Wednesday, October 26, 2016

Earth covered, Terraced, Molded Dome Structures

If you spin a vessel containing a liquid around the vertical axis, the lower/outer surface of the liquid will mold to the inner surface of the container, while the upper/inner surface of the liquid will form a parabolic cavity. Use a liquid that hardens to a solid, and this is a simple way to create a single-piece dome.

One advantage of a single-piece structure is that it can be very leak-resistant, and domes can be quite strong. The combination of these two characteristics makes molded domes ideal starting points for earth covered buildings, but to keep the earth from sliding off the dome, it's necessary to berm the sides thickly, so the surface of the earth covering slopes more gently than the dome itself.

However, if terrace forming indentations are built into the mold, the resulting dome will be better at supporting its earth covering, and there will be less need for wide berming.

Unless drainage is built into the mold, or drilled into the dome after molding, heavy precipitation will result in overflow, with excess water from higher terraces flowing onto the soil retained by lower terraces, so it would make sense to use a sandier soil mix in the lower terraces, and plants that thrive in such an environment.

The mold can include a protrusion in the bottom to create a hole in the top of the dome for a skylight. Similarly, holes for windows and doors (with reinforced edges and overhangs) may also be designed into the mold, and hardware for mounting doors and windows fitted into the mold before molding.

Once in use, a growing mass of plant roots will help keep the earth covering in place.