• Title/Summary/Keyword: shear resisting capacity

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Evaluation of Dynamic Behavior of moment resisting frame under probabilistic ground motions (확률론적 지진하중에 의한 모멘트 골조의 동적 거동평가)

  • 권오성;한상환
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.05a
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    • pp.565-570
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    • 2001
  • Base shear and roof drift relation was acquired from experiment of 3 story ordinary moment resisting frame which was designed using gravity loads. To evaluate the dynamic behavior of the frame, analytical model was generated from experimental result. Dynamic analysis was performed using the analytical model subjected to earthquake ground motions with 500, 1000, and 2400 years of return period. And capacity spectrum method was adopted to find the performance points of the frame. Both dynamic analysis and CSM showed that the performance of the frame meet the life safety objectives suggested by FEMA 273 and ATC 40.

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Seismic Performance Evaluation of Non-Seismic Reinforced Concrete Buildings Strengthened by Perimeter Steel Moment Frame (철골 모멘트골조로 보강된 철근콘크리트 건물의 내진성능 평가)

  • Kim, Seonwoong
    • Journal of the Earthquake Engineering Society of Korea
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    • v.24 no.5
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    • pp.233-241
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    • 2020
  • This paper is to investigate the retrofitting effect for a non-seismic reinforced concrete frame strengthened by perimeter steel moment frames with indirect integrity, which ameliorates the problems of the direct integrity method. To achieve this, first, full-scale tests were conducted to address the structural behavior of a two-story non-seismic reinforced concrete frame and a strengthened frame. The non-seismic frame showed a maximum strength of 185 kN because the flexural-shear failure at the bottom end of columns on the first floor was governed, and shear cracks were concentrated at the beam-column joints on the second floor. The strengthened frame possessed a maximum strength of 338 kN, which is more than 1.8 times that of the non-seismic specimen. A considerable decrease in the quantity of cracks for the strengthened frame was observed compared with the non-seismic frame, while there was the obvious appearance of the failure pattern due to the shear crack. The lateral-resisting capacity for the non-seismic bare frame and the strengthened frame may be determined per the specified shear strength of the reinforced columns in accordance with the distance to a critical section. The effective depth of the column may be referred to as the longitudinal length from the border between the column and the foundation. The lateral-resisting capacity for the non-seismic bare frame and the strengthened frame may be reasonably determined per the specified shear strength of the reinforced columns in accordance with the distance to a critical section. The effective depth of the column may be referred to as the longitudinal length from the border between the column and the foundation. The proposed method had an error of about 2.2% for the non-seismic details and about 4.4% for the strengthened frame based on the closed results versus the experimental results.

Cyclic Behavior of Interior Joints in Post Tensioned Flat Plate Slab Systems (내부 포스트 텐션 플랫 플레이트 슬래브 기둥 접합부의 이력거동)

  • Kee Seong Hoon;Han Sang Whan;Ha Sang-Su;Lee Li Ryung
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05a
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    • pp.107-110
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    • 2005
  • In general, post tensioned (PT) flat plate slab systems have been used as a Gravity Load Resisting System (GLRS) in buildings. Thus, these systems should be constructed with Lateral Force Resisting Systems (LFRS) such as shear walls and moment resisting frames. When lateral loads such as winds or earthquakes occur, lateral load resisting systems undergo displacement by which connected gravity systems experience lateral displacement. Therefore, GLRS should have some lateral displacement capacity in order to hold gravity loads under severe earthquakes and winds. Since there are the limited number of researches on PT flat plate slab systems, the behavior of the systems have not been well defined. This study investigated the cyclic behavior of post tensioned flat plate slab systems. For this purpose, an experimental test was carried out using 4 interior PT flat plate slab-column specimens. All specimens have bottom reinforcement in the slab around the slab-column connection. Test variables of this experimental study are vertical load level and tendon distribution patterns.

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Development of Connection Details for a Double Split Tee Connection Without a Shear Tab (전단탭이 없는 상·하부 스플릿 티 접합부의 접합부상세 개발)

  • Yang, Jae Guen;Kim, Yong Boem
    • Journal of Korean Society of Steel Construction
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    • v.28 no.1
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    • pp.53-64
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    • 2016
  • The double split tee connection, a type of beam-to-column moment connection, exhibits different behavioral characteristics according to changes in the thickness of the T-stub flange, the gauge distance of the high-strength bolt, and the number and diameter of high-strength bolts. In general, the double split tee connection is idealized and designed so that a T-stub fastened to the top and bottom supports a flexural moment, and a shear tab supports a shear force. However, if the double split tee connection is applied to low-and medium-rise steel structures, the size of the beam member becomes small, and thus the shear tab cannot be bolted to the web of a beam. In this regard, this study was conducted to propose connection details to ensure that the double split tee connection with a geometric shape can display sufficient shear resisting capacity. To this end, experiments were conducted using full-scale specimens for the double split tee connection.

Shear Resistance Capacity Length of Traditional Wooden Frame's Wall divided into Small Frame (세부목골조로 구성된 전통목골조 벽체 전단저항능력)

  • Hwang, Jong-Kook;Kwon, Yang-Hee;Bae, Dong-Hun
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.35 no.3
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    • pp.11-18
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    • 2019
  • The purpose of this study was to estimate the resistance capacity of a traditional wooden house with shear walls made of wood panel. In order to achieve the purpose of the study, the load - displacement test was carried out and the resistance moment values of the shear walls were proposed. The shear walls were made by placing studs with a nominal dimension of $38mm{\times}89mm$ at intervals of 600 mm, and attaching 12 mm thick plywood with 8-d size pegs at intervals of 150 mm. The type of traditional building wall was classified and showed the moment resistance ability of each wall type. This value is expressed as a proportional value divided by the moment resisting capacity of the standard size shear walls not divided into the divided small frames. Although some frames have proportional values larger than 1.0 even though they have openings, most of them show values smaller than 1.0. Also, even without the openings, it showed a smaller value than 1, such as 0.84 and 0.67.

Experimental Study on Low Cyclic Loading Tests of Steel Plate Shear Walls with Multilayer Slits

  • Lu, Jinyu;Yu, Shunji;Qiao, Xudong;Li, Na
    • International journal of steel structures
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    • v.18 no.4
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    • pp.1210-1218
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    • 2018
  • A new type of earthquake-resisting element that consists of a steel plate shear wall with slits is introduced. The infill steel plate is divided into a series of vertical flexural links with vertical links. The steel plate shear walls absorb energy by means of in-plane bending deformation of the flexural links and the energy dissipation capacity of the plastic hinges formed at both ends of the flexural links when under lateral loads. In this paper, finite element analysis and experimental studies at low cyclic loadings were conducted on specimens with steel plate shear walls with multilayer slits. The effects caused by varied slit pattern in terms of slit design parameters on lateral stiffness, ultimate bearing capacity and hysteretic behavior of the shear walls were analyzed. Results showed that the failure mode of steel plate shear walls with a single-layer slit was more likely to be out-of-plane buckling of the flexural links. As a result, the lateral stiffness and the ultimate bearing capacity were relatively lower when the precondition of the total height of the vertical slits remained the same. Differently, the failure mode of steel plate shear walls with multilayer slits was prone to global buckling of the infill steel plates; more obvious tensile fields provided evidence to the fact of higher lateral stiffness and excellent ultimate bearing capacity. It was also concluded that multilayer specimens exhibited better energy dissipation capacity compared with single-layer plate shear walls.

Evaluation and Improvement of Deformation Capacities of Shear Walls Using Displacement-Based Seismic Design

  • Oh, Young-Hun;Han, Sang-Whan;Choi, Yeoh-Soo
    • International Journal of Concrete Structures and Materials
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    • v.18 no.1E
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    • pp.55-61
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    • 2006
  • RC shear walls are frequently used as lateral force-resisting system in building construction because they have sufficient stiffness and strength against damage and collapse. If RC shear walls are properly designed and proportioned, these walls can also behave as ductile flexural members like cantilevered beams. To achieve this goal, the designer should provide adequate strength and deformation capacity of shear walls corresponding to the anticipated deformation level. In this study, the level of demands for deformation of shear walls was investigated using a displacement-based design approach. Also, deformation capacities of shear walls are evaluated through laboratory tests of shear walls with specific transverse confinement widely used in Korea. Four full-scale wall specimens with different wall boundary details and cross-sections were constructed for the experiment. The displacement-based design approach could be used to determine the deformation demands and capacities depending on the aspect ratio, ratio of wall area to floor plan area, flexural reinforcement ratio, and axial load ratio. Also, the specific boundary detailing for shear wall can be applied to enhance the deformation capacity of the shear wall.

Shear Performance of High-Strength Reinforced Concrete Beams using Fly-Ash Artificial Lightweight Aggregate (석탄회 인공경량골재를 사용한 고강도 콘크리트 보의 전단성능)

  • Chung, Soo-Young;Yun, Hyun-Do;Park, Wan-Shin
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.6 no.4
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    • pp.233-242
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    • 2002
  • This study is to investigate experimentally the shear capacity of high-strength lightweight-aggregate reinforced concrete beams subjected to monotonic loading. Ten beams made of fly-ash artificial lightweight high-strength concrete were tested to determine their diagonal cracking and ultimate shear capacities. The variables in the test program were longitudinal reinforcement ratio; which variabled (between 0.83 and 1.66 percent), shear span-to-depth ratio (a/d=1.5, 2.5 and 3.5), and web reinforcement(0, 0.137, 0.275 and 0.554 percent). Six of the test beams had no web reinforcement and the other six had web reinforcement along the entire length of the beam. Most of beams failed brittly by distinct diagonal shear crack, and have reserved shear strength due to the lack of additional resisting effect by aggregate interlocking action after diagonal cracking. Test results indicate that the ACI Building Code predictions of Eq. (11-3) and (11-5) for lightweight concretes are unconservative for beams with tensile steel ratio of 1.66, a/d ratios greater than 2.5 without web reinforcement. Through a more rational approach to compute the contribution of concrete to the shear capacity, a postcracking shear strength in concrete is observed.

A Study on the Shear Resisting Effect of Filling-up Carbon Fiber Rod Plastic in Reinforced Concrete Beams with web Reinforcement (전단보강근이 있는 철근콘크리트보의 매립형 CFRP 전단보강효과에 대한 연구)

  • Kim, Woo-Hyoun;Lee, Hyoung-Seok;Kim, Young-Sik;Park, Sung-Moo
    • Journal of Korean Association for Spatial Structures
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    • v.5 no.2 s.16
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    • pp.65-71
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    • 2005
  • The reinforced concrete becomes deteriorated. In strengthening of reinforced concrete structure, it is recently useing FRP. In research, flexural strengthening of reinforced concrete beam can be Efficient design. But shear srengthening og reinforced concrte beam can't be Efficient design by variable cause. The purpose of this study is to investigate the shear resisting effect of filling-up CFRP in reinforced concrete beams with web reinforced. Ten specimens were manufactured and tested. In the test result, it was analysis. The main variables in the test were a space of web reinforcement and a direction of CFRP.

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Seismic design of beam-column joints in RC moment resisting frames - Review of codes

  • Uma, S.R.;Jain, Sudhir K.
    • Structural Engineering and Mechanics
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    • v.23 no.5
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    • pp.579-597
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    • 2006
  • The behaviour of reinforced concrete moment resisting frame structures in recent earthquakes all over the world has highlighted the consequences of poor performance of beam column joints. Large amount of research carried out to understand the complex mechanisms and safe behaviour of beam column joints has gone into code recommendations. This paper presents critical review of recommendations of well established codes regarding design and detailing aspects of beam column joints. The codes of practice considered are ACI 318M-02, NZS 3101: Part 1:1995 and the Eurocode 8 of EN 1998-1:2003. All three codes aim to satisfy the bond and shear requirements within the joint. It is observed that ACI 318M-02 requires smaller column depth as compared to the other two codes based on the anchorage conditions. NZS 3101:1995 and EN 1998-1:2003 consider the shear stress level to obtain the required stirrup reinforcement whereas ACI 318M-02 provides stirrup reinforcement to retain the axial load capacity of column by confinement. Significant factors influencing the design of beam-column joints are identified and the effect of their variations on design parameters is compared. The variation in the requirements of shear reinforcement is substantial among the three codes.