• Title/Summary/Keyword: tendons

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Design Method for Continuous IPC Girder bridges (IPC 거더의 연속화 설계 방안)

  • 한만엽;황의승;박준범
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10b
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    • pp.1007-1012
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    • 2000
  • This study is to present a design method using continuous tendons in IPC girders. Present design methods use just concrete to make continuity between girders. In these design methods cracks occur in almost every joint area of girders. This means that these girders act as simple beam instead of continuous beams. The design method which is presented here uses continuous tendons between girders. In this method the cracks could be restrained. So the girders behave as continuous beams, which this method allows the span length gets longer than simple girders and also the section height could get lower. In this way the number of piers and the weight of super structure could be reduced which means the construction cost could also be reduced.

Overestimation of Ultimate Tendon Stress in a Prestressed Concrete Beam with Unbonded Tendons (비부착 긴장재를 갖는 프리스트레스트 콘크리트 보에서 긴장재 응력의 과대평가)

  • 이종윤;임재형;문정호;신경재
    • Journal of the Korea Concrete Institute
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    • v.11 no.4
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    • pp.73-81
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    • 1999
  • The present study is to examine the ACI code equations for computing the unbonded tendon stress at flexural failure of prestressed beams. The equations examined for their validity are Eq. 18-4 and Eq. 18-5 of the ACI 318-95. Since the possibility of overestimation was expected with the equations, a numerical study, first, was carried out with influential variables included. From this study, it was found that amount of reinforcements, effective prestress, location of tendons, and loading type may affect the overestimation of the unbonded tendon stress. Then, an experimental study was carried out with those variables. A total of 8 specimens was tested to prove the theoretical findings as well as the effect of those variables. As a result. it was proven that the ACI Code equations can overestimate significantly the unbonded tendon stress for certain cases.

Verification for Axisymmetric Modeling of Dome Tendons in Nuclear Containment Building (원전 격납건물 돔 텐던의 축대칭 근사화에 대한 타당성 고찰)

  • Jeon Se Jin;Chung Chul Hun;Kim Young Jin;Chung Yun Suk
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.81-84
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    • 2004
  • Prestressing tendons in a nuclear containment building dome are non-axisymmetrically arranged in most cases. However, simple axisymmetric modeling of the containment has been often employed in practice, which requires the axisymmetric approximation of the actual tendon arrangements in the dome. A procedure was previously proposed that can implement the actual 3D tendon stiffness and prestressing effect into the axisymmetric model for CANDU type. This paper further verifies and compares some methodologies adopted in the proposed scheme through some numerical examples.

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A Study on the Development Length of Fiber Reinforced Polymer Tendon by Direct Pullout Test (직접인발실험에 의한 FRP Tendon의 정착 길이 산정에 관한 연구)

  • Lee, Seung-Joo;Jung, Woo-Tai;Park, Young-Hwan;Hwang, Geum-Sic
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.11a
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    • pp.837-840
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    • 2006
  • This paper presents the experimental results on the development length of FRP tendons by direct pullout test. Two types of FRP tendons, namely, CFCC tendon and KICT tendon, and PS tendon were investigated. The development length defined as the minimum embedment length required to develop the ultimate tensile strength was suggested using the test results. It was found that the development length from the direct pullout test was greater than those of various standards. This may result from the fact that the wedge effect does not exist because there is no prestressing force in the direct pullout test. Further study and experiment are necessary to derive the reasonable development length for FRP tendon.

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A continuity method for bridges constructed with precast prestressed concrete girders

  • Lee, Hwan Woo;Barnes, Robert W.;Kim, Kwang Yang
    • Structural Engineering and Mechanics
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    • v.17 no.6
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    • pp.879-898
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    • 2004
  • A method of making simply supported girders continuous is described for bridges with spans of 30-45 m. The splicing method takes advantage of an induced secondary moment to transform the self-weight stresses in the precast simply supported girders into values representative of a continuous girder. The secondary moment results from prestressing of continuity tendons and detensioning of temporary tendons in the girders. Preliminary sections are selected for spliced U-girder bridges with a range of span lengths. Use of the proposed technique results in girder depth reductions of 500-800 mm when compared to standard simply supported I-girder bridges. The flexural behavior of an example bridge with 40-m spans is examined to illustrate the necessary considerations for determining the optimum sequence of splicing operations.

Musculoskeletal Ultrasound Application in Cervical Spine: Pictorial Essay (경추부의 초음파 적용: 임상화보)

  • Yoon, Yong-Soon;Lee, Jung-Hoo;Kim, Eun-Sil;Lee, Kwang Jae
    • Clinical Pain
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    • v.20 no.2
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    • pp.74-85
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    • 2021
  • Ultrasound (US) can depict of various anatomical structures, such as muscles, tendons, ligaments, nerve roots, and vessels, around the neck. The usage of US around the neck is increasing due to its quick and easy application for guided injection for nerves, tendons, and joints. This article elaborates the degenerative diseases causing neck pain, sonoanatomy, and the use of US for diagnosis and intervention; for example, small nerves around the neck, cervical root, stellate ganglion, medial branches, greater occipital nerve (GON), and third occipital nerve (TON). The aim of this review article is to lead readers to understand the anatomy around the neck and structural relations, and to get to know about several US-guided intervention of the neck.

Postoperative Ultrasound Findings of the Rotator Cuff Tendon after Arthroscopic Repair of a Rotator Cuff Tear (회전근개 파열의 수술적 치료 후 회전근개 초음파 소견)

  • Kwon, Dong Rak
    • Clinical Pain
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    • v.19 no.2
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    • pp.64-69
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    • 2020
  • Ultrasound (US) imaging is an efficient, easy to use, rapid, dynamic, noninvasive, with rare side-effects and inexpensive tool allowing for facilitated diagnosis and management of the painful shoulder. It also has advantages over other imaging modalities in the evaluation of the postoperative shoulder for rotator cuff integrity and correct anchor and suture placement, as well as rotator cuff analysis following repair surgery. Early postoperative tendons frequently had a hypo- echoic echo texture and the absence of a fibrillar pattern, which might be misinterpreted as recurrent tears. however, these features often normalized into tendons with an increased echo texture and the reappearance of a fibrillar pattern at 6 months. Based on these sequential findings, the US findings within 3 months after surgery should be interpreted with caution to accurately understand and monitor the repaired tendon status.

A Study on the Application Case in Civil Structures of Fiber Reinforced Composites (Bridges) (섬유복합재료(FRP)의 건설 적용 사례 연구(교량편))

  • Han Bog-Kyu;Hong Geon-Ho;Kim Ki-Soo
    • Composites Research
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    • v.19 no.2
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    • pp.35-41
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    • 2006
  • FRPs have been used widely and demonstrated in the field of aero industries etc., and began to be used as new construction materials of civil structures. Pre-stressing tendons, reinforcing bars etc. are all examples of the many diverse applications of FRP in new structures. Especially, 40 of all-FRP bridges were reported. The reason why FRP composites were used fur construction materials of civil structures, has been that the working time and the cost of maintenance can be reduced because of the effect of their lightness and durabilities. The purpose of this paper is to report the examples of the many diverse applications of Fiber Reinforced Plastic in construction materials of civil structures.

Flexor Tendon Rupture Secondary to Gout

  • Jeremy V. Lynn;Amy L. Strong;Kevin C. Chung
    • Archives of Plastic Surgery
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    • v.50 no.5
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    • pp.492-495
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    • 2023
  • Extra-articular deposition of monosodium urate crystals is a widely recognized manifestation of gout. However, gouty infiltration of flexor tendons in the hand resulting in tendon rupture is exceedingly rare. This case report highlights a patient with gouty infiltration of flexor tendons in the right middle finger resulting in rupture of both the flexor digitorum profundus and flexor digitorum superficialis. Given the extent of gouty infiltration and need for pulley reconstruction, the patient was treated with two-stage flexor tendon reconstruction. Febuxostat was prescribed preoperatively to limit further deposition of monosodium urate crystals and continued postoperatively to maximize the potential for long-lasting results. Prednisone was prescribed between the first- and second-stage operations to prevent a gout flare while the silicone rod was in place. In summary, tendon rupture secondary to gouty infiltration is the most likely diagnosis in patients with a history of gout presenting with tendon insufficiency.

Concomitant variations of the tibialis anterior, and extensor hallucis longus, and extensor hallucis brevis muscles

  • Jenilkumar Patel;Graham Dupont;Joho Katsuta;Joe Iwanaga;Lukasz Olewnik;R. Shane Tubbs
    • Anatomy and Cell Biology
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    • v.56 no.1
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    • pp.137-140
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    • 2023
  • Tibialis anterior (TA) muscle originates from the lateral surface of tibia and its tendon attaches to the medial cuneiform and base of the first metatarsal. The TA muscle is responsible for both dorsiflexion and inversion of the foot. We present a case of bilateral TA muscle variations that diverge slightly from the current classification systems of this muscle. Recognizing variations such as these may be important for anatomists, surgeons, podiatrists, and physicians. Following routine dissection, an accessory tendon of the TA muscle was found on both sides. Accessory tendons of the extensor hallucis longus and extensor hallucis brevis joined to form a common tendon on both sides. We believe that this unique case will help further the classification systems for the tendons of the TA and also be informative for clinical anatomists as well as physicians treating patients with pathology in this region.