Classifications

• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
  • E02D27/00—Foundations as substructures
  • E02D27/32—Foundations for special purposes
  • E02D27/34—Foundations for sinking or earthquake territories
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
  • E02D3/00—Improving or preserving soil or rock, e.g. preserving permafrost soil
  • E02D3/02—Improving by compacting
  • E02D3/10—Improving by compacting by watering, draining, de-aerating or blasting, e.g. by installing sand or wick drains

Definitions

• the present invention relates to a vibration-damping arrangement of the kind defined in the preamble of Claim 1, and also to the use of such an arrangement.
• Variants of this technique allow the container to include cellular plastic bodies or the like in addition to a pressurised gas.
• the container- formed screen can be cast firmly in place in the shaft, for instance by filling the shaft with a hardenable or a curable liquid mass, into which the container is submerged and the mass then allowed to harden.
• the submersion of the vibration-damping screen into such a liquid-like mass in a slot-like shaft can be facilitated by mounting/fastening a major surface of the container to a plate, for instance a concrete plate of the same size and area as the container.
• the vibration-damping screen can be fitted to a frame structure that facilitates submersion of the screen in the liquid-like mass against the action of the buoyancy forces of the screen/container in said casting mass.
• Another alternative in this regard involves connecting the lower edge of the screen container to a heavy horizontal bar whose mass is sufficiently great to draw the gas-filled container into the liquid mass in the shaft. It is, of course, conceivable to first insert the screen-forming container into the shaft in an inflated and sealed state, and then introduce the liquid hardenable mass into the shaft.
• the screen may, of course, be placed in the shaft and anchored therein in a non-inflated/non-pressurised state and then inflated/pressurised in the presence of or in the absence of a flowable hardenable mass.
• the flexible vibration-damping screen is subjected to high internal gas pressures in its operative state, and the container is expected to remain sealed over a long period of time under the influence of the vibrations whose propagation shall be refracted or absorbed by the screen.
• a screening container of this kind is usually manufactured from thin plastic sheeting, metallised sheeting or plastic sheeting laminates of a flexible nature and of high mechanical strength, high impermeability and that can be welded effectively.
• the weld seams are, of course, critical and are preferably welded at the plant producing said containers, with no part being produced in the field itself.
• the damping screen may be provided with inflation valves for inflation of the container in the location in which it shall be used, whereafter the valves are closed or the container is sealed-off prior to finally placing the device in its position of use, either in the ground or in a water mass.
• one object of the present invention is to provide a flexible container intended to form a vibration-damping or vibration reflecting screen in water or earth layers, where said container is produced in the absence of pressurising gas so that it can be transported in a non-inflated state, for example in a rolled-up state or a coiled state, to the location in which the screening container shall be installed, and where said container can be pressurised non-invasively with a predetermined gas volume prior to, during or subsequent to inserting the container into said shaft/place of use.
• the invention is based on the concept of placing a gas-generating device in the container in conjunction with the manufacture and permanent sealing of said container.
• the gas- generating device is of a kind that can be activated without penetrating the container wall.
• the gas generating l o device may include a sealed plastic film cushion that is divided into two spaces which are mutually separated by a membrane that can be ruptured by applying an external force mechanically via the container wall and the walls of said cushion.
• the spaces provided in the cushion may include respective suitable chemical substances which when brought together generate a pre-chosen gas volume, wherewith the gas thus generated ruptures the
• a container made, for instance, of heat insulating material is filled with gas in a solid or liquid state and then placed in the cushion. The purpose of the heat insulating material is to delay the
• the heat insulating material may be surrounded by a gas-tight container that may be provided with valve means or closure means that can either be opened by remote control or may be adapted to be opened automatically by the gas pressure when said pressure reaches a given level. This enables a pre-chosen volume of gas (in liquid or solid state) to be metered in a simple and
• the device may include a pressurised container comprised of suitable material (a gas tank, gas flask) that can be opened from outside the wall of the closed container, without penetrating said wall.
• suitable material a gas tank, gas flask
• the gas-generating device may, of course, be activated by mechanical action, by heating said device or by remote control, for instance by wireless actuation, such as via radio waves and with a selected time delay with regard to gas development in relation to the time of actuation.
• the present invention enables the flexible container for the vibration-damping screen to be manufactured in a permanently sealed state in the absence of any substantial internal free gas volume, so that the container will require only a small storage and transportation space and so that the container can be folded together or coiled into a transport-friendly and handling-friendly form with regard to its transportation to the location at which the container shall form the vibration-damping screen, by virtue of its flexible wall material.
• the invented container can be inflated at its place of use, by activating the gas generating device before or after inserting the container into the slit-like shaft or trench, either before or after optional filling of the shaft with a floatable, hardenable mass.
• the container may be carried by a structure that keeps the container in an outwardly tensioned state.
• the container may be coupled to a heavy body, for instance at the bottom edge surface of the container, so as to hold down the container in its inflated state in a liquid non-hardened mass.
• an inventive container is mounted on at least one side of a concrete structure, such as a concrete plate, having essentially the same area as the container, to enable the container to be readily inserted into the slot-like shaft or trench and held therein in connection with bringing the vibration-damping screen into its final position.
• a concrete structure such as a concrete plate
• Thin plastic sheeting that can be used for the manufacture of a screening container arrangement according to the invention consists of a laminate or metallised foil of the kind typically used for vacuum packaging in the food industry.
• An application of the present invention is found within earthquake technology, to reduce or to eliminate the effect of cyclic loading in water-saturated sand.
• cyclic loading of water-saturated sand there occurs a pore water pressure that promotes the quicksand phenomenon (liquefaction).
• the water-saturated sand gradually looses its strength, which can result in significant reduction in the bearing capacity of foundations and piles, or trigger a slope failures.
• the build-up of pore water overpressure is already reduced by small gas quantities (less than 1%) in a water-saturated sand. This effect can be achieved by installing gas-filled flexible containers (cushions) in an earth layer beneath the groundwater surface.
• the pore water overpressure is compensated for by a reduction in the volume of gas in the cushions (the cushions are compressed), as in the case of a shock absorber.
• the volume of the cushions increases when the earthquake or landslip has ceased and the pore water pressure diminishes.
• cylindrical or spherical containers are installed in shafts narrow trenches or predrilled holes.
• the shaft or the drill hole may be filled with suitable container-protecting material.
• the effect afforded by the containers can be enhanced by combining the containers with draining means.
• vibration-damping devices are installed in water masses to reduce the propagation of shock waves.
• the technology applied is similar to that employed in the case of ground-installed insulating screens, although with the screen anchored either to a wall or to some other installation to be protected against the influence of vibrations.
• FIG. 1 is a schematic illustration of a container constructed in accordance with the invention
• Fig. 2 is a schematic sectional view taken on the line II-II in Fig. 1 (See the mistake in Fig.
• Fig. 3 is a sectional view of a ground-installed slot-like shaft in which an inventive container has been inserted, said container being mounted on a supporting structure and cast in a hardened mass in the shaft;
• Fig. 4 is a view taken on the line IV-IV in Fig. 3;
• Fig. 5 is a variant in a reproduction corresponding to Fig. 2;
• Fig. 6 illustrates a further variant in a reproduction corresponding to Fig. 2.
• Fig. 1 illustrates a generally parallelepipedic, sealingly closed container 1, which is formed by the sealed connection of flexible gas-impervious foil sheets.
• the container 1 has height and width dimensions A, B in the order of metres, and a thickness or diametrical dimension C in the order of decimetres.
• the container may be produced by laying two sheets of foil material on one another and joining said sheets together with a weld seam.
• the container 1 is essentially empty when in a closed state, with the exception of a gas generating device 2 enclosed in the container 1, wherewith the container can be rolled up, folded up, etc., to facilitate transportation of the container from its place of manufacture to its place of use.
• the gas generating device 2 includes a closed plastic foil cushion 21 of significantly smaller volume than the volume of the container 1.
• the cushion 21 is divided by a membrane 22 into two spaces 23, 24 which contain respectively a first chemical substance (e.g. an acid) 25 and a second chemical substance (e.g. a salt) 26.
• the membrane 22 can be caused to burst, by applying external forces F against the cushion 21 via the container walls.
• the first chemical substance will come into contact with the second chemical substance and therewith generate gas in the cushion 21, which is gradually burst by the established gas pressure so that gas will flow out into the interior of the container 1 and therewith fill the same.
• the volume of gas generated can be predetermined by appropriate dosing of the chemical substances, so that the container 1 will be given a predetermined gas filling that is well adapted to the use conditions.
• the container 1 may be conveniently mounted on a supporting structure, for instance on a concrete slab 3, having the same area as the main surfaces of the container 1, for insertion into a slot-like shaft or narrow trench formed in the ground 5.
• the containers 1 are pressurised with a predetermined gas volume, either before or after positioning the supporting structure 3 in the shaft or trench 4.
• the shaft or trench 4 may have a depth of 10 m, for instance.
• the liquid mass 6 exerts pressure against the containers 1, wherein the magnitude of said pressure depends on the depth and the density of the mass 6.
• the mass 6 hardens in its state of pressure equilibrium.
• the pressurised gas in the containers 2 provides effective screening/dampening of vibrations that propagate generally in the direction x and can be assumed to propagate in a direction normal to the extensional plane of the containers 1.111
• Fig. 4 illustrates a series of structures 3 with containers 1 cast in the mass b in a slot-like shaft or trench 4 formed in the ground.
• the concrete sheet or slab 3 can be replaced by a column-like element (pile or drain) and the container 1 can be installed directly in a slot 4 or a drill hole.
• the liquid mass b may be replaced with drainage material.
• Fig. 5 illustrates an alternative gas generating device 2 which may include a pressure gas vessel 121 having an emptying valve 122 which can be opened with the aid of a drive element 123 that can be activated by a receiver 124 capable of receiving a signal from an externally located operator-controllable transmitter 125.
• Fig. 6 illustrates a further alternative gas generating device 2 that may include gas in a liquid or a solid state 126.
• the gas can be placed in a heat insulating casing 127 which may surround a gas-tight vessel 128 or which may itself form a gas-tight vessel 128.
• the gas-tight vessel 128 may include valve means 129 where the valve is triggered at a chosen overpressure to allow the gas to fill the container 1.
• the heat insulation 127 enables dosing of the liquid or solid gas volume to be readily achieved in a convenient fashion and also to retain the dosage of cooled liquid or solid gas to be retained over a relatively long period of time sufficient to enable the casing 127 with a possible vessel 128 to be inserted into the container 1 with a good margin, before any significant amount of gas has time to leave the casing 127 or the vessel 128.
• the heat insulation 127 or a possible valve means 129 can be ch'osen to delay the actual inflation of the container 1 for a selected period of time, so as to provide sufficient time for comfortable transportation of a selected period of time, so as to provide sufficient time for comfortable transportation of the container 1 and its insertion into its position of use prior to inflating the container 1 with said gas.
• the valve means 129 may be opened by remote control.
• the gas-generating device may, of course, include known means for delaying gas generation subsequent to triggering the gas-generating device.

Landscapes

• Engineering & Computer Science (AREA)
• Structural Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Environmental & Geological Engineering (AREA)
• Mining & Mineral Resources (AREA)
• Paleontology (AREA)
• Civil Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Soil Sciences (AREA)
• Agronomy & Crop Science (AREA)
• Filling Or Discharging Of Gas Storage Vessels (AREA)
• Fluid-Damping Devices (AREA)

Applications Claiming Priority (3)

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• 2003
  • 2003-03-04 SE SE0300565A patent/SE0300565L/sv not_active IP Right Cessation
  • 2003-09-04 EP EP03816181A patent/EP1599636A1/en not_active Withdrawn
  • 2003-09-04 CA CA002518422A patent/CA2518422A1/en not_active Abandoned
  • 2003-09-04 JP JP2004569145A patent/JP4072537B2/ja not_active Expired - Fee Related
  • 2003-09-04 US US10/548,293 patent/US20060207190A1/en not_active Abandoned
  • 2003-09-04 WO PCT/SE2003/001373 patent/WO2004079103A1/en active Application Filing
  • 2003-09-04 AU AU2003256212A patent/AU2003256212A1/en not_active Abandoned

Non-Patent Citations (1)

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