EP1034414A1 - Load creation apparatus and method - Google Patents
Load creation apparatus and methodInfo
- Publication number
- EP1034414A1 EP1034414A1 EP98959355A EP98959355A EP1034414A1 EP 1034414 A1 EP1034414 A1 EP 1034414A1 EP 98959355 A EP98959355 A EP 98959355A EP 98959355 A EP98959355 A EP 98959355A EP 1034414 A1 EP1034414 A1 EP 1034414A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- container
- liquid
- mass
- load
- density
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
- B66C15/00—Safety gear
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01G—WEIGHING
- G01G21/00—Details of weighing apparatus
- G01G21/26—Counterweights; Poise-weights; Sets of weights; Holders for the reception of weights
Definitions
- This invention relates to load creation apparatus, and to a method of testing the ability of a load bearing structure to bear a test mass that is created using such a load creation apparatus.
- the invention relates particularly, but not exclusively, to loads which are used for testing the load bearing characteristics of hoists, cranes, davits, winches and other load bea ⁇ ng structures.
- the invention also relates to the testing of static load bea ⁇ ng structures, such as foundation piles, badges, floors, jetties and wharves.
- the invention does not relate or extend to containers and apparatus in general that are not adapted or designed for load creation and testing purposes.
- load bearing apparatus such as hoists, cranes, davits and winches
- load bearing apparatus such as hoists, cranes, davits and winches
- test masses are m the range of a few met ⁇ c tonnes to more than a few thousand met ⁇ c tonnes and, in most cases, are m the range of 25% in excess of the safe working load of the load bea ⁇ ng structure or apparatus.
- Earlier test masses have been made of concrete or metal. Over a pe ⁇ od of time, such test masses made of concrete can chip or crack and may thus loose their o ⁇ gmal precision of mass due to wear and tear Metal objects will tend to rust, and may in some cases suffer from metal fatigue or crack propagation. Furthermore, these tests are conducted only periodically. It is appreciated that between tests, the storage of these solid test masses can create an inconvenient storage problem. Furthermore, the problem is exacerbated when a range of test masses, required for different apparatus, must be stored.
- a cubic meter of pure water at 40°C weighs around 7.7 kg less than another cubic meter of water at 3.98°C.
- the density of pure water at 40°C is around 992.3 kg m" 3 , whereas at 3.98°C it is around 1000 kg m"J
- the density of sea water taken from the open sea may vary between approximately 1020 and 1030 kg m" 3 .
- the salinity of sea-water varies typically from 34 to 37 °/oo and has been found to be as low as 5 °/oo in the Finland and as much as 41 °/oo in the northern part of the Red Sea.
- the difference of density in sea water is caused mainly by the variation in temperature and salinity.
- Fresh water and sea water are the most common liquids used to fill the weight testing bags. Hence, if a bag is filled consistently with the same amount of liquid, the vagaries of liquid density means that the bag may not necessarily contain the same mass on each occasion.
- the vagaries discussed above mean that it is often necessary to weigh the mass using a weighing device such as a load cell or dynamometer. Although weighing the mass, at the time of using the test mass, can ensure that the vagaries of the amount of liquid and the prevailing density of the liquid are taken into account, the use of a weighing device, in turn, presents another set of problems. It is appreciated that the calibration (and indeed the maintenance of that calibration) of weighing devices used for masses in the range of a few thousand tonnes is expensive and not straightforward. Furthermore, the precision of the calibration is lost progressively over time, which means that the expensive process calibration must be repeated regularly. For example, in British Standard BS 7121, the weighing device or weighbridge used to ascertain the value of the mass must, at the time of conducting the test, have been calibrated and certified within the last twelve months.
- the weighing devices In the field of weight testing, the weighing devices usually include electrical components and circuitry.
- electrical weighing devices presents peculiar problems in applications where inflammable materials are in close proximity. For example, when testing cranes that are used in petroleum production facilities, it is necessary to ensure that the electrical weighing devices are shielded, so that any sparks from the weighing device will not initiate ignition of the petroleum products in the vicinity.
- test load bearing structure which must be tested with a test load is found in the piles used as a foundation of buildings.
- a test method is defined in A.S.T.M. D 1143-8 (American Society for Testing and Materials) which is entitled "Standard Test Method for Piles Under Static Axial Compressive Load.”
- the test loads are usually created by soil, rock, concrete, steel or water-filled tanks. These solid masses are usually solid, and are often in the form of large concrete blocks.
- An object of the present invention is to overcome or substantially ameliorate at least some of the disadvantages of the p ⁇ or art, and it is not intended that the invention m its broadest aspect must necessa ⁇ ly overcome all of the abovementioned problems m the p ⁇ or art.
- a load creation apparatus adapted to create a specified mass for testing a load bea ⁇ ng structure, comp ⁇ smg- a liquid impervious container; means for filling the container with liquid to create a mass, suspension means for suspending the container such that said load bea ⁇ ng structure is able to bear said mass; and wherein the container is provided with determination means for determining the mass of any liquid in the container from the density and volume of the liquid.
- the determination means may be provided m the form of said container being substantially shaped as a regular geomet ⁇ c shape at least at those regions that are adjacent the liquid in the container such that the volume of liquid in said container is readily calculable
- the determination means may be provided m the form of said container being provided with walls which, in use, are up ⁇ ght at least at those regions that are adjacent the liquid m the container Preferably, the walls, in use, are generally vertical at least at those regions that are adjacent any liquid in the container.
- the determination means may be provided in the form of said container being provided with a base that has a predetermined surface area.
- the base may be orthogonal, and the base may be level.
- the determination means may include a calibrated gauge which provides a visual indication of the level of liquid to which the container must be filled when the liquid has a particular density.
- the visual indication may be adjustable in accordance with the density of the liquid.
- the liquid impervious container may be made of flexible material.
- the means for filling may be in the form of an opening for said container.
- the means for emptying the container may be in the form of liquid discharge valve in the base of the container.
- the suspension means may be in the form of a central strap which extends generally through the center of gravity of said container when liquid is in the container.
- the container may be divided into partitions by an internal web that connects internal surfaces of the container, said web functioning as a structural brace for the container when the container contains liquid.
- Liquid may be able to flow from one partition to an adjoining partition through vents located in the web.
- the walls of the container may be provided with flat reinforcing components which enable the walls, in use, to remain upright.
- at least some of the walls of the container may be connected one to another with reinforcing struts, each of the struts functioning as a structural brace for the container when the container contains liquid.
- an arrangement for creating a specified mass for testing a load bea ⁇ ng structure compnsmg a plurality of load creation apparatus each of which are suspended, wherein said plurality of apparatus are juxtaposed with respect to one another.
- the juxtaposed apparatus may be connectable by vents that enable at least one of the apparatus in the arrangement to be filled with liquid received from at least one other of said plurality of apparatus.
- the vents may be in the form of a flexible duct that is able to interconnect adjacent apparatus.
- the apparatus may be used for testing the ability of a load bea ⁇ ng structure to bear a specified test mass
- the arrangement may be used for testing the ability of a load bea ⁇ ng structure to bear a specified test mass
- a method of testing the ability of a load bea ⁇ ng structure to bear a specified test mass comp ⁇ sing the steps of: using suspension means to suspend at least one load creation apparatus such that said load bea ⁇ ng structure is able to bear a mass created by said load creation apparatus, said apparatus compnsmg a liquid impervious container, filling said container with liquid to create said mass; and using determination means provided on said container to determine said mass of the liquid from the volume and density of the liquid
- the method may involve the step of ascertaining the volume and density of the liquid and thereby determining the mass of the liquid therefrom
- the determination means are provided in the form of said container being provided with walls which, in use, are upright at least at those regions that are adjacent the liquid in the container and said container being provided with a base that has a predetermined surface area, and wherein said method involves the step of calculating the volume of said liquid by multiplying the base surface area by the height of said liquid in the container and determining the value of the mass of the liquid therefrom.
- the method may involve the step of ascertaining the density of liquid and thereby determining the amount of liquid with which to fill the container in order to produce the specified mass.
- a plurality of said apparatus may be suspended in accordance with the abovementioned arrangement.
- Liquid may be poured initially into one of said plurality of apparatus, and liquid from said one apparatus may flow to at least one other of said plurality of apparatus.
- one of more of said other apparatus are provided each with a valve which prevents the liquid from escaping from the apparatus such that the liquid is constrained to flow to at least one other of said apparatus until all the apparatus in the arrangement have been substantially filled to the required level.
- the valve may be a float valve that is opened and closed by a floatable mechanism.
- a load creation apparatus adapted to create a specified mass for testing a load bearing structure, comprising: a liquid impervious container; means for filling the container with liquid to create a load; and suspension means for suspending the container such that said load bearing structure is able to bear said mass; wherein said container is provided with upright walls.
- the apparatus may be used for testing the ability of a foundation pile to bear a specified test mass.
- the arrangement may be used for testing the ability of a foundation pile to bear a specified test mass.
- test mass is intended to be suspended such that a "load bearing structure” is able to bear the test mass.
- structure is not intended to introduce any limitation on the type of structure, apparatus or machine that is able to be tested.
- embodiments of the invention may be used for testing lifting machines such as hoists, cranes, davits and winches where the load is suspended from the apparatus.
- Other embodiments of the invention may be used to create a compressive load to be borne by load bearing structures such as structural foundation piles.
- the invention may be used to test a wide range of load bearing device which must be tested with a specified test mass.
- Figure 1 shows a perspective view of an embodiment of a load creation apparatus
- Figure 2 shows a cross-sectional view of the embodiment of the load creation apparatus in Figure 1 ;
- Figure 3 is a plan view of the embodiment of Figures 1 and 2;
- Figure 4 is an under-side view of the embodiment of Figures 1, 2 and 3;
- Figure 4A is a perspective drawing of a further embodiment showing an internal corner of a container having reinforcing strips attached to the internal surfaces;
- Figure 4B shows a cross-sectional view of a modification of the embodiment in Figure 4A in which the reinforcing strips are provided with reinforcing struts to reinforce the surfaces of the container;
- Figure 5 illustrates another embodiment of the invention consisting of an arrangement of three load creation apparatus
- Figure 6 illustrates a further embodiment of the invention consisting of an arrangement of two load creation apparatus positioned one above the other;
- Figure 7 illustrates a more complex embodiment of the invention consisting of an arrangement of twenty load creation apparatus arranged in two tiers;
- Figure 8 shows an embodiment of a calibrated density gauge positioned adjacent a slit
- Figure 9 shows a plate that is usable with the density gauge of Figure 8.
- Figure 9 A shows the plate of Figure 9 slideably and fastenably mounted in the slot shown in Figure 8;
- Figure 10 illustrates a modification of the plate of Figure 9, a difference being that the plate in Figure 10 is provided with a pivoting float valve that guards the opening at the upper end of the plate;
- Figure 11 illustrates an embodiment of a vent that is usable for connecting one load creation apparatus to another
- Figure 12 illustrates a connection between ducts of adjacent containers
- Figure 13 illustrates another embodiment of an alternate connection between ducts of adjacent containers
- Figure 14 illustrates an embodiment of a load creating apparatus that is suspended by a rig, such that a structural foundation pile is able to bear the mass created by the load bearing structure
- Figure 15 is a side view of an embodiment similar to that of Figure 14, except that the embodiment in Figure 15 uses two decks of containers.
- Figure 1 shows a perspective view of an embodiment of a load creation apparatus, which is generally indicated as 15.
- the embodiment is shown in Figure 2 from a side view, and in Figures 3 and 4 from a plan and under-side view respectively.
- the load creation apparatus 15 is provided with a liquid impervious container in the form of container 16.
- the container 16 is made of a woven polyester fiber coated with PVC that is blended with a special resin, but may also be made from any other suitable tough, liquid impervious material.
- the liquid impervious container 16 is provided with means for filling the container with liquid. In the present embodiment, this is provided simply as an open top for the container through which liquid is able to be poured. Other alternatives may have the container provided with a closed top with a restricted liquid inlet.
- the liquid impervious container 16 is also provided with means for emptying the container which, in the embodiment, is in the form of liquid discharge valve 30 located m the base of the container.
- the resulting mass is suitable for use as a test load that can be suspended, such that a load bea ⁇ ng structure under test (not shown) is able to bear the mass in the container 16.
- the load bearing structure or devices may be a hoist, crane, davit, winch, or other pulling or lifting machine or any such device that must be tested by suspending a specified load. These may also include static load bea ⁇ ng structures such as foundation piles.
- the apparatus 15 is also provided with suspension means for suspending the container 16 such that a load bea ⁇ ng structure (not shown) is able to bear the mass m the container.
- the suspension means m the embodiment, includes a central strap 31 which extends generally through the center of gravity of the container 16 when it contains liquid.
- the strap passes through a sleeve running through the center of the container 16.
- the bottom end of the strap is provided with an oversized eyelet 33 that prevents the central strap 31 from pulling through the sleeve.
- the eyelet 33 serves a further function of enabling another container to be suspended beneath the present container 16.
- a reinforced PVC plate 34 is provided at the base of the container to act as a further reinforcement for the central strap 31 , in order to anchor the end of the strap to the base of the container.
- the top end of the strap is provided with an attachment means m the form of a hook 29.
- the hook is formed with a supporting boss 28.
- the underside of the boss 28 is provided with an eyelet.
- the hook 29 is detachably fastened to the central strap 31 by means of a shackle 32 that passes through the eyelet that is on the underside of the boss 28.
- the central strap 31 carries the bulk of the mass in the container 16.
- the support means for the container 16 may also include secondary supports 25 that extend from the hook 29 to the peripheral edges of the container 16.
- the entire apparatus 15 is able to be suspended from the load bea ⁇ ng structure using the hook 29 to suspend the container, aided by the central strap 31 and the secondary supports 25, such that the load bearing structure is able to bear the mass of the apparatus 15.
- the secondary supports 25 are attached to the container 16 by being connected to external straps 22 that are evenly spaced around the upper rim and sides of the container.
- the ends of the external straps 22 are provided with shackles 24 to facilitate attachment of the external straps 22 to the secondary supports 25.
- the external straps 22 extend down the side of the container and, as seen in Figure 4, the external straps 22 surround the underside of the container and undergird the container 16.
- the container is effectively cradled in a web of external straps 22.
- the external straps 22 pass through sleeves 23 located on the side faces and on the under-surfaces of the container. The sleeves 23 hold the external straps 22 in place.
- additional strengthening straps 35 are used to connect the web of external straps 22 to the reinforced PVC plate 34.
- the reinforcing plate 34 is thus joined to both of the external straps 22 and the central strap 31.
- the plate 34 therefore acts as a connection between the central strap 31 and external straps 22.
- the internal and external straps are thus able to co-operate to support the mass in the container.
- the edge margins or rim of the container may be provided with some form of structural reinforcement.
- the reinforcement may be in the form of struts that brace the rim of the container in its intended shape.
- the face of the container may also be provided with reinforcing plates to enable the container to maintain its overall defined shape.
- the central strap 31 and the secondary supports 25 are made of webbing material or other suitable weight-bearing material.
- the strap and the secondary supports may be reinforced with or made entirely of wire, or other suitable strong material. Determination Means
- each load creation apparatus is provided with determination means for determining the mass of any liquid in the container from the density and volume of the liquid.
- the invention relies on the fact that the mass of liquid is able to be determined from the volume and density of the liquid.
- the relevant equation is:
- Liquid Mass (kg) Liquid Volume (m 3 ) x Liquid Density (kg m *3 )
- the mass is a constant and is fixed by virtue of the size of the load specified in the load test. The figure would probably be specified by the manufacturer of the load bearing structure or by a certification authority.
- the above equation shows why the volume of liquid is inversely proportional to the liquid density. In other words, if the density and volume are known, then the mass of the liquid is able to be determined, without the need for a weighing device or apparatus. This is the basis of how the present embodiment is able to avoid the use of a weighing device for determining the mass of the liquid.
- the user is able to ascertain the density of the liquid using a hydrometer.
- Common liquids drawn from large reservoirs such as the sea or rivers, take a long time to change temperature in response to changes in ambient temperature. Once the liquid density has been measured, it is found that the density reading is generally constant for a period of time usually sufficient for the load test to be performed.
- the user makes use of the determination means to ascertain the required level of liquid with which the container must be filled.
- the determination means may use other forms of determination means that are designed to automatically control the required amount of liquid. Calculating The Mass By Determining The Volume And Density
- the means for determining the mass of liquid in the container is present in the form of the container 16 being substantially shaped as a regular geometric shape, at least at those regions that are adjacent the liquid in the container such that the volume of liquid in the container is readily calculable.
- embodiments of the invention can include containers shaped in any regular geometric shape, so long as it is possible to readily perform accurate calculations to ascertain the volume.
- the container 16 is provided with walls which, in use, are upright at least at those regions that are adjacent the liquid in the container.
- the container is made of flexible material, only those portions of the container that are filled with liquid would normally take on the final shape. Without liquid in the container, the upper portions of the container may sag slightly, but this is not critical provided that these portions do conform to the final defined shape when water is filled to up those levels.
- the upright walls enable the volume of the liquid to be ascertained simply by multiplying the surface area of the base by the height of the liquid in the container. Accuracy is ensured when the walls are generally vertical at least at those regions that are adjacent any liquid in the container. Strict compliance with 90° uprightness, although desirable, is not strictly required, provided that the amount of divergence does not cause the mass of liquid to vary outside the prescribed limits. For example, in the British Standard BS 7121, the mass must be ⁇ 1.0%, and the degree of the measurement and arrangement of the walls of the container 16 must be such as to ensure that the necessary precision is attainable.
- the calculation is more readily performed if the base has a lcnown area, and if the base is kept generally level during use.
- the invention in its broadest aspect does not require the base to be orthogonal, since it is sufficient for the base surface area to simply be known so that it can be multiplied by the height.
- the shape of the base may be orthogonal, square, rectangular, circular or any other shape.
- having an orthogonal-shaped base means that it is easier to arrange the containers closely side by side.
- the base is square because it retains the benefit of having an orthogonal shape, while also ensu ⁇ ng that the mass of liquid m the container will be evenly dist ⁇ ubbed about the centre of gravity, as compared to more elongated-shaped bases.
- up ⁇ ght walls in the present embodiment in Figure 1 to 4 is a feature that confers an advantage on the apparatus
- the advantage of having up ⁇ ght walls is that the volume of the liquid may be calculated readily by simply multiplying the base area by the height of the liquid contained in the up ⁇ ght container. Further embodiments of the up ⁇ ght walls will be discussed in the context of arrangements consisting of a plurality of containers.
- the load creation apparatus 15 in Figure 1 is suspended in such a manner that a load bea ⁇ ng structure (not shown), such as a crane for example, is able to bear the created load.
- the container 16 of the load creation apparatus 15 is filled with liquid
- the density of the liquid is ascertained with a hydrometer, and then the volume of liquid (and hence the height of liquid) required to produce the mass specified for a test is ascertained
- the container is filled with liquid up to the height required to produce the specified mass
- the specified mass is achieved accurately, without the need of a weighing device
- This type of apparatus and this method are thus free of the potential problems associated with weighing devices which tend to lose accuracy and/or precision over a pe ⁇ od of time
- the walls or panels of the container 16 are made of flexible materials, but the container, when filled with liquid, is not flexible in the sense that the container does not permit the liquid to find its own shape.
- the shape of the container 16 is achieved intentionally by providing the container with flat sheet-like orthogonal walls. However, m practice, having merely four up ⁇ ght walls and a flat base is sufficient only for containing very small masses of liquid. For larger masses of liquid, the liquid would cause the walls of a simple open topped container to bulge outwards under the force of the liquid attempting to find its own shape. Since the shape of the container 16, in the present embodiment, is important to the working of the apparatus, the container 16 is divided into partitions by an internal web 18 that connects internal surfaces of the container.
- the web counter-acts the tendency of the walls to bulge outwardly under the influence of the water pressure.
- the web therefore functions as a structural brace for the container when it contains liquid.
- the webs may intersect. Liquid is able to flow from one partition to an adjoining partition through vents located in the web.
- the webs provide sufficient bracing to enable the container to retain its shape adequately when the container is filled substantially with liquid.
- the flexible faces of the container 16 may be further reinforced with sheets of plates made of ⁇ gid mate ⁇ al such as PVC.
- FIG. 4 A uses flat reinforcing components which enable the walls, in use, to remain up ⁇ ght.
- the reinforcing components are m the form of reinforcing st ⁇ ps 70 which reinforce the faces of the container 16
- the reinforcing st ⁇ ps 70 are attached or fastened to internal faces of the container, as shown in Figure 4A.
- the reinforcing components may also be attached to external faces of the container.
- the stnps are made of a suitably stiff mate ⁇ al or webbing, such as those that cont ⁇ bute a high degree of stiffness, similar to those used in conveyor and pulley belts.
- the reinforcing strips may be flat, as illustrated m Figure 4A, or the reinforcement may be in the form of stiff rods (not shown).
- the reinforcing components may also be m the form of flat stiff panels that are attached to the sides of the container.
- Other suitable materials are PVC, polyester or fibreglass.
- the reinforcing st ⁇ ps 70 provide stiffness to the faces of the container which enables the container to maintain the lateral faces in an up ⁇ ght disposition
- faces of the container are connected with reinforcing struts 71 that are used to brace the sides of the container by linking surfaces of the container one to another.
- the struts 71 are detachable.
- the reinforcing struts 71 can be made of solid or flexible mate ⁇ al. Flexible struts are acceptable since these are able to provide structural reinforcement when the strut is in tension.
- the struts 71 may be in the form of st ⁇ ps or may be in the form of solid components.
- the surfaces of the container are provide with shackles 72 that are used to connect the reinforcing struts 71 to the inner surfaces of the container. It is possible for these struts 71 to act as an alternative to using the reinforcing internal webs 18. When the container is filled with water, the struts 71 are placed in tension to hold the lateral faces of the container in the necessary up ⁇ ght disposition.
- Liquid mass (kg) Liquid volume (m 3 ) x Liquid density (kg m" 3 )
- Liquid mass (kg) Container base area (m ⁇ ) x Liquid height (m) x Liquid density (kg m ⁇ 3 )
- liquid mass liquid mass
- liquid density liquid density
- container base area The mass is specified by the test to be conducted. The density is ascertained from ambient conditions, and the base area is a fixed value.
- va ⁇ able in the equation is the height of the liquid in the container.
- the height of liquid is inversely proportional to the density of the liquid
- the load creation apparatus 15 is provided with a calibrated gauge shown in Figure 8
- the calibrated gauge is in the form of a liquid density meter 20
- the density meter 20 provides a visual indication of the level of liquid to which the container must be filled, when the liquid is at a particular density.
- the meter 20 is adjustable to take into account va ⁇ ations in the density of the liquid a ⁇ sing from changes in ambient conditions.
- calibrated gauges are provided on all four sides of the container 16.
- each meter 20 provides a scale, in this case, ranging from liquid densities of 0.990 g/cm 3 to 1.040 g/cm 3 , which is a typical range of densities of fresh water and sea water.
- the scale provides an indication of the height of liquid to which the container 16 must be filled in order to achieve a specified mass. For example, a container designed to create a ten tonne mass would have a liquid density meter 20 that would indicate the correct amount of liquid necessary to achieve a mass of ten tonnes.
- This meter would be adjustable so that the user would know how much the vary the height of the liquid, depending on the prevailing liquid density, in order to achieve a mass of ten tonnes.
- the above equation teaches that the lower the density of the liquid, the larger amount of liquid that required to be poured into the container 16, and vice versa.
- the calibrated gauge is simply a scale that has been positioned accurately on the container, so that for each density value, the scale indicates the height of liquid, corresponding to that density, that is required to achieve the specified mass.
- FIG. 8 and 9 A further embodiment of a calibrated gauge is shown in Figures 8 and 9 In this embodiment, a calibrated density scale 40, ranging from liquid densities of 0.990 g/cm 3 to
- 1.040 g/cm 3 is located on the side margin of an elongated slit 39. Liquid m the container is able to exit the container through the slit 39.
- a pair of grooves 42 is provided on either side of the slit 39. The grooves together form a slot on which a plate 41 is slideably mounted, as seen in Figure 9 A.
- the edge margins of the plate 41 are provided with a resilient coating, perhaps m the form of a rubber, polymer foam or any such resilient mate ⁇ al that can enhance the liquid-tight seal that is preferably formed between the plate 41 and the grooves 42.
- the plate 41 functions in a similar manner to a sluice valve that is shdeable up and down in the slot.
- the liquid in the container 16 is only able to exit through the slit 39 after the liquid reaches the level of the top end of the plate 41, marked A-A in the drawing.
- the level of liquid m the container 16 is controllable by sliding the plate 41 up and down between the grooves 42
- the positioning of the plate in the grooves is determined by the density scale 40
- the plate is positioned to set the required height of the liquid when the liquid has a density of 1.015 g/cm 3
- the plate is able to set the upper height of the liquid in the container, because an excess liquid will flow out of the container once the liquid reaches the height A-A of the plate.
- the gauge in Figures 8, 9 and 9A acts as a sluice valve which is able to vary the level of liquid in the container 16.
- the gauge in Figures 8, 9 and 9A acts as a sluice valve which is able to vary the level of liquid in the container 16.
- the plate is provided with holes 43 which are used in conjunction with some form of fastening device such as screws to fix the plate to the slot in the required position.
- the weight of the container itself 16 and the weight of the shackles, web, straps etc. will also add to the total mass that is borne by the structure. Therefore, when designing the calibrated gauge, it is preferred that the weight of the components be considered as part of the overall equation, as follows:
- Test mass (kg) Liquid volume (m 3 ) x Liquid density (kg m" 3 ) + Apparatus mass (kg)
- an apparatus such as m Figure 1 may be used to create a range of masses.
- the calibrated gauge may be designed to indicate the heights of liquids required for a range of masses.
- a set of different gauges may be provided for the user to select the approp ⁇ ate gauge, depending on the mass to be created. Charts may also be provided for making such modifications of mass.
- two or more load creation apparatus are able to be suspended and juxtaposed with respect to one another.
- Containers are available in a va ⁇ ety of standard weights, each intended to create a particular mass. A plurality of these containers can be combined to form the total mass required When creating an arrangement of two or more containers, the overall stability of the arrangement must be considered. For example, in order to create a nine tonne load, an arrangement of a five tonne container, sandwiched between a pair of two tonne containers, would provide better stability than, say, an arrangement of a five and four tonne container.
- Figure 5 illustrates an arrangement of three load creation apparatus that are suspended from a beam 36. (The beam is suspended from a load bea ⁇ ng apparatus). The apparatus are juxtaposed with respect to one another. The containers 16B, on either side of the central container 16A, are of equal capacity to ensure the stability of the overall arrangement.
- the up ⁇ ght walls of the container provide an advantage of being able to readily determine the volume of liquid m the container.
- the up ⁇ ght walls provide a further advantage in that the surfaces of each container are able to be juxtaposed closely to an adjacent container. This is m contrast to the p ⁇ or art.
- the pear-shaped amorphous bags disclosed earlier in the United Kingdom patents 2,047,414B and 2,072,351 are used m arrangements of more than one bag, the pear-shaped bags cannot be juxtaposed as closely to one another as those containers of embodiments of the present invention that have up ⁇ ght walls.
- the arrangements of the type shown m Figure 5 tend to take up less space than arrangements that use the earlier pear-shaped amorphous bags.
- the apparatus are able to be more closely juxtaposed when the base of the container of the apparatus are orthogonally-shaped, such as m the shape of a square or rectangle
- the juxtaposed containers are connectable by vents that enable at least one of the containers in the arrangement to be filled with liquid received from at least one of the other containers m the arrangement. Liquid flows from container to container through the vents.
- the vents are in the form of flexible ducts 47 that interconnect adjacent containers. An example of a vent is shown in Figure 11
- Figure 12 shows how two flexible ducts 47 A, 47B from adjacent containers 16A, 16B are able to be connected by a coupling 48 which comp ⁇ ses a pair of ⁇ ngs, one ⁇ ng on each of the ducts, such that the ducts are connected when the pair of ⁇ ngs are forced together with a f ⁇ ction Fit.
- a coupling 48 which comp ⁇ ses a pair of ⁇ ngs, one ⁇ ng on each of the ducts, such that the ducts are connected when the pair of ⁇ ngs are forced together with a f ⁇ ction Fit.
- Other mechanisms may be contemplated to produce the connection of the ducts, for instance, catches or screw threaded ends may be used
- Figure 13 shows how two flexible ducts from two adjacent containers 16A, 16B are joined together when the adjacent containers are juxtaposed closely.
- the duct 47A from one container 16A is sheathed withm the duct 47B of the other container 16B in a male-female connection. The
- Interconnection of containers is best effected between containers that are shaped orthogonally, because when orthogonally shaped containers are placed side by side, the flat walls discourage the adjacent containers from rotating. In contrast, when the containers have rounded surfaces, the suspended bags may have a tendency to swivel, and this could place stress on the vents that inter-connect the containers. Thus, m those arrangements that do not have the benefit of up ⁇ ght- walled containers, the vents should be designed with sufficient slack, so that they do not become taught in the event that the containers rotate slightly.
- the vents are designed to allow liquid to flow through the vents.
- the opening at level A-A is adjusted to the level required m accordance with the density scale, as has been desc ⁇ bed m connection with Figures 8 and 9
- the opening is surrounded by a flexible duct 47
- the flexible duct is able to channel or direct the overflow liquid to another location where it is required to fill other of the containers, rather than letting the liquid overflow out of the full container
- the exit of liquid from the container is controlled by the height at which the slit 39 is blocked by the shdable plate 41 of Figure 11 Therefore, since the flexible vent is connected to the opening in the plate 41, liquid is able to flow through the flexible duct 47, wherever the plate is slidably located along the grooves 42.
- the vent may either be elongated in shape to encompass the entire slit 39, or may be removeably attached at different points on the calibrated density scale device 40 to match the positioning of the opening created by the plate 41.
- vents The function of the vents is to provide an interconnection between apparatus 16 in the a ⁇ angement. It is assumed that the vents would connect adjoining containers, but it is conceivable that if the vents are formed m lengths, such as hoses, the vents may connect containers m the arrangement that are not directly adjacent. An example is shown m Figure 6 in which the upper and lower apparatus 16A, 16B are not directly adjacent. Procedure For Filling Arrangements of Plurality of Interconnected Apparatus
- arrangements of a plurality of containers are able to be interconnected.
- Liquid can flow between the containers. Filling of the containers in the arrangement might start, for example, with filling just one container, preferably one which is close to the center of gravity of the entire arrangement. Subsequently, liquid from this initially-filled apparatus flows to one or more of the other apparatus. Since there are no apparatus in the arrangement that are cut off from the circulation of liquid in the arrangement, the liquid is able to find its own level throughout the arrangement, and eventually fill all the apparatus in the arrangement. This filling of all the containers is achieved by using only a single hose or pump, rather than a number of hoses as was required in the prior art.
- FIG 5 liquid is first poured into the center container 16A.
- the adjacent containers 16B on either side of the center container 16A receive liquid that flows from the center container 16A.
- FIG 6 another example is shown where the upper apparatus 16A is filled initially. Once the upper apparatus 16A is filled, liquid exits the upper container and flows down to the lower apparatus 16B suspended beneath.
- the containers 16A, 16B are interconnected by a lengthy vent in the form of a long hose 37.
- the end portions of the hose 37 are secured to the respective apparatus by coupling or other suitable water-tight fastening mechanism.
- test mass created by such structures must be accurate often to within ⁇ 1% of the specified mass.
- each one of the apparatus in the overall arrangement is provided with a means for determining the mass of liquid inside the container.
- this is achievable by the user ensuring that each container is filled to the correct height necessary to create the specified mass. For example, if the embodiment in Figure 5 is to be filled with water from a nearby river, the user would start by ascertaining the density of the river water. Next, the liquid density meter 20 on each container is adjusted to indicate the correct level of water required for each container. Then the containers are each filled to the correct level prescribed the liquid density meter 20 on the container.
- each apparatus may be provided with one or more of the sluice valves illustrated in Figure 8.
- the level of water in each apparatus in the a ⁇ angement is individually controlled by its own “determination means". Since the mass of each individual apparatus is guaranteed to be accurate when filled to the level prescribed by the liquid density meter, the total mass of the overall arrangement is thereby ensured.
- Figure 7 shows a much more complex arrangement of a plurality of apparatus.
- interconnecting the containers because it ensures that a large arrangement will be filled with liquid without becoming unstable during the filling process. It would be extremely dangerous for such a large mass of liquid, which might be several hundred or thousand tonnes, to suddenly become unstable.
- one possible procedure would be to commence filling by pouring liquid into the center apparatus 16A of the upper tier. Liquid from these center apparatus 16A would flow equally to the adjoining apparatus 16B, and eventually to the end apparatus 16C. Thus, the top tier of apparatus would be filled while maintaining overall stability of the arrangement. Subsequently, liquid from the end containers would be directed down to the lower tier through vents in the form of elongated hoses 37 found on either side of the overall arrangement. Next, the outer apparatus 16D of the lower tier would begin to fill, and so forth until the overall arrangement of a plurality of apparatus has been filled.
- a "determination means” is used which is a modification of the sluice valve of Figures 8, 9 and 9A.
- the modification is shown in Figure 10.
- a slideable plate 41 in Figure 10 which is also slideably mounted in the slot between grooves 42, is different in the sense that the upper end A-A of the plate is guarded by a float valve 45.
- the float valve 45 pivots about an axis shown as A-A in Figure 10.
- float valves 45 are used to block all except usually one of the externally-facing slits of the apparatus on the tier. Only one, or at least a very limited number, of the externally facing slits on the same tier are left open without the use of a float valve. Preferably, this one, or limited number of open valves, is located at a point where the liquid will reach at or close to the end of the filling sequence.
- the use of float valves for all except a limited number of the externally facing slits ensures that all the containers in the tier are filled substantially before any liquid is allowed to overflow from the upper tier into the lower tier.
- the liquid level in the over-filled containers begins to fall.
- the float valve pivots open, and the liquid in each container stops draining out of the container.
- the use of the present embodiment is considered to be very straightforward.
- To create a test mass the required number of apparatus are suspended such that the load bearing structure is able to bear the apparatus.
- the apparatus are interconnected.
- the density of the liquid is ascertained, and the gauge for each container is set accordingly.
- a hose is used to fill one of the containers, and eventually all the containers will be filled to the correct amount to accurately produce the specified test mass.
- the liquid is drained from the apparatus by opening the outlet valve 30.
- the bag can be folded and stored for further use.
- the present invention is able to create an accurate mass without relying on a weighing device, means that the present invention is able to be used in proximity to flammable materials without the degree of danger that would be associated if an electrical weighing device were to be required.
- Figure 14 illustrates an embodiment of a load creating apparatus that is suspended using a suspensions means, in such a manner that a foundation pile 50 is able to bear the load created by the apparatus.
- the suspension means is in the form of a rig 60.
- the load creation apparatus 15 is suspended from the test rig 60 which imparts the mass to the foundation pile 50.
- the containers 16 of the load creation apparatus 15 are suspended from the rig 60, and filled with liquid to create the specified test mass required to test the pile.
- Figure 15 is a side view of a similar embodiment to that of Figure 14 which uses two decks of containers.
- the load In some testing procedures, such as A.S.T.M. D 1143, the load must be added in increments of 25%. For instance, the initial load is applied first at 25% of the pile design load. Then the load is increased to 50%, then 75%, then 100% of the design load, each time the load is borne by the structure for several hours to provide time to observe any settling of the pile. Then, the load is decreased in similar increments.
- Embodiments of the load creation apparatus are ideally suited to adding and taking away precise percentages of the pile design load. The incremental increase and decrease of the load would be more easily accomplished than in the case where the load is created by solid blocks of concrete.
- a compressive load is borne by the load bearing structure.
- load bearing structures that may be tested include bridges, wharf decks, jetties, and other static load bearing structures. Even surfaces such as floors and decks may have a stipulated load bearing capacity, and these structures may also be tested using embodiments of the invention.
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- Engineering & Computer Science (AREA)
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
Description
Claims
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SG9704136 | 1997-11-25 | ||
SG9704136 | 1997-11-25 | ||
PCT/SG1998/000095 WO1999027330A1 (en) | 1997-11-25 | 1998-11-25 | Load creation apparatus and method |
Publications (2)
Publication Number | Publication Date |
---|---|
EP1034414A1 true EP1034414A1 (en) | 2000-09-13 |
EP1034414A4 EP1034414A4 (en) | 2001-10-24 |
Family
ID=20429797
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP98959355A Withdrawn EP1034414A4 (en) | 1997-11-25 | 1998-11-25 | Load creation apparatus and method |
Country Status (4)
Country | Link |
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EP (1) | EP1034414A4 (en) |
AU (1) | AU1517399A (en) |
MY (1) | MY120351A (en) |
WO (1) | WO1999027330A1 (en) |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2932267B1 (en) * | 2008-06-05 | 2010-08-20 | Oxycoupage Et Soudure De Champ | DEVICE FOR SUPPORTING BEACONS |
CN101852642A (en) * | 2010-04-16 | 2010-10-06 | 苏州和宇科技有限公司 | Hoisting test water bag |
WO2014177920A1 (en) | 2013-05-03 | 2014-11-06 | Atrac Inc. | Proof load bag system and method |
CN103953081A (en) * | 2014-05-23 | 2014-07-30 | 陆剑 | Ballasting system for pile foundation detection of engineering |
GB2597529B (en) * | 2020-07-27 | 2023-06-28 | Tugdock Ltd | Inflatable vessel |
CN114620198B (en) * | 2021-12-24 | 2023-07-18 | 武昌船舶重工集团有限公司 | Load test method and test tool |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2296171A1 (en) * | 1974-12-27 | 1976-07-23 | Delattre Levivier | Modular element for making up structural test loads - has watertight region with vertical tube passing through it |
DE2824940A1 (en) * | 1978-06-07 | 1979-12-20 | Friedrich Geb | Suspension container for liquid or bulk materials - is flexible bag with carrier belts seamed to form carrier loops |
EP0018075A1 (en) * | 1979-03-07 | 1980-10-29 | Water Weights (International) Limited | Weight testing apparatus |
JPS61129533A (en) * | 1984-11-28 | 1986-06-17 | Oval Eng Co Ltd | Measuring instrument for mass of liquid within tank |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1457457A (en) * | 1974-05-09 | 1976-12-01 | Philograph Publications | Liquid displacement measuring vessel particularly for educations use |
FR2554230A1 (en) * | 1983-10-26 | 1985-05-03 | Air Liquide | Method and apparatus for determining the weight or mass of a liquefied gas contained in a tank |
JPH0961227A (en) * | 1995-08-25 | 1997-03-07 | Yazaki Corp | Building method for output correcting database of payload measuring sensing element and weight vessel |
-
1998
- 1998-11-25 MY MYPI9805353 patent/MY120351A/en unknown
- 1998-11-25 EP EP98959355A patent/EP1034414A4/en not_active Withdrawn
- 1998-11-25 AU AU15173/99A patent/AU1517399A/en not_active Abandoned
- 1998-11-25 WO PCT/SG1998/000095 patent/WO1999027330A1/en active Application Filing
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2296171A1 (en) * | 1974-12-27 | 1976-07-23 | Delattre Levivier | Modular element for making up structural test loads - has watertight region with vertical tube passing through it |
DE2824940A1 (en) * | 1978-06-07 | 1979-12-20 | Friedrich Geb | Suspension container for liquid or bulk materials - is flexible bag with carrier belts seamed to form carrier loops |
EP0018075A1 (en) * | 1979-03-07 | 1980-10-29 | Water Weights (International) Limited | Weight testing apparatus |
JPS61129533A (en) * | 1984-11-28 | 1986-06-17 | Oval Eng Co Ltd | Measuring instrument for mass of liquid within tank |
Non-Patent Citations (2)
Title |
---|
PATENT ABSTRACTS OF JAPAN vol. 010, no. 322 (P-511), 31 October 1986 (1986-10-31) -& JP 61 129533 A (OVAL ENG CO LTD), 17 June 1986 (1986-06-17) * |
See also references of WO9927330A1 * |
Also Published As
Publication number | Publication date |
---|---|
WO1999027330A1 (en) | 1999-06-03 |
MY120351A (en) | 2005-10-31 |
EP1034414A4 (en) | 2001-10-24 |
AU1517399A (en) | 1999-06-15 |
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