminum members with multi-cell section are very complex and tension failure mode are occured in experiment. In this paper, the aluminum members are modeled to be able to represent the tension failure mode and, characteristics of bending collapse of aluminum members with multi-cell section by experimental method are compared with the results of PAM-CRASH.

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2D and 3D numerical analysis on strut responses due to one-strut failure

  • Zhang, Wengang;Zhang, Runhong;Fu, Yinrong;Goh, A.T.C.;Zhang, Fan
    • Geomechanics and Engineering
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    • v.15 no.4
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    • pp.965-972
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    • 2018
  • In deep braced excavations, struts and walers play an essential role in the whole supporting system. For multi-level strut systems, accidental strut failure is possible. Once a single strut fails, it is possible for the loads carried from the previous failed strut to be transferred to the adjacent struts and therefore cause one or more struts to fail. Consequently, progressive collapse may occur and cause the whole excavation system to fail. One of the reasons for the Nicoll Highway Collapse was attributed to the failure of the struts and walers. Consequently, for the design of braced excavation systems in Singapore, one of the requirements by the building authorities is to perform one-strut failure analyses, in order to ensure that there is no progressive collapse when one strut was damaged due to a construction accident. Therefore, plane strain 2D and three-dimensional (3D) finite element analyses of one-strut failure of the braced excavation system were carried out in this study to investigate the effects of one-strut failure on the adjacent struts.

Collapse simulations of a long span transmission tower-line system subjected to near-fault ground motions

  • Tian, Li;Pan, Haiyang;Ma, Ruisheng;Qiu, Canxing
    • Earthquakes and Structures
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    • v.13 no.2
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    • pp.211-220
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    • 2017
  • Observations from past strong earthquakes revealed that near-fault ground motions could lead to the failure, or even collapse of electricity transmission towers which are vital components of an overhead electric power delivery system. For assessing the performance and robustness, a high-fidelity three-dimension finite element model of a long span transmission tower-line system is established with the consideration of geometric nonlinearity and material nonlinearity. In the numerical model, the Tian-Ma-Qu material model is utilized to capture the nonlinear behaviours of structural members, and the cumulative damage D is defined as an index to identify the failure of members. Consequently, incremental dynamic analyses (IDAs) are conducted to study the collapse fragility, damage positions, collapse margin ratio (CMR) and dynamic robustness of the transmission towers by using twenty near-fault ground motions selected from PEER. Based on the bending and shear deformation of structures, the collapse mechanism of electricity transmission towers subjected to Chi-Chi earthquake is investigated. This research can serve as a reference for the performance of large span transmission tower line system subjected to near-fault ground motions.

Experimental Study on The Bending Collapse Characteristics of Aluminum Rectangular Tubes (알루미늄 사각관의 굽힘붕괴특성에 관한 실험적 고찰)

  • Kim, Chang-Soo;Chung, Tae-Eun;Kang, Shin-You
    • Transactions of Materials Processing
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    • v.7 no.1
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    • pp.49-58
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    • 1998
  • In this paper the bending collapse characteristics of 6XXX series aluminum rectangular tubes were studied with a pure bending collapse test rig which could apply the pure bending moment without imposing additional shear and tensile forces. Under the pure bending moment, there occured three kinds of bending collapse modes-local buckling delayed buckling and tensile failure-depending on the a, b, t (depth width thickness) and material properties. Experimental results are compared with the results of finite element method and other methods.

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Evaluation of Plastic Collapse Pressure for Steam Generator Tube with Non-Aligned Two Axial Through-Wall Cracks (두 개의 비대칭 축방향 관통균열이 존재하는 증기발생기 세관의 소성붕괴압력 평가)

  • Moon Seong-In;Chang Yoon-Suk;Lee Jin-Ho;Song Myung-Ho;Choi Young-Hwan;Kim Young-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.8 s.239
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    • pp.1070-1077
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    • 2005
  • The $40\%$ of wall thickness criterion which has been used as a plugging rule is applicable only to a single cracked steam generator tubes. In the previous studies performed by authors, several failure prediction models were introduced to estimate the plastic collapse pressures of steam generator tubes containing collinear or parallel two adjacent axial through-wall cracks. The objective of this study is to examine the failure prediction models and propose optimum ones for non-aligned two axial through-wall cracks in steam generator tubes. In order to determine the optimum ones, a series of plastic collapse tests and finite element analyses were carried out for steam generator tubes with two machined non-aligned axial through-wall cracks. Thereby, either the plastic zone contact model or COD based model was selected as the optimum one according to axial distance between two clacks. Finally, the optimum failure prediction model was used to demonstrate the conservatism of flaw characterization rules for various multiple flaws according to ASME code.