• 제목/요약/키워드: Tunnel

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Anomalous Muscles of the Wrist Encountered During Endoscopic Carpal Tunnel Surgery

  • Park, Se-Hyuck
    • Journal of Korean Neurosurgical Society
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    • 제62권1호
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    • pp.90-95
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    • 2019
  • Objective : Anomalous muscles of the wrist are infrequently encountered during carpal tunnel surgery. Anatomic variants of the palmaris longus (PL), flexor digitorum superficialis, lumbricalis and abductor digiti minimi (ADM) have been reported but are usually clinically insignificant. Anomalies of the wrist muscles, encountered during endoscopic carpal tunnel surgery have rarely been described. I conducted this study to evaluate muscular anomalies of the volar aspect of the wrist, encountered during endoscopic carpal tunnel surgery. Methods : I studied a consecutive series of 1235 hands in 809 patients with carpal tunnel syndrome who underwent single-portal endoscopic carpal tunnel release (ECTR) from 2002 to 2014. Nine hundred seventy-three hands in 644 patients who had minimal 6-month postoperative follow-up were included in the study. The postoperative surgical outcome was assessed at least 6 months after surgery. Results : In eight patients, anomalous muscles were found under the antebrachial fascia at the proximal wrist crease and superficial to the ulnar bursa, passing superficial to the transverse carpal ligament. Those anomalous muscles were presumed to be variants of the PL or accessory ADM muscle, necessitating splitting and retraction to enter the carpal tunnel during the ECTR procedure. Other muscle anomalies were not seen within the carpal tunnel on the endoscopic view. The surgical outcome for all eight wrists was successful at the 6-month postoperative follow-up. Conclusion : Carpal tunnel surgeons, especially those using an endoscope should be familiar with unusual findings of anomalous muscles of the wrist because early recognition of those muscles can contribute to avoiding unnecessary surgical exploration and unsuccessful surgical outcomes.

Development of Tunnel Asset Management (TAM) Program

  • Hamed Zamenian;Dae-Hyun (Dan) Koo
    • 국제학술발표논문집
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    • The 5th International Conference on Construction Engineering and Project Management
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    • pp.576-582
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    • 2013
  • Typical highway infrastructure systems include roadway pavement, drainage systems, tunneling, and other hardware components such as guardrails, traffic signs, and lighting. Tunnels in a highway system have provided significant advantages to overcoming various natural challenges including crossing underneath bodies of water or through mountainous areas. While only a few tunnel failure cases have been reported, the failure rate is likely to increase as these assets age and because agencies have not emphasized tunneling asset management. A tunnel system undergoes a deterioration life cycle pattern that is similar to other infrastructure systems. There are very few agencies in the United States implementing comprehensive tunnel asset management programs. While current tunnel asset management programs focus on inspection, maintenance, and operation safety, there is an increasing need for the development of a comprehensive life cycle tunnel asset management program. This paper describes a conceptual framework for a comprehensive tunnel asset management program. The framework consists of three basic phases including a strategic plan, a tactical plan, and an operational plan to provide better information to the decision makers. The strategic plan is a basic long term approach of tunnel asset management. The tactical plan determines specific objectives and the operational plan actually applies asset management objectives in practice. The information includes operational condition, structural condition, efficiency of the system, emergency response, and life cycle cost analysis for tunnel capital improvement project planning.

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Factor analysis of subgrade spring stiffness of circular tunnel

  • Xiangyu Guo;Liangjie Wang;Jun Wang;Junji An
    • Earthquakes and Structures
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    • 제26권3호
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    • pp.229-237
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    • 2024
  • This paper studied the subgrade spring stiffness and its influencing factors in the seismic deformation method of circular tunnel. Numerical calculations are performed for 3 influencing factors: stratum stiffness, tunnel diameter and burial depth. The results show that the stratum stiffness and tunnel diameter have great influence on the subgrade spring stiffness. The subgrade spring stiffness increases linearly with stratum stiffness increasement, and decreases with the tunnel diameter increasement. When the burial depth ratio (burial depth/tunnel diameter) exceeds to 5, the subgrade spring stiffness has little sensitivity to the burial depth. Then, a proposed formula of subgrade spring stiffness for the seismic deformation method of circular tunnel is proposed. Meanwhile, the internal force results of the seismic deformation method are larger than that of the dynamic time history method, but the internal force distributions of the two methods are consistent, that is, the structure exhibits elliptical deformation with the largest internal force at the conjugate 45° position of the circular tunnel. Therefore, the seismic deformation method based on the proposed formula can effectively reflect the deformation and internal force characteristics of the tunnel and has good applicability in engineering practice.

수치해석적 접근을 통한 2Arch 터널의 거동양상 고찰 (A Study on Behavior of 2-Arch Tunnel by Numerical Approach)

  • 김상균;박동욱
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2003년도 봄 학술발표회 논문집
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    • pp.225-232
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    • 2003
  • The behaviour of ground induced by tunneling of 2arch tunnels may differ from the one caused by usual type tunnels. This paper describe the behaviour created by the size of pilot tunnel and the condition on the construction method of center piller Also, loads acting on the supports of the first tunnel and the center pillar during the excavation of second tunnel is investigated by numerical analyses. The results of numerical analyses are compared to the data records of measurement results, i.e. force on the support system and ground displacement.

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터널조명용 광원의 경제성 비교 (The Comparison of the Economical Efficiency of Light Sources for a Tunnel Lighting)

  • 이진우
    • 조명전기설비학회논문지
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    • 제25권2호
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    • pp.32-42
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    • 2011
  • In this paper to compare the economical efficiency of light sources for a tunnel lighting, we define a model tunnel and design tunnel lighting. And to examine economical efficiency of various tunnel lightings we compare the lighting expenses of tunnels. The results shows high pressure sodium lamps are more economical than fluorescent lamps.

터널 설계시 지하수의 고려방안 (Groundwater Considerations in Tunnel Design)

  • 이인모;김용진
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 1993년도 봄 학술회 논문집
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    • pp.1-8
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    • 1993
  • This paper concerns the analytical concept of tunnel design for the case where the groundwater level remains almost to a standstill even though the steady state groundwater flow occurs through tunnel drainage systems. The effect of the seepage force is considered in analysis. Two case strudies are made : the one the round shape tunnel ; the other the horse shape. The design moments, shear forces and axial forces are calculated and these results are compared to the case of water proof tunnel design as well as the case of the tunnel design without groundwater consideration.

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DESIGN OF THE CEMENT DEEP MIXING FOUNDATION FOR THE BUSAN-GEOJE IMMERSED TUNNEL

  • Kim, Yong-Il
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 추계 학술발표회 3차
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    • pp.96-103
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    • 2010
  • The GK immersed tunnel as a part of the Busan-Geoje Fixed Link Project, introduced the immersed tunnel method into Korea for the first time. This challeging project to be completed in 2010 will open a new era to link oceans of the world with optimized design and safety for future use. The immersed tunnel method would possibly suitable for use in construction of a sub sea tunnel from Korea to Japan and from Korea to China that could potentially be built in the distant future. We hope the techniques learned from the Busan-Geoje Fixed Link Project can be applied to further projects in the near future.

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교통도로 TUNNEL 조명의 이해 (II) (The Understanding of Road TUNNEL Lighting(II))

  • 이은풍
    • 기술사
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    • 제33권1호
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    • pp.68-74
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    • 2000
  • Until the first stage of the 1990's years, Korean are not concern so much the facilities of traffic tunnel, because of them are the short length and also the quantity of them are not over the several tens in Korea. But, in latest many tunnels has been constructed and are designed in expressway and local national roads. The government office concerned forecast the numbers of tunnel are increased about 300 until the 2003 years, and then we need more interesting about the facilities of tunnel . In the tunnel, the first above of all important facilities is lighting installations which are required much electric energy and continuing maintenance.

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터널 건설 프로젝트 리스크 분석 및 리스크 정량화 모델 개발에 관한 연구 (Risk Factors Analysis and Quantitative Risk Assessment Model for Tunnel Construction Project)

  • 정승아;안성진
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2023년도 봄 학술논문 발표대회
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    • pp.363-364
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    • 2023
  • The tunnel construction projects is demanded more efficient risk management measures and loss forecasts to prepare for risk losses from an increase in the trend of tunnel construction. This study aims to analyze the risk factors that caused the loss of material in actual tunnel construction and to develop a quantified predictive loss model, based on the past loss record of tunnel construction projects.

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고속열차의 터널 주행시 실외 압력 변화 및 미기압파 저감을 위한 수치해석적 연구 (Numerical Study of Reduction of External Pressure Variation and Micro-Pressure Wave for high-speed train in tunnel)

  • 이정욱;윤수환;곽민호;이동호;권혁빈
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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    • pp.158-164
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    • 2011
  • When a train passes a conventiaonl tunnel at high speed, external pressure variation problem arises. It is known that this issue can be reduced by control the tunnel length. We studied the variances of external pressure variation within the tunnel, by altering length of the dummy tunnel duct. We also studies the variances of micro-pressure waves at the exit of tunnel, by altering surface area of dummy tunnel duct. For analyzing this train-tunnel relation problem, axisymmetric steady compressible flow solver was used.

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