• Title/Summary/Keyword: construction Joints

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Structural Performance of Precast Concrete Arch with Reinforced Joint (보강된 이음부를 가진 조립식 프리캐스트 콘크리트 아치의 구조성능)

  • Chung, Chulhun;Joo, Sanghoon;Choi, Dongchan;Lee, Jongyun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.1
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    • pp.29-47
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    • 2014
  • The masonry stone arch bridge, due to its superior durability and aesthetics, has been one of the oldest and popular types of short span bridges. In Europe, this type of bridges have been continuously constructed, and numerous related researches have been conducted until recently. However, there are few construction cases in Korea since the economic efficiency and the construction effectiveness is not contentable. Therefore, this study proposed the reinforced joint to improve structural performance of the conventional arch systems which is proposed by previous researchers. The structural performance of the proposed reinforced joint, which consists of the transverse loop joint and the longitudinal reinforcement, is validated by experimental test of an arch bridge which is constructed using precast concrete segments. Based on this results of the experimental test, it is concluded that the strength of arch bridges can be enhanced by applying the proposed reinforced joints since the reinforced joint restrains hinge behavior and relative displacement between segments with a little reinforcement.

An Experimental Study on the Block Shear Rupture of Angle Tension Members (인장력을 받는 ㄱ형강의 블록전단 파단에 관한 실험적 연구)

  • Kim, Bo Young;Lee, Kyu Kwong;Choi, Mun Sik
    • Journal of Korean Society of Steel Construction
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    • v.10 no.4 s.37
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    • pp.721-730
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    • 1998
  • In this paper, an experimental study have been many studies on the joints of steel structure, for it has great influences on the safety of structures. Research on block shear rupture of the joint receiving pure tension have been done in foreign countries, but not in Korea. This study focuses on the propriety of block shear design code, according to limited state design criteria of steel structures recently established in Korea, by an experiment on the joint of angle tension members. The methods of this study were to compare other study results on block shear rupture mode and ultimate capacity, and to evaluate the propriety of the criteria design code. The result is that tension yield shear ruptures and shear yield tension ruptures happened at the joint, and the experimental rupture load was 15% higher than the capacity entered in the criteria design code. We conclude that it is necessary to revaluate the block shear design code presented by many studies on the limited state design criteria of steel structures.

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A Study on the Residual Stress in the Welded Joints with Different Details (용접상세의 변화에 따른 용접이음부의 잔류응력에 관한 연구)

  • Lim, Cheong Kweon;Park, Moon Ho
    • Journal of Korean Society of Steel Construction
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    • v.10 no.4 s.37
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    • pp.709-720
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    • 1998
  • In order to study the distribution of welding residual stress through the plate thickness. experiment and analysis of fillet welding details were carried out. Especially, a residual stress in the weld root part of T-joint fillet weld whose measurement was difficult up to now was measured. By using the heat input and the number of the weld layers as parameters, the distribution of the 3-dimensional residual stress was investigated. As a result, we can say that with increasing the heat input, the residual stress in the weld toe and weld root barely changes. But, the area of the tensile residual stress became wide. Then, comparing a single pass with multi-pass weld method, it was found that the residual stress decreased more in multi-pass than in single pass. Moreover, it was found the thing that the area of tensile residual stress by multi-pass is lower than that by single-pass in the near weld part.

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An Experimental Study on the Strength of the Frame consisting of Concrete Filled Steel Tubular Column-H Beam under Alternately Repeated Horizontal Loading (반복하중을 받는 콘크리트충전 강관기둥-H형강보 골조의 강도에 관한 실험적 연구 -접합부 보강형식과 콘크리트충전에 따른 효과-)

  • Lee, Seong Do;Kim, Pil Jung
    • Journal of Korean Society of Steel Construction
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    • v.10 no.4 s.37
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    • pp.641-655
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    • 1998
  • It researched several jointing-methods of frame consisting of a concrete-filled steel tubular column and H-shaped beam. These beam-to-column connections is parameters to following: columns of square shape pipe infilled with or without concrete, joints assembled two types of diaphragm, outside-type and through-type. And it is testing that cyclically lateral loadings used hydraulic ram. In testing. we'll be on purposed to estimate the hysteretic behavior, strength and stiffness, energy absorption capacity, deformation capacity and failure configuration of each specimen. It is concluded that the frame specimens with outside-type are more stable and exhibit more energy absorption capacity compared with the through-type, in column of filled with concrete.

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Production Mechanism of Residual Stress Generated by Multi-Pass Welding of the steel Pipe (강관 적층용접부 잔류응력의 생성기구)

  • Chang, Kyong Ho;Yang, Sung Chul;Kang, Jae Hoon
    • Journal of Korean Society of Steel Construction
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    • v.13 no.4
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    • pp.327-335
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    • 2001
  • The characteristics and production mechanism of residual stress generated by multi-pass welding of the steel pipe were elucidated from the results of three-dimensional thermal elastic-plastic FEM analysis. When the steel pipe was jointed by multi-pass welding, the stress components of circumferential direction and radial direction near welded joints on the inner surface and the outer surface of the pope were tensile. The stress component of axial direction on the inner surface was tensile and on the outer surface was compressive. On the other hands, the production mechanism of residual stress generated by multi-pass welding of the steel pipe was investigated. Residual stress generated by welding of the steel pipe was investigated not only by the thermal history but also by geometrical shape. Then, the generality of the production mechanism of residual stress generated by multi-pass welding was confirmed.

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Tensile Strength of Plate with Bolt Hole and Bearing Strength of Bolted Connection by Oxygen Torch Cut (볼트홀을 산소토치로 천공한 강재의 인장강도 및 지압이음강도)

  • Park, Yong Myung;Lee, Kun Joon;Kim, Dong Hyun;Ju, Ho Jung
    • Journal of Korean Society of Steel Construction
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    • v.26 no.6
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    • pp.617-626
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    • 2014
  • In this paper, experiments for the evaluation of tensile strength of steel plate with bolt hole and bearing strength of bolted connection were performed, where bolt holes were punched by drilling and oxygen torch, respectively. For the tensile tests, drilled and oxygen torch punched steel plate specimens of 10mm and 15mm thickness were made from structural angles and H-shapes, respectively. For the bearing strength evaluation, test specimens were fabricated with base plates and splice plates those were also punched by drilling and oxygen torch, respectively. The Vicker's hardness were measured around the bolt hole to investigate material property change due to heat effect by oxygen torch cut. Numerical analysis was also performed to investigate the bearing strength of bolted joints due to the increase of hardness around the bolt hole by oxygen torch cut.

Inelastic Buckling Analysis of Frames with Semi-Rigid Joints (부분강절 뼈대구조의 비탄성 좌굴해석)

  • Min, Byoung Cheol
    • Journal of Korean Society of Steel Construction
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    • v.26 no.3
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    • pp.143-154
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    • 2014
  • An improved method for evaluating effective buckling length of semi-rigid frame with inelastic behavior is newly proposed. Also, generalized exact tangential stiffness matrix with rotationally semi-rigid connections is adopted in previous studies. Therefore, the system buckling load of structure with inelastic behaviors can be exactly obtained by only one element per one straight member for inelastic problems. And the linearized elastic stiffness matrix and the geometric stiffness matrix of semi-rigid frame are utilized by taking into account 4th terms of taylor series from the exact tangent stiffness matrix. On the other hands, two inelastic analysis programs(M1, M2) are newly formulated. Where, M1 based on exact tangent stiffness matrix is programmed by iterative determinant search method and M2 is using linear algorithm with elastic and geometric matrices. Finally, in order to verify this present theory, various numerical examples are introduced and the effective buckling length of semi-rigid frames with inelastic materials are investigated.

Development of an Automated Pavement Crack Sealing Machine and Its Economic Feasibility Analysis (크랙실링 자동화 장비의 개발 린 경제적 타당성 분석)

  • Lee, Jeong-Ho;Lee, Jun-Bok;Jeong, Hyung-Hoon;Kim, Young-Suk
    • Korean Journal of Construction Engineering and Management
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    • v.7 no.6
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    • pp.151-164
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    • 2006
  • Numerous efforts are currently underway to automate pavementcrack and joint sealing activities. Productivity improvements, improved safety and quality, and reduced road user costs motivate these developments. Recently, an automated pavement crack sealing machine has been developed to automate the process of sealing pavement cracks and joints in Korea. This paper mainly describes the results of the economic feasibility analysis revealed through its overall performance evaluation and field tests. Finally, it is concluded that the automated machine exceeds the performance in terms of productivity, safety, and quality required in conventional method, thus making the machine economically feasible.

Evaluation of Clamping Forces according to Length-to-diameter Ratios and Preserved Thread Lengths of High Strength Bolts (고력볼트의 길이-직경비 및 여유나사길이에 따른 조임력 평가 연구)

  • Kim, Sang Seup;Kim, Sung Yong;Kim, Kyu Suk
    • Journal of Korean Society of Steel Construction
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    • v.12 no.3 s.46
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    • pp.259-268
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    • 2000
  • In the friction-type joints the external applied load is transmitted by frictional force acting on the contact area of the plates fastened by the high strength bolts. This frictional force is proportional to the product of the bolt clamping force and slip coefficient of the faying surface. But the bolt clamping force is dependent on many factors when the turn-of-nut method is used. The preserved thread length and length-to-diameter ratios are one of the major factors governing the bolt clamping force. This paper presents the correct method of high strength bolt tightening through the experiment on the mechanical properties on sets of high strength bolts in accordance with preserved thread length and length-to-diameter ratios.

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Structural performance of timber frame joints - Full scale tests and numerical validation

  • Aejaz, S.A.;Dar, A.R.;Bhat, J.A.
    • Structural Engineering and Mechanics
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    • v.74 no.4
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    • pp.457-470
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    • 2020
  • The force resisting ability of a connection has direct implications on the overall response of a timber framed structure to various actions, thereby governing the integrity and safety of such constructions. The behavior of timber framed structures has been studied by many researchers by testing full-scale-connections in timber frames so as to establish consistent design provisions on the same. However, much emphasis in this approach has been unidirectional, that has focused on a particular connection configuration, with no research output stressing on the refinement of the existing connection details in order to optimize their performance. In this regard, addition of adhesive to dowelled timber connections is an economically effective technique that has a potential to improve their performance. Therefore, a comparative study to evaluate the performance of various full-scale timber frame Nailed connections (Bridled Tenon, Cross Halved, Dovetail Halved and Mortise Tenon) supplemented by adhesive with respect to Nailed-Only counterparts under tensile loading has been investigated in this paper. The load-deformation values measured have been used to calculate stiffness, load capacity and ductility in both the connection forms (with and without adhesion) which in turn have been compared to other configurations along with the observed failure modes. The observed load capacity of the tested models has also been compared to the design strengths predicted by National Design Specifications (NDS-2018) for timber construction. Additionally, the experimental behavior was validated by developing non-linear finite element models in ABAQUS. All the results showed incorporation of adhesive to be an efficient and an economical technique in significantly enhancing the performance of various timber nailed connections under tensile action. Thus, this research is novel in a sense that it not only explores the tensile behavior of different nailed joint configurations common in timber construction but also stresses on improvising the same in a logical manner hence making it distinctive in its approach.