Substructure 1 : All that part of a structure below the beatings of simple and continuous spans, skewbacks or arches and top of footings of rigid frames; including backwalls, wingwalls and wing protection railings
Ilan Kelman (ed.), Vulnerability and Resilience Definitions and References, Version 2, 2007. http://www.islandvulnerability.org/docs/vulnres.pd f, (Vulnr and Resilience - Brit) {524}