Theoretical Analysis and Model Testing of the Deformation Characteristics and Failure Mechanism of a Blocking Airbag System in a Tunnel Under External Pressure

Chen, Jing; Yan, Shuwang; Sun, Liqiang; Lang, Ruiqing

doi:10.1007/978-981-13-0017-2_34

Cited by 2 publications

(6 citation statements)

References 4 publications

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“…Water was also used to simulate the flooding behind the plug. The idea of using a small-scale tunnel was also implemented in [32,35,36] to test friction and stability characteristics, as well as the deployment of small scale inflatables. Similarly to Phase 1, testing activities carried out as part of Phase 2 were focused on the following three main areas:…”

Section: Results Of Experimental Evaluationsmentioning

confidence: 99%

“…In the quarter-scale tests (1.22 m tunnel diameter) completed during this phase, the inflatable plug was taken safely to the reference pressure of 468 kPa while holding a flooding pressure of 330 kPa without slipping [88,89]. As a reference, the reduced-scale studies carried out in [32,35,36] included tunnel diameters in the range of 0.2 m to 0.4 m for pressures in the range of 10 kPa to 50 kPa. The decoupling of the functions of the plug membrane prevented compromising unloaded segments of fabric material during pressurization.…”

Section: Phase 2bmultiple Layer Membrane Design Initial Testingmentioning

confidence: 99%

“…In terms of the geometrical design of the inflatable plug, the fitted shape adopted during Phases 1 and 2 was replaced by a straight cylindrical segment that simplified part of the manufacturing process. In this regard, the studies conducted in [32][33][34][35][36] have also adopted this simple geometric configuration in their studies at different scales. The plug's cylindrical segment required an amount of oversizing, defined as the ratio of the plug circumference to the effective circumference of the tunnel, at the point where the plug is to be used.…”

Section: Phase 2bmultiple Layer Membrane Design Initial Testingmentioning

confidence: 99%

“…Maintaining the single-hose design, a 0.3-m diameter hose with metal braiding provided the needed resiliency and durability, but with less flexibility than similar diameter multilayer composite or Kevlar/silicone hoses. According to reduced-scale experimentation reported in the literature [32][33][34][35][36]89] the interaction between the inflatable plug and the means that convey the pressurization fluid to the plug was trivial and did not constitute a matter of significant concern. However, in full-scale experimentation and field implementation, problems can occur as the size and stiffness of the inflation hose can affect the deployment, which in turn could affect the final positioning, and ultimately diminish the sealing capacity and leakage containment ability of the plug.…”

Section: Phase 3prototype System Testing and Demonstrationmentioning

confidence: 99%

“…Flooding of transportation tunnel systems is a problem in Asia too. Several studies were recently conducted in China and South Korea to assess flooding risk [31] and to develop small-scale inflatable systems [32][33][34][35][36]. Other similar and more recent efforts in Europe include the INFLATER project [37], also the inflatables developed in Spain [38,39] and Germany [40] for creating flood barriers of virtually any length along a body of water or other surface-related flood hazards, but not for flooding events in confined environments such as tunnels.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Large-scale inflatable structures for tunnel protection: a review of the Resilient Tunnel Plug project

Sosa

Thompson

Holter

et al. 2020

J Infrastruct Preserv Resil

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The protection of underground civil infrastructure continues to be a high priority for transportation and transit security agencies. In particular, rail transit tunnels running under bodies of water are susceptible to disruptions due to flooding caused by extraordinary climatic events such as hurricanes or other events resulting from human activities. Several events have taken place in the past decades that have demonstrated the need to mitigate vulnerabilities or, at least, minimize the consequences of catastrophic events. Although it is impossible to prevent all situations that can lead to flooding, damage can be substantially decreased by reducing the area affected by the event. To minimize the effects of an event, a possible approach is to compartmentalize the tunnel system by creating temporary barriers that can contain the propagation of flooding until a more permanent solution can be implemented. One way to create a temporary barrier is by the deployment of a large-scale inflatable structure, also known as an inflatable plug. In such an application, the inflatable structure is prepared for placement, either permanently or temporally, and maintained ready for deployment, inflation, and pressurization when needed. The internal plug pressure imparts a normal force against the tunnel wall surface with the friction between the plug and tunnel surfaces opposing axial movement of the plug. The sealing effectiveness depends on the ability of the inflatable structure to self-deploy and fit, without human intervention, to the intricacies of the perimeter of the conduit being sealed. Primary design constraints include having the plug stowed away from the dynamic envelope of the trains and being able to withhold the pressure of the flooding water. This work presents a compilation of the main aspects of the activities completed for the development of large-scale inflatable structures as part of the Resilient Tunnel Plug (RTP) Project. The main test results and lessons learned are presented to demonstrate the viability of implementing large-scale inflatable plugs for the containment of flooding in rail tunnels systems. Over 400 coupon and specimen tests, 200 reduced scale tests, and 100 full-scale tests were conducted to demonstrate the efficacy of the design of different prototypes over a 10-year research and development project. The culmination of the work was 12 large-scale flooding demonstrations where the inflatable tunnel plug was shown able to be deployed remotely and withstand a simulated flooding event.

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Section: Results Of Experimental Evaluationsmentioning

confidence: 99%

Section: Phase 2bmultiple Layer Membrane Design Initial Testingmentioning

confidence: 99%

Section: Phase 2bmultiple Layer Membrane Design Initial Testingmentioning

confidence: 99%

Section: Phase 3prototype System Testing and Demonstrationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Large-scale inflatable structures for tunnel protection: a review of the Resilient Tunnel Plug project

Sosa

Thompson

Holter

et al. 2020

J Infrastruct Preserv Resil

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Mechanism Analysis of Airbag Explosion Suppression and Energy Absorption in a Flexible Explosion Suppression System

Wang

Han

et al. 2023

Fire

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The unfixed flame propagation velocity of a gas explosion and the fixed response time of explosion suppression devices are the important reasons for the poor protective effect of active explosion suppression. A flexible explosion suppression method based on buffer energy absorption is detailed in this study. The explosion suppression system consists of an explosive characteristic monitoring system, an explosion suppression agent system, and an explosion suppression airbag. An empty pipe experiment and an explosion suppression experiment with a flexible-airbag gas-explosion suppression device were conducted in a 20.5 m-long pipe with an inner diameter of 180 mm. The flame propagation velocity and maximum overpressure values were compared between the two groups of experiments. The experimental results show that the flame wave propagation can be completely suppressed by the explosion suppression device under certain pressure. The occurrence time of maximum overpressure at each pressure measuring point is also analyzed. P3 is generally later than P4, which verifies the existence of energy absorption and explosion suppression effect of airbag. Finally, the energy absorption effect of the airbag is analyzed theoretically. The shock wave overpressure calculated in the sealing limit state of the airbag is 0.3432 MPa, and the maximum error is 7.8%, which provides reliable guidance and prediction for the experimental process in the future.

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Theoretical Analysis and Model Testing of the Deformation Characteristics and Failure Mechanism of a Blocking Airbag System in a Tunnel Under External Pressure

Cited by 2 publications

References 4 publications

Large-scale inflatable structures for tunnel protection: a review of the Resilient Tunnel Plug project

Large-scale inflatable structures for tunnel protection: a review of the Resilient Tunnel Plug project

Mechanism Analysis of Airbag Explosion Suppression and Energy Absorption in a Flexible Explosion Suppression System

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