| 摘要 |
<p>A cylindrical storage tank for installation underground in a horizontal position comprises a hollow cylindrical body and two end caps joined to opposite end portions of the cylindrical body. The end caps are outwardly convex and generally spherical at their central portions but frusto-conical adjacent their junctions with the cylindrical body. The radius of curvature of the spherical portions is equal to the radius of the cylindrical body and the frusto-conical portion of each end cap forms an angle adjacent the bottom of the tank with an underground support surface, when the tank is installed horizontally underground, which substantially corresponds to the natural angle of repose of recommended backfill material such as sand or gravel, whereby voids otherwise likely to occur beneath the end caps if the end caps were completely hemispherical are eliminated.</p> |
