Xerxes Corporation

Other

Albert F Dorris

Robin Berg

John R Burwell

John Richard Smith

Kiet T Ly

Joseph Plecnik

A low profile deadman is shaped such that it can be placed alongside a storage tank on a conventionally-sized flatbed trailer. In one preferred embodiment, the deadman includes at least one chamfered edge.

Low profile deadman and method for shipping the same with a tank

A triple-walled underground storage tank is provided with primary, secondary and tertiary walls. Between each two adjacent walls, an annular space is provided. The annular space is continuous throughout, and permits the flow of liquid therein. Monitors may be provided separately for each annulus, to detect the formation of leaks, or a lack of containment, in either wall defining the annular space. In one embodiment, the tertiary wall is a smooth cylinder formed about the circumferential ribs of the secondary wall. In the alternative embodiment, the rib-bearing wall is the tertiary wall, and the walls and annular materials of the tank are formed within a female mold. In either case, a tank prepared from integral ribs, with superior robustness and strength, is provided with triple containment.

Triple walled underground storage tank

A method for calculating underground storage tank (UST) buoyancy and buoyancy safety factors defines boundaries of side areas such that the boundaries do not overlap for multiple tank installations. Installation plan information may be input over a medium such as the Internet. The computer calculates the buoyancy and buoyancy safety factor and returns this information to the requesting party over the same medium. This technique allows installers to verify the adequacy of installation plans quickly. Records of the information provided by the installer may be kept so the recipient of the information (typically the UST manufacturer) can reconcile differences between the actual installation and the installation plan in the event of UST flotation. The information may be provided on a paper form supplied by the installer. In preferred embodiments, the calculations are tailored to installation guidelines (often provided by the UST manufacturer), which may specify such parameters as spacing between tanks in multi-tank installations, some or all deadman dimensions, slab dimensions, etc. Preferred embodiments generate a form letter that includes the installation plan information and the results of the buoyancy and/or buoyancy safety factor calculations.

Underground storage tank buoyancy and buoyancy safety factor calculation method and apparatus

A triple-walled underground storage tank is provided with primary, secondary and tertiary walls. Between each two adjacent walls, an annular space is provided. The annular space is continuous throughout, and permits the flow of liquid therein. Monitors may provided separately for each annulus, to detect the formation of leaks, or a lack of containment, in either wall defining the annular space. In one embodiment, the tertiary wall is a smooth cylinder formed about the circumferential ribs of the secondary wall. In the alternative embodiment, the rib-bearing wall is the tertiary wall, and the walls and annular materials of the tank are formed within a female mold. In either case, a tank prepared from integral ribs, with superior robustness and strength, is provided with triple containment.

A method for modeling the behavior of an underground structure such as an underground storage tank under seismic loads includes the steps of constructing separate finite element models for the ribs, tank and fill material. The fill material model comprises a plurality of three-dimensional solid &ldquo;brick&rdquo; elements. The tank model comprises a plurality of three dimensional plate/shell elements. The rib model comprises a plurality of beam elements. The nodal points for the beam elements correspond to nodes defining one edge of the tank shell. The tank/rib model is preferably joined to the soil model through a plurality of radial link elements between the brick and shell elements. Spring elements may also be added for stability. A dynamic vertical or horizontal forcing function from an earth quake is then applied to the model. Stress and/or displacement results from horizontal and vertical forcing functions may then be combined if desired. The forcing functions are preferably taken from an actual earthquake, although simulated forcing functions may also be used.

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Edina, MN, United States of America

Albert F Dorris