STRUCTURE

THERMOSHELTER is a lightweight prestressed vault with extraordinary performance under earthquake, snow loads and high wind conditions. A composite structure is created when the tensioning roof forces a prestress into the rigid insulation. In practice this stress is about 3 psi, also enough to contain thermal movement even in extreme conditions. Temperature induced changes of compression have been a critical consideration and particular attention has been paid to issues of long term creep, choosing a conservative low-level pressure. Compression values for the EPS foam are taken from published and code tested values developed for geofoam blocks for geotechnical uses. Structural consideration of the interior plaster finish of the arch doubles its strength and quadruples its stiffness.

THERMOSHELTER is necessarily an arch. To date, semicircular and modified parabolic arches have been built. Length of the vaults are unlimited. Spans are limited by block wall thickness and prestress level.