• Title/Summary/Keyword: shear design

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Retrofitting by adhesive bonding steel plates to the sides of R.C. beams. Part 2: Debonding of plates due to shear and design rules

  • Oehlers, Deric. J.;Nguyen, Ninh T.;Bradford, Mark A.
    • Structural Engineering and Mechanics
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    • v.9 no.5
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    • pp.505-518
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    • 2000
  • A major cause of premature debonding of tension face plates is shear peeling (Jones et al. 1988, Swamy et al. 1989, Ziraba et al. 1994, Zhang et al. 1995), that is debonding at the plate ends that is associated with the formation of shear diagonal cracks that are caused by the action of vertical shear forces. It is shown in this paper how side plated beams are less prone to shear peeling than tension face plated beams, as the side plate automatically increases the resistance of the reinforced concrete beam to shear peeling. Tests are used to determine the increase in the shear peeling resistance that the side plates provide, and also the effect of vertical shear forces on the pure flexural peeling strength that was determined in the companion paper. Design rules are then developed to prevent premature debonding of the plate ends due to peeling and they are applied to the strengthening and stiffening of continuous reinforced concrete beams. It is shown how these design rules for side plated beams can be adapted to allow for propped and unpropped construction and the time effects of creep and shrinkage, and how side plates can be used in conjunction with tension face plates.

Ductility Confinement of RC Rectangular Shear Wall (장방형 철근 콘크리트 전단벽의 연성 보강)

  • 강수민;박홍근
    • Journal of the Korea Concrete Institute
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    • v.14 no.4
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    • pp.530-539
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    • 2002
  • In designing the boundary confinement of shear walls, the current design provisions and recommendations are empirical and prescriptive; they specify a certain confinement length and details, regardless of the actual requirement of ductility Therefore, they are inappropriate to the performance based-design. The purpose of the present study is to develop a ductility design method that Is applicable to the performance based-design of shear wall. For the purpose, experimental studies were performed to investigate variations in the ductility of shear walls with the length of the boundary confinement. Five specimens modeling the compressive zone of cross sections with different confinement area were tested against eccentric vertical load. Through the experimental studies, strength, ductility, and failure mode of the compression zone were investigated. In addition, nonlinear numerical analyses for the overall cross-sections of shear wall were performed to investigate variations of the stress and strain profiles with the length of compression zone. On the basis of the experimental and numerical studies, a ductility design method for shear wall was developed. By using the proposed design method, for a given ductility demand, the area of lateral confinement and corresponding reinforcement ratio can be precisely determined so that the ductile behavior and economical design are assured.

Behaviour and design of stainless steel shear connectors in composite beams

  • Yifan Zhou;Brian Uy;Jia Wang;Dongxu Li;Xinpei Liu
    • Steel and Composite Structures
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    • v.46 no.2
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    • pp.175-193
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    • 2023
  • Stainless steel-concrete composite beam has become an attractive structural form for offshore bridges and iconic high-rise buildings, owing to the superior corrosion resistance and excellent ductility of stainless steel material. In a composite beam, stainless steel shear connectors play an important role by establishing the interconnection between stainless steel beam and concrete slab. To enable the best use of high strength stainless steel shear connectors in composite beams, high strength concrete is recommended. To date, the application of stainless steel shear connectors in composite beams is still very limited due to the lack of research and proper design recommendations. In this paper, a total of seven pushout specimens were tested to investigate the load-slip behaviour of stainless steel shear connectors. A thorough discussion has been made on the differences between stainless steel bolted connectors and welded studs, in terms of the failure modes, load-slip behaviour and ultimate shear resistance. In parallel with the experimental programme, a finite element model was developed in ABAQUS to simulate the behaviour of stainless steel shear connectors, with which the effects of shear connector strength, concrete strength and embedded connector height to diameter ratio (h/d) were evaluated. The obtained experimental and numerical results were analysed and compared with existing codes of practice, including AS/NZS 2327, EN 1994-1-1 and ANSI/AISC 360-16. The comparison results indicated that the current codes need to be improved for the design of high strength stainless steel shear connectors. On this basis, modified design approaches were proposed to predict the shear capacity of stainless steel bolted connectors and welded studs in the composite beams.

Shear Design of Trapezoidally Corrugated Steel Webs (제형 파형강판 복부판의 전단 설계)

  • Moon, Jiho;Yi, Jongwon;Choi, Byung-Ho;Lee, Hak-Eun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.4A
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    • pp.497-505
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    • 2008
  • Corrugated steel webs resist only shear force because of the accordion effects. The shear force in the web can cause three different buckling mode: local, global, and interactive shear buckling modes. The shear behavior of the corrugated steel webs have been investigated by several researchers. However, shear buckling behavior of the corrugated webs are not clearly explained yet. And, it lead the conservative design. This paper presents shear strength of trapezoidally corrugated steel webs. A series of the tests were also conducted to verified proposed shear strength. Firstly, local, global, and interactive shear buckling equations provided by previous researchers were rearranged as a simple form considering the profiles of the existing bridges with corrugated steel webs. And, global and interactive shear buckling coefficient, and shear buckling parameter for corrugated webs were suggested in this study. Inelastic buckling strength can be determined from buckling curves based on the proposed shear buckling parameter. From the test results of this study and those of previous researchers, it can be found that suggested shear strength provides good estimation of those of trapezoidally corrugated steel webs.

Crack-controlled design methods of RC beams for ensuring serviceability and reparability

  • Chiu, Chien-Kuo;Saputra, Jodie;Putra, Muhammad Dachreza Tri Kurnia
    • Structural Engineering and Mechanics
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    • v.82 no.6
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    • pp.757-770
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    • 2022
  • For the design of flexural and shear crack control for reinforced concrete (RC) beams related to serviceability and reparability ensuring, eight simply-supported normal-strength reinforced concrete (NSRC) beam specimens are tested and the existing high-strength reinforced concrete (HSRC) experimental data are included in the investigation of this work. According to the investigation results of flexural and shear cracks, this works modifies the existing design formulas to determine the spacing of the tensile reinforcement for the flexural crack control of a HSRC/NSRC beam design. Additionally, for a specified shear crack width of 0.4 mm, the allowable stresses of the shear reinforcement are also identified. For the serviceability and reparability ensuring of HSRC/NSRC beams, this works proposes the relationship curves between the maximum flexural width and allowable stress of the tensile reinforcement, and the relationship curves between the shear crack width and allowable shear force that can be used to do the crack width control directly.

Block Shear Failure : State of the Arts (블록전단파괴 : State of the Arts)

  • Jang, Sun-Jae;Lee, Woo-Chul;Lim, Nam-Hyoung;Lee, Chin-Ok
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.75-78
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    • 2008
  • Limit states of a tension member are the yielding of gross section, fracture of net section, and block shear failure. Block shear failure is very complicated than other limit state because of interaction of tension and shear failure. Block shear failure is studied continuously since the 1970s. However, failure model to estimate the strength of block shear failure provided in current design specifications is not reflective of the failure mode observed in the various experimental studies. Comparisons between the experimental results and design rules in various specifications about the block shear failure were conducted in this study. Also, the need for further studies of block shear failure were proposed.

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Shear bond failure in composite slabs - a detailed experimental study

  • Chen, Shiming;Shi, Xiaoyu;Qiu, Zihao
    • Steel and Composite Structures
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    • v.11 no.3
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    • pp.233-250
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    • 2011
  • An experimental study has been carried out to reveal the shear-bond failure mechanism of composite deck slabs. Thirteen full scale simply supported composite slabs are studied experimentally, with the influence parameters like span length, slab depth, shear span length and end anchorage provided by steel headed studs. A dozen of strain gauges and LVDTs are monitored to capture the strain distribution and variation of the composite slabs. Before the onset of shear-bond slip, the longitudinal shear forces along the span are deduced and found to be proportional to the vertical shear force in terms of the shear-bond strength in the m-k method. The test results are appraised using the current design procedures. Based on the partial shear-bond connection at the ultimate state, an improved method is proposed by introducing two reduction factors to assess the moment resistance of a composite deck slab. The new method has been validated and the results predicted by the revised method agree well with the test results.

An Evaluation of ACI 349 Code for Shear Design of CIP Anchor (직매형 앵커기초의 전단설계를 위한 ACI 349 Code의 평가)

  • Jang Jung-Bum;Hwang Kyeong-Min;Suh Yong-Pyo
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2005.04a
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    • pp.464-470
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    • 2005
  • The numerical analysis is carried out to identify the influence of design factors to shear capacity of cast-in-place (CIP) anchor in ACI 349 Code that is available for the design of fastening system at Nuclear Power Plant (NPP) in this study. The MASA program is used to develop the numerical analysis model and the developed numerical analysis model is verified on a basis of the various test data of CIP anchor. Both $l/d_o$ and $c_1/l$ we considered as design factors. As a result, the variation of $l/d_o$ has no influence on the shear capacity of CIP anchor but $c_1/l$ has a large influence on the shear capacity of CIP anchor, Therefore, it is proved that ACI 349 Code may give a non-conservative results compared with real shear capacity of CIP anchor according to $c_1/l$.

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Shear Experiments on Concrete Filled PHC Pile with Composite Shear Connectors with Rebar Holes (보강 철근 정착 홀을 갖는 합성 전단연결재를 적용한 콘크리트 충전 PHC말뚝의 전단성능 평가)

  • Kim, Jeong-Hoi;Park, Young-Shik;Min, Chang-Shik
    • Journal of the Korea Concrete Institute
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    • v.29 no.3
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    • pp.259-266
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    • 2017
  • The purpose of this study was to contribute to the field application cost effectively and reasonably by developing the functional piles that reinforces shear force. CFP pile (Concrete Filled Pretensioned Spun High Strength Concrete Pile with Ring type Composite shear connectors) developed in this study increases the shear stress by placing composite shear connector and filling the concrete into hollow part of the pile. By placing the reinforcement (H13-8ea) and the reinforcement (H19-8ea) into hollow section inside of PHC piles, it also improves the shear strength due to increasing steel ratio. It reinforces shear strength effectively by dowel force that is generated by putting reinforcement (H13-8) into the holes of composite shear connectors for the composite behavior of filled concrete and PHC pile. The study was reviewed and compared the calculated result of the shear strength by limit state design method highway bridge design standards (2012) and experiment result of the shear strength by KS F 4306. We can design the shear strength reasonably as the safety ratio of 2.20, 2.15, 2.05 is shown comparing to design shear strength, according to design shear strength on each cross sections and the experiment results of the CFP pile.

Modified FHWA Design Method Considering Bending Stiffness of Soil Nail (휨강성을 고려한 수정 FHWA 쏘일네일 설계법 제안)

  • Kim, Nak-Kyung;Jung, Jung-Hee;Ju, Yong-Sun;Kim, Sung-Kyu
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.1406-1416
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    • 2008
  • Soil nailing is used as a method of slope stabilization and excavation support. The design method of soil nail are based on experience or assumption of interaction between soil and reinforcement. Most design methods simply considers the tension of reinforcement for analysis of slope stabilization. Soil nails interact with soils under combined loading of shear and tension. Jewell & Pedley(1990) suggested a design equation of shear force with bending stiffness and discussed that the magnitude of the maximum shear force is small in comparison with the maximum axal force. However, they have used a very conservative limiting bearing stress on nails. This paper discusses that the shear strength of soil nails should not be disregarded with proper bearing stresses on nails. The modified FHWA design method was proposed by considering shear forces on nails with bending stiffness.

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