• Title, Summary, Keyword: 운영 중 해저 터널

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The development of a back analysis program for subsea tunnel stability under operation: longitudinal direction (운영 중 해저 터널의 안정성 평가를 위한 역해석 프로그램 개발: 종단방향)

  • An, Joon-Sang;Kim, Byung-Chan;Moon, Hyun-Koo;Song, Ki-Il
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.18 no.6
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    • pp.545-556
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    • 2016
  • If a back analysis is used in various measurement information for the estimation of an operating subsea tunnel safety, it is possible to obtain the results within efficient error rate. With such a commercial geotechnical analysis program as FLAC3D, back analysis is performed with a DEA which was validated in previous studies. However, there is a problem that is relatively a time-consuming analysis. For this reason, beam-spring model-based FEM solver which takes shorter relative analysis time, was developed by Python language, and then combined with the built-DEA. In order to consider the assessment of safety of an operation tunnel near real-time, a program for longitudinal direction tunnel was developed due to its relative easy development for analysis solver engine.

The development of a back analysis program for subsea tunnel stability under operation: transversal tunnel section (운영 중 해저 터널의 안정성 평가를 위한 역해석 프로그램 개발: 횡단방향)

  • An, Joon-Sang;Kim, Byung-Chan;Lee, Sang-Hyun;Song, Ki-Il
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.19 no.2
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    • pp.195-212
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    • 2017
  • When back analysis is used for the assessment of an operating subsea tunnel safety in various measurement information such as stress, water pressure and tunnel lining and ground stiffness degradation, the reliable results within tolerable error rate can be obtained. By utilizing a commercial geotechnical analysis program FLAC3D, back analysis can be performed with a DEA which has already been successfully validated in previous studies. However, relative more time-consumption is the drawback of this approach. For this reason, this study introduced beam-spring model-based on FEM solver which uses less analysis time relatively. Beam-spring program capable of structural analysis of a circular tunnel section was developed by using Python language and combined with the built-DEA. From the measurement datum, expected to estimate the stability of an operation tunnel close to real-time.

The review about ultra long subsea tunnel design under high water pressure (고수압 초장대 해저터널에 관한 연구)

  • Jun, Duk-Chan;Kim, Ki-Lim;Hong, Eui-Joon;Kim, Chan-Dong;Lee, Young-Joon;Hong, Cheor-Hwa
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.19 no.6
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    • pp.829-843
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    • 2017
  • Subsea tunnel needs to be built over 50 km long to connect between nations and continents. However there are only 19 tunnels longer than 5 km until recently. And there is no history of constructing and operating tunnel longer than 50 km. In Korea, subsea tunnels with a length of more than 50 km are being planned, such as Korea~Japan, Korea~China, Honam~Jeju subsea tunnels. Because of the geographical conditions of Korea, most of these tunnels are inter-contry tunnels. So technology preemption for the subsea tunnel construction is getting more and more important. Most of these subsea tunnels are ultra-long tunnels under high water pressure conditions. So new technologies are required such as ventilation and disaster prevention of high-speed tunnels, securing of structural stability under high pressure conditions, and pressure reduction in high-speed conditions. These technologies are different from those of ground tunnels. Therefore, this paper describes the ultra-long subsea tunnel design under high water pressure of maximum 16 bars through the Honam (land) - Jeju (island) virtual subsea project. We proposed a reasonable solution to various problems such as securing structural stability in high pressure condition and ventilation disaster prevention system of ultra long-tunnel.

A Study on Standard Construction Process Management System for Prediction of Proper Construction Period of Subsea Tunnel (해저터널 적정 공사기간 예측을 위한 표준공정관리 체계 연구)

  • Bae, Keunwoo
    • Korean Journal of Construction Engineering and Management
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    • v.18 no.4
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    • pp.36-47
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    • 2017
  • As a typical domestic subsea tunnel construction the Gadeok subsea tunnel applying the method of immersed tunnel has been completed and the Boryeong-Taean subsea tunnel is under construction using NATM. The high-speed railway subsea tunnels between the Honam and Jeju are under consideration, and the feasibility of constructing subsea tunnels with Japan and China is also under consideration. However, it is difficult to provide the process plan information for the construction work such as the analysis of the feasibility of the subsea tunnel and the prediction of the proper construction period because there is no case of domestic construction for it applying the shield TBM method. Due to economic and other reasons, government organizations are reluctant to apply the shield TBM, and there is lack of data on the construction process management field using the shield TBM method. Therefore, a standard construction process management system for the subsea tunnel is needed to analyze the feasibility of the subsea tunnel and to predict the proper construction period. By presenting the standard construction process management system of subsea tunnels such as WBS, Network Diagram, and construction period calculation model, I hope to contribute technically and economically to future subsea tunnel projects.

DEA optimization for operating tunnel back analysis (운영 중 터널 역해석을 위한 차분진화 알고리즘 최적화)

  • An, Joon-Sang;Kim, Byung-Chan;Moon, Hyun-Koo;Song, Ki-Il;Su, Guo-Shao
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.18 no.2
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    • pp.183-193
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    • 2016
  • Estimation of the stability of an operating tunnel through a back analysis is a difficult concept to analyze. Specially, when a relatively thick lining is constructed as in case of a subsea tunnel, there will be a limit to the use of displacement-based tunnel back analysis because the corresponding displacement is too small. In this study, DEA is adopted for tunnel back analysis and the feasibility of DEA for back analysis is evaluated. It is implemented in the finite difference code FLAC3D using its built-in FISH language. In addition, the stability of a tunnel lining will be evaluated from the development of displacement-based algorithm and its expanded algorithm with conformity of several parameters such as stress measurements.

Management and concept of the monitoring system considering the characteristics of subsea tunnels (해저터널의 특성을 고려한 계측 개념 및 관리 방안)

  • Park, Eui-Seob;Shin, Hee-Soon;Cheon, Dae-Sung;Jung, Yong-Bok
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.15 no.5
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    • pp.523-536
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    • 2013
  • In order to ensure the safety of the subsea tunnel during its construction and operation, unlike the underground structures on land, the special monitoring system is essential which considers the characteristics of subsea tunnels in addition to conventional stress and displacement measurements applied to existing land tunnels. Therefore, the concept applied to NATM is reorganized to evaluate the stability of subsea tunnels. And the observation system for making a monitoring plan, the critical strain theory for tunnel safety management and MS monitoring methods for detecting the local failure and crack initiation of rock and supports, are introduced. Finally, the scheme of monitoring and management for subsea tunnels by using these methods is suggested.

Design considerations and field applications on inflatable structure system to protect rapidly flooding damages in tunnel (해저터널 급속차폐를 위한 팽창구조체의 설계 및 현장적용에 대한 연구)

  • Kim, Hyeob;Kang, Si-On;Yoo, Kwang-San;Kim, Sang-Hwan
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.19 no.2
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    • pp.161-177
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    • 2017
  • This paper presents the design considerations and field applications on inflatable structure system to protect rapidly flooding damages in large section tunnel. This inflatable structure system is very valuably used to protect passively and rapidly the possibilities of tunnel damages by flooding threats and unusual leakage to be occurred during and after underground infrastructure. In particular, this system should be necessary in subsea tunnel. The predominant factors in the design of inflatable structure system are the leakage and friction characteristics between the inflater and tunnel liner. The analytical and experimental studies are performed to develop the design considerations and to examine the design parameters of the inflatable structure system. The analytical solutions are developed using membrane theory to suggest the design considerations. The relative friction tests of several fabric materials are also carried out to determine the friction characteristics according to the different friction conditions between inflater and tunnel surface. The test results show that the friction coefficients in wet surface condition are about 20% lower than the values in dry surface condition. In addition, virtual design of tunnel protection system for two virtual subsea tunnel sites which is under reviewing in Korea, is carried out based on this research. It is expected that the results of this research will be very useful to understand the inflater structure design and development the technology of tunnel protection structures in the future.

Risk Assessment of Submerged Floating Tunnels based on Fuzzy AHP (퍼지 AHP를 이용한 수중터널의 재해위험도 분석)

  • Han, Sang-Hun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.7
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    • pp.3244-3251
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    • 2012
  • In the construction and operation of large marine structure, hazard risk analysis is one of important factors. Therefore, this paper investigates the hazard risk indexes and evaluates the risk level in the construction and operation of SFT on the basis of expert survey and Fuzzy analytic hierarchy process. Hazard risk is divided into natural hazard risk (earthquake, typhoon, tsunami, and ice collision) and human factor hazard risk (fire, explosion, traffic accident, ship or submarine collision). Also, the influence of hazard risk indexes on SFT was evaluated in tunnel tube, supporting system, ventilation tower, foundation, and connection part. As the hazard risk level of SFT is compared with those of bridge, underwater tunnel, and immersed tunnel, the intrinsic risk level of SFT was evaluated. Tsunami and earthquake had higher risk level in natural hazard risk, and the risk levels of fire and explosion were higher in human factor hazard risk. Hazard risk level of SFT was 1.4 times higher than immersed tunnel, and 3.2 times higher than bridge.

A Study on the Contents for Operation of Tunnel Management Systems Using a View Synthesis Technology (영상정합 기술을 활용한 터널관리시스템의 운영 효율성 제고를 위한 콘텐츠 연구)

  • Roh, Chang-gyun;Park, Bum-Jin;Kim, Jisoo
    • The Journal of the Korea Contents Association
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    • v.16 no.6
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    • pp.507-515
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    • 2016
  • In South Korea, there are a large number of tunnels because of the mountainous terrain, and to overcome this characteristics, lengths of tunnels are more longer than existing tunnels. The need to improvement current tunnel management contents is giving rise for accidents in tunnel section is continuously increased although lots of efforts to reduce the accidents. Conventionally, disaster prevention have been focused on the Tunnel Management Systems, tunnel operators generally tend to depend on CCTV images for most contents of detailed traffic flow managing. In this paper, investigation about current Tunnel Management Systems contents using IPA survey was conducted, and Priority Improvement Contents(Accident Situation Management Support, 2nd Accident Management Support, Traffic Flow Monitoring), which importance are high, but satisfaction are low, are deducted. Also, CCTV images, lack intuitive understanding, are judged as a main cause of low satisfaction of those contents. To overcome those limitations of the existing Tunnel Management Systems, this study sought to develop a technology for the synthesis of road images to derive traffic information from synthesis images, and the contents improvement stragegy is established. Tunnel operators-oriented satisfaction survey on new contents was carried out, and scored 4.2 on a 5-point scale. This has confirmed that the availability of new contents and at this stage, with pushing ahead of long-tunnels and undersea tunnels construction, politic applications are expected.

Seismic response characteristics according to the supporting conditions of middle slab of double-deck undersea tunnel using the centrifuge testing (원심모형 실험을 이용한 해저 복층터널 중간슬래브 지지조건에 따른 지진 응답특성)

  • Um, Ki-Yoon;Park, Inn-Joon;Kwak, Chang-Won;Jang, Dong-In
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.20 no.2
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    • pp.347-360
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    • 2018
  • Due to the concentration and congestion of traffic in Seoul metropolitan area, effective utilization of underground space is required, and construction of various underground structures such as a double deck tunnel is increasing. Double deck tunnels are divided into upper and lower runways, and the most important part is middle slab. To investigate seismic behavior of middle slab, experimental study is required because of the complexity of the load and the mechanism of earthquake. In this study, centrifugal model tests were conducted to investigate the response characteristics of earthquake response according to the support conditions of the middle slab of a double deck tunnel. Artificial, Ofunato (short period) and Hachinohe (long period) seismic waves were employed in the experimental study. As a result, it was confirmed that the acceleration attenuation of elastomeric bearings condition was 10.6% in artificial earthquake, 13.6% in Ofunato earthquake, and 10.3% in Hachinohe earthquake. The results indicate that elastomeric bearings have some advantages in the viewpoint of seismic behaviors.