• Title/Summary/Keyword: Wall reinforcement

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Nonlinear 3-D behavior of shear-wall dominant RC building structures

  • Balkaya, Can;Schnobrich, W.C.
    • Structural Engineering and Mechanics
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    • v.1 no.1
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    • pp.1-16
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    • 1993
  • The behavior of shear-wall dominant, low-rise, multistory reinforced concrete building structures is investigated. Because there are no beams or columns and the slab and wall thicknesses are approximately equal, available codes give little information relative to design for gravity and lateral loads. Items which effect the analysis of shear-wall dominant building structures, i.e., material nonlinearity including rotating crack capability, 3-D behavior, slab-wall interaction, floor flexibilities, stress concentrations around openings, the location and the amount of main discrete reinforcement are investigated. For this purpose 2 and 5 story building structures are modelled. To see the importance of 3-D modelling, the same structures are modelled by both 2-D and 3-D models. Loads are applied first the vertical then lateral loads which are static equivalent earthquake loads. The 3-D models of the structures are loaded in both in the longitudinal and transverse directions. A nonlinear isoparametric plate element with arbitrarily places edge nodes is adapted in order to consider the amount and location of the main reinforcement. Finally the importance of 3-D effects including the T-C coupling between walls are indicated.

Development of Design Program for Block-type Reinforced Earth Retaining Wall (블록식 보강토 옹벽 설계프로그램 개발)

  • Lee, Chung-Won;Yoo, Ji-Hoon;Min, Yeon-Sik;Chang, Dong-Su;Lim, Hyun-Taek;Moon, Yong-Bae;Kim, Seung-Tai;Kim, Yong-Seong
    • Journal of The Korean Society of Agricultural Engineers
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    • v.56 no.6
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    • pp.75-84
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    • 2014
  • This study aims to develop the program for design of a reinforced earth retaining wall. For this purpose, the external stability such as overturning, sliding and bearing capacity and the internal stability such as pull-out failure and tensile rupture of the reinforced earth retaining wall with the reinforcement spacing and the backfill inclination were examined. In addition, the calculated results from the developed program were verified by comparing with the simulated results based on the three-dimensional finite element analysis. It is expected that this program contributes to effective design of the reinforced earth retaining wall.

Axially-loaded multiplanar tubular KTX-joints: numerical analysis

  • Zhang, Chenhui;Zou, Bo;Yang, Guotao
    • Steel and Composite Structures
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    • v.42 no.2
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    • pp.173-190
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    • 2022
  • With the development of spatial structures, the joints are becoming more and more complex to connect tubular members of spatial structures. In this study, an approach is proposed to establish high-efficiency finite element model of multiplanar KTX-joint with the weld geometries accurately simulated. Ultimate bearing capacity the KTX-joint is determined by the criterion of deformation limit and failure mechanism of chord wall buckling is studied. Size effect of fillet weld on the joint ultimate bearing capacity is preliminarily investigated. Based on the validated finite element model, a parametric study is performed to investigate the effects of geometric and loading parameters of KT-plane brace members on ultimate bearing capacity of the KTX-joint. The effect mechanism is revealed and several design suggestions are proposed. Several simple reinforcement methods are adopted to constrain the chord wall buckling. It is concluded that the finite element model established by proposed approach is capable of simulating static behaviors of multiplanar KTX-joint; chord wall buckling with large indentation is the typical failure mode of multiplanar KTX-joint, which also increases chord wall displacements in the axis directions of brace members in orthogonal plane; ultimate bearing capacity of the KTX-joint increases approximately linearly with the increase of fillet weld size within the allowed range; the effect mechanism of geometric and loading parameters are revealed by the assumption of restraint region and interaction between adjacent KT-plane brace members; relatively large diameter ratio, small overlapping ratio and small included angle are suggested for the KTX-joint to achieve larger ultimate bearing capacity; the adopted simple reinforcement methods can effectively constrain the chord wall buckling with the design of KTX-joint converted into design of uniplanar KT-joint.

A Feasibility Analysis on Steel Net Gabion Reinforcement of Reinforced Earth-retaining Wall (자연친화적인 보강토 옹벽의 철판망 gabion 보강재 타당성 분석)

  • Chung, Dae-Seouk
    • Journal of Environmental Science International
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    • v.17 no.2
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    • pp.135-140
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    • 2008
  • Steel net gabion is eco-friendly retaining wall structure showing favorable ability to overcome construction and environmental restriction and also to resist corrosion, chemical attack and degradation. This paper is dealt with the applicability of gabion metal net as a substitution of existing strengthening material. Pull out test was carried out to verify the applicability of gabion metal net. According to results, the increase of surcharge loading and horizontal load resulted in a yield of metal net. The stress at the time of yield was in the range of elasticity. Accordingly, gabion metal net can be substituted for existing geogrid and there is a need for experiment and analysis of arrangement direction and durability of gabion steel net.

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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A Study on the Deformation Behavior of Nonwoven Geotextiles Reinforced Soil Walls Based on Literature Reviews (문헌조사에 근거한 부직포 보강토옹벽의 거동에 관한 연구)

  • Won, Myoung-Soo;Kim, Tae-Wan;Roh, Jae-Kune;Kim, Hyoung-Wan
    • Journal of the Korean Geosynthetics Society
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    • v.9 no.1
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    • pp.21-30
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    • 2010
  • To understand the deformation behavior of nonwoven geotextiles(NWGT) reinforced soil wall, analyses of load-elongation properties, soil-reinforcement interface friction, laboratory model tests, and field cases throughout literature reviews are being studied in this paper. According to the analyses results, the stiffness and tensile strength of NWGT is increased in proportion to confinement pressures, and the interface shear strength at soil-NWGT appeared to be stronger than soil-geogrid interface. The deformation at the beginning of loading on NWGT reinforced soil wall is larger than geogrid reinforced soil wall, but the wall deformation with NWGT is smaller than the wall of geogrid after passing some loading point in laboratory model tests. Case analysis results have shown that the facing of NWGT reinforced soil wall should be rigid enough to be used as a permanent wall, and NWGT and in-situ poor soil can be used for reinforcement and backfill respectively if the wall is constructed as pre-reinforced soil body and with post-facing that has a full-height rigid concrete.

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The Role of Wall Facing on the Stability of Reinforced Soil Wall (전면판의 연속성이 보강토체의 안정성에 미치는 영향)

  • 임유진;정종홍
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.10a
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    • pp.465-472
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    • 1999
  • A small scale model reinforced soil wall was constructed in a laboratory to investigate role of the wall facing and the effect of construction sequence on the wall. A panel type facing system and a block facing system are introduced for test. These two different types of facing adapt different construction procedure. The model wall is built with geogrid reinforcement, sand, and the facings on rigid surface. The model wall is instrumented with earth pressure gauges, LVDTs, and strain gauges. It is found in this study that the reinforced soil wall system built with geogrids and panel type facing system be the safest reinforced soil wall ever compared to the block type facing. Thus, it is recommended that study for the wall system be necessary for further wide usage in the future.

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Effects of Vertical Spacing and Length of Reinforcement on the Behaviors of Reinforced Subgrade with Rigid Wall (보강재 간격 및 길이가 강성벽 일체형 보강노반의 거동에 미치는 영향)

  • Kim, Dae-Sang;Park, Seong-Yong;Kim, Ki-Hwan
    • Journal of the Korean Geosynthetics Society
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    • v.11 no.4
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    • pp.27-35
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    • 2012
  • Facings of mechanically stabilized earth retaining walls have function to fix the reinforcement and prevent backfill loss, but the walls are lack of structural rigidity capable of resisting applied loads. The reinforced subgrade with rigid wall was developed to have the structural functions under train loading. Though it has lots of advantages such as small deformation after construction, its negative side effects of economics and difficult construction were mainly mentioned and not practically used. To apply it for railroad subgrade, this study focus on the construction cost down and the enhancement of constructability without functional loss. To do so, the behaviors of reinforced subgrade with rigid wall were evaluated with the change of the vertical spacing and length of reinforcement. Small scale model tests (1/10 scale) and 3 m full scale tests were performed to evaluate deformation characteristics of reinforced subgrade under simulated train loading. Even though it uses short reinforcement, it showed small horizontal displacement of wall and plastic settlement of subgrade. Also, it was verified that not only 30 cm but also 40 cm of vertical spacing of reinforcement had good performance in serviceability aspects.

Seismic analysis of RC tubular columns in air-cooled supporting structure of TPP

  • Wang, Bo;Yang, Ke;Dai, Huijuan;Bai, Guoliang;Qin, Chaogang
    • Earthquakes and Structures
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    • v.18 no.5
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    • pp.581-598
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    • 2020
  • This paper aims to investigate the seismic behavior and influence parameters of the large-scaled thin-walled reinforced concrete (RC) tubular columns in air-cooled supporting structures of thermal power plants (TPPs). Cyclic loading tests and finite element analysis were performed on 1/8-scaled specimens considering the influence of wall diameter ratio, axial compression ratio, longitudinal reinforcement ratio, stirrup reinforcement ratio and adding steel diagonal braces (SDBs). The research results showed that the cracks mainly occurred on the lower half part of RC tubular columns during the cyclic loading test; the specimen with the minimum wall diameter ratio presented the earlier cracking and had the most cracks; the failure mode of RC tubular columns was large bias compression failure; increasing the axial compression ratio could increase the lateral bearing capacity and energy dissipation capacity, but also weaken the ductility and aggravate the lateral stiffness deterioration; increasing the longitudinal reinforcement ratio could efficiently enhance the seismic behavior; increasing the stirrup reinforcement ratio was favorable to the ductility; RC tubular columns with SDBs had a much higher bearing capacity and lateral stiffness than those without SDBs, and with the decrease of the angle between columns and SDBs, both bearing capacity and lateral stiffness increased significantly.

A Study on the Development of Reinforced Earth wall by Geotextile (토목섬유를 이용한 보강토옹벽의 개발)

  • 도덕현;유능환
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.28 no.2
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    • pp.63-73
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    • 1986
  • The model was developed by applying the principles of Bacot and Vidal to measure the behavior of deformation of the reinforced earth wall, and various tasts were performed by using the plastic fabric filter and the galvanized steel plate as a strip. The results obtained are as follows; 1. When the reinforced earth wall is deformed by the load, the strip is completely reinforced by the backfill materials and changed to the rigid block state, under the state of failure which permits sliding only, the next theoretical equation is formed. (H/L) . tan$\theta$ [cosO-sinOtanO] =2sinO[tan($\theta$ +0) +tanO] 2.The degree of the mutual reinforcement of the backfill material and the strip depend on the physical characteristics of the each material especially the angle of shearing resistance of the backfill material is desirable over 20$^{\circ}$ and, if it is over 400, its function could be a maximum. 3.The distribution of the maximum tensile strain of the reinforcement is changing with the height of reinforced earth wall, and when the height from bottom of the reinforced earth wall is 1.85 to 3. 35m, the maximum tensile strain appears at 2m from the skin element. The maximum tensile strain is increased by the depth of the reinforced earth wall from surface, and increased with the lapse of time after construction. 4.The failure surface of the reinforced earth wall by the concrete skin was about 60$^{\circ}$and the failure behavior of the reinforced earth wall in which the fabric filter was buried was slow, and so the pore pressure could be decreased. 5.It is possible to construct the fabric retained earth wall by the plastic fabric filter only. And the reinforcing effect between the steel plate and the plastic fabric filter is not largely different. however, in the aspect of the economic durability, the plastic fabric filter is more advantageous. 6.The reinforcing action mainly depends on the width and the length of the reinforcing materials, if possible, the full width is advantageous to enlarge the contact area with backfill. but considering the economic aspect, it is neccessary to develop the method controlling the space of the strip.

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