Evaluation of Inflatable Dams for In-System Storage Utilization in CSO Abatement

J Infrastruct Preserv Resil

Holter

et al. 2020

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: Introductionmentioning

confidence: 99%

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

J Infrastruct Preserv Resil

Holter

et al. 2020

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“…Inflatable plugs for the protection of tunnels are, to a certain extent, similar to inflatable dams used for diversion structures, check structures for flood control, overflow weirs, flashboard and gate replacement, sluice gates, and barriers for erosion (14). Inflatable dams were invented in the 1960s and since then have been used extensively across the world and in the United States (15,16). Recently, inflatable rubber dams were installed in large sewer lines to control stormwater and wastewater and reduce pollution during heavy rain events in areas such as the New York Harbor (17).…”

mentioning

confidence: 99%

Testing of Full-Scale Inflatable Plug for Flood Mitigation in Tunnels

Transportation Research Record: Journal of the Transportation R

Barbero

2014

The protection of high-risk underwater and underground assets, such as rail and road tunnels, is a high priority. Disasters and extraordinary events can significantly disrupt the functionality of such critical civil infrastructure. Events such as the 2012 flooding of New York City, when Hurricane Sandy caused seven subway tunnels and three vehicular tunnels to flood and remain inoperable for several days, have demonstrated the need for methods to mitigate vulnerabilities to or, at least, minimize the consequences of those events. Conventional emergency sealing systems are not always installed or operational during extraordinary events; this situation has prompted the investigation of alternative solutions, such as inflatable plugs capable of sealing off and protecting an underground system by stopping hazards. The development and testing of confined inflatable structures was performed at West Virginia University to verify the viability of flood containment with an inflatable plug in a tunnel section. The work was performed under the Resilient Tunnel project, which has progressed from the production of a proof of concept, air-inflated prototype to reduced and full-scale prototypes pressurized with water and subjected to back pressure for flooding simulations. This work summarizes the results of tests performed at full scale for the evaluation of the conformity of an inflatable plug to a typical tunnel section as well as the plug's ability to withstand simulated flooding and maintain axial stability. The tests comprised deployment, inflation, pressurization, and flooding simulation. The test results demonstrated that an inflatable plug could be installed and deployed and could seal a tunnel section by holding test pressures, while maintaining axial stability, with manageable levels of water leakage.

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Experimental investigation of initial deployment of inflatable structures for sealing of rail tunnels

Tunnelling and Underground Space Technology

Barbero

2017