• Title/Summary/Keyword: Reinforcement Effects

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Evaluation of Reinforcement Effects According to Reinforcement Type and Grouting Method (지반보강재의 형상과 그라우팅 방법에 따른 보강효과 평가)

  • Park, Jongseo;Kim, Taeyeon;Lee, Bongjik
    • Journal of the Korean GEO-environmental Society
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    • v.20 no.8
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    • pp.13-20
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    • 2019
  • In order to ground reinforcement, the chemical grouting, the anchor, the soil nailing system, the micropile, etc. can be mentioned by the methods widely used in domestic. The above ground reinforcement methods are developed by various methods depending on the type of reinforcement, installation method, presence of prestress, grouting method, etc. However, in common, the strength of reinforcement, the friction force of grout and reinforcement and the friction force of grout and ground are the main design variables. Therefore, the optimized ground reinforcement is a material with a high tensile strength of the reinforcement itself, the friction force between the reinforcement and the grout is high, and the application of an optimal grouting method is necessary to improve the friction force between the grout and the ground. In this study, a total of 20 model tests were conducted to analyze the reinforcement effects according to the shape of the reinforcement and the grouting method. As a result of the test, As a result of the experiment, it is judged that the reinforcing effect is superior to the perforated + wing type reinforcement and post grouting method.

Modifying Inappropriate Behaviors of Nursery School Children through Token and Social Reinforcement (토오컨강화와 사회적강화를 이용한 유아원 아동의 부적절한 학습행동의 수정)

  • Kim, Jin Sook
    • Korean Journal of Child Studies
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    • v.8 no.2
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    • pp.61-71
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    • 1987
  • The effects of token and social reinforcement on inappropriate study behaviors of nursery school children were investigated. The subjects were three nursery school boys, and the target behaviors were : 1) out-of-seat behaviors, 2) bothering other children, and 3) disruptive behaviors. The ABAB(Reversal) design was used in this experiment. It consisted of four periods : baseline, reinforcement I, reversal, and reinforcement II. During the reinforcement period, social reinforcement as well as token reinforcement was applied. In all three subjects, inappropriate study behaviors decreased during the reinforcement periods (I, II), and increased during the reversal period, showing the effects of token and social reinforcement. The subjects showed stability in three post-experimental tests, indicating that modification of inappropriate study behaviors was being maintained.

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Effects of details of lattice reinforcement for punching shear strength of slab-column connections (슬래브-기둥 접합부의 뚫림 전단강도에 대한 래티스 보강상세의 영향)

  • Kim, You-Ni;Park, Hong-Gun
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.11a
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    • pp.17-20
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    • 2006
  • A flat plate-column connection is susceptible to brittle punching shear failure, which may result in the necessity of shear reinforcement. In previous, experimental tests were performed to study the capacity of slab-column connections strengthened with various shear reinforcement, and the capacity of the specimens with lattice reinforcement are superior to the others. In present study, to study for effects of details of lattice reinforcement, experimental studies was performed. Main parameters are the amount of lattice shear reinforcement, arrangement of lattice and the effect of flexural re-bar. And capacity of the specimen with small amount of lattice reinforcement was higher than the capacity of other shear reinforcement.

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Effects of joint aspect ratio on required transverse reinforcement of exterior joints subjected to cyclic loading

  • Chun, Sung Chul
    • Earthquakes and Structures
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    • v.7 no.5
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    • pp.705-718
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    • 2014
  • This paper presents an analytical model for determining the transverse reinforcement required for reinforced concrete exterior beam-column joints subjected to reversed cyclic loading. Although the joint aspect ratio can affect joint shear strength, current design codes do not consider its effects in calculating joint shear strength and the necessary amount of transverse reinforcement. This study re-evaluated previous exterior beam-column joint tests collected from 11 references and showed that the joint shear strength decreases as the joint aspect ratio increases. An analytical model was developed, to quantify the transverse reinforcement required to secure safe load flows in exterior beam-column joints. Comparisons with a database of exterior beam-column joint tests from published literature validated the model. The required sectional ratios of horizontal transverse reinforcement calculated by the proposed model were compared with those specified in ACI 352R-02. More transverse reinforcement is required as the joint aspect ratio increases, or as the ratio of vertical reinforcement decreases; however, ACI 352R-02 specifies a constant transverse reinforcement, regardless of the joint aspect ratio. This reevaluation of test data and the results of the analytical model demonstrate a need for new criteria that take the effects of joint aspect ratio into account in exterior joint design.

A Study on Grid Effect and Applicability of Composite Reinforcement (그리드효과 및 복합보강재의 적용성에 관한 연구)

  • 김홍택;이형규;김승욱
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.11c
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    • pp.95-104
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    • 1999
  • In this study, laboratory pull-out tests and finite element modeling are carried out focused on the grid effects of geogrid and the analyses of friction characteristics associated with interaction behaviors of the composite reinforcement composed of geogrid with a superior function in tensile resistance and geotextile with sufficient drainage effects. In addition, drainage effects of the geotextile below geogrid are examined based on the analysis of finite difference numerical modeling. From the present investigation, it is concluded that the geosynthetic composite reinforcement in the weathered granite backfills may possibly be used to achieve effects on both a reduction of deformations and an increase of the tensile resistance, together with drainage effects due to the geotextile.

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An Experimental Study on the Earth Pressure Effect of Vertical Reinforcements (연직보강재의 토압경감 효과)

  • 문경선;이상덕
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.10a
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    • pp.457-464
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    • 1999
  • The active earth pressure on the retaining wall is reduced by 3-Dimensional effects of the ground. Therefore, the test was focused on reducing the earth pressure on the retaining wall by inserting the vertical reinforcement in the backfill ground to develope the 3-Dimensional effects. Model tests in sand were peformed to measure the 3-Dimensional effects of the vertical reinforcement on the active earth pressure and its distribution and results were compared with the theories. The size of the vertical reinforcement, the geometry of the backfill space, and the wall friction of vertical reinforcement were varied. It was observed that the active earth pressure and its distribution on the underground structure were affected by the size of the vertical reforcements and wall friction.

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Studies on the Development of Bearing Capacity Reinforcement for the Foundation of Soil (기초지반의 지지력보강공법에 관한 연구)

  • 유동환;최예환;유연택
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.30 no.1
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    • pp.38-49
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    • 1988
  • This paper presented as follows results of laboratory model tests with various shaped footings on soil bed reinforced with the strips on the base of behaviour of soil structure according to the loads and triaxial test results reinforced with geotextiles. Their parameters studied were the effects on the bearing capacity of a footing of the first layer of reinforcement, horizontal and vertical spacing of layers, number of layers, tensile strength of reinforcement and iclination load to the vertical 1.Depending on the strip arrangement, ultimate bearing capacity values could be more improved than urreinforced soil and the failure of soil was that the soil structure was transfered from the macrospace to microspase and its arrangement, from edge to edge to face to face. 2.The reinforcement was produced the reinforcing effects due to controlling the value of factor of one and permeable reinforcement was never a barrier of drainage condition. 3.Strength ratio was decreased as a linear shape according to increment of saturation degree of soil used even though at the lower strength ratio, the value of M-factor was rot influenced on the strength ratio but impermeable reinforcement decreased the strength of bearing capacity. 4.Ultimate bearing capacity under the plane-strain condition was appeared a little larger than triaxial or the other theoretical formulars and the circular footing more effective. 5.The maximum reinforcing effects were obtained at U I B=o.5, B / B=3 and N=3, when over that limit only acting as a anchor, and same strength of fabric appeared larger reinforcing effects compared to the thinner one. 6.As the LDR increased, more and more BCR occurred and there was appeared a block action below Z / B=O.5, but over the value, decrement of BCR was shown linear relation, and no effects above one. 7.The coefficient of the inclination was shown of minimum at the three layers of fabrics, but the value of H / B related to the ultimate load was decreased as increment of inclination degree, even though over the value of 4.5 there wasn't expected to the reinforcing effects As a consequence of the effects on load inclination, the degree of inclination of 15 per cent was decreased the bearing capacity of 70 per cent but irnproved the effects of 45 per cent through the insertion of geotextile.

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Effects of confinement reinforcement and concrete strength on nonlinear behaviour of RC buildings

  • Yon, Burak;Calayir, Yusuf
    • Computers and Concrete
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    • v.14 no.3
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    • pp.279-297
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    • 2014
  • This paper investigates the effects of confinement reinforcement and concrete strength on nonlinear behaviour of reinforced concrete buildings (RC). For numerical application, an eleven-storey and four bays reinforced concrete frame building is selected. Nonlinear incremental static (pushover) analyses of the building are performed according to various concrete strengths and whether appropriate confinement reinforcement, which defined in Turkish seismic code, exists or not at structural elements. In nonlinear analysis, distributed plastic hinge model is used. As a result of analyses, capacity curves of the frame building and moment-rotation curves at lower end sections of ground floor columns are determined. These results are compared with each other according to concrete strength and whether appropriate confinement reinforcement exists or not, respectively. According to results, it is seen that confinement reinforcement is important factor for increasing of building capacity and decreasing of rotations at structural elements.

Comparison of behaviour of basal reinforced piled embankment with two layer of reinforcement

  • Balaban, Eren;Onur, Mehmet I.
    • Geomechanics and Engineering
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    • v.16 no.3
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    • pp.233-245
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    • 2018
  • Interest to basal reinforced piled embankments is increasing recently due to their rapid construction and reliability. A comprehensive parametric study is conducted to determine effects of pile properties, reinforcement stiffness, embankment properties and soft soil properties into settlements, pressures and excess pore water pressure development and dissipations. Results which are obtained by using one-layer reinforcement during construction are compared with the results obtained by using two-layer reinforcement during construction. Finite element method is used during the parametric study. Second layer of reinforcement is placed in five different positions in order to reveal effects of reinforcement position into behaviour. Traffic load is also taken into consideration during the study. Differences between the results without presence of traffic loading and with presence of traffic loading is stated in this the study.

An Evaluation of Pullout Behavior Characteristics of the Steel Strip Reinforcement Bolted with Braced Angles (버팀재 볼트 접합형 강재스트립 보강재의 인발거동특성 평가)

  • 김홍택;방윤경;정중섭;박시삼;김현조
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.10a
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    • pp.419-426
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    • 2002
  • In this study, the steel strip reinforcement bolted with braced angles is displayed skin friction resistance as well as passive resistance through existing the steel strip reinforcement. To understand pullout behavior characteristics, friction effects between soil and reinforcement are evaluated with the width of reinforcement, magnitude of surcharge, and existence of passive resistance member through laboratory pullout test. To analyze interference effects for passive resistance member, various tests are carried on case that the number, the location, and the spacing of braced angles are different. Using this test result, pullout resistance factor is calculated to consider location of braced angles and degree of interference for spacing ratio.

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