DEVICE, SYSTEM AND METHOD FOR PERFORMING A ROTATIONAL STATIC LOAD TEST ON A HELICAL PILE.

Description

/ 8 DEVICE, SYSTEM AND METHOD FOR PERFORMING A ROTATIONAL STATIC LOAD TEST ON A PILE HELICAL TECHNICAL FIELD

[001] The present invention relates to a device, system and method intended for testing the tensile load of helical metal piles or similar, using a system that applies and measures the axial load applied by means of rotation, having its application in the field of geotechnical engineering.

[002] The invention allows a static load test to be performed on a helical metal pile without the use of a hydraulic cylinder, using, for the application of axial tensile load, the rotational movement provided by the pile installation equipment itself to obtain the axial load capacity of the pile and several derived parameters. FUNDAMENTALS OF THE INVENTION

[003] Helical metal piles are a type of foundation consisting of a central shaft (solid or hollow) to which helical plates of varying or constant diameters are welded, with specific spacing between them. The number and diameter of the helices are defined according to the soil characteristics and load-bearing capacity required in the project.

[004] The basic components of a helical pile are: guide section and extensions. The guide section is the first section installed in the field; it is where the augers are attached. The extensions are smooth rods (without augers) or rods with a screw-on, socket-type coupling system that are added to the guide section so that it reaches the depth and soil with the required resistance specified in the project and / or to increase the number of augers in the pile. The screw-on, socket-type coupling system Petition 870260001379, dated 07 / 01 / 2026, page 25 / 35 / 8 is a mechanical connection technique commonly used in pipelines, metal structures or machine components, to join two parts in a robust and secure manner.

[005] The central shaft may have a hollow circular (tubular) section, a solid square section, or any other shape known to a person skilled in the art, having the function of transferring torque during installation and the force to the augers when the pile is put into service by the mobilization of the surrounding soil.

[006] To determine the axial tensile load capacity of helical metal piles, reaction systems composed of metal beams or trusses supported on the ground are commonly used, where the axial load is applied by means of a hydraulic cylinder.This system has the following limitations and drawbacks: (i) the load to be applied is limited by the capacity of the hydraulic cylinder used, which implies the need to have cylinders of various capacities for each application, which can be manually or electrically operated, with the electric type requiring a power supply; (ii) the cylinder stroke may limit the applied load due to deformation of the bearing ground of the reaction system plus the displacement of the pile itself, causing the test to be stopped and subsequently restarted, or special hydraulic cylinders with a large displacement capacity may be used, which may make the test unfeasible; and (iii) in general, the load test is performed by a team different from the one that executed the pile, as it requires a range of different equipment and tools, which incurs increased costs for labor and invested capital.

[007] The state of the art includes pile testing techniques, but there is no disclosure of devices that perform the test as achieved by the present invention. Document KR101606887 describes a foundation tube testing apparatus for helical piles. The apparatus Petition 870260001379, dated 07 / 01 / 2026, page 26 / 35 / 8 comprises: a cone coupling unit which has a cylindrical tube shape, and has a load cell mounted thereon and is coupled to an upper part of a piezocone to continuously measure the cone's front end resistance, the frictional force of a sleeve and the water pressure between tubes in a tube insertion process to move with the piezocone. A lower connecting body coupled to an upper portion of the cone coupling part to be moved together with the cone coupling part, and having a lower hollow portion provided in a central portion thereof, and an upper connecting body in which the upper part is combined with the lower part of the helical pile and which acts with the helical pile while the lower part is combined on top of the lower connecting body so that free rotation is enabled, and the upper hollow portion is included in the central part.

[008] In turn, document CN102051890 describes a machine for testing in pile construction in construction projects. The technical solution in this document refers to an inspection vehicle that includes a cargo vehicle, a crane, a pile driver, a pressure measuring platform and a jack, a main pressure measuring beam that is installed on the vehicle chassis, and a pressure gauge is installed in the middle of the main pressure measuring beam. A pile driving machine and the jack are installed respectively in front of and behind the pressure measuring beam, the support legs are installed at both ends of the transport vehicle chassis, the support legs being connected to the support leg cylinders. The pressure measuring support beam is installed on the side and the oil cylinder of the pressure measuring support beam is connected to the pressure measuring support beam. Petition 870260001379, dated 07 / 01 / 2026, page 27 / 35 / 8

[009] Aiming to overcome the problems presented by the conventional load application system for performing static load tests, the present invention makes it possible to perform static tensile load tests without the use of a hydraulic cylinder, with the load being applied by means of rotation of the pile performed by the installation equipment itself, immediately at the end of the installation. The present invention makes performing the test less expensive, faster and more efficient.

[010] In order to overcome the limitations of the state of the art, the present invention describes a device for performing a static rotational load test on a helical pile comprising a central shaft; at least one axial bearing; and at least one load cell; wherein the at least one load cell and the at least one axial bearing are mounted inside a housing.

[011] In addition, the present invention further describes a system for performing a static rotational load test on a helical pile comprising the device for performing the static rotational load test and a metal support that rests on the ground.

[012] Furthermore, the present invention also describes a method for performing a static rotational load test on a helical pile comprising the steps of: coupling the system for performing a static rotational load test to the helical pile to be tested; positioning the installation equipment and connecting it to the system; rotating the central axis in order to rotate the pile; measuring the axial tensile load on the pile by means of the load cell; displaying the axial load value on a screen of a user device. BRIEF DESCRIPTION OF THE FIGURES

[013] Figure 1 is a front view of the device of the present invention connected to the stake fixed to the ground. Petition 870260001379, dated 07 / 01 / 2026, page 28 / 35 / 8

[014] Figure 2 is a side view of the device of the present invention connected to the stake fixed to the ground.

[015] Figure 3 is a side view of the system of the present invention connected to the installation equipment. DESCRIPTION OF THE INVENTION

[016] The following detailed description refers to figures in which embodiments of the present invention are represented, by way of non-limiting illustration. These embodiments are described in such a way as to allow a person skilled in the art to reproduce their results. Other embodiments are possible and can be carried out without departing from the concept and scope of the present invention. The following detailed description should therefore not be understood in a restrictive or limiting manner.

[017] As shown in Figures 1 and 2, the present invention describes a system for performing static load tests on helical piles (10) or similar piles. The load is applied to the soil (30) surrounding the augers by means of rotation of the pile (10), just as it is installed in the soil (30), using the same installation equipment (20), the natural downward displacement of the pile (10) being prevented by a device (100) supported on a metal support (160) which is supported on the surface of the soil (30). The load test performed with this system can be carried out on piles of any length, any installation angle, any size and type of central shaft and any auger composition.

[018] The device (100) for performing a static rotational load test consists of a central shaft (140) where the pile (10) to be tested and the installation equipment (20) are connected. The coupling is made by means of spigot and socket type connections with bolts or pins, Petition 870260001379, dated 07 / 01 / 2026, p. 29 / 35 / 8 in the same way that the couplings of the various parts of the helical metal pile are made (10).

[019] The central axis (140) comprises a shoulder (150) that rests on an axial bearing (110). This, in turn, is supported on a tubular (column type) load cell that measures the load applied by the helical metal pile (10) to the surrounding soil (30), which is characterized as being the soil in the region of the pile helices, i.e., close to the guide section. The central axis (140) passes through the central hole of the load cell (120).

[020] The load cell may operate based on electrical resistance strain gauges or vibrating wire or equivalent capable of converting mechanical stress into an electrical signal or any other measurable type. The load cell is capable, through calibration, of indicating the load mobilized by the pile directly on the screen of a user device.

[021] The load cell and the axial bearing (110) are fitted tightly inside a housing (130) that prevents any relative lateral movement between the shoulder (150) of the central shaft (140), the axial bearing (110) and the load cell.

[022] The housing (130) is equipped with a bottom and cover with a central hole that allows the passage and free rotation of the central shaft (140).

[023] This assembly consisting of the central shaft (140), axial bearing (110), load cell and housing with bottom and cover (130) is called a device (100) for performing a rotational load test.

[024] The bottom of the casing (130) is then supported on a metal support (160) capable of supporting the load of the test. The metal support (160) must be hollow in order to allow the passage of the central shaft (140) for coupling to the pile to be tested. Petition 870260001379, dated 07 / 01 / 2026, page 30 / 35 / 8

[025] The metal support (160) on which the device for carrying out the rotational load test rests is then supported on the ground surface (30) by means of wooden sleeper beams, grids or shoes for distributing the load on the ground surface (30).

[026] The assembly formed by the device (100) for performing rotational load testing and the metal support (160) on which it rests, which in turn rests on the ground (30), is called the system (200) for performing rotational load testing. As shown in figure 3, the system (200) is connected to the installation equipment (20) so that the load test can be performed on the pile (10).

[027] The present invention also relates to a method for rotational load testing on a helical pile (10) comprising the following steps: - disconnect the installation equipment (20) after installing the helical metal pile (10) into the ground (30); - position and couple the rotational load test system (200) to the metal pile (10) to be tested by means of the socket and tip connection with bolts or pins, where the lower end of the central shaft (140) is coupled to the pile (10) to be tested; - Position the helical metal pile installation equipment (20) in a convenient position and connect it to the rotational load test system (200) by means of the screw or pin connection, where the upper end of the central shaft (140) is coupled to the installation equipment (20); - rotate the assembly formed by the central axis (140) and stake (10) to be tested. - measure the axial tensile load on the pile (10) using the load cell; - Display the axial load value on a user device screen. Petition 870260001379, dated 07 / 01 / 2026, p. 31 / 35 / 8

[028] The positioning of the installation equipment is defined in the field and depends mainly on the topography and the existence of interferences. This definition is made at the time of assembly, by the operators. The installation equipment does not need to be positioned on the same plane as the pile or in the same position in which it was parked to perform the pile installation.

[029] The user device can be any electronic device capable of displaying information through a screen, such as a smartphone, tablet, computer, among others. The type of device may vary according to the embedded electronics and data transmission system.

[030] The helical shape of the pile helices (10) causes the pile to tend to penetrate the soil (30), but, as the displacement is prevented by the rotational load test system, an axial tensile load will arise in the pile (10).

[031] The rotation can be increased precisely in stages so that the resulting axial load respects the load increments required to perform the static load test, as indicated in the technical standard NBR 16903 (ABNT, 2020).

[032] The axial displacement of the soil (30) can be correlated with the rotation of the pile (10) by means of a proportion with the pitch of the augers. Petition 870260001379, dated 07 / 01 / 2026, pages 32 / 35

Claims

1 / 2 CLAIMS 1. Device (100) for performing static rotational load test on a helical pile (10) characterized in that it comprises: a central shaft (140); at least one axial bearing (110); and at least one load cell; wherein at least one load cell and at least one axial bearing (110) are mounted inside a housing (130).

2. Device (100), according to claim 1, characterized in that the central shaft (140) connects to the stake (10) and to the installation equipment (20) by means of socket and spigot type connections with screws or pins.

3. Device (100), according to claim 1 or 2, characterized in that the central shaft (140) comprises a shoulder that rests on the axial bearing (110).

4. Device (100), according to claim 1, characterized in that the housing (130) is of the type with a bottom and cover that allow the passage and free rotation of the central shaft (140).

5. Device (100), according to claim 1 or 4, characterized in that the bottom of the housing (130) rests on a metal support (160), wherein the metal support (160) is hollow for passage of the central shaft (140).

6. Device (100), according to claim 5, characterized in that the metal support (160) rests on the ground surface (30) and comprises sleeper fire pits, grates or footings.

7. System (200) for performing static rotational load test on a helical pile (10) characterized in that Petition 870250046565, dated 04 / 06 / 2025, page 34 / 39 2 / 2 comprises the device (100) defined in any of claims 1 to 6 and a metal support (160) that rests on the ground (30).

8. Method for performing a static rotational load test on a helical pile (10) characterized in that it comprises the steps of: coupling the system (200), defined in claim 7, to the helical pile (10) to be tested; positioning the installation equipment (20) and connecting it to the system (200); rotating the central axis (140) in order to rotate the pile (10); measuring the axial tensile load on the pile (10) by means of the load cell; displaying the axial load value on a screen of a user device.

9. Method according to claim 8, characterized in that the step of coupling the system (200) is preceded by the step of uncoupling the installation equipment (20) after the installation of the helical pile (10) into the ground (30).

10. Method according to claim 8, characterized in that the lower end of the central shaft (140) is coupled to the stake (10) and the upper end of the central shaft (140) is coupled to the installation equipment (20), wherein the connections are made by means of a spigot and socket type connection with bolts or pins. Petition 870250046565, dated 04 / 06 / 2025, p. 35 / 39

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