Adjustable anchor pile method static load testing device

Abstract

The application discloses a kind of adjustable anchor pile method static load testing device, belongs to anchor pile method static load testing technical field, it solves the technical problem that the horizontal degree of existing anchor pile method static load testing device is adjusted difficult, anchor pile quantity is more, test cost is high and test time is long.It contains test pile, anchor pile, crossbeam, loading device, support assembly and anchoring connecting device. Among them, support assembly is fixedly connected with crossbeam, the height of support rod in support assembly is adjusted to realize the adjustment of the horizontal degree of crossbeam, secondly, anchoring connecting device contains steel strand pre-buried in reinforced steel strand cage and counter-pulling locking device, using the high tensile strength of steel strand provides counterforce for test pile, reduces the anchor pile quantity, reduces test cost and shortens test time, the counter-pulling locking device contains locating block and clamping block, by the interaction of the taper surface of locating block and clamping block, inward shrinkage holds tightly steel strand, and steel strand will produce the effect of more and more tight.

Description

Technical Field

[0001] This invention relates to the field of static load testing technology using anchor piles, specifically to an adjustable static load testing device for anchor piles. Background Technology

[0002] Static load testing is a test to assess the bearing capacity of building foundation piles. It involves applying vertical pressure to the top of the test pile in stages, measuring the settlement of the pile top under different loads, obtaining auxiliary curves for the static load test, and then deriving parameters such as the characteristic value of the vertical compressive bearing capacity of the single pile based on the curves.

[0003] There are two main loading methods for static load testing of foundation piles: the surcharge method and the anchor pile method. Small-tonnage static load tests often use the surcharge method, while large-tonnage static load tests often use the anchor pile method. A Chinese utility model, CN 217105249 U, discloses a testing device for static load testing using the anchor pile method. This device uses a loading device to lift the main beam, which then transfers the force to an auxiliary beam. The auxiliary beam is connected to the anchor bars pre-embedded in the anchor piles via a clamp assembly. Multiple anchor piles distributed around the test pile provide counter-tension. By controlling the applied load of the loading device, the test pile is subjected to graded loading to achieve the detection of the foundation pile's bearing capacity. This device solves the problem of the anchor bars easily breaking off from the auxiliary beam when welded to it. However, it has the following shortcomings in its use:

[0004] 1. During the leveling process of the main beam and auxiliary beam, the leveling of the main beam and auxiliary beam is difficult due to the mutual interference of multiple fastening points on the auxiliary beam and the mutual interference between the main beam and auxiliary beam. It is impossible to ensure that the threaded rod in the clamp assembly and the anchor bar in the anchor pile are evenly stressed during the test, which may lead to uneven load or overload, and there is a risk that the threaded rod and the reinforcing bar may be easily pulled off.

[0005] 2. The leveling of the main beam and auxiliary beam can only be adjusted under the condition of hoisting or with the use of other auxiliary tools, which poses a safety hazard, or requires the addition of other auxiliary tools;

[0006] 3. The main beam and auxiliary beam are combined with the crossbeam structure and connected to the anchor bars in the multiple anchor piles around the test pile to provide the test pile with the counter-tension force. The large number of anchor piles results in high testing costs and long testing time. On the other hand, the large number of crossbeams makes the structure complicated and increases the costs of manufacturing, transportation and testing.

[0007] With the emergence of numerous super high-rise buildings, the ultimate bearing capacity of single piles used in foundations is increasing, making the aforementioned defects in existing anchor pile static load testing devices more prominent. To solve these technical problems, it is urgent to provide an adjustable anchor pile static load testing device to overcome the shortcomings of existing technologies. Summary of the Invention

[0008] The present invention aims to provide an adjustable anchor pile static load testing device to solve the technical problems of difficulty in adjusting the horizontality of the crossbeam, safety hazards, large number of anchor piles, high testing cost and long testing time.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] An adjustable anchor pile static load testing device includes anchor piles arranged on both sides of the test pile, a crossbeam placed above the anchor piles, a loading device located below the crossbeam, and anchoring connection devices arranged on both sides of the crossbeam. The loading device includes a hydraulic jack, the upper end of which is connected to the lower surface of the crossbeam through an upper pad, and the lower end of which is connected to the upper surface of the test pile through a lower pad. The device is characterized by:

[0011] Adjustable height support components are provided on both sides of the crossbeam. These components include hollow support legs that are detachably connected to the crossbeam, and universal adjustable feet located at the bottom of the support legs. The universal adjustable feet are provided with a base, a hinge joint, a limiting plate, a support rod, a locking nut, and a fixing nut from bottom to top. The base is fixed to the ground. The lower end of the hinge joint is rotatably connected to the base via a pin. The upper end face of the hinge joint is provided with a cylindrical groove. A detachably connected limiting plate is provided on the cylindrical groove. The lower end of the support rod is provided with a hemispherical head. The support rod is rotatably positioned in the cylindrical groove of the hinge joint via the hemispherical head. The support rod is provided with external threads. The locking nut is sleeved on the end of the support rod near the hemispherical head via the external threads. The fixing nut is placed above the locking nut. The fixing nut is sleeved on the support rod via the external threads and is fixedly connected to the support leg.

[0012] The anchoring connection device includes a steel strand cage embedded in the anchor pile, steel strands pre-embedded in the steel strand cage, and a reverse-pull locking device for fixing the steel strands to the crossbeam. The reverse-pull locking device includes a connecting plate fixedly connected to the crossbeam, a positioning block placed on the connecting plate, and multiple clamping blocks placed inside the positioning block. The connecting plate has a through hole through which the steel strands pass. The positioning block has multiple inverted conical inner holes. The clamping block has an inverted conical surface on the outside and a cylindrical hole on the inside. The clamping block has a symmetrical two-half structure. The steel strands pass through the through hole in the connecting plate, the inverted conical inner hole in the positioning block, and the cylindrical hole in the clamping block from bottom to top. When the steel strands are pulled downwards, the interaction between the inner conical surface of the inverted conical inner hole in the positioning block and the outer conical surface of the inverted conical surface in the clamping block causes the clamping block to contract inwards and clamp the steel strands, thus fixing the steel strands to the crossbeam.

[0013] Furthermore, there are four support components, arranged symmetrically on both sides of the crossbeam in a figure-eight shape.

[0014] Furthermore, the height of the outer conical surface of the inverted conical surface in the clamping block is greater than the height of the inner conical surface of the inverted conical inner hole in the positioning block.

[0015] Furthermore, the lower center of the crossbeam extends downwards and protrudes.

[0016] Furthermore, the steel strand is a standard type steel strand made of seven steel wires twisted together, with a nominal tensile strength grade of 1860MPa.

[0017] Furthermore, a displacement detection device is installed at the center of the test pile, which includes a fixed bracket fixed to the ground, a support pipe passing through both sides of the hydraulic jack and detachably connected to the fixed bracket, a connecting seat fixed in the middle of the support pipe, and a displacement sensor installed on the connecting seat. The probe of the displacement sensor contacts the upper surface of the lower pad.

[0018] Furthermore, there are four displacement sensors, evenly arranged on the same circumference with the center of the test pile as the center.

[0019] Furthermore, the connector is magnetic, and the support tube is made of carbon steel.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] 1. Adjustable height support components are arranged on both sides of the crossbeam. By rotating the screw in the support component, the length of each support component can be adjusted individually, so that the horizontality of the crossbeam can be adjusted when it is fixed on the ground. The adjustment is simple and convenient, ensuring that the steel strand is evenly stressed and improving the safety and stability of static load testing.

[0022] 2. The base of the support component is connected by a pin, which can ensure that the base maintains good contact with the ground under certain slope conditions, meet the needs of adjusting the horizontality of the beam under various working conditions, and has a wider range of applicable working conditions.

[0023] 3. An anchoring connection device that uses steel strands pre-embedded in the steel strand cage to fix the crossbeam with counter-tension is adopted. By utilizing the high tensile strength of the steel strands, the tensile strength of a single anchor pile is greatly improved, and the counter-tension of the anchoring connection device is greatly improved. Under the condition that the vertical compressive bearing capacity of the tested single pile is the same and the diameter of the anchor pile is the same, the number of anchor piles can be reduced by at least 1 / 2. This reduces the additional pile manufacturing cost, shortens the testing time, and reduces the testing cost. At the same time, it reduces the number of crossbeams, simplifies the crossbeam structure, reduces the manufacturing and transportation costs of crossbeams, shortens the crossbeam installation and commissioning cycle, and improves the overall testing efficiency.

[0024] 4. When the steel strand is pulled downwards, the inner conical surface of the positioning block in the anti-pull locking device interacts with the outer conical surface of the clamping block, causing the clamping block to contract inwards and tighten the steel strand, fixing the steel strand to the crossbeam. By using this conical wedge connection structure to fix the steel strand, the steel strand will produce an effect of becoming tighter as it is pulled, which further improves the reliability of the testing device. Its structure is simple, easy to disassemble and assemble, and low in cost. Attached Figure Description

[0025] Figure 1 This is a structural schematic diagram of an embodiment of the present invention.

[0026] Figure 2 yes Figure 1 Main view

[0027] Figure 3 yes Figure 2 AA section view

[0028] Figure 4 yes Figure 2 Top view

[0029] Figure 5 yes Figure 1 Enlarged view of local N

[0030] Figure 6 yes Figure 4 Sectional view of BB

[0031] Figure 7 yes Figure 3 Enlarged view of local M

[0032] Figure 8 yes Figure 7 Sectional view of CC

[0033] Figure 9 This is a schematic diagram of the clamping block according to an embodiment of the present invention.

[0034] Figure 10 yes Figure 9 Top view

[0035] Attached reference numerals: 1. Test pile; 2. Anchor pile; 3. Crossbeam; 4. Loading device; 4-1. Upper pad; 4-2. Hydraulic jack; 4-3. Lower pad; 5. Support assembly; 5. Support leg; 5-1. Fixing nut; 5-2. Locking nut; 5-3. Support rod; 5-4. Hinge joint; 5-5. Pin; 5-6. Base; 5-7. Limiting plate; 5-8. Anchoring connection device; 6. Connecting plate; 6-1. Steel strand; 6-2. Positioning block; 6-3. Clamping block; 6-4. Reinforcing steel strand cage; 6-5. Displacement detection device; 7. Fixed bracket; 7-1. Support pipe; 7-2. Displacement sensor; 7-3. Connecting seat; 7-4. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] The adjustable anchor pile static load testing device provided by this invention, such as... Figures 1 to 3 As shown, it includes anchor piles 2 arranged on both sides of the test pile 1, a crossbeam 3 placed above the anchor piles 2, a loading device 4 located below the crossbeam 3, and anchoring connection devices 6 arranged on both sides of the crossbeam 3. The loading device 4 includes a hydraulic jack 4-2, the upper end of which is connected to the lower surface of the crossbeam 3 through an upper pad 4-1, and the lower end of which is connected to the upper surface of the test pile 1 through a lower pad 4-3. Its characteristic is that:

[0038] Adjustable height support components 5 are provided on both sides of the crossbeam 3, such as... Figure 1 , Figure 7 , Figure 8 As shown, it includes a hollow support leg 5-1 detachably connected to the crossbeam 3, and a universal adjustable foot located at the bottom of the support leg 5-1. The universal adjustable foot, from bottom to top, includes a base 5-7, a hinge joint 5-5, a limiting plate 5-8, a support rod 5-4, a locking nut 5-3, and a fixing nut 5-2. The base 5-7 is fixed to the ground. The lower end of the hinge joint 5-5 is rotatably connected to the base 5-7 via a pin 5-6. The upper end face of the hinge joint 5-5 has a cylindrical groove. A detachable limiting plate 5-8 is provided on the groove. A hemispherical head is provided at the lower end of the support rod 5-4. The support rod 5-4 is rotatably set in the cylindrical groove of the hinge joint 5-5 through the hemispherical head. The support rod 5-4 is provided with external threads. The locking nut 5-3 is sleeved on the end of the support rod 5-4 near the hemispherical head through the external threads. The fixing nut 5-2 is placed above the locking nut 5-3. The fixing nut 5-2 is sleeved on the support rod 5-4 through the external threads and is fixedly connected to the support leg 5-1.

[0039] Anchoring connection device 6, such as Figure 1 , Figure 2 , Figure 6As shown, it includes a steel strand cage 6-5 embedded in the anchor pile 2, steel strands 6-2 pre-embedded in the steel strand cage 6-5, and a reverse tension locking device for fixing the steel strands 6-2 to the crossbeam 3. The reverse tension locking device includes a connecting plate 6-1 fixedly connected to the crossbeam 3, a positioning block 6-3 placed on the connecting plate 6-1, and multiple clamping blocks 6-4 placed inside the positioning block 6-3. The connecting plate 6-1 is provided with a through hole through which the steel strands 6-2 pass, and the positioning block 6-3 is provided with multiple inverted conical inner holes. The clamping blocks 6-4... The outer surface of 4 is an inverted conical surface, and the inner surface is a cylindrical hole. The clamping block 6-4 has a symmetrical two-half structure. The steel strand 6-2 passes through the through hole in the connecting plate 6-1, the inverted conical inner hole in the positioning block 6-3, and the cylindrical hole in the clamping block 6-4 from bottom to top. When the steel strand 6-2 is pulled downward, the inner conical surface of the inverted conical inner hole in the positioning block 6-3 interacts with the outer conical surface of the inverted conical surface in the clamping block 6-4, causing the clamping block 6-4 to contract inward and hug the steel strand 6-2, thus fixing the steel strand 6-2 to the crossbeam 3.

[0040] In the above embodiment, adjustable height support components 5 are provided on both sides of the crossbeam 3. On the one hand, after the crossbeam 3 is hoisted above the test pile 1 and anchor pile 2, the support components 5 can be fixedly connected to the crossbeam 3, and the crossbeam 3 can be supported on the ground by the support components 5, reducing the operation time for adjusting the crossbeam 3 in the hoisted state and avoiding safety hazards. On the other hand, by adjusting the height of each support component 5 individually, the horizontality of the crossbeam 3 in the fixed state on the ground can be adjusted, ensuring that the steel strand 6-2 is evenly stressed, and improving the safety and stability of the static load test.

[0041] In the above embodiment, after loosening the locking nut 5-3 of the support component 5 from the fixing nut 5-2 by a certain distance, the support rod 5-4 is rotated to screw the support rod 5-4 into or out of the fixing nut 5-2, changing the length distance between the support leg 5-1 and the base 5-7, thereby adjusting the length of the support component 5 and thus adjusting the level of the crossbeam 3. After the level of the crossbeam 3 is adjusted, the locking nut 5-3 is rotated to make it close to the fixing nut 5-2, locking the level of the crossbeam 3 and improving stability. The base 5-7 is movably connected to the hinge joint 5-5 through the pin 5-6, so that when the ground has a certain slope, the bottom surface of the base 5-7 can fully contact the ground, which can meet the need to adjust the level of the crossbeam 3 under a certain slope, and has a wider range of applicable working conditions.

[0042] In the above embodiment, steel strands 6-2 pre-embedded in the steel strand cage 6-5 are used to fix the crossbeam 3 with counter-tension. The high tensile strength of the steel strands 6-2 is used to improve the tensile strength of a single anchor pile 2, thereby increasing the counter-tension of the anchoring connection device 6.

[0043] In the above embodiments, in order to efficiently and quickly fix the steel strand 6-2 onto the crossbeam 3, such as... Figure 1 , Figure 2 , Figure 6 As shown, when the anti-pull locking device described in the anchoring connection device 6 is in use, the inner conical surface of the positioning block 6-3 interacts with the outer conical surface of the clamping block 6-4. The clamping block 6-4, which is a two-half structure, retracts inward to hug the steel strand 6-2, fixing the steel strand 6-2 to the crossbeam 3. By using this conical wedge-tight structure to fix the steel strand 6-2, the steel strand 6-2 will become tighter and tighter as it is pulled. The structure is simple, easy to assemble and disassemble, low in cost, and high in work efficiency.

[0044] To improve the sensitivity of the horizontal adjustment of beam 3, such as Figure 1 As shown, there are 4 support components 5, which are symmetrically arranged on both sides of the crossbeam (3) in a figure-eight shape.

[0045] To facilitate the removal of clamping block 6-4 from positioning block 6-3, such as Figure 6 As shown, the height of the outer conical surface of the inverted conical surface in clamping block 6-4 is greater than the height of the inner conical surface of the inverted conical inner hole in positioning block 6-3, leaving space for the disassembly of clamping block 6-4.

[0046] To increase the strength and rigidity of beam 3, such as Figure 2 As shown, the middle of the crossbeam 3 extends downward and protrudes. The crossbeam has a frame-like structure that is larger in the middle and smaller at both ends, which helps to improve the stability of the entire force transmission system.

[0047] To further improve the tensile strength of anchor pile 2, steel strand 6-2 is a standard type steel strand made of seven steel wires, with a nominal tensile strength grade of 1860MPa.

[0048] To provide a testing device compatible with this adjustable anchor pile static load testing device, such as... Figure 1 , Figure 4 , Figure 5 As shown, a displacement detection device 7 is installed at the center of test pile 1. This device includes a fixed bracket 7-1 fixed to the ground, a support pipe 7-2 passing through both sides of a hydraulic jack 4-2 and detachably connected to the fixed bracket 7-1, a connecting seat 7-4 fixed in the middle of the support pipe 7-2, and a displacement sensor 7-3 mounted on the connecting seat 7-4. The probe of the displacement sensor 7-3 contacts the upper surface of the lower pad 4-3. The fixed bracket 7-1 and the support pipe 7-2 have a detachable connection structure, facilitating installation and disassembly during testing and reducing space occupation during transportation.

[0049] To improve the accuracy of pile top settlement measurement data, such as Figure 1 , Figure 5As shown, the displacement detection device 7 contains four displacement sensors 7-3, which are evenly arranged on the same circumference with the center of the test pile 1 as the center. The four sets of data measured by the four displacement sensors 7-3 can be statistically analyzed.

[0050] In order to quickly load and unload the displacement sensor 7-3 in the displacement detection device 7 and quickly adjust the detection position of the displacement sensor 7-3, the connecting seat 7-4 is magnetic, the support tube 7-2 is made of carbon steel, the displacement sensor 7-3 is installed on the connecting seat 7-4, and the connecting seat 7-4 is magnetically attached to the support tube 7-2.

[0051] It should be noted that in the prior art, the anchor bars commonly used in anchor piles are usually HRB400 grade steel bars. According to the standard GB1499.2-2018 "Hot-rolled ribbed steel bars for reinforced concrete", the tensile strength Rm of HRB400 grade steel bars is 540MPa. In the embodiments of the present invention, the steel strands pre-embedded in the steel strand cage are prestressed concrete steel strands, usually seven steel wires twisted into a standard type steel strand. According to GB / T5224-2014 "Steel strands for prestressed concrete", the tensile strength Rm of the steel strands ranges from 1470MPa to 1960MPa. Therefore, it can be seen that the tensile strength of a single steel strand of the same diameter is 2.72 to 3.62 times that of a single steel rebar. Comparing the commonly used tensile strength Rm of a single steel strand to 1860 MPa, the tensile strength of a single steel strand of the same diameter is 3.44 times that of a single steel rebar. Therefore, when the same number of steel strands and steel rebars of the same diameter are embedded in the same single anchor pile, the tensile strength of the anchor pile using steel strands is 3.44 times that of the anchor pile using steel rebar. Existing anchor pile static load testing devices use a structure where reinforcing bars embedded in anchor piles are welded or bolted to a crossbeam to provide counter-tension. Because this anchoring connection is limited by the tensile strength of the reinforcing bars, at least four anchor piles are required around the test pile to ensure sufficient counter-tension. In the embodiment of this invention, the anchoring connection device 6 uses steel strands 6-2 pre-embedded in a steel strand cage 6-5 to fix the crossbeam 3, providing counter-tension to the test pile 1. Compared with existing anchor pile static load testing devices, this method uses steel strands of equal diameter and quantity instead of reinforcing bars. Under the same testing conditions, the number of anchor piles can be reduced by at least half, reducing additional pile manufacturing costs, shortening testing time, and reducing testing costs. Simultaneously, it reduces the number of crossbeams, simplifies the crossbeam structure, reduces manufacturing and transportation costs, shortens the installation and commissioning cycle, and improves the overall testing efficiency.

[0052] Working principle:

[0053] Select the test pile 1 to be tested, and arrange two anchor piles 2 symmetrically on both sides of the test pile 1. Pre-embed steel strands 6-2 in the steel strand cages 6-5 of the anchor piles 2; hoist the crossbeam 3 above the test pile 1 and anchor piles 2, connect the support components 5 on both sides of the crossbeam 3 respectively, and fix the loading device 4 between the crossbeam 3 and the test pile 1; rotate the length of the support rods 5-4 in the four support components 5 so that the lower surface of the crossbeam 3 contacts the upper surface of the upper pad block 4-1 at the upper end of the hydraulic jack 4-2, and at the same time make the upper surface of the crossbeam 3 horizontal, thus completing the initial adjustment of the height and level of the crossbeam 3. Positioning blocks 6-3 are placed on the four connecting plates 6-1 above the crossbeam 3. Clamping blocks (6-4) are placed in the multiple inverted conical inner holes of the positioning blocks 6-3. The steel strand 6-2 is straightened using a hydraulic puller. The steel strand 6-2 passes through the through hole of the connecting plate 6-1, the inverted conical inner hole of the positioning block 6-3, and the inner cylindrical hole of the clamping block (6-4) from bottom to top. The clamping block 6-4 is wedged into the inverted conical inner hole of the positioning block 6-3. The hydraulic jack 4-2 is activated to push upward a short distance. The crossbeam 3 moves the positioning blocks 6-3 and the clamping blocks (6-4) inside the positioning blocks 6-3. Together, they rise a short distance, and the steel strand 6-2 is pulled downwards a short distance. Through the interaction between the inner conical surface of the positioning block 6-3 and the outer conical surface of the clamping block 6-4, the clamping block 6-4 of the two-part structure retracts inward to hug the steel strand 6-2, fixing the steel strand 6-2 to the crossbeam 3. At this time, by readjusting the length of the support rod 5-4 in the four support components 5, the level of the crossbeam 3 is finely adjusted. Finally, the locking nut 5-3 on the support rod 5-4 is rotated to make it close to the fixing nut 5-2, locking the position of the level of the crossbeam 3, and completing the work of adjusting the level of the crossbeam 3.

[0054] During the static load test, the jacking force of the hydraulic jack 4-2 is set as required. The hydraulic system drives the hydraulic jack 4-2 to push upward. The jacking force of the hydraulic jack 4-2 is transmitted to the crossbeam 3 through the upper pad 4-1. The crossbeam 3 is then subjected to an upward thrust in the middle and a downward tension at both ends by the steel strands 6-2. When the jacking force of the hydraulic jack 4-2 reaches the set value, the jacking force will not increase further. At this time, the upward thrust and downward tension of the crossbeam 3 are equal, keeping it in a static state. The jacking force of the hydraulic jack 4-2 is then fully applied to the test pile 1 through the lower pad 4-3. This state is maintained according to the static load test time requirements. After the static load holding time is reached, the amount of settlement generated by the test pile 1 will be measured by the displacement sensor 7-3 and displayed on the monitor. Set the jacking force of hydraulic jack 4-2 to be applied in stages, and apply it to test pile 1 in stages. The settlement of a single pile under different loads is obtained by actual measurement, thereby achieving the purpose of pile bearing capacity testing.

[0055] It should be noted that, in this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixing," "setting," etc., should be interpreted broadly. For example, "fixing" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0056] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

Claims

1. An adjustable anchor pile static load testing device, comprising anchor piles (2) arranged on both sides of a test pile (1), a crossbeam (3) placed above the anchor piles (2), a loading device (4) located below the crossbeam (3), and anchoring connection devices (6) arranged on both sides of the crossbeam (3), wherein the loading device (4) comprises a hydraulic jack (4-2), the upper end of the hydraulic jack (4-2) is connected to the lower surface of the crossbeam (3) through an upper pad (4-1), and the lower end of the hydraulic jack (4-2) is connected to the upper surface of the test pile (1) through a lower pad (4-3), characterized in that: Adjustable height support devices (5) are provided on both sides of the crossbeam (3), including hollow support legs (5-1) that are detachably connected to the crossbeam (3) and universal adjustable feet at the bottom of the support legs (5-1). The universal adjustable feet are provided with a base (5-7), a hinge joint (5-5), a limiting plate (5-8), a support rod (5-4), a locking nut (5-3), and a fixing nut (5-2) from bottom to top. The base (5-7) is fixed to the ground. The lower end of the hinge joint (5-5) is rotatably connected to the base (5-7) through a pin (5-6). The upper end face of the hinge joint (5-5) is provided with a cylinder. A cylindrical groove is provided, on which a detachable limiting plate (5-8) is provided. The lower end of the support rod (5-4) is provided with a hemispherical head. The support rod (5-4) is rotatably set in the cylindrical groove of the hinge joint (5-5) through the hemispherical head. The support rod (5-4) is provided with an external thread. The locking nut (5-3) is sleeved on the end of the support rod (5-4) near the hemispherical head through the external thread. The fixing nut (5-2) is placed above the locking nut (5-3). The fixing nut (5-2) is sleeved on the support rod (5-4) through the external thread and is fixedly connected to the support leg (5-1). The anchoring connection device (6) includes a steel strand cage (6-5) embedded in the anchor pile (2), a steel strand (6-2) pre-embedded in the steel strand cage (6-5), and a reverse tension locking device for fixing the steel strand (6-2) to the crossbeam (3). The reverse tension locking device includes a connecting plate (6-1) fixedly connected to the crossbeam (3), a positioning block (6-3) placed on the connecting plate (6-1), and multiple clamping blocks (6-4) placed inside the positioning block (6-3). The connecting plate (6-1) is provided with a through hole through which the steel strand (6-2) passes, and the positioning block (6-3) is provided with multiple inverted conical inner holes. The clamping block (6-4) has an inverted conical surface on the outside and a cylindrical hole on the inside. The clamping block (6-4) is a symmetrical two-half structure. The steel strand (6-2) passes through the through hole in the connecting plate (6-1), the inverted conical inner hole in the positioning block (6-3), and the cylindrical hole in the clamping block (6-4) from bottom to top. When the steel strand (6-2) is pulled downward, the inner conical surface of the inverted conical inner hole in the positioning block (6-3) interacts with the outer conical surface of the inverted conical surface in the clamping block (6-4), causing the clamping block (6-4) to contract inward and hug the steel strand (6-2), thus fixing the steel strand (6-2) on the crossbeam (3).

2. The adjustable anchor pile static load testing device according to claim 1, characterized in that: There are 4 support devices (5), which are symmetrically arranged on both sides of the crossbeam (3) in a figure-eight shape.

3. The adjustable anchor pile static load testing device according to claim 1, characterized in that: The height of the outer cone surface of the inverted conical surface in the clamping block (6-4) is greater than the height of the inner cone surface of the inverted conical inner hole in the positioning block (6-3).

4. The adjustable anchor pile static load testing device according to any one of claims 1-3, characterized in that: The lower center of the crossbeam (3) extends downward and protrudes.

5. The adjustable anchor pile static load testing device according to any one of claims 1-3, characterized in that: The steel strand (6-2) is a standard type steel strand made of seven steel wires twisted together, with a nominal tensile strength grade of 1860MPa.

6. The adjustable anchor pile static load testing device according to any one of claims 1-3, characterized in that: A displacement detection device (7) is also provided at the center of the test pile (1), which includes a fixed bracket (7-1) fixed to the ground, a support pipe (7-2) passing through both sides of the hydraulic jack (4-2) and detachably connected to the fixed bracket (7-1), a connecting seat (7-4) fixed in the middle of the support pipe (7-2), and a displacement sensor (7-3) installed on the connecting seat (7-4). The probe of the displacement sensor (7-3) contacts the upper surface of the lower pad (4-3).

7. The adjustable anchor pile static load testing device according to claim 6, characterized in that: There are four displacement sensors (7-3), which are evenly arranged on the same circumference with the center of the test pile (1) as the center.

8. The adjustable anchor pile static load testing device according to claim 6, characterized in that: The connector (7-4) is magnetic, and the support tube (7-2) is made of carbon steel.

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