An improved, low cost, semi-permanent, rigid, double-walled, modularly expandable, light-weight, man-portable, field-erectable, structure having a multi-use interior useful space, comprising in assembled use combination:
- a) at least one end portion structure which is a semi-circle in plan view, said end portion comprising,
- i. a plurality of substantially identical generally rectangular double-wall side wall panel modules, said side wall panel modules having a box construction with an inner wall and outer wall, a horizontal bottom end, a horizontal top end, vertical lateral sides and a vertical height longer than its width defining an eave height,
- ii. said side wall panel modules being joined to each other along said vertical sides, and as conjoined, together defining a substantially continuous wall spaced a substantially uniform radial distance from a common center along the circumference of said semi-circle,
- iii. a plurality of substantially identical double-wall roof panel modules, said roof panel modules having a box construction with an outer roof face and an inner ceiling face,
- iv. each said roof panel modules being a generally geometrical isosceles triangle as seen in plan view and having an outer marginal edge defining an outer eave edge, and two sides joining at said common center of said semi-circle,
- v. said roof panel modules being joined to the tops of said side wall panel modules adjacent said outer marginal edge with said eave edge projecting beyond said outer wall of said conjoined double-wall side wall modules,
- vi. said roof panel modules being conjoined to adjacent roof panel modules to form a generally conical semi-circular roof structure having a peak at said common center that is higher than said eave height and defining a support-free space interior of said inner wall and said ceiling;
- b) at least one straight section structure comprising a plurality of modular segments, each segment comprising:
- i. a pair of spaced-apart substantially identical generally rectangular double-wall side wall panel modules, said side wall panel modules having a box construction with an inner wall and outer wall, a horizontal bottom end, a horizontal top end, vertical lateral sides and a vertical height longer than its width defining an eave height that is substantially the same as the eave height of said end portion,
- ii. a pair of substantially identical double-wall roof panel modules, said roof panel modules having a box construction with an outer roof panel and an inner ceiling panel,
- iii. each said roof panel modules being a generally a geometrical rectangle as seen in plan view and having a width substantially equal to the width of said segment side wall panel module, an outer marginal edge defining an outer eave edge, two generally parallel sides and an inner ridge box end,
- iv. each of said roof panel modules being joined to the top of one of said pair of side wall panel modules adjacent said outer marginal edge with said eave edge projecting beyond said outer wall of said double-wall side wall panel modules,
- v. the inner ridge box ends of said roof panel modules being joined to each other along a ridge elevated above said eave height to form a span having vertical side walls, and a sloped roof down from a generally straight ridge,
- vi. said straight section segment having a length between a first and a second side substantially equal to the width of said segment side wall panel module, and defining between said side edges, said spaced-apart opposed inner wall panels and said ceiling panels, a support-free space interior of said span;
- c) the diameter of said end portion semi-circle is substantially equal to the span width of said straight section segment;
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- d) said end portion structure is positioned with its diameter aligned with the span width of said straight section segment structure and said end portion structure is joined to said first end of said straight section segment structure along adjoining wall panel and roof panel modules to provide a longhouse structure that is stadium-shaped as seen in plan view, and whose longitudinal length is expandable simply by adding segments to said straight section structural portion.