SUITABLE THIN SHELL STRUCTURAL CONFIGURATIONS FOR EARTH SHELTERED HOUSIN

An earth sheltered house is one whose building envelope is substantially in contact with soil, without necessarily being totally underground. Hence, it can provide the commonly sought attributes of a residence, including natural light, exterior views, and curb appeal. It also exhibits strong energy performance, lower maintenance, and good storm protection.;Despite the longer-term life cycle cost advantages of earth sheltered buildings, a current hindrance to the mass market acceptance of earth sheltered housing is higher initial cost which is caused, in part, by the inability of conventional rectilinear structural systems to support economically the massive soil loads imposed on earth covered buildings.;Due to the inherent strength of curvilinear thin shell concrete structures, they are logically suited to earth sheltered applications where they could possibly contribute to alleviating the present initial cost problem in earth sheltered housing.;In deference to the premise that technical suitability is no guarantee of innovation acceptance in the housing industry, a survey of the nontechnical impediments to housing innovation was first undertaken. These impediment areas include: market inhibitions; builder trepidations; industry constraints; and financing problems. Attempts at large-scale implementation of innovations in housing must transcend technical feasibility and deal with these formidable innovation impediments.;As a result of an architectural design program written under contract for the Department of Energy, with the author serving as principal investigator, it was possible to include a rather extensive (but necessarily subjective) evaluation of the architectural potential for earth sheltered shell structures. The architectural potential was deemed adequate to warrant a more rigorous engineering suitability investigation.;Engineering suitability dimensions included structural effectiveness, constructability, and economy of construction for single- and double-curvature thin shell structures. Structural effectiveness was evaluated by rigorously analyzing the strength and stability performance of domes and arches having profiles ranging from hemispherical to very flat. Constructability was determined by reviewing the state of the art in residential thin shell construction practice. Economy of construction was evaluated by obtaining professional cost estimates for the structural shell portions of selected dome and arch earth sheltered designs.;Overall engineering suitability and architectural potential are deemed to be adequate, although non-engineering impediments to housing innovation appear to raise significant questions regarding the potential for mass market implementation of thin shell structures in earth sheltered housing.