• Title/Summary/Keyword: shear-wall

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Analysis of settlements of space frame-shear wall-soil system under seismic forces

  • Jain, D.K.;Hora, M.S.
    • Earthquakes and Structures
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    • v.8 no.5
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    • pp.1255-1276
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    • 2015
  • The importance of considering soil-structure interaction effect in the analysis and design of RC frame buildings is increasingly recognized but still not penetrated to the grass root level owing to various complexities involved. It is well established fact that the soil-structure interaction effect considerably influence the design of multi-storey buildings subjected to lateral seismic loads. The shear walls are often provided in such buildings to increase the lateral stability to resist seismic lateral loads. In the present work, the linear soil-structure analysis of a G+5 storey RC shear wall building frame resting on isolated column footings and supported by deformable soil is presented. The finite element modelling and analysis is carried out using ANSYS software under normal loads as well as under seismic loads. Various load combinations are considered as per IS-1893 (Part-1):2002. The interaction analysis is carried out with and without shear wall to investigate the effect of inclusion of shear wall on the total and differential settlements in the footings due to deformations in the soil mass. The frame and soil mass both are considered to behave in linear elastic manner. It is observed that the soil-structure interaction effect causes significant total and differential settlements in the footings. Maximum total settlement in footings occurs under vertical loads and inner footings settle more than outer footings creating a saucer shaped settlement profile of the footings. Each combination of seismic loads causes maximum differential settlement in one or more footings. Presence of shear wall decreases pulling/pushing effect of seismic forces on footings resulting in more stability to the structures.

Damage and deformation of new precast concrete shear wall with plastic damage relocation

  • Dayang Wang;Qihao Han;Shenchun Xu;Zhigang Zheng;Quantian Luo;Jihua Mao
    • Steel and Composite Structures
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    • v.48 no.4
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    • pp.385-403
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    • 2023
  • To avoid premature damage to the connection joints of a conventional precast concrete shear wall, a new precast concrete shear wall system (NPSW) based on a plastic damage relocation design concept was proposed. Five specimens, including one monolithic cast-in-place concrete shear wall (MSW) as a reference and four NPSWs with different connection details (TNPSW, INPSW, HNPSW, and TNPSW-N), were designed and tested by lateral low-cyclic loading. To accurately assess the damage relocation effect and quantify the damage and deformation, digital image correlation (DIC) and conventional data acquisition methods were used in the experimental program. The concrete cracking development, crack area ratio, maximum residual crack width, curvature of the wall panel, lateral displacement, and deformed shapes of the specimens were investigated. The results showed that the plastic damage relocation design concept was effective; the initial cracking occurred at the bottom of the precast shear wall panel (middle section) of the proposed NPSWs. The test results indicated that the crack area ratio and the maximum residual crack width of the NPSWs were less than those of the MSW. The NPSWs were deformed continuously; significant distortions did not occur in their connection regions, demonstrating the merits of the proposed NPSWs. The curvatures of the middle sections of the NPSWs were lower than that of the MSW after a drift ratio of 0.5%. Among the NPSWs, HNPSW demonstrated the best performance, as its crack area ratio, concrete damage, and maximum residual crack width were the lowest.

Effect of shear wall location in rigid frame on earthquake response of roof structure

  • Ishikawa, Koichiro;Kawasaki, Yoshizo;Tagawa, Kengo
    • Structural Engineering and Mechanics
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    • v.11 no.6
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    • pp.605-616
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    • 2001
  • The purpose of this study is to investigate the effect of the shear wall location in rigid frames on the dynamic behavior of a roof structure due to vertical and horizontal earthquake motions. The study deals with a gabled long span beam supported by two story rigid frames with shear walls. The earthquake response analysis is carried out to study the responses of the roof: vibration mode, natural period, bending moment and horizontal shear force of the bearings. The study results in the following conclusions: First, a large horizontal stiffness difference between the side frames is caused by the shear wall location, which results in a large vertical vibration of the roof and a large shear force at the side bearings. Second, in this case, the seismic design method for ordinary buildings is not useful in determining the distribution of the static equivalent loads for the seismic design of this kind of long span structures.

DEVELOPMENT OF A REFINED STRUCTURAL MODEL FOR COMPOSITE BLADES WITH ARBITRARY SECTION SHAPES (임의의 단면 형상을 갖는 복합재료 블레이드의 첨단 구조해석 모델 개발)

  • Jung, Sung-Nam;Inderjit Chopra
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 1999.11a
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    • pp.215-218
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    • 1999
  • A general structural model, which is an extension of the Vlassov theory, is developed for the analysis of composite rotor blades with elastic couplings. A comprehensive analysis applicable to both thick-and thin-walled composite beams, which can have either open- or closed profile is formulated. The theory accounts for the effects of elastic couplings, shell wall thickness, and transverse shear deformations. A semi-complementary energy functional is used to account for the shear stress distribution in the shell wall. The bending and torsion related warpings and the shear correction factors are obtained in closed form as part of the analysis. The resulting first order shear deformation theory describes the beam kinematics in terms of the axial, flap and lag bending, flap and lag shear, torsion and torsion-warping deformations. The theory is validated against experimental results for various cross-section beams with elastic couplings.

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Space-Time Characteristics of the Wall Shear-Stress Fluctuations in an Axial Turbulent Boundary Layer with Transverse Curvature

  • Shin, Dong-Shin;Lee, Seung-Bae;Na, Yang
    • Journal of Mechanical Science and Technology
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    • v.19 no.8
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    • pp.1682-1691
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    • 2005
  • Direct numerical simulation database of an axial turbulent boundary layer is used to compute frequency and wave number spectra of the wall shear-stress fluctuations in a low-Reynolds number axial turbulent boundary layer. One-dimensional and two-dimensional power spectra of flow variables are calculated and compared. At low wave numbers and frequencies, the power of streamwise shear stress is larger than that of spanwise shear stress, while the powers of both stresses are almost the same at high wave numbers and frequencies. The frequency/streamwise wave number spectra of the wall flow variables show that large-scale fluctuations to the rms value is largest for the stream wise shear stress, while that of small-scale fluctuations to the rms value is largest for pressure. In the two-point auto-correlations, negative correlation occurs in streamwise separations for pressure, and in span wise correlation for both shear stresses.

A Study on Shear strength and Friction Properties of Fiber-Mixed Soil as Backfill Material in Reinforced Earth Wall (섬유혼합 보강토의 전단강도특성 및 마찰특성 연구)

  • 조삼덕;김진만;안주환
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.10a
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    • pp.651-658
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    • 2002
  • A series of experimental study are performed to evaluate the shear strength and friction properties of fiber-mixed soil as backfill material in reinforced earth wall. In order to evaluate the properties of shear strength the big-size direct shear tests are carried out and on the friction properties, the shear friction tests and the pull-out tests are performed. In the results, when the mixed ratio of the net type fiber is 0.2%, the reinforcement effect was better than the others. Also the reinforcement effect of the net type fiber was larger than that of the line type fiber.

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Construction Method for Forming Concrete Shear Keys at Vertical Construction Joints of Slurry Walls (지하연속벽 수직시공이음부에 콘크리트 전단키를 형성하는 시공기술)

  • Lee, Jeong-Young;Kim, Seung-Weon;Kim, Doo-Kie
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2023.05a
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    • pp.401-402
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    • 2023
  • The shear connection of the vertical construction joint of a slurry wall by the concrete shear key has excellent structural performance and is economical and eco-friendly. However, technology for forming concrete shear keys in the underground is still underdeveloped. This paper proposes the development of the construction technology required to form a concrete shear key at the vertical construction joint of the slurry wall.

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Dry Connections for Precast Shear Wall Systems (프리캐스트 전단벽 시스템의 건식접합부에 관한 연구)

  • Hong, Sung-Gul;Lim, Woo-Young
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.05a
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    • pp.530-533
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    • 2006
  • This thesis investigates the behavior of precast wall systems with a new vertical connection which are proportioned by the displacement based design. The proposed precast wall systems are supposed to provide additional spaces and seismic strengthening in remodeling existing residential buildings. For a fast remodeling constructions using PC walls require an efficient, economic fabrication method. A C-type vertical connections for PC wall systems is proposed for transfer of bending moment between walls in the vertical direction while a shear key in the center of wall is prepared to transfer shear forces by bearing. The proposed vertical connection allows us easy fabrication because of different direction of slots at the edges of wall. The dimension of C-type connection components are determined by engineering models and a series of test.

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Evaluation on Seismic Performance of Existing Frame retrofitted with RC CIP Infill Walls (기존 골조의 내진성능 향상을 위한 철근콘크리트 현장타설 끼움벽의 보강성능 평가)

  • Kim, Sun-Woo;Yun, Hyun-Do;Kim, Yun-Su;Ji, Sang-Kyu
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.53-56
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    • 2008
  • A reinforced concrete (RC) cast-in-place (CIP) infill wall retrofitting method may provide an improved seismic performance and economical efficiency for the non-ductile rahmen structures. In this study, four one story-one bay non-ductile frame were constructed and retrofitted with CIP infill wall to evaluate seismic performance of CIP infill wall-frame. From the test results, infill wall-frame exhibited a marked increase in shear strength compared to non-ductile RC frame specimen. But the ductility and story-drift at maximum load were decreased when shear strength of infill wall larger than that of existing RC frame. Therefore, it is confirmed that adequate reinforcement detail is required to assure sufficient seismic performance.

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Precast Shear Wall Systems with C Type Connections (C형 접합부를 이용한 프리캐스트 전단벽 시스템에 관한 연구)

  • Hong, Sung-Gul;Lim, Woo-Young
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2006.03a
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    • pp.217-224
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    • 2006
  • This thesis investigates the behavior of precast wall systems with a new vertical connection which are proportioned by the displacement based design. The proposed precast wall systems are supposed to provide additional spaces and seismic strengthening in remodeling existing residential buildings. For a fast remodeling constructions using PC wails require an efficient, economic fabrication method. A C-type vertical connections for PC wall systems is proposed for transfer of bending moment between walls in the vertical direction while a shear key in the center of wall is prepared to transfer shear forces by bearing. The proposed vertical connection allows us easy fabrication because of different direction of slots at the edges of wall. The dimension of C-type connection components are determined by engineering models and a series of test.

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