Apparatus for building support piers from one or successive lifts formed in a soil matrix

[0001] In a main aspect, the present invention relates to a device for building a support pillar consisting of one or more compacted layers formed of aggregate material. The device allows the creation or construction of a single or multi-layer pillar in the soil matrix, while strengthening the soil near the pillar. The device thus provides for the formation of a cavity in the soil matrix by forcing a hollow tube device into this soil matrix, followed by lifting the tubular device, introducing aggregate through the tubular device into a section of the cavity under the raised tubular device, and then moving the tubular device downwards for compaction aggregate material, while the aggregate material is injected transversely to the soil matrix.

[0002] US Patent No. 5,249,892 discloses a method and apparatus for building short aggregate pillars on site. The process involves drilling a cavity in a soil matrix, followed by the introduction and compaction of successive layers or layers of aggregate material in the cavity to form a pillar that can provide structural support. Such pillars are made by first drilling a hole or recess in the soil matrix, removing the drill, placing a relatively small, separate aggregate layer in the recess, and then compacting the aggregate layer in the recess using a mechanical compactor. The mechanical compactor is usually removed after the compaction of each layer, after which additional aggregate is placed in the cavity to form the next compacted layer or deck. Aggregate layers or layers that are compacted during the pillar formation process typically have a diameter of 2 to 3 feet (60 to 92 cm) and a height of about 12 inches (30 cm).

[0003] The above device and process ensure the creation of rigid and effective stabilizing columns or pillars that can be used to support the structure. The mentioned method of building the pillar, however, has limitations related to the depth at which it is possible to carry out the process of forming the pillar in an economic manner, as well as the speed at which the process can be carried out. Another limitation is that for some soil types, especially sandy soils, there may be caving when drilling a well or forming process, which may require the use of temporary lining, such as steel pipe lining. The use of steel cladding significantly slows down the pillar forming process, thus increasing the cost of building such pillar. The process described in Patent No. 5,249,892 is therefore limited to the construction of pillars in soils of a certain type at depths not exceeding about 25 feet (7.2 meters).

[0004] As a result, a need arose for a mechanical pillar-making device that can be successfully and economically used to form or build pillars at greater depths, with faster assembly speeds, and in sands and other soils that are unstable during drilling. without the need for a temporary cladding, but with the features and advantages exhibited by the method, a device and construction of short aggregate pillars disclosed in Patent No. 5,249,892, as well as providing additional benefits.

[0005] JP59055913 describes a sand pile mixed with a binder and having a casing consisting of a steel pipe having a foot, a sheath located at its lower end edge, a large number of through holes leading to the sheath, and a binder supply pipe located on the top of this sheath. Said document discloses the features according to the preamble of claim 1.

[0006] JP ​​62242011 describes a method and apparatus for constructing a shallow pile reinforcing the ground. A weight is placed on a soft surface to prevent the surface layer of soil from rising, after which a pipe is introduced into the ground, which is simultaneously rotated. In this case, the pile recess is formed by the conical part of the helical drill bit. When the cavity reaches a certain depth, the screw drill is pulled out while turning it in the opposite direction, and a mixture of cement and sand is introduced into the cavity through the bottom end of the pipe.

SUMMARY OF THE INVENTION [0007] The invention is defined in the attached independent claim to which reference should now be made. In addition, optional features can be found in the dependent claims appended thereto.

Briefly, the present invention can be used in a method of assembling a pillar made of one or more layers or seams formed from aggregate material with or without additives, which includes the steps of placing, pushing or injecting into the soil matrix an elongated and hollow pipe having specially shaped lower front element and unique pipe configuration, filling the aggregate with empty pipe with the lower front element, releasing from the lower frontal element a predetermined amount of aggregate material during lifting of the empty pipe in the recess made in the soil matrix with a predetermined and gradually increased distance, and then exerting on the empty pipe and its special lower frontal element an axial static vector force and optional forces dynamic vectors, which aims to transfer energy to the surface of the upper layer of released aggregate material through the lower end of the empty pipe, causing the layer of aggregate material to thicken, as well as forcing the aggregate material into the side walls of the cavity in transverse or perpendicular directions with respect to the main axis. Tilting the empty pipe followed by pushing it down using an axial or vertical static vector force and optional dynamic vector forces results in the aggregate material being impacted, which is not separated by the empty pipe from the side walls of the cavity during impact, which causes compaction and compaction of aggregate material, as well as forcing the material laterally outwardly into the soil matrix due to lateral forces exerted on the aggregate material and the soil matrix. The compacted aggregate material thus forms a "layer" which generally has a diameter or dimension measured in the lateral direction larger than the recess formed by the hollow tube and the bottom end element, which results in a pillar formed of one or more layers.

[0009] The aggregate material is poured from the special lower end element of the hollow pipe when lifting this special lower front element, preferably carried out in successive, predetermined steps, first above the bottom of the recess and then above the upper part of each of the subsequent layers of the pillar formed in the cavity and the adjacent soil matrix during the process. Aggregate material poured out of the hollow pipe is compacted due to the compaction forces exerted by the hollow pipe and the special bottom end piece after lifting this hollow pipe to expose a portion of the cavity when discharging the aggregate material into said exposed part. The hollow pipe is then moved down to compact the aggregate and push it in a direction transverse to the soil matrix. The aggregate material is therefore compacted in predetermined, subsequent stages or layers. The process is repeated continuously along the length or depth of the pit, which results in the formation of a column or pillar of aggregate in the soil matrix, which consists of separately compacted layers or layers. In this way, it is possible to build, in a relatively short time, a pillar having a length of forty (40) feet (12 meters) or more, which is done without removing the empty pipe from the soil. The formed pillar also usually has a larger cross-section than the hollow pipe.

[0010] Various types of aggregate material can actually be used to carry out the process, including many types of crushed stone coming from quarries, and with reused, crushed concrete. The additives may be in the form of water, dry cement or cement paste, such as cement slurry consisting of water, cement and sand, water ash, hydrated lime or slaked lime, it is also possible to use any other additive that can provide increased load capacity or improved characteristics structural of the formed pillar. Combinations of these materials may also be used in the process.

[0011] A hollow pipe with a special bottom end element can be placed in the soil matrix by pushing and / or introducing by means of vibration acting in the vertical direction or by driving a hollow pipe in the vertical direction into the soil having a front end and a special bottom end element, which is made is with the participation of a force with axial or vertical static vector, and optionally with the participation of forces with dynamic vectors. The soil displaced due to the initial insertion, pushing and / or vibration of the hollow pipe with a special lower frontal element is generally displaced and rammed in a direction transverse to the pre-existing soil matrix, as well as compacted downwards. If a hard or dense soil layer is encountered, such a hard or dense layer can be pierced by drilling or pre-drilling this layer to form a cavity or channel in which an empty pipe with a special bottom end element can be placed and moved.

[0012] The hollow tube is usually formed as a fixed diameter tube having a spherical bottom face element, which may include an internal valve mechanism located near or within the bottom face element, or a valve mechanism located at the bottom end of the face element. The hollow pipe generally has a cylindrical shape with a constant, constant and smaller diameter in the upper section of the pipe. The lower end of the hollow pipe having a spherical shape or larger outer diameter (i.e., the lower end element) is integrated into the hollow pipe or can be formed separately and attached to the lower end of the hollow pipe of smaller diameter. The lower front element also has a generally cylindrical shape, its outer diameter or the shape of the outer cross section is larger than that of the rest of the hollow pipe, and is also coaxial with the central axis of the hollow pipe. [0013] The front end of the lower end element is shaped in such a way as to facilitate its entry into the soil matrix and ensure the transfer of forces with the desired vectors to the surrounding soil, as well as to the aggregate material poured from the empty pipe. The transition between the smaller pipe section with smaller diameter and the lower end element is frusto-conical. Similarly, the bottom of the front element is conical in shape to ensure easier soil penetration and compaction. The front end of the bottom face includes a sacrificial plug that penetrates through the soil matrix during the initial placement of the empty pipe in this soil matrix, while preventing soil from entering the empty pipe. The sacrificial plug is then removed from the end of the empty pipe to expose the end channel when the empty pipe is lifted for the first time, whereby the aggregate material can get into the cavity by lifting the empty pipe. [0014] The front end of the lower front element may further include an outlet channel with a mechanical valve that is closed during initial penetration into the soil matrix, hollow pipe and the lower front element, but which can be opened when they are raised to pour out aggregate material. It is also possible to use other types of valve mechanisms and front end shapes to ensure easier initial infiltration into the soil matrix, to allow aggregate material to be poured when the hollow pipe is raised, and to provide vector forces using the front end or bottom end element in to thicken subsequent layers.

[0014] The device may further comprise means for placing the lifting anchor in the formed pillar, as well as an indicator mechanism for measuring the displacement of the bottom of the formed pillar after its loading, for example, during load tests. Such auxiliary elements are introduced through the hollow tube during the forming of the pillar.

[0015] The object of the present invention is therefore to provide a device comprising a hollow pipe with a lower front element of a special construction, suitable for making a pillar of compacted aggregate material containing additives or not, which enters a depth greater than possible or used with known manufacturing technology short aggregate pillars.

[0016] Still another object of the invention is to provide a pillar forming device of compacted aggregate material, which does not require the use of temporary steel lining during the forming process, especially in soils susceptible to infarction, for example, in sandy soils.

[0017] Still another object of the invention is to provide a pillar forming device of compacted aggregate material, which may contain many optional additives, including a mixture of stones, addition of water, addition of dry cement, addition of cement paste, addition of water, cement and sand, addition of ash water, the addition of hydrated lime or slaked lime or other types of additives that are intended to improve the soil matrix design features, aggregate materials and the pillar formed.

[0018] Another object of the invention is to provide a pillar forming device that can be used to quickly and efficiently build compact multilayer pillars and / or pillars comprising only a single layer.

[0019] These and other objects, advantages and features of the invention will be set forth in the detailed description below.

BRIEF DESCRIPTION OF THE DRAWINGS [0020] The detailed description below is made with reference to the drawing comprising the following figures:

Fig. 1 is a schematic view of an empty pipe with a bottom end element that is pushed, pressed or driven into the soil using vertical static vector forces and optional dynamic forces;

Fig. 2 is a schematic view of the next step following that of Fig. 1, in which the aggregate material is placed in a funnel and introduced into an empty pipe;

Fig. 3 shows a cross-section of a funnel having double insulating shock absorbers and which can be used in connection with a hollow pipe;

Fig. 3A is a cross-sectional view of the isometric funnel and hollow tube of Fig. 3;

Fig. 3B is an isometric view of the funnel and the empty pipe of Fig. 3;

Fig. 4 is a schematic cross-sectional view of a hollow pipe having an internal narrowing or non-return valve;

Fig. 5 is a schematic view illustrating the step of optionally feeding water, cement slurry or other additive material to the hollow pipe, here being recirculated to a water tank or cement slurry;

Fig. 6 is a schematic view illustrating the step following that of Fig. 2, in which the hollow pipe with its lower front element is raised to a predetermined distance to temporarily expose the hollow cavity made in the soil matrix, which allows the filled hollow hollow to be quickly filled aggregate cavities;

Fig. 7 is a schematic view illustrating the method step following that of Fig. 6, in which the bottom valve at the bottom of the empty pipe is opened, which causes aggregate to spill into the exposed or empty section of the cavity;

Figures 8A and 8B are schematic cross-sectional views of an alternative device and stage shown or illustrated in Fig. 7, wherein the lower end element of the hollow tube includes a sacrificial plug that is lowered to the bottom of the cavity formed in Fig. 8;

Fig. 8C is a cross-sectional view of the sacrificial plug of Fig. 8B taken along the line 8C-8C in Fig. 8B;

Fig. 9 is a schematic view in which the hollow pipe and its associated lower frontal exert a vertical static vector force and optional dynamic forces to move the empty pipe and the lower frontal down to a predetermined distance causing impact and compacting of aggregate material poured from an empty pipe and pushing the aggregate material in a transverse direction to the soil matrix;

Fig. 10 is a schematic view of the hollow pipe and its bottom face which are raised a predetermined distance to form a second layer;

Fig. 11 is a schematic view of the hollow tube and bottom end member during a vertical vector force displacing the hollow pipe and bottom end member down a predetermined distance to form a second compacted layer on the upper surface portion of the first compacted layer;

Fig. 12 is a schematic view of an empty pipe with a reinforcing steel rod element or indicator element attached to the layer for mounting inside the pillar;

Fig. 13 is a schematic view of a hollow pipe in which optionally water or cement-sand slurry is combined with aggregate in a hollow pipe;

Fig. 14 shows a vertical cross section of a special lower front element with a flap type bottom valve;

Fig. 15 is a cross-sectional view of the lower front member of Fig. 14 taken along lines 15-15;

Fig. 15A is a cross-sectional view of a portion of an alternate lower end element of the type shown in Fig. 14;

Fig. 16 is a cross-sectional view of a special lower end element having a sacrificial plug at the lower end, similar to Fig. 8A;

Fig. 17 is a cross-sectional view of a special lower end element with an anchor or indicator element attached to the lifting layer;

Fig. 18 shows a cross-section of a partially formed multi-layer pillar;

Fig. 19 is a cross-sectional view of a completely formed multilayer pillar;

Fig. 20 is a cross-sectional view of the formed multilayer pillar with the reinforcing steel member having an attached layer, which allows the formed pillar to include a lifting anchor element or indicator element for subsequent load tests;

Fig. 21 is a cross-sectional view of the formed pillar subjected to pre-loading or being subjected to a test to determine the load factor carried out on the completely formed pillar;

Fig. 22 is a graph illustrating graphs with a comparative test load of the present invention with results regarding a drilled concrete pile made in the same soil matrix formation;

Fig. 23 is a schematic cross-sectional view illustrating how to use the device according to the invention to form a single-layer pillar or pillar in which, after raising the device to an increased distance from the bottom of the pit initially created using the device, one or more layers are formed in the soil matrix;

Fig. 24 is a schematic cross section illustrating the continuation of the method of Fig. 23;

Fig. 25 is a schematic cross section illustrating the continuation of the step in Fig. 24; and

Fig. 26 is a schematic cross section illustrating the continuation of the method of Figs. 22-24.

DESCRIPTION OF THE PREFERRED EMBODIMENT

General structure [0021] Figures 1, 2, 5, 6, 7, 9, 10, 11, 13, 18, 19 show the general structure of the device or mechanism for forming pillars and its variants, as well as alternative subsequent steps in implementing the method , which produce the resulting known pillar structure, while Figures 8A, 8B, 12, 16, 17, 20, 23-26 show embodiments illustrating fragments and uses of the device according to the invention. Regarding Fig. 1, the method is used to place the pillars in the soil matrix, which requires soil strengthening to become stiffer or stronger. A great variety of soils may require the device of the present invention, in particular sandy and loamy soils. Thanks to the device according to the invention, it is possible to build pillars consisting of one or more layers, which is done using aggregate, and optionally using aggregate with additional materials such as cement slurry consisting of water, cement and sand, which the pillars have greater stiffness and strength than many aggregate pillars known in the art, which can be economically extended to or built at depths greater than many prior art pillars, can be formed without using a temporary steel sheath, as is the case with many prior art pillars, and which can be assembled faster than many known pillars from the state of the art.

[0022] In a first stage, the hollow tube or hollow shaft 30 having a longitudinal axis 35 and comprising or comprising a special lower front element 32, and associated funnel 34 for aggregate at the upper end, is pushed into the soil matrix 36 using the in Fig. 3 a drive device 37 employing static, axial vector force, and optionally oscillating or driven vertically (axially), or both, accompanied by forces with a dynamic vector. The part of the soil matrix 36, which includes the volume of material displaced by pushing the section of the hollow pipe 30 having the special lower front element 32, is mainly pressed in laterally, thereby compacting the adjacent soil matrix 36. As shown in Fig. 1, the hollow pipe 30 may include a cylindrical steel pipe 30 having a longitudinal axis 35 and an outer diameter in the range of, for example, 6 to 14 inches (15 to 36 cm). In the event that a layer of hard or dense soil prevents the empty tube 30 and the special bottom face 32 from being pushed into the soil matrix 36, such a hard or dense layer may be drilled or pre-drilled, after which the pushing process can be continued using the drive device 37 .

[0023] Usually, the hollow tube 30 has a uniform cylindrical outer shape, although other shapes may be used. Although the outside diameter of the hollow tube 30 is usually from 6 to 14 inches (from 15 to 36 cm), other diameters can also be used in the device of the invention. Also, usually, the hollow pipe 30 is extended or pushed into the soil matrix 36 to the full depth of the pillar, for example up to 40 feet (12 m) or more. The hollow tube 30 is usually attached to a drive shaft 42 at the top end, which can be gripped by the drive device or mechanism 37 to push and optionally vibrate or whip the hollow tube 30 into the soil matrix 36. Hopper 34, which contains a container 43 for aggregate materials, usually insulated by insulating shock absorbers 46, 48 from the stem 42. The oscillating or driving device 37 which is attached to the mandrel 42 can be supported by a rope, excavator boom or crane. The weight of the hopper 34, the oscillating or driving device 37 (with optional additional weight) and the empty pipe 30 can be large enough to provide a static force vector without the need for a separate drive mechanism exerting static force. The static force vector can optionally be increased by a mechanism with vertically vibrating and / or whipping dynamic force.

[0024] Figs. 3, 3A and 3B illustrate a special feature preferably associated with the funnel 34. Double insulating shock absorbers 46, 48 are attached to the upper and lower side of the funnel 34, which aims to reduce the vibration build-up of the funnel 34 and provide a larger funnel assembly structural integrity. The mandrel 42 is attached to the pipe 30 to exert static and dynamic forces on the pipe 30. The mandrel 42 is isolated from the funnel 34, and is thus moved relative to the shock absorbers 46, 48.

[0025] Fig. 4 shows the optional feature of the hollow pipe 30. A damper, a pinch valve, a non-return valve or other type of valve mechanism 48 may be mounted inside the hollow pipe 30 or in a special bottom end member or bottom end section 32 of the hollow pipe 30. or completely close the internal passage of the empty pipe 30 and stop or control the flow or movement of aggregate materials 44 and optional additive materials. This valve 48 can be mechanically or hydraulically opened, partially opened and closed to control the movement of aggregate materials 44 through the empty pipe 30. It can also act as a gravity like a one-way valve that opens when lifted and closes when lowered for aggregate 44.

[0026] Fig. 14 shows the structure of a known lower end element or section 32. This lower front element is cylindrical, although other shapes can be used. Usually, the outer diameter of the lower face 32 is greater than the nominal outer diameter of the upper section 33 of the hollow tube 30 and is from 10 to 18 inches (25-45 cm), although other diameters and / or cross-sectional shapes may be used in practice. Thus, the front member 32 may have the same cross-sectional dimensions as or smaller than the hollow pipe 30, however such a configuration is usually not preferred.

[0027] Figs. 14, 15 and 15A show a structure that does not form part of the invention having a valve mechanism embedded in the front element 32. The front element 32 has a frustoconical bottom section or a bottom section 50 with an outlet 52 of aggregate material 44, which it opens and closes when the valve plate 54 reveals and covers the opening 52. The valve plate 54 is mounted on a rod 56 moving in a hub 59 held in position by radial struts 58 attached to the walls of the internal channel 32 of the hollow pipe 30. The plate 54 moves to the closed position when the empty pipe 30 is forced down the die soil 36 and moves to the open position when the empty pipe 30 is raised, which allows aggregate material 44 to flow. The opening of the valve 54 is controlled or restricted by a rod 56 which has a head 56a limiting the sliding movement of the rod 56. The hollow pipe 30 can therefore be driven into the desired depth 81 (Fig. 6), and the opening 56 is closed at this time by means of a plate 54. Then, when the empty pipe 30 is raised (for example, by a distance of 91 shown in Fig. 10), the plate 54 goes down due to the force of gravity, whereby the aggregate material 44 can flow through the holes 52 into the recess formed by raising the empty pipe 30. Then, the pipe 30 is struck or hammered downwards, which closes valve plate 54 and compacting the discharged material to form compacted layer 72. In the case of the structure shown in Fig. 14, 15 and 15A, the valve plate 54 moves due to the force of gravity. However, the rod 56 can alternatively be replaced or assisted in displacement by hydraulic, mechanical or electric drive. According to the invention, plate 54 is replaced by sacrificial plug 64. Further alternatives are the use of the bottom plate of the mechanism with a lifting anchor or the mechanism with the warning device 70, as described below. Also, the one-way valve 38 of the mechanism of Fig. 4 can be used instead of the valve mechanism shown in Figs. 14, 15 and 15A.

[0028] Usually, the inner diameter of the hollow tube 30 and the front member 32 are equal and equal, although the outer diameter of the front member 32 is greater than the outer diameter of the hollow pipe 30. Alternatively, when the valve mechanism 54 is used, the inner diameter of the front member 32 may be larger than the inside diameter of the hollow pipe 30. The front member 32 may be integral with the hollow pipe 30 or formed separately and bolted or welded to this hollow pipe 30. Typically, the inner diameter of the hollow tube 30 is from 6 to 10 inches (from 15 to 25 cm) and the outer diameter of the front member 32 is from about 10 to about 18 inches (from 25 to 45 cm). The opening 53 of Fig. 14 located at the lower end or front end of the front member 32 may be equal to or smaller than the internal diameter of the front member 32. For example, referring to Fig. 14, the front member 32 may have an inner diameter of 12 inches (30 cm) and the opening 53 may have a diameter of 6 to 10 inches (15 to 25 cm), while in Fig. 16 showing an embodiment of the invention comprising a sacrificial plug , which will be described below, the outlet opening of the front member 32 has the same diameter as the internal diameter of the front member 32 and the hollow tube 30.

[0029] Also, the plate or valve 54 can be configured to facilitate closing when the empty pipe 30 is pushed down into the soil matrix 36 or towards the aggregate material 44 in the cavity formed. For example, the diameter of the member 54 may exceed the diameter of the opening 53, as shown in Fig. 14, or the edge 55 of the valve member may be beveled, as shown in Fig. 15A, thereby cooperating with the beveled edge 59 of the opening 53. When a static force or other downward force is exerted on the empty pipe 30, the valve plate 54 is then kept closed in the opening 53.

[0030] The spherical bottom face 32 of the hollow tube 30 typically has a length in the range of one to three times greater than its diameter or maximum lateral dimension.

The front member 32 provides greater lateral compressive forces exerted on the soil matrix 36 when the pipe 30 penetrates or is pushed into the soil, thereby facilitating the subsequent passage of the smaller diameter section 33 of the empty pipe 30. The front and rear edges 50, 63 of the front element 32 having the shape truncated cones facilitate lowering or penetration and lateral compaction of the soil 36, due to their shape design. Rear edge 63 shown in Fig. 14 facilitates lifting the hollow tube 30 and front member 32, and transverse compaction of the soil matrix 36 during the lifting step of the method. Again, this allows the shape of the front member 32. Usually, the front and rear edges 50, 63 form an angle of 45 ° ± 15 ° with the longitudinal axis 35 of the hollow tube 30.

[0031] Fig. 5 shows another feature of the hollow pipe 30. At the bottom of the hopper 34 or at the upper end of the hollow pipe 30 there is an inlet port 60 and an outlet port 62 that allow the addition of water or cement slurry, such as a cement slurry consisting of water, cement and sand, as an additive to aggregate in the case of special construction pillars. The function of outlet port 62 is to maintain a water level or an additional level when they effectively provide easier aggregate flow, as well as allow recirculation of cement slurry from the tank back to the tank to facilitate mixing and maintain a relatively constant water pressure or cement slurry. Inlet port 60 and outlet port 62 can lead directly to hopper 34 or to empty pipe 30 (see Fig. 13) or they can be connected using separate channels or ducts to the front element 32. It should be noted that in the hollow pipe 30, above the front element 32, as shown in Fig. 2, cement grout outlet openings 31 can be located assist in releasing cement paste into the annular space around the empty pipe 30 and preventing the cavity from being filled with soil from matrix 36.

[0032] Figs. 8A, 8B, 8C and 16 show an alternative feature of the lower front element 32 which corresponds to the front element of the device according to the invention. Instead of the bottom or bottom slide valve 54, sacrificial plug 64 is used to protect front face 32 from clogging when pushing front face 32 down through soil matrix 36. End cap 64 can be configured in any of many ways. For example, it may be flat, sharp or beveled. It can also be arched. If it is beveled, it may form an angle of 45 ° ± 25 ° to the horizontal axis 35. The end cap 64 may include a number of outwardly deflecting legs 87 positioned to fit into a central hole 89 located in the bottom face 32 and to hold the end cap 64 in place until the first empty tube 30 is lifted and aggregate flows out 44 from hole 52 to the exposed section of the cavity.

[0033] Fig. 17 shows another alternative feature of the lower face 32. Slidable plate 54 and rod 56 for plate support 54 includes a channel or axial tube 57 that allows the reinforcing element or rod 68 attached to bottom plate 70 to be positioned. Rod 68 and the plate 70 is released at the bottom of the cavity formed and used to provide a lifting anchor or indicator device for measuring the lower pillar displacement during the load test. The sliding rod 68 attached to the bottom plate 70 can be replaced by a sacrificial plug 64 closing the opening of the special front element 32 when pushing it into the soil matrix 36, and it can also act as a platform for the lifting anchor and indicator element when they are assembled. The valve plate 54 may be omitted or may be held in position when using the installed anchor and indicator elements. In Fig. twenty there is shown a lifting anchor 68, 70 or indicator element in position when forming the pillar using the invention, the plate or valve 54 being omitted.

Mode of action:

[0034] Fig. 1 shows a typical first step in the operation of the known devices described.

An empty pipe 30 with a special front element 32 and an attached upper mandrel 42 and a connected hopper assembly 34, is pushed into the soil matrix 36 by means of a force with a vertical or axial static vector, which is usually accompanied by forces with a dynamic vector exerted by the drive device 37 or by weight of components. In fact, using a pipe 30 with a special front member 32 having the dimensions and configuration described above, it is usually sufficient to exert a force vector of 5-20 tonnes on it. Fig. 2 shows the placement of aggregate 44 in the funnel 34, when the hollow pipe 30 and the elements connected thereto reach the planned depth 81 of the pillar in the soil matrix 36. Fig. 6 shows the subsequent upward displacement or elevation of an empty pipe 30 oz a predetermined lifting distance 91, typically 24 to 48 inches (60 to 120 cm), to expose a portion of the recess 102 located under the front element 32 of the bottom section in the soil matrix 36 .

[0035] Fig. 7 illustrates the opening of the bottom valve 54 enabling it to fill with aggregate 44 and optional additions to the space or parts 85 of the cavity 102 located under the special front element 32 after lifting the empty pipe 30 and its connected components. The valve 54 can be opened when lifting the empty pipe 30 due to the weight of the aggregate 44 located on the upper side of the valve 54. Alternatively, the valve 54 can be actuated, for example, by a hydraulic mechanism, or it is also possible to lift the empty pipe 30 and then add aggregate, which flows through the valve opening 53 due to the operation of the valve 54. Alternatively, the internal valve 38 can be opened during lifting or after lifting. Alternatively, to demonstrate the application of the invention, if there is no valve 54, sacrificial plug 64 is released from the end of the front member 32, usually due to the force exerted by the weight of aggregate material 44 directed through the hollow pipe 30, when the special front member 32 is lifted from the bottom 81 formed recess 102 for the pillar.

[0036] Fig. 9 shows the subsequent downward pushing of the hollow pipe 30 and the components connected thereto, and closing of the bottom valve 54 to compact the aggregate 44 in the cavity part 85, thereby pushing the aggregate 44 and optional additives in the transverse direction, as well as vertically down to the soil matrix 36. The predetermined distance of displacement when pushing down is usually equal to the lift distance 91 minus one foot (30 cm), which aims to achieve the thickness of the finished layer 72 of one foot (30 cm) after having passed the predetermined lift distance 91 of the empty pipe 30 The designed layer thickness 72 may be different than one foot (30 cm) depending on the specific requirements of the shaped pillar and on the design features of soil matrix 36 and aggregate 44. [0037] The compaction of aggregate material 44 discharged into the emptied portion 85 of the cavity for transverse horizontal displacement of the aggregate material 44, as well as the vertical compaction thereof is important when using the invention.

[0038] Fig. 10 shows the creation of the next or second layer by lifting the hollow pipe 30 and its connected components by another predetermined distance 91A, usually 24 to 48 inches (60 to 120 cm), to allow the bottom valve 54 to open the use of the embodiment in which the valve 54 is used and the passage or displacement of aggregate 44 and optional additions to a part of the recess 85A, which has been opened or exposed by lifting the pipe 30.

[0039] After raising the empty pipe in the range of two (2) to four (4) feet (60 to

120 cm) it is usually lowered (as described below) to form a pillar layer 72 having a vertical dimension of one (1) foot (30 cm), which is typical for the pillar materials described herein. The axial dimension of layer 72 may therefore be in the range of ¾ to 1/5 of the distance 91 by which the hollow pipe 30 is lifted. However, the embodiment shown in Fig. 23 26 is an alternative compaction method which is adapted to the device according to the invention.

[0040] Fig. 11 shows the downward pushing of the hollow pipe 30 and its components and closing of the bottom valve 54 to concentrate the aggregate 44 in the freshly exposed portion of the cavity 85A shown in Fig. 10 and to press the aggregate 44 and optional additives in the direction transverse to the soil matrix 36. The pushing distance is equal to the lifting distance minus the thickness of the designed layer. When using a method involving the use of sacrificial plug 64, the bottom opening 50 may remain open during aggregate compaction 44.

[0041] Fig. 18 shows a partially formed pillar made using the process described, in which a plurality of layers 72 were successively formed by compaction, and the hollow tube 30 is lifted during aggregate filling 44 parts of cavity 85X. Fig. 19 shows a completely formed pillar 76 made using the process described. Fig. 20 shows the formed pillar 76 with the lifting anchor 68, 70 mounted or with the indicator element installed. FIG. 21 shows an optional step of pre-loading the formed pillar 76 carried out by placing on the formed pillar, for example, a weight 75, and an optional test to determine the coefficient carried out on the formed pillar 76 consisting of a plurality of compacted layers 72.

[0042] Figs. 23 to 26 show an alternative method of forming a pillar using the device described. The hollow pipe 30 is initially forced or rammed into the soil matrix 36 to the desired depth of 100. The bottom extreme end of the front member 32 includes a valve mechanism 54 with a rod (68) and a plate (70) or equivalent sacrificial plug 64. Injecting the empty pipe 30 into the soil vertically downwards, this creates a recess 102 (Fig. 23). Assuming that the special bottom face 32 is substantially cylindrical, the recess 102 is substantially cylindrical and may or may not retain the full diameter configuration associated with the shape and diameter of the special bottom face 32.

[0043] After achieving the desired penetration in the soil matrix 36 (Fig. 23), the hollow tube 30 is lifted up the formed cavity (Fig. 24). During its lifting, the aggregate material 44 and optional additional materials are unloaded below the lower end of the special lower front element 32.

[0044] Optionally, additional materials are discharged into the annular space 104 formed between the upper section 33 of the hollow tube 30 and the inner walls of the formed cavity 102. It should be noted that the additional materials can flow through the auxiliary transverse channels 108 or additional conduits 110 located in the empty pipe 30. As the empty pipe 30 is lifted, the recess 102 is filled. The additive materials located in the annular space 104 can also be forced outside into the soil matrix 36, which is accomplished thanks to and using the configuration of the special lower front element 32 during its lifting.

[0045] The hollow pipe 30 is therefore usually lifted over substantially the entire length of the initially formed recess 102 and then, as shown in Fig. 25, again moved downwards, which compresses the material in the recess 102 and forces it towards transverse to the soil matrix 36 (Fig. 25). The distance the empty pipe 30 is moved down depends on various factors, including the dimensions and shape of the cavity 102, the composition and mixture of aggregate materials and additives, the forces acting on the empty pipe 30 and the characteristics of the soil matrix 36. Displacement usually it continues until the bottom end or bottom of the special bottom face element 32 is at or near the bottom 81 of the previously formed recess 102.

[0046] After the second downward movement is completed, the hollow tube 30 is usually lifted to the full length of the cavity 102, again unloading the aggregate and optional additive materials during this lifting, and again filling the newly formed cavity 102A (Fig . 26). The full lowering and full lifting cycle is carried out at least twice, and optionally three or more times, in order to inject more aggregate 44 and optional additional materials transversely into the soil matrix 36. The cycles can also be changed in various ways, for example, full lifting and lowering is possible, followed by full lifting and partial lowering or partial lifting and lowering, and a combination of the above operations is also possible.

Summary considerations:

[0047] In order to facilitate the flow and feeding of aggregate material 44 through the empty pipe 30, it is possible to use water, cement paste or other liquid. Water can be fed into the empty pipe 30 directly or via the funnel 34. It can be under pressure or a suitable pressure can be obtained by using the funnel 34 as a reservoir. Water, cement paste or other liquid thus effectively enables aggregate to flow, especially in the case of a hollow pipe 30 of small diameter, i.e. pipe 30 with a diameter of 5 to 10 inches (12 to 25 cm). It should be noted that for all described embodiments, the size of the inner pipe duct 30 and / or the outlet opening is at least 4.0 times the maximum aggregate size. The use of water as a lubricant is particularly desirable when each of the layers 72 has a vertical height of about 12 inches (30 cm) and the inner diameter of the pipe 30 is approximately (15 to 25 cm) between 6 and 10 inches .

[0048] It has been noticed that the diameter of the cavity 102 formed in the soil matrix 36 is relatively smaller than with many alternative pillar forming techniques. The method uses a recess 102 with a relatively small diameter or a small size of the hole leading to the soil matrix 36, however, it allows the pipe 30 to be forced or displaced to a considerable depth and then to form a pillar whose dimensions in the horizontal direction are larger than the external dimensions of the pipe 30. The hollow tube 30 and the special bottom face 32, which are described below, therefore allow the use of aggregate 44 containing additives, including or without liquid materials, to form one or more layers by compacting and moving the material into horizontal direction. The compacted layers 72 are in a vertical direction and the aggregate 44 is displaced in a transverse direction, which results in a highly coherent pillar structure.

Test results:

[0049] Fig. 22 shows the results of testing of pillars made using the device of the present invention and compared with the results of the drilled concrete pillar. The graph illustrates the displacement of three pillars made according to the invention (curves A, B, C) compared to the drilled concrete pillar known in the art (curve D), where the pillars were subjected to loads increasing to the maximum load, and then the loads were reduced to zero. The tests were carried out under the conditions described below using a steel reinforced concrete pillar constituting the test control pillar.

[0050] To create a drilled concrete pillar (Test D), a hole or recess was made with a diameter of about 8 inches (20 cm) and a depth of 20 feet (6

m), which was filled with concrete. A steel reinforcing bar was placed to ensure the structural integrity of the drilled concrete pillar. To facilitate compressive load tests, a cardboard element with a diameter of 12 inches (30 cm) was placed in the upper part of the pillar. For all four tests, a low to medium grain, medium density sand matrix was used, which in the Penetration Blow Counts (SPT) standard test showed 3 to 17 beats per foot. Groundwater was located at a depth of about 10 feet (3 m) from the ground surface.

[0051] The aggregate pillars according to the invention, designated in tests A, B and C, were made using a hollow tube 30 with an outer diameter of six (6) inches (15cm) and a special bottom end element 32 with an outer diameter of 10 inches ( 25 cm). Only aggregate was used in tests A and B. In test C, aggregate and cement paste were used. In Test A, predetermined two-foot (60 cm) lifting displacements and predetermined down-pushing displacements of one foot (30 cm) were used, which resulted in a series of layers of one foot (30 cm). In Test B, predetermined three-foot (92 cm) upward displacements and predefined two-foot (60 cm) downward displacements were used, which again resulted in one-foot (30 cm) layers. In Test C, predetermined upward displacements of two feet (60 cm) and predetermined downward displacements of one foot (30 cm) were used, and a cement paste additive was used.

[0052] Data analyzes can be associated with rigidity or coefficient of built pillars. At a 0.5 inch (2.5 cm) deviation, test A corresponded to a load of 27 tonnes, test B corresponded to a load of 35 tonnes, test C corresponded to a load of 47 tonnes, and test D corresponded to a load of 16 tonnes. With this degree of deviation (0.5 inch ~ 2.5 cm) and using test B as the standard test and comparison basis, the relative stiffness coefficient for test B is 1.0, for test A is 0.77, for test C is 1 , 34, and for test D is 0.46. The standard pillar, or test B, is 2.19 times stiffer than the control test pillar, i.e. test D. The standard pillar, i.e. test B, is 1.30 times stiffer than the pillar from test A, while the pillar from test C containing the cement slurry additive is 2.94 times more rigid than the concrete pillar known from the prior art (test D). It follows that the coefficients of the pillars formed using the invention are substantially better than the coefficient of the drilled and steel reinforced concrete pillar (test D). These tests also show that a process involving a three-foot (92 cm) lifting and two-foot (60 cm) downward displacement is better than a process involving a two-foot (60 cm) lifting and one-foot (30 cm) downward displacement. The tests also showed that the use of a cement paste additive substantially increased the stiffness of the formed pillar for deviations less than about 0.75 inches (2 cm), but did not substantially increase the stiffness of the formed pillar compared to test B for deviations greater than about 0 , 9 inches (2.2 cm).

[0053] Due to the fact that in the device according to the invention the bottom end 32 of the hollow tube or hollow shaft 30 has a larger cross-sectional area, various advantages are obtained. First, when using the lower valve mechanism 54, the device configuration reduces the likelihood of aggregate material becoming blocked in the device during the formation of the cavity 102 in the soil matrix 36, as well as when partially pulling the empty pipe 30 out of the soil matrix 36 to expose or create the cavity 85 in soil matrix 36. In addition, this configuration allows the lower front element 32 to transfer additional energy associated with static force vectors and dynamic force vectors, as well as impacting the aggregate 44 located in the recess 70. Another advantage is that the friction of the empty pipe 30 against the side formed in the substrate of the recess 102 is reduced due to the fact that the effective diameter of the hollow tube 30 is smaller than the effective diameter of the bottom face 32. Therefore, the cross-sectional area of ​​the remaining part of the hollow pipe 30 is reduced. This allows it to be injected faster into the soil and allows pushing through formations that could be regarded as more compact or stiff. The larger cross-sectional area of ​​the front member 32 also increases the possibility of providing a recess section 102 with dimensions that allow the introduction of a larger volume of aggregate 44 than would be associated with the remaining portion of the hollow shaft 30, so that additional layer material is provided during the formation of layer 72 longitudinal (axial) and transverse (trans axial) directions. The reduced friction of the hollow pipe 30 against the side of the cavity 102 formed in the soil 36 also provides the advantage of easier lifting of the hollow pipe 30 during pillar formation.

[0054] In this method, the lowest layer 72 may have a larger effective diameter and contain a different amount of aggregate delivered to it. Thus, the bottom layer 72 or the lowest layer in the pillar 76 can be configured to have a larger cross-section as well as a greater depth when forming the base for the pillar 76. In other words, by way of example, the lowest part or lowest layer 72 can be formed by raising the hollow shaft 30 by three feet (92 cm), and then reducing the height of layer 72 to one foot (30 cm), while subsequent layers 72 can be created by raising the hollow shaft 30 by two feet (60 cm) and then reducing the height of layer 72 to one foot (30 cm).

[0055] As mentioned above, the finished pillar 76 may be subjected to a preload after its creation by applying a static load or dynamic load 75 to the top surface of the pillar 76 for a predetermined period of time (see Fig. 21). Thus, a load 75 can be applied to the upper surface of the pillar 76 for a time ranging from 30 seconds to 15 minutes, or longer. This application of force can also constitute a "coefficient indicator test" to the extent that the static load 75 exerted on the upper surface of the pillar 76 can be supplemented by measuring the deviation occurring as a result of the static load 75. The coefficient indicator test can be performed during the pre-loading of each of the pillars, which aims to achieve two goals in one activity, namely: (1) applying the pre-load and (2) performing the coefficient indicator test.

[0056] The aggregate material 44 used to form the pillar 76 may vary. Thus, pure aggregate stone can be placed in the recess 85. Such stone may have a nominal diameter of 40 mm with a stone content with a nominal diameter of less than 2 mm not exceeding 5%. Next, cement slurry can be introduced into the material formed, as described above. The cement slurry can be introduced simultaneously with the aggregate 44, or sooner or later.

[0057] When using vibration at a certain frequency to exert dynamic force, the vibration frequency of the force exerted on the hollow shaft or hollow tube 30 is preferably in the range of 300 to 3000 cycles per minute. The ratio of the different diameters of the hollow tube or shank 30 to the diameter of the front member 32 is usually in the range of 0.92 to 0.50. As mentioned previously, the angle of the lower oblique chamfer relative to the longitudinal axis 35 may be from 30 ° to 60 °.

[0058] Another feature of the pillar forming method is that it can be carried out by introducing a hollow pipe 30 with a special bottom end element 32 to the total depth 81 of the pillar being formed. The hollow pipe 30 and the special lower front element 32 are then continuously lifted to the full length of the formed pillar, with aggregate and / or cement paste or other liquid being forced into the cavity when lifting the empty pipe 30 and the special lower front element 32. Then, after reaching the upper part of the formed pillar, the hollow pipe 30 and the special lower front element 32 can be statically pushed again, and optionally enlarged by a vibration mechanism and / or a driving mechanism with dynamic force down or towards the bottom of the formed pillar. Aggregate 44 and / or cement paste or other material filling the cavity after its emptying is moved laterally to the soil matrix during its movement by the downwardly moving hollow pipe 30 and the front element 32. The method can then be repeated by lifting the hollow pipe 30 and the front member 32 either to the remaining length or depth of the formed pillar or to a shorter length, in each case the lifting of the empty pipe 30 is accompanied by filling the newly formed cavity with aggregate and / or liquid material. In this way, the material forming the pillar can be one layer or series of layers, while the additional material and optional cementitious slurry and / or other additives are displaced in the transverse direction to the sides of the hollow cavity and to the soil matrix.

[0059] It has been noted that the mechanism ensuring the implementation of the procedures and methods described above can operate in an accelerated manner. The downward movement of the hollow tube 30 and the front member 32 can be carried out relatively quickly, for example, in two minutes or faster. Gradually lifting the hollow tube 30 and front member 32 to a partial or full distance in the cavity formed may take even less time, depending on the distance of the lifting displacement and the lifting speed. Thus, the pillar is formed from the soil matrix 36 within a few minutes. The speed of building is therefore significantly higher with the methodology and device according to the invention.

[0060] Various modifications and changes may be made to the methodology and the device within the scope of the invention as defined by the claims. It is therefore possible to change the structure of the invention and the way it works. Alternative hollow tube configurations, dimensions, cross-sectional shapes and pipe lengths can be used. It is possible to change the configuration and use of the special front element 32. The enlarged or spherical end member 32 may be used in conjunction with one or more hollow tube sections 30 with increased outer diameter having various shapes and configurations. The invention is therefore limited only by the following claims.