Designing Buildings: Created page with "[https://www.gov.uk/government/publications/glossary-abbreviations-and-references High Speed Rail (Crewe – Manchester) Environmental Statement, Glossary, abbreviations and refe..."

2022-11-23T08:50:37Z

Created page with "[https://www.gov.uk/government/publications/glossary-abbreviations-and-references High Speed Rail (Crewe – Manchester) Environmental Statement, Glossary, abbreviations and refe..."

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[https://www.gov.uk/government/publications/glossary-abbreviations-and-references High Speed Rail (Crewe – Manchester) Environmental Statement, Glossary, abbreviations and references], published by the Department for Transport in 2022, defines porous (tunnel) portals as: ‘Perforated structures at tunnel portals (entrances), usually formed of concrete, designed to allow the passage of air from the tunnel. These reduce both air pressure changes and the noise generated when a high speed train enters a tunnel.’

= Related articles on Designing Buildings =

* Cut-and-cover tunnel.
* High Speed 2 (HS2).
* Portal frame.
* Railway engineering.
* Trenchless technology.
* Tunnel.
* Tunnels of the world.
* Underpass construction.

[[Category:DCN_Definition]] [[Category:Definitions]]

Porous portal - Revision history

Designing Buildings: Created page with "[https://www.gov.uk/government/publications/glossary-abbreviations-and-references High Speed Rail (Crewe – Manchester) Environmental Statement, Glossary, abbreviations and refe..."