Trafficked surfaces built on foundations which remain substantially undisturbed during seasonal climatic cycles, particularly in permafrost and near permafrost regions where considerable disturbance of the ground beneath foundations is otherwise common. The foundations include combinations of insulation layers, heat sinks and/or thermal bleeds which dampen and prevent the cyclic climatic seasonal variations from affecting the earthen support under the foundations, in both cut and fill sections, and in embankments and backfills adjacent the sections.
This Application is a division of application Ser. No. 291,815, filed Sept. 25, 1972, now U.S. Pat. No. 3,804,543; which in turn is a division of application Ser. No. 112,635, filed Feb. 4, 1971, now U.S. Pat. No. 3,722,378.
A thermosyphon for use in frozen or unfrozen soil includes an evaporator tion embedded in the soil, a condenser section exposed to ambient air, an intermediate section connecting the two sections and a heat exchanger connected to a mechanical refrigeration source and operable to cool either the condenser or the intermediate section of the thermosyphon during periods when the ambient temperature is higher than that at which passive thermosyphonic cooling occurs.
A road surface is warmed by means of a two-phase thermosyphon with an easily vaporizable liquid partially filling a sealed container. A portion of the container serves as a condenser and another portion as an evaporator. If at least a portion of the evaporator is above the boiling point of the liquid, the liquid will boil and the vapor will rise into the condenser part of the thermosyphon, and if the condenser part is in an environment below the condensing temperature of the vapor, the vapor will condense, thereby radiating heat and warming the surrounding environment. The condenser is elongated and installed underground so as to lie closely beneath the road surface. A thermally insulating layer is provided below the condenser part so as to more efficiently utilize the radiated heat. The evaporator may be of a double-tube structure such that the liquid can flow through the entire length thereof even if these tubes include rising and falling sections. A plurality of such thermosyphons and the insulating layer may be used together as a prefabricated panel.
The present invention is directed to a hybrid thermosyphon which may be rapidly deployed to create a frozen soil barrier for containing toxic spills. In a particular embodiment, a plurality of thermosyphons are deployed for freezing the soil around and under a defined area of soil; each thermosyphon contains a working fluid and includes an evaporator section for contact with the soil for removing heat therefrom by evaporation of the working fluid. A condenser section in flow communication with evaporator section and remote from the soil transfers heat from the working fluid to ambient by heat exchange and subsequent condensation of the working fluid when the ambient is lower than the temperature of the soil. An active refrigeration stage in heat exchange relation with at least a portion of the condenser section removes heat from the working fluid by heat exchange when the ambient is above the soil temperature. Sensors may be provided for sensing the ambient temperature for selectively operating the active refrigeration stage.
The object of the present invention to provide a method for thawing frozen ground for laying concrete primarily at a construction site by use of a continuous length of circulating hose placed on the frozen ground inside and/or adjacent a concrete form or over the area where the concrete will be laid, covering the circulating hose with a layer of aggregate material for insulation from cold air leaving the ends of the circulating hose protruding from the aggregate connecting the ends of the hose to a source of heated liquid to circulate warm liquid through the circulating hose to thaw the frozen ground, laying the concrete over the identified area while continuing to circulate heated liquid in the circulating hose to prevent the concrete from freezing, leaving the portion of the hose in the aggregate under the concrete by cutting the ends protruding from the aggregate, removing the remaining portions of the hose.
The object of the present invention to provide a method for thawing frozen ground for laying concrete primarily at a construction site by use of a continuous length of circulating hose placed on the frozen ground inside and/or adjacent a concrete form where the concrete will be laid, covering the circulating hose with a layer of aggregate material for insulation from cold air caving the ends of the circulating hose protruding from the aggregate connecting the ends of the hose to a source of heated liquid to circulate warm liquid through the circulating hose to thaw the frozen ground, laying the concrete in the concrete form while continuing to circulate heated liquid in the circulating hose to prevent the concrete from freezing, leaving the portion of the hose in the form under the concrete by cutting the ends protruding from the aggregate, removing the remaining portions of the hose.
