Apparatus for plate load testing and method for conducting plate load testing

Abstract

To provide a plate load testing apparatus and a plate load testing method that can accurately perform a plate load testing by applying the required weight for the plate load testing. [Solution] The plate load test apparatus (100) of the present invention comprises a load loading device (20) for applying a load, the load loading device (20) having a plate holding part (2) for holding a plate (1) used in a plate load test, the plate holding part having two plate guides (3) for guiding the plate (1) held on the side of the load loading device when it is lowered, each of the lower ends of the plate guides (3) has a taper (3A), and in the area between the two plate guides (3) there is a load pipe (4) which has the function of applying the weight of the load loading device to a load cell (9) used in a plate load test, and a winch (10) which lowers and raises the plate (1) along the plate guides (3).

Description

Technical Field

[0001] The present invention relates to a plate load test, and particularly to a device for plate load test and a method for plate load test that can perform the plate load test easily, accurately and safely.

Background Art

[0002] In a plate load test, which is a test for measuring the bearing capacity of the ground, depending on the roadbed depth, it is necessary to load a large weight (10t or more). However, carrying such a large weight of counterweight for each test position requires a great deal of labor and cost. Therefore, it has been proposed to use a heavy machine at the site where the plate load test should be performed as a reaction device to load the weight required for the test. However, when selecting a reaction device (heavy machine), it is necessary to arrange the support point of the heavy machine at a distance of 1 m or more from the outer edge of the loading plate. However, the heavy machines that can arrange the support point of the heavy machine at a distance of 1 m or more from the outer edge of the loading plate and obtain the necessary reaction force are extremely limited. When using a large heavy machine running on an endless track belt such as a hydraulic excavator, there is a problem that the road surface of the work site is damaged by the endless track belt when traveling between the test positions of the plate load test. In addition, when using a rough terrain crane as a heavy machine, there is a problem that it is difficult to secure a qualified driver. Using such a heavy machine instead of the counterweight of the plate load test has problems such as difficulty in securing the heavy machine and soaring costs. Furthermore, depending on the heavy machine used, the distance between the loading part of the heavy machine and the ground is often large, and members for raising the height must be installed. However, the greater the distance for raising the height, the more unstable the state becomes, accompanied by danger.

[0003] In addition, the plates used in plate load tests are heavy (for example, a 750mm diameter plate K75 weighs about 90kg), and conventional technology required two workers to move them. When heavy plates are moved manually by workers, the weight of the plate is placed on the workers, resulting in a significant physical burden and potentially leading to accidents. While it is possible to move the flat board using a wheelbarrow if the distance to be moved is short, transporting a heavy flat board with a wheelbarrow can be dangerous, especially on uneven work sites, as it can lead to falls and other accidents.

[0004] Other conventional technologies have been proposed to reduce the labor involved in plate load tests (see Patent Documents 1 and 2). However, these technologies (Patent Documents 1 and 2) reduce the labor involved in control and other aspects of the test, and are not related to the aforementioned problems that arise when heavy machinery is used as a counterweight. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2002-296159 [Patent Document 2] Japanese Patent Publication No. 2010-210559 [Overview of the project] [Problems that the invention aims to solve]

[0006] This invention was proposed in view of the problems of the prior art described above, and aims to provide a plate load testing apparatus and a method for conducting a plate load testing that can solve the above problems, accurately perform a plate load test, and apply the weight required for the plate load test. [Means for solving the problem]

[0007] The plate load testing apparatus (100) of the present invention is Equipped with a load-bearing device (20: for example, a 25t tire roller) for applying load, The load-applying device (20) has a plate holder (2) for holding a plate (1: plate for plate loading test) used in a plate loading test, The plate holding portion (2) is provided with two plate guides (3) that guide the plate (1) held on the side of the load-applying device (20) when it is lowered or raised, and a taper (3A) is formed at the lower end of each plate guide (3). A load pipe (4) is provided in the region between the two flat plate guides (3) and has the function of loading (transmitting) the weight of the load loading device (20) onto the flat plate (1: or the load cell 9 placed on the flat plate 1), The device is characterized by having a winch (10) that lowers and raises the flat plate (1) along the flat plate guide (3).

[0008] A flat plate with a diameter of 750 mm can be selected as the flat plate used in this invention. However, this invention is not limited to a flat plate with a diameter of 750 mm. For example, a flat plate with a diameter of 300 mm or a flat plate of other sizes may also be used.

[0009] In the present invention, it is preferable that the flat plate holding portion (2) includes an upper flat plate holding member (5) provided on the upper part of the flat plate guide (3) and surrounding the upper part of the flat plate (1) in contact with the flat plate guide (3), and a lower flat plate holding member (6) provided on the lower end of the flat plate guide (3) and supporting the lower edge of the flat plate (1) in contact with the flat plate guide (3). Furthermore, in the plate load testing apparatus of the present invention, the load application device (20) can be not only a tire roller but also other heavy machinery, etc.

[0010] The present invention relates to a method for performing a plate load test using the plate load test apparatus described above (100: plate load test apparatus according to either claim 1 or claim 2), The process of installing an outrigger (19) on the side opposite to the flat plate holding part (2) of the load-applying device (20: for example, a tire roller), The process of placing the plate (1) at the test position during a plate load test, The method is characterized by including a step of moving the plate (1) from the test position to the plate holding section (2) after the plate loading test is completed. [Effects of the Invention]

[0011] According to the present invention having the above configuration, the plate load testing apparatus (100) of the present invention uses a load loading device (20: for example, a 25t tire roller), so the load required for the test can be secured by adding the vehicle weight of the load loading device (20) to the plate (1) for plate load testing. Furthermore, since the vehicle weight of the load loading device (20) can be applied to the plate (1) via the load pipe (4), raising timbers and the like are unnecessary, and there is no need to install raising timbers under the heavy machinery, thus reducing dangerous work. If a tire roller is used as the load-bearing device (20), it will run on tires, and therefore will not damage the paved surface of the construction site like heavy machinery with tracks. Furthermore, if the load-bearing device (20) is a tire roller, it can be operated by a qualified site worker, eliminating the need to provide a dedicated operator as is required when using a crane.

[0012] In this invention, a flat plate guide (3) is provided to guide the flat plate (1) held on the side of the load-applying device (20) as it is lowered, and a taper (3A) is formed at the lower end of the flat plate guide (3). When the jig (1A) provided for suspending the flat plate (1) by the winch (10) reaches the taper (3A) of the flat plate guide (3), the angle between the taper (3A) and the flat plate (1) (the angle shown by arrow R8 in Figure 8) opens up, and since the flat plate guide (3), which had been restricting the flat plate (1) from becoming horizontal and stabilizing, is no longer present, the flat plate (1) moves to a horizontal position and rotates in an attempt to stabilize. As a result, the flat plate (1) is prevented from becoming perpendicular to the ground at the predetermined position (the position where the flat plate loading test should be performed) and being pressed into the ground, and the flat plate (1) is always placed in the predetermined position in a horizontal state. Furthermore, when the flat plate (1) is placed in the predetermined position, the jig (1A) is always facing upwards, so that the jig (1A) faces the ground and is pressed into the ground, preventing errors from occurring in the flat plate loading test results. Furthermore, since the worker does not need to move the flat plate (1), the worker does not need to transport or move heavy objects. [Brief explanation of the drawing]

[0013] [Figure 1] This is a reference perspective view showing a plate load test being performed using a plate load test apparatus according to an embodiment of the present invention. [Figure 2] This is an explanatory diagram showing the flat plate used for flat plate loading tests set up at the test location. [Figure 3] This is a reference perspective showing a flat plate for a flat plate load test held to the side of a tire roller, before any testing is being conducted. [Figure 4] This is an explanatory diagram showing the state of the lower member for holding the flat plate when the flat plate for flat plate loading testing is held on the side of a tire roller. [Figure 5] This is an explanatory diagram showing the state of the lower member for holding the flat plate when the flat plate for flat plate loading testing is not held to the side of the tire roller. [Figure 6]It is an explanatory diagram showing a state where a flat plate for a plate load test descends from a state of being held on the side of a tire roller to a test position. [Figure 7] In the state of FIG. 6, it is an explanatory diagram showing various forces acting on the flat plate for a plate load test and the wire. [Figure 8] It is an explanatory diagram showing a state where the flat plate for a plate load test has descended to the taper of the guide. [Figure 9] It is an explanatory diagram showing a state where the flat plate for a plate load test is arranged at the test position. [Figure 10] It is an explanatory diagram showing a state where the flat plate for a plate load test is pulled up from the state of FIG. 9 and abuts on the taper of the guide. [Figure 11] It is an explanatory diagram showing a state where the flat plate for a plate load test is pulled up from the test position to the taper of the guide. [Figure 12] It is a flowchart showing a procedure for performing a plate load test using the plate load test device according to an embodiment of the present invention, and showing the procedure until a load is applied and a settlement amount is measured. [Figure 13] It is a flowchart showing a procedure for performing a plate load test using the plate load test device according to an embodiment of the present invention, and showing the procedure following the procedure shown in FIG. 12. [Figure 14] It is a side view of a tire roller holding a flat plate for a plate load test on the side. [Figure 15] It is a side view of a tire roller in which an outrigger is jacked up on the side opposite to the side where the plate load test is performed when performing the plate load test. [Figure 16] It is a front view of a tire roller in which an outrigger is jacked up on one side and a load cell and a jack are arranged below a load pipe on the opposite side.

Mode for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. As shown in Figure 1, the plate load test apparatus 100 according to the illustrated embodiment consists of a tire roller 20 (for example, a 25t tire roller) which is the load loading device. In Figure 1, which shows the state in which a plate load test is being performed using the tire roller 20, a plate load test plate 1 (hereinafter referred to as "plate") is placed to the side of the tire roller 20 and the plate load test is performed. By applying the weight of the tire roller 20, the load necessary for conducting a flat plate load test can be obtained. Since the weight of the tire roller 20 can be applied to the flat plate 1 via the load pipe 4, raising timbers and the like are unnecessary, eliminating the need for dangerous work such as installing raising timbers under heavy machinery. In this case, if heavy machinery with continuous tracks is used, there is a risk that the heavy machinery will damage the constructed road surface when it travels through the construction site. In contrast, moving the tire roller 20 will not damage the construction site or the finished road surface at the construction site. Furthermore, if the load-applying device (20) is a tire roller, it can be operated by a qualified on-site worker, eliminating the need to provide a dedicated operator as is required when using a crane. Furthermore, the relationship between loading pressure and settlement obtained from the plate load test results can be used, for example, to examine the bearing capacity and settlement (amount) of a structural foundation.

[0015] In Figure 1, a flat plate holding section 2 is provided on the side of the tire roller 20. Two flat plate guides 3 are provided on the flat plate holding section 2, extending vertically or parallel to each other to guide the flat plate 1 when lowering and raising it. A load pipe 4 is provided at a position midway between the two flat plate guides 3, extending vertically and parallel to the flat plate guides 3. The load pipe 4 is in contact with the jack 12 during the flat plate loading test, and when the jack 12 is jacked up, the weight of the tire roller 20 is loaded onto the flat plate 1 via the load pipe 4 and load cell 9. In other words, the load pipe 4 has the function of loading (transmitting) the weight of the tire roller 20 onto the flat plate 1. In the illustrated embodiment, a flat plate 1 with a diameter of 750 mm is selected. However, it is not limited to a flat plate with a diameter of 750 mm; it can also be applied to a flat plate with a diameter of 300 mm or other sizes. As shown in Figure 2, the flat plate 1 is provided with two jigs 1A, which protrude upward when the flat plate 1 is placed on the ground. These two jigs 1A are located at both ends of the diameter of the circular flat plate 1. In other words, the two jigs 1A are located at two points symmetrically with respect to the center point of the circular plate 1. These two jigs 1A are for engaging with wires 11 wound around two winches 10 shown in Figure 3. Locking devices (not shown) at the ends of the two wires engage with the jigs 1A, and by unwinding or winding these wires with the winches 10, the flat plate 1 is lowered or raised along the flat plate guide 3.

[0016] In Figure 1 again, a flat plate 1 is placed directly below the two flat plate guides 3, and a load cell 9 for measuring load and a jack 12 are placed on the flat plate 1. The jack 12 is provided to jack up the vehicle in order to add the weight of the tire roller 20 to the load cell 9. A settlement measurement beam 13 and a settlement measurement gauge 14 are provided on a flat plate 1. The end of the settlement measurement beam 13 that is separated from the flat plate 1 is supported by a beam holder 15, a beam support column 16, and a beam mounting base 17 at a predetermined distance from the flat plate 1. The settlement measurement gauge 14 comprises a gauge body 14A, a support column 14B, and a base 14C, and has the function of measuring the settlement of the flat plate 1. The settlement measurement beam 13 and the settlement measurement gauge 14 are conventionally known. Although not explicitly shown, the mounting base 17 and beam 13 are also provided on the side of the tire roller 20 not shown (the left side of the tire roller 20 in Figure 1). The beam 13 is approximately 5m long and extends from below the tire roller 20 to the left side of the tire roller 20 (not shown) in Figure 1. Two gauges 14 are also provided; in Figure 1, another gauge 14 is provided on the back side of the load cell 9 (the side not shown), for a total of two gauges 14 being used.

[0017] In Figure 1, a housing section 20A is provided in front of (to the right in Figure 1) the installation position of the flat plate guide 3 on the side of the tire roller 20. The housing section 20A is composed of a fence-like member that protrudes outward from the side of the tire roller 20 and houses test equipment (jack 12, settlement measurement beam 13, beam holder 15, beam support column 16, beam mounting base 17, etc.). However, since the load cell 9 and the sinkage measurement gauge 14 are affected by vibrations generated when the tire roller 20 moves, it is preferable to load them into a regular passenger car, which experiences less vibration during movement, and transport them by passenger car. Here, the flat plate 1 is not stored in the storage section 20A. As mentioned above, the flat plate 1 is heavy (approximately 90 kg for a φ750 flat plate), and it would require considerable effort to put it in and take it out of the storage section 20A. Also, as will be explained later, the tire roller 20 can be moved while the flat plate 1 is held to the side of the tire roller 20. In Figure 1, the symbols 20B, 20C, and 20D represent the driver's seat, front wheels, and rear wheels, respectively. The state in which the flat plate 1 is held by the tire roller 20 is also shown in Figures 3 and 14.

[0018] When conducting a plate load test, the plate 1 is placed on the ground (or road surface) as shown in Figures 1 and 2. Here, the plate 1 is placed on the ground while being guided by two plate guides 3, so the relative position of the tire roller 20 and the plate 1 at the time the plate 1 is placed on the ground is always constant. Therefore, the relative position of the position where the plate load test should be conducted and the tire roller 20 is also always constant, and by parking the tire roller 20 at a position that has a constant relative relationship with the position where the plate load test should be conducted and lowering the plate 1, the plate 1 can be reliably placed at the position where the plate load test should be conducted.

[0019] The following describes how the flat plate 1 is moved (descended) from a state where it is held on the side of the tire roller 20 as shown in Figure 3 to a state where it is placed in the position for the flat plate loading test as shown in Figure 2, or moved (raised) from a state where it is placed in the position for the flat plate loading test as shown in Figure 2 to a state where it is held on the side of the tire roller 20 as shown in Figure 3, with reference to Figures 2 to 11. In Figure 3, the flat plate 1 is held by the upper flat plate holder 5 and the lower flat plate holder 6. In this state, the flat plate 1 is held in contact with the flat plate guide 3, and the ground-side edge (lower part) of the flat plate 1 is supported by the lower flat plate holder 6. Figure 2 shows the state in which the upper flat plate holder 5 and the lower flat plate holder 6 do not support the flat plate 1. The configuration in which the lower member 6 for holding the flat plate supports the flat plate 1 will be described later with reference to Figures 4 and 5. Even if a force (arrow R2 in Figure 2) acts on the flat plate 1 in a direction that causes it to rotate away from the side of the tire roller 20, centered on the point where the flat plate 1 is in contact with the lower flat plate holding member 6, the upper flat plate holding member 5 covers the side of the flat plate 1 that is further away from the side of the tire roller 20 than the upper edge of the flat plate 1 (see Figure 3), thus preventing the flat plate 1 from separating from the side of the tire roller 20. As a result, the flat plate 1 is held parallel to the two flat plate guides 3 by the two flat plate guides 3. Although not explicitly shown, in the configuration shown in Figure 3, two jigs 1A (see Figure 2) facing upward when placed on the ground are engaged with locking devices (not shown) at the ends of the wire 11, and these locking devices (not shown) are provided at the ends of the wire 11 which is wound around the two winches 10 shown in Figure 3. In other words, the gravitational force acting on the flat plate 1 is supported by the lower member 6 for holding the flat plate, as well as by the wire 11 and winches 10 via the locking devices engaged with the jigs 1A.

[0020] The following describes how to place the plate 1 at the position where the plate loading test will be performed, as shown in Figure 2, starting from the state shown in Figure 3. First, as will be described later with reference to Figures 4 and 5, from the state shown in Figure 3, the lower member 6 for holding the flat plate, which supports the lower edge of the disc 1, is rotated to release its engagement with the flat plate 1. By releasing the engagement between the lower member 6 for holding the flat plate and the flat plate 1, the flat plate 1 no longer interferes with the lower member 6 for holding the flat plate and can descend freely. Then, the winch 10 is driven to unwind the wire 11 and lower the flat plate 1.

[0021] Here, the mechanism for engaging the flat plate 1 with the lower member 6 for holding the flat plate, or for disengaging the flat plate 1 from the lower member 6 for holding the flat plate, will be explained with reference to Figures 4 and 5. For the sake of simplicity in illustration, the flat plate 1 is not shown in Figures 4 and 5. In Figure 4, the lower plate holder 6 is configured in a roughly L-shape, and supports the lower edge of the flat plate 1 with a bent portion 6C consisting of a long side 6A and a short side 6B bent perpendicularly to it. The lower plate holder 6 is integrally fixed (by welding or other known methods) to a cylindrical side stopper 7 at a fixing portion 6D located in the middle of the long side 6A. The side stopper 7 is inserted into a hole (not shown) drilled in the side surface 3E of the flat plate guide 3 and is supported on the side surface 3E of the flat plate guide 3 so as to be rotatable in the direction of arrow R4. When the side stopper 7 rotates in the direction of arrow R4, the L-shaped lower plate holder 6 also rotates in the direction of arrow R4. An L-shaped bracket 8 is fixed to the back surface 3B of the flat plate guide 3. The L-shaped bracket 8 has a rising portion 8A that rises in the direction of arrow L4 in Figure 4, and a through hole 8B (Figure 5) is formed in the rising portion 8A. A sliding stopper 18 is inserted into the through hole 8B, and the sliding stopper 18 is inserted in a manner that allows it to slide in the direction of arrow S4. The sliding stopper 18 is then supported on the L-shaped bracket 8 (flat plate guide 3) so as to be slidable in the direction of arrow S4. In the state shown in Figure 4, the slidable stopper 18 protrudes toward the viewer in Figure 4, and the portion of the slidable stopper 18 that protrudes toward the viewer in Figure 4 engages with the lower plate-holding member 6. Therefore, the lower plate-holding member 6 does not rotate in the direction of arrow R41 (counterclockwise in Figure 4) from the state shown in Figure 4. As a result, even when the flat plate 1 is placed on the bent portion 6C of the lower plate-holding member 6, the state shown in Figure 4 is maintained.

[0022] From the state shown in Figure 4, if the slidable stopper 18 is slid in the direction of arrow S4, away from the viewer in Figure 4, the engagement between the slidable stopper 18 and the lower plate-holding member 6 is released. Although not clearly shown, the left region of the lower plate-holding member 6 shown in Figure 4 is heavier than the right region. Therefore, when the engagement between the slidable stopper 18 and the lower plate-holding member 6 is released, the lower plate-holding member 6 rotates in the direction of arrow R41, resulting in the state shown in Figure 5. In the state shown in Figure 5, the lower member 6 for holding the flat plate is positioned parallel to the flat plate 1, and the bent portion 6C of the lower member 6 for holding the flat plate does not interfere with the downward movement of the flat plate 1. Here, sliding the slidable stopper 18 in a direction perpendicular to the plane of Figure 4 (towards the viewer or away from the viewer) is done manually by an operator, but it can also be done by a mechanical or control structure.

[0023] As shown in Figure 5, once the lower member 6 for holding the flat plate extends vertically (up and down in Figure 5) and does not interfere with the descent of the flat plate 1, the wire 11 (Figure 3) is unwound from the winch 10 (Figure 3). By unwinding the wire 11, the flat plate 1 descends along the flat plate guide 3 as shown in Figure 6 (arrow D6). As described above, the tip of the wire 11 is locked and connected to the jig 1A on the flat plate 1. Here, reference numeral 3A indicates the taper of the flat plate guide 3. In Figure 7, which shows the balance of forces in the state of Figure 6, let T be the tension in the wire 11, G be the gravitational force acting on the plate 1, and θ be the angle between the direction in which the wire 11 extends and the perpendicular line. Since the plate 1 shown in Figure 6 is suspended from the upper right (diagonally) (in Figure 6), a load FGR of the same magnitude but in the opposite direction acts on the plate 1, as shown in Figure 7, with FG = Tsinθ. The load FGR presses the plate 1 against the plate guide 3, enabling stable upward and downward movement along the plate guide 3. A taper 3A is formed at the lower end of the flat plate guide 3. When the center of the flat plate 1 (or center of gravity: located on the straight line connecting the positions where the two jigs 1A are installed) reaches the taper 3A, the distance between the flat plate 1 and the taper 3A of the flat plate guide 3 increases. At this point, the flat plate guide (3), which had been restricting the flat plate (1) from becoming horizontal and stabilizing, is no longer present, so the flat plate (1) rotates in an attempt to move to a horizontal position and stabilize. As a result, the angle between the taper (3A) and the flat plate (1) (the angle shown by arrow R8 in Figure 8) widens, and the flat plate 1 rotates around jig 1A from the position of the solid line in the direction of arrow R8. In Figure 8, the rotated flat plate 1 is shown by a dashed line. When the flat plate 1 rotates in the direction of arrow R8, jig 1A is positioned above the taper 3A of the flat plate 1. As a result of rotating (plate 1) from the position indicated by the solid line in Figure 8 in the direction of arrow R8, plate 1 is positioned with jig 1A above it, and as shown in Figure 9, it is placed on the ground (the position where the plate load test should be performed) with jig 1A positioned above it. Therefore, the flat plate 1 will not be pressed into the ground in a perpendicular position to the ground where the flat plate load test is to be performed, and the flat plate 1 will be placed in the designated position in a horizontal position. Furthermore, when the flat plate 1 is placed in the designated position, the jig 1A will always be facing upwards, thus preventing the jig 1A from being pressed into the ground. Although not clearly shown in Figure 9, the jig 1A on the flat plate 1 is connected to the wire 11 by engaging with a locking device (not shown) at the tip of the wire 11. However, during the flat plate loading test, the connection between the jig 1A and the locking device (not shown) on the wire 11 is released.

[0024] The following describes the process after the plate load test is completed, in which the plate 1 moves (rises) from the state shown in Figure 2 to the state shown in Figure 3, where the plate 1 is held on the side of the tire roller 20. As shown in Figure 10, the jig 1A of the flat plate 1 is connected to a locking device (not shown) at the lower end of the wire 11, and the flat plate 1 is lifted. When the flat plate 1 is lifted, it rises from its position on the ground (Figures 2 and 9) and comes into contact with the lower end 3C of the flat plate guide 3 (i.e., the lower end of the taper 3A). At that time, a force acts on the flat plate 1, centered on the contact point between the flat plate 1 and the lower end 3C of the flat plate guide, due to the tension of the wire 11, causing it to rotate from the position shown by the solid line to the position shown by the dotted line (in the direction of arrow R11), as shown in Figure 11. In the illustrated embodiment, the lower end portion 3C of the flat plate guide 3 is the lower end portion of the taper 3A. In Figures 10 and 11, the relative position of the jig 1A on the flat plate 1 determines whether or not the flat plate 1 rotates in the direction of arrow R11 (Figure 11). That is, if the jig 1A is positioned to the left of the boundary portion (corner) between the taper 3A and the lower end portion 3C (see Figures 10 and 11), the flat plate 1 rotates as indicated by arrow R11. On the other hand, if the jig 1A is positioned to the right of the boundary portion (corner) between the taper 3A and the lower end portion 3C, the flat plate 1 does not rotate. The flat plate 1 rotates as indicated by arrow R11 until it contacts the front 3D of the flat plate guide 3 (the left side of the flat plate guide 3 in Figure 11). When the winch is wound up to 10 (Figure 3), the flat plate 1 rises while in contact with the front 3D of the flat plate guide 3, reaching the position shown in Figure 3.

[0025] As the flat plate 1 rises while in contact with the front surface 3D of the flat plate guide 3, if the lower edge of the flat plate 1 rises to a position above the through-hole 8B of the rising section in Figure 5, the lower flat plate holding member 6 rotates in the direction of arrow R5 in Figure 5 to position it below the through-hole 8B of the rising section. Then, the slidable stopper 18 (see Figure 4) is slid toward the viewer in Figure 5, engaging the lower flat plate holding member 6 with the slidable stopper 18 to prevent the lower flat plate holding member 6 from rotating in the opposite direction of arrow R5 (state as in Figure 4). In this state, if the flat plate 1 is lowered slightly so that its lower edge contacts the lower flat plate holding member 6, the flat plate 1 will be held by the winch 10 and wire 11, and its lower part will be supported by the lower flat plate holding member 6. At this time, the upper edge of the flat plate 1 will be covered (surrounded) by the upper flat plate holding member 5. Thus, the operation of raising the flat plate 1 to the position shown in Figure 3 is completed.

[0026] Next, with reference to Figures 12 to 16, the procedure for the plate load test according to the illustrated embodiment will be described. In Figure 12, in step S1, the tire roller 20 is moved to a predetermined flat plate load test position. As shown in Figures 14 and 3, the flat plate 1 is held on the side of the tire roller 20, so the tire roller 20 is movable. In step S2, it is determined whether the tire roller 20 has arrived at the plate load test position. If the tire roller 20 has arrived at the test position (step S2 is "Yes"), proceed to step S3; if the tire roller 20 has not arrived at the test position (step S2 is "No"), return to step S1 (a loop of step S2 being "No").

[0027] In step S3, the engagement between the lower member 6 for holding the flat plate and the flat plate 1 is released in the manner described with reference to Figures 4 and 5. In step S4, the wire 11 (Figure 3) is wound down from the winch 10 (Figure 3) to lower the plate 1. The lowered plate 1 is placed in the position where the plate loading test should be performed, with the jig 1A facing upwards, as described with reference to Figures 6 to 9. In step S5, it is determined whether or not plate 1 has been placed in the test position. If, as a result of the determination in step S5, plate 1 has been placed in the test position (step S5 is "Yes"), the process proceeds to step S6. If plate 1 has not yet been placed in the test position (step S5 is "No"), the process returns to step S4. Steps S4 and S5 are steps in which the flat plate 1 is placed in the test position.

[0028] In the plate load test using the plate load test apparatus 100 of the illustrated embodiment, the weight of the tire roller 20 is transmitted to the load cell 9 via the load pipe 4 and jack 12. However, it is conceivable that the body of the tire roller 20 may tilt too much, creating a dangerous situation. Therefore, in step S6, the jacks constituting the outrigger 19 are installed on the side of the tire roller 20 opposite to the side where the load pipe 4 (Figure 1) is installed (the side on which the plate load test is performed). By installing the outrigger 19, the tire roller 20 is prevented from tilting during the plate load test. Figures 15 and 16 show the state with the outriggers 19 installed. In Figure 15, wheel chocks 21 are installed on the rear wheels of the tire roller 20. Figure 16 shows the state where a load cell 9 and a jack 12 are installed on the side of the tire roller 20 opposite to the side with the outriggers 19, and the load pipe 4 can load the weight of the tire roller 20 onto the load cell 9 and jack 12. Step S6 is the process of installing the outrigger 12 on the opposite side of the tire roller 20 from where the flat plate holding portion 2 is provided. Here, the steps of lowering the flat plate 1 in steps S4 and S5 and placing it in the test position can be performed prior to the step of installing the outrigger 19 in step S6, as shown in Figure 12, but steps S4 and S5 can also be performed after step S6.

[0029] In step S7 of Figure 12, the test equipment, which includes the settlement measurement beam 13, beam mounting base 17, beam support column 16, beam holder 15, and settlement measurement gauge 14 (gauge body 14A, support column 14B, and base 14C), is installed at the plate load test location as described with reference to Figure 1. In step S8, as explained in Figure 1, a load cell 9 for measuring load and a jack 12 are placed on the flat plate 1. Then, in step S9, a plate load test is performed. The plate load test itself is performed in a known manner as described above, but in the illustrated embodiment, the weight of the tire roller 20 is loaded onto the load cell 9 via the load pipe 4 by jacking up the jack 12. In this respect, it differs from the prior art. Then, in step S9, the amount of settlement of the flat plate 1 is measured using the settlement measurement gauge 14.

[0030] Step S10 determines whether the plate load test in Step S has been completed. If the plate load test has been completed in Step S10 (Step S10 is "Yes"), proceed to Step S11; if the plate load test has not been completed (Step S10 is "No"), return to Step S9. In step S11 (completion of the plate load test), the load (vehicle weight of the tire roller 20) that was applied to the plate 1 in step S9 via the load pipe 4, jack 12, and load cell 9 is released. Then, the test equipment such as the load cell 9, jack 12, settlement measurement gauge 14, settlement measurement beam 13, beam holder 15, beam support column 16, and beam mounting base 17 are removed. Then, the process proceeds to step S12 in Figure 13.

[0031] In step S12, shown in Figure 13, the outrigger 19 installed in step S6 is removed. Then, in step S13, the flat plate 1 is hoisted up by the winch 10 in the manner described in Figures 10 and 11. In step S14, it is determined whether the rolled-up flat plate 1 is held on the side of the tire roller 20. More specifically, it is determined whether the flat plate 1 is held along the front surface 3D (Figure 11) of the flat plate guide 3 positioned on the side of the tire roller 20, and whether the lower edge of the flat plate 1 has risen to a position above the through hole 8B (Figure 5, a component for engaging the lower flat plate holding member 6 with the flat plate support position). In other words, step S14 determines whether the flat plate 1 has reached a position on the side of the tire roller 20 where it is supported by the lower member 6 for holding the flat plate. In step S14, if the flat plate 1 is held against the side of the tire roller 20 (step S14 is "Yes"), proceed to step S15; otherwise, if the flat plate 1 is not held against the side of the tire roller 20 (step S14 is "No"), return to step S13 (loop for step S14 being "No").

[0032] In step S15 (the flat plate 1 is held on the side of the tire roller 20), the flat plate 1 is supported by the lower flat plate holding member 6. As a result, the flat plate 1 is held by the winch 10 and the wire 11, and its lower part is supported by the lower flat plate holding member 6. Furthermore, the upper edge of the flat plate 1 is covered (surrounded) by the upper flat plate holding member 5. As a result, the flat plate 1 is held on the side of the tire roller 20 in the manner shown in Figure 3. Steps S13 to S15 are the process of moving the plate 1 from the test position to the plate holding section 2 after the plate loading test is completed. Here, the step of removing the outrigger 19 in step S12 is performed prior to the steps of raising the flat plate 1 and supporting it with the lower flat plate holding member 6 in steps S13 to S15 in Figure 13, but the steps of steps S13 to S15 may be performed prior to the step of step S12.

[0033] In Figure 13, in step S16, the test equipment and devices removed in step 11 are stored in the storage section 20A of the tire roller 20. As mentioned above, the load cell 9 and the sinkage measurement gauge 14 are affected by vibrations when the tire roller 20 is running, so it is preferable to transport them in a regular automobile. In step S17, the tire roller 20, loaded with the plate 1 used in the plate load test and the test equipment, is moved from the test location (test site) where steps S1 to S16 were performed. In step S18, for example, it is determined whether the plate load test has been completed at all test locations where the plate load test is scheduled to be performed. In step S18, for example, if the plate load test has been completed at all scheduled test locations (step S18 is "Yes"), the process proceeds to step S19; otherwise, the process returns to step S1 in Figure 12. In step S19 (completion of all plate load tests at the planned test locations), the tire roller 20 is moved to the designated removal location (vehicle storage area, etc.), and the plate load tests are completed.

[0034] The illustrated embodiments are for illustrative purposes only and are not intended to limit the technical scope of the present invention. [Explanation of Symbols]

[0035] 1. Flat plate (flat plate for flat plate load testing) 2... Flat plate holding part 3. Guide for flat plates 3A... Taper 4. Load-bearing pipes 5. Upper member for holding flat plate 6. Lower member for holding flat plate 9. Load cell 10...Winch 19. Outrigger 20... Tire Roller 100...Plate load testing apparatus

Claims

1. Equipped with a load-applying device, The load-applying device has a plate holder that holds a plate used in a plate load test. The plate holding section is provided with two plate guides that guide the plate held on the side of the load-applying device when it is lowered or raised, and a taper is formed at the lower end of each plate guide. A load pipe is provided in the region between the two flat plate guides and has the function of applying the vehicle weight of the load-applying device to the flat plate, A device for testing flat plate loads, characterized by having a winch that lowers and raises the flat plate along the flat plate guide.

2. The flat plate holding portion comprises an upper flat plate holding member provided on the upper part of the flat plate guide and surrounding the upper part of the flat plate in contact with the flat plate guide, and a lower flat plate holding member provided on the lower end of the flat plate guide and supporting the lower edge of the flat plate in contact with the flat plate guide, according to claim 1, for flat plate loading testing apparatus.

3. A method for performing a plate load test using a plate load test apparatus according to either claim 1 or claim 2, A step of installing an outrigger on the side of the load-bearing device opposite to the side on which the flat plate holding portion is provided, The process of placing the plate at the test position during a plate load test, A method characterized by including the step of moving the plate from the test position to the plate holding section after the plate loading test is completed.

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