• 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.

• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.1
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• pp.109-117
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• 2016

This paper is focused on the determination of friction parameter which is a predominant factor in the design of inflatable structure system. 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 construction. In particular, this system should be necessary in subsea tunnel. This study presents the experimental results obtained from the relative friction characteristics tests of the fabric materials that constitute the inflatable structure. In order to evaluate the relative friction behaviour of the inflatable structure system, friction tests and scaled model tunnel friction tests are carried out. The friction tests are carried out to determine the friction coefficient for different surface conditions between tunnel and inflatable structure. These friction coefficients are then evaluated and compared with the result obtained from the model tunnel friction tests. Interaction behaviours between tunnel and system are also reviewed and described in this study. The results clearly show that the friction coefficients derived from scaled model slippage tests are about 12% lower than values obtained from the friction tests. In addition, this study will be necessary to verify the real friction behaviour with prototype tests before applying in practice.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.3
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• pp.295-303
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• 2015

This paper presents the study of leakage effect due to multi-cell inflater of rapid protection system to protect the possibilities of tunnel damages by flooding threats and unusual leakage to be occurred during and after subsea tunnel construction. Particularly, this protect system should be necessary in subsea tunnel. This research concentrates the physical model tests due to several multi-cell inflater to study protection capacity of leakage between the inflater and tunnel liner. A 27:1 small scale model are used in the model tests. The leakage rate, water pressure and axial displacement of inflater are measured during the model tests. According to the results, the minium leakage rate clearly shows in the case of two-cell inflater compared with in other cases. It is concluded that the results of this research will be very useful to understand the fundamental information of inflater structure design and development the technology of tunnel protection structures in the future.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.3
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• pp.27-34
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• 2024

The direct and indirect damages caused by fires in underground utility tunnels have a great impact on society as a whole, so efforts are needed to prevent and manage them in advance. To this end, research is ongoing to prevent disasters such as fire flooding by applying digital twin technology to underground utility tunnels. A network is required to transmit the sensed signals from each sensor to the platform. In essence, it is necessary to analyze the application of wireless networks in the underground utility tunnel environments because the tunnel lacks the reception range of external wireless communication systems. Within the underground utility tunnels, electromagnetic interference caused by transmission and distribution cables, and diffuse reflection of signals from internal structures, obstacles, and metallic pipes such as water pipes can cause distortion or size reduction of wireless signals. To ensure real-time connectivity for remote surveillance and monitoring tasks through sensing, it is necessary to measure and analyze the wireless coverage in underground utility tunnels. Therefore, in order to build a wireless network environment in the underground utility tunnels. this study minimized the shaded area and measured the actual cavity environment so that there is no problem in connecting to the wireless environment inside the underground utility tunnels. We analyzed the data transmission rate, signal strength, and signal-to-noise ratio for each section of the terrain of the underground utility tunnels. The obtained results provide an appropriate wireless planning approach for installing wireless networks in underground utility tunnels.

• The KIPS Transactions:PartD
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• v.13D no.6 s.109
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• pp.775-788
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• 2006

Many disaster monitoring systems are constantly studied to prevent disasters such as environmental pollution, the breaking of a tunnel and a building, flooding, storm earthquake according to the progress of wireless telecommunication, the miniaturization of terminal devices, and the spread of sensor network. A disaster monitoring system can extract information of a remote place, process sensor data with rules to recognize disaster situation, and provide work for preventing disaster. However existing monitoring systems are not enough to predict and prevent disaster, because they can only process current sensor data through utilizing simple aggregation function and operators. In this paper, we design and implement a disaster prevention system to predict near future dangerous area through using outside sensor network and spatial Information. The provided prediction technique considers the change of spatial information over time with current sensor data, and indicates the place that could be dangerous in near future. The system can recognize which place would be dangerous and prepare the disaster prevention. Therefore, damage of disaster and cost of recovery would be reduced. The provided disaster prevention system and prediction technique could be applied to various disaster prevention systems and be utilized for preventing disaster and reducing damages.