Anti-pulling test device for cable-stayed anchor rod of photovoltaic flexible support

Abstract

The utility model provides an anti-pulling test device for a cable-stayed anchor rod of a photovoltaic flexible support, the anti-pulling test device comprises a detection module, a plurality of steel piles, a pressure-bearing table and a detection frame, the pressure-bearing table is supported at the tops of the steel piles, and the detection frame is clamped on the pressure-bearing table; a hollow hydraulic jack is arranged on the detection surface of the detection frame; an anchor rod passage is arranged on the pressure-bearing table, an anchor rod passing passage is arranged on the detection frame, and an anchor rod to be detected can be stretched and detected by the hollow hydraulic jack after sequentially passing through the anchor rod passage and the anchor rod passing passage; the detection module comprises a pressure meter and a deformation detection part, the pressure meter is used for detecting the pressure of the hollow hydraulic jack, and the deformation detection part is used for detecting the deformation degree of the anchor rod. The multiple steel piles are used for forming the pile group foundation, the rigidity is large, the vertical bearing capacity and the horizontal bearing capacity are both high, in other words, the reaction force of a testing system is large, deformation is small and stable, and the problems that a soft foundation is insufficient in reaction force, large in deformation, uneven in deformation, unstable and the like are solved.

Description

Technical Field

[0001] The utility model relates to a pull-out resistance testing device for an oblique anchor rod of a photovoltaic flexible support. Background Art

[0002] The photovoltaic flexible mounting system is a large-span, high-headroom, multi-span structure. It requires prestressed steel cables to be tensioned between two fixed points. The two fixed points utilize a rigid structure with externally inclined steel strands providing support and reaction forces. This system not only addresses the poor environmental adaptability and high development costs of traditional photovoltaic mounting systems, but also enables comprehensive utilization of site space. It is suitable for applications requiring a wide array span and installation height, such as fish-based solar systems, sewage treatment plants, mountainous areas, agricultural solar systems, and forest solar systems.

[0003] In photovoltaic flexible support technology, the anchoring of the diagonal steel strands is a key structural design factor. Using a conventional foundation for anchoring can be difficult, lacking pullout resistance, and requiring high soil quality. Using an enlarged-head anchor rod foundation reduces costs while ensuring pullout resistance and, to a certain extent, lowering soil quality requirements. Furthermore, the enlarged-head anchor rod shortens the anchoring section, making construction easier and more adaptable. Because the enlarged-head anchor rod foundation is inclined, it is called a diagonal anchor rod.

[0004] To ensure the pullout resistance of cable-stayed anchor bolts, pullout resistance testing is necessary. Currently, pullout resistance is generally evaluated using the load-uplift curve of the pullout test. Currently, the pullout resistance testing device for cable-stayed anchor bolts is mainly an in-situ testing system, which mainly includes a reaction structure, a beam, a high-pressure oil pump, and a jack.

[0005] In areas like fish ponds and tidal flats, deep, soft soil foundations often have low strength and large deformation. The reaction force structure of the inclined anchor rods needs to provide both vertical and horizontal bearing capacity. However, due to the soft and thick foundation, the reaction force is often insufficient. During testing, the reaction force structure deforms significantly and unevenly. Furthermore, during testing, the reaction force structure sinks due to the weak foundation, resulting in unstable test data. Therefore, further research is needed to successfully complete the pullout resistance testing of photovoltaic flexible support systems in soft soil areas such as fish ponds and tidal flats. Utility Model Content

[0006] In order to solve the problems of large and uneven deformation of the reaction structure during the test due to weak and thick foundation and insufficient reaction force, as well as unstable test data due to sinking of the reaction structure, the present application proposes a pull-out test device for the inclined anchor rod of a photovoltaic flexible support, which includes a detection module, a plurality of steel piles, a pressure-bearing platform and a detection frame. The pressure-bearing platform is supported on the top of the steel piles, and the detection frame is clamped on the pressure-bearing platform. The pressure-bearing platform is supported on the steel piles only by gravity. The pressure-bearing platform can be directly removed from the top of the steel piles by lifting it upward.

[0007] The detection frame has a detection surface perpendicular to the anchor rod to be detected, and a hollow hydraulic jack is arranged on the detection surface; a downwardly extending clamping piece is provided on the lower side of the detection frame, and the detection frame is clamped on the pressure platform by the clamping piece;

[0008] An anchor passage is provided on the pressure platform, and an anchor passage is provided on the inspection frame. The anchor rod to be inspected can pass through the anchor passage and the anchor passage in sequence and then be stretched and inspected by a hollow hydraulic jack; a pile hole is provided on the pressure platform corresponding to each steel pile, and the steel pile can be sunk into the foundation through the corresponding pile hole;

[0009] The detection module includes a pressure gauge and a deformation detection part. The pressure gauge is used to detect the pressure of the hollow hydraulic jack, and the deformation detection part is used to detect the deformation of the anchor rod. The deformation detection part includes an instrument bracket inserted in the foundation, a dial indicator installed on the instrument bracket, and a reference plate fixed on the anchor rod to be detected. The reference plate is located between the hollow hydraulic jack and the dial indicator. The side of the reference plate facing the dial indicator forms a reference surface, and the pointer of the dial indicator contacts the reference surface of the reference plate.

[0010] Preferably, 1-5 detection racks are set on the same pressure platform.

[0011] In this application, in order to simplify the description, the inclined anchor rod is referred to as the anchor rod for short.

[0012] The present application utilizes a number of steel piles to form a pile group foundation, which has high rigidity and high vertical and horizontal bearing capacity. That is, the reaction force of the test system is large, and the deformation is small and stable, which solves the problems of insufficient reaction force, large deformation, uneven deformation, and instability in soft foundations. The present application as a whole does not have a non-detachable connection structure between the detection module, steel piles, pressure platform and detection frame, which is easy to install and remove and has convenient construction. The detection module, pressure platform and detection frame can be quickly disassembled and transferred, and the circulation effect is improved. And due to the simple installation and convenient operation, the detection efficiency can be improved.

[0013] The sinking holes serve as positioning holes for the steel piles, preventing them from sinking and deviating, and facilitating their connection to the bearing platform. If individual positioning is used to construct the steel piles, due to construction errors, the connection between the steel piles and the bearing platform can only be made based on the actual construction position. This connection typically requires on-site welding or pouring, resulting in extended construction time and difficulty in disassembly. Steel piles can also be recycled, reducing inspection costs.

[0014] Sinking the steel piles into the foundation through the pile holes can not only eliminate the guide frame when sinking the steel piles, saving construction costs, but also avoid the problem of the pressure platform being unable to be installed due to construction errors and the need to sink the steel piles again.

[0015] During testing, the pullout test device described in this application uses a hollow hydraulic jack to pull out the anchor bolt to be tested, thereby applying a pullout load to the anchor foundation. This pullout load is then transferred to the steel pile via the test frame and the bearing platform. During the test, the detection module monitors the pullout force and displacement in real time, generating a load-to-pullout curve, which effectively determines the pullout bearing capacity of the anchor foundation.

[0016] Since the detection frame is installed on the pressure platform in a clamping manner, even if the anchor rod has a certain deviation due to construction error, the error can be eliminated by moving the detection frame. When the inclination angle of the anchor rod has an error, the error can be eliminated by setting a gasket between the pressure platform and the clamping frame or by setting a gasket between the hollow hydraulic jack and the detection surface.

[0017] Specifically, the pressure platform includes a frame base, a pile hole is set on the frame base, and a cover plate is installed on the top of the pile hole. After the steel pile is completely sunk, the cover plate is detachably installed on the frame base via anchor bolts, and the top of the steel pile can be pressed against the cover plate. Since the pressure platform is mainly subjected to downward pressure and horizontal thrust during the inspection process, it is only necessary to press the top of the steel pile against the cover plate, and use the edge of the pile hole to resist the horizontal thrust, so that the pressure platform can be stably supported on the steel pile. The cover plate is installed on the top of the pile hole in a detachable manner, so that the height of the cover plate can be adjusted according to the actual sinking of the steel pile. In actual construction, the height of the pile top of the steel pile will generally not be reached after the steel pile is completely sunk, and there will always be a height difference. If the cover plate is installed in a detachable manner, the height of the cover plate can be adjusted according to the height of the pile top.

[0018] The steel piles are driven through the pile holes to withstand the horizontal thrust transmitted by the bearing platform. Since welding is not required, the bearing platform can be directly lifted and transported before removing the cover plate. Alternatively, the cover plate can be removed first and then lifted and transported. Anchor bolts can be made of precision-rolled rebar or standard steel bolts.

[0019] Further, for facilitating the sinking of the steel pile, a guide seat is arranged on the frame base corresponding to at least one pile hole, the pile hole is arranged in the guide seat, and a guide plate is arranged around the pile hole, and the guide seat is welded to the frame base. By using the guide plate, the verticality of the steel pile during sinking can be effectively improved.

[0020] Specifically, the detection frame comprises two triangular frames arranged at intervals, each triangular frame comprises a horizontal beam arranged horizontally, a bearing beam and a support beam welded to the horizontal beam, wherein the two ends of the bearing beam and the support beam away from the horizontal beam are welded together, and the two triangular frames are connected together through the cross plate; the surface of each bearing beam inclined towards the upper side becomes a support surface perpendicular to the anchor rod to be detected, the support surfaces of the two bearing beams are coplanar, and the support surfaces of the two bearing beams together form a detection surface; an anchor rod passing channel is formed between the two triangular frames; and the clamping piece is welded to the lower side of the horizontal beam. The design can conveniently arrange the detection frame on the pressure bearing table, wherein the clamping piece is used to transmit the horizontal force generated during detection, and the detection frame is only movably placed on the pressure bearing table, so that the installation speed and disassembly speed can be accelerated, thereby improving the detection speed and efficiency.

[0021] Further, to reduce detection errors, the reference surface of the reference plate is perpendicular to the extension direction of the anchor rod to be detected.

[0022] Further, to improve the stability of the detection frame on the pressure bearing table, an upper pin hole is formed on the detection frame, a lower pin hole is formed on the pressure bearing table, and a pin or a screw rod can be arranged in the upper pin hole and the lower pin hole.

[0023] Specifically, to reduce the detection cost, the steel pile is pulled out and recycled after the test is completed.

[0024] When the uplift test device of any one of the above-mentioned embodiments is used to test the uplift performance of the cable-stayed anchor rod, the specific steps are as follows:

[0025] (1) arranging the pressure bearing table in the area of the anchor rod to be detected which has been completed, so that the anchor rod to be detected passes through the anchor rod passing channel upwards;

[0026] (2) sinking the steel pile into the foundation by taking the pile hole as a guide hole, then fixing the cover plate on the pressure bearing table by using the anchor bolt, and making the steel pile press against the cover plate;

[0027] (3) placing the detection frame on the pressure bearing table, so that the anchor rod to be detected passes through the anchor rod passing channel upwards, then connecting the hollow hydraulic jack to the anchor rod to be detected and supporting it on the detection surface, so that the stretching direction of the hollow hydraulic jack extends along the axial direction of the anchor rod to be detected; and installing the detection module at the same time;

[0028] (4) Start the hollow hydraulic jack to test the pull-out bearing capacity of the anchor to be tested, use the detection module to measure the tension of the hollow hydraulic jack and the pull-out displacement of the anchor to be tested, obtain the load-pull-out amount curve, and obtain the pull-out bearing capacity of the anchor to be tested based on the load-pull-out amount curve;

[0029] (5) Remove the hollow hydraulic jack, inspection frame and pressure platform in sequence and move them to a testing location; pull out the steel piles for recycling. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural diagram of an embodiment of the present utility model.

[0031] Figure 2 This is a top view of the pressure platform.

[0032] Figure 3 yes Figure 2 Center AA view.

[0033] Figure 4 It is a three-dimensional diagram of the detection frame.

[0034] Figure 5 It is a top view of the guide seat.

[0035] Figure 6 yes Figure 5 View from the middle BB direction. DETAILED DESCRIPTION

[0036] The following is an explanation of the pull-out test device for the inclined anchor rod of the photovoltaic flexible support in this application. In the following description, the anchor rod refers to the inclined anchor rod. Figures 1-6 In the accompanying drawings, the direction of the first arrow X indicates the direction of the first axis, and the direction of the second arrow Y indicates the direction of the second axis. The first axis direction and the second axis direction both extend in the horizontal direction and are perpendicular to each other.

[0037] The pull-out test device specifically includes a detection module, six steel piles 30, a pressure platform 20 and two detection frames 10. The steel piles are sunk into the foundation, the pressure platform 20 is supported on the top of the six steel piles only by gravity, and the two detection frames are arranged at intervals on the pressure platform.

[0038] The pressure bearing platform 20 comprises a frame base 210 and six guide seats 22 arranged on the frame base 210, each of which corresponds to a steel pile 30. The frame base 210 is rectangular and is welded by two mutually parallel longitudinal beams 21 and three mutually parallel cross beams 23, wherein the longitudinal beams 21 extend along the second axis direction and the cross beams 23 extend along the first axis direction. The two ends of the three cross beams are welded on one longitudinal beam respectively, and the three cross beams are arranged at intervals, and the space between the adjacent two cross beams forms an anchor rod passage 25, that is, the anchor rod passage is arranged on the pressure bearing platform. In the embodiment, the longitudinal beams and the cross beams are both made of H steel. Figure 2 In the figure, the detection frame 10 is indicated by a dashed line to show its position. Figure 2 In the figure, the cover plate 26 and the anchor bolt 27 described below are removed.

[0039] The six guide seats 22 are all arranged on the longitudinal beams and are located on the two sides of the three cross beams respectively, that is, one guide seat 22 is arranged on each side of each cross beam, and all the guide seats 22 are welded on the longitudinal beams. Please refer to Figure 5 and Figure 6 each of which comprises a top plate 221 and a first vertical plate 222, a second vertical plate 223 and a third vertical plate 226 welded on the lower surface of the top plate, and the first vertical plates 222 are arranged in two pieces and are parallel to each other. Among them, the first vertical plates extend along the second axis direction and are arranged at intervals, and the second vertical plates and the second vertical plates both extend along the first axis direction. On the side of each first vertical plate away from the other first vertical plate, three second vertical plates 223 are arranged, and the three second vertical plates on the same side are arranged at intervals along the second axis direction. Two third vertical plates are arranged between the two first vertical plates, and the two third vertical plates are arranged at intervals along the second axis direction, and the space enclosed by the two first vertical plates and the two third vertical plates forms a pile sinking hole 224, so that the first vertical plates and the third vertical plates form guide plates, and the pile sinking hole penetrates upwardly through the top plate. That is, the pile sinking hole 224 on the frame base 210.

[0040] It can be understood that the arrangement of the guide plates is not limited to the above description, and in other embodiments, independent guide plates can also be arranged by using steel plates to splice into a pile sinking hole, or a combination of angle steel and steel plate to form a pile sinking hole, and a channel steel with notched opposite slots to splice into a pile sinking hole.

[0041] To facilitate disassembly, in this embodiment, anchor bolt holes 225 are provided in the top plate. Anchor bolts 27 pass through these holes 225 and the cover plate 26, and are then screwed with locking nuts 28, securing the cover plate to the top plate and allowing it to be removably mounted on top of the pile driving holes. When sinking the steel pile, it is lowered into the foundation through the pile driving holes. The pile driving holes serve as guide holes for the steel piles. After the steel piles are lowered, the cover plate is mounted on the frame base via the anchor bolts, with the top of the steel pile resting against the cover plate. In this embodiment, the steel piles are specifically H-shaped steel piles. After testing, the H-shaped steel piles are removed and recovered. It is understood that the steel piles may also be steel pipe piles or other types of steel piles. In this embodiment, the anchor bolts are specifically made of finely rolled threaded steel. Therefore, a locking nut is screwed onto the lower end of the locking bolt after it extends downward from the longitudinal beam. It is understood that in other embodiments, the anchor bolts may also be standard steel bolts.

[0042] In this embodiment, a guide seat 22 is provided for each steel pile. It is understood that in other embodiments, guide seats may not be provided for some steel piles, so that the steel piles are directly pressed against the lower surface of the frame base 210.

[0043] In this embodiment, the web of the longitudinal beam is positioned horizontally. The guide seat is supported on the web and located between the longitudinal beam flanges. A hole is provided in the web of the longitudinal beam, directly below the pile driving hole. The top plate of the guide seat is welded to the longitudinal beam flange, and the first, second, and third vertical plates are all welded to the web of the longitudinal beam to ensure the connection strength between the guide seat and the longitudinal beam.

[0044] In this embodiment, two inspection frames 10 are provided on a pressure platform. Each inspection frame 10 includes two spaced-apart tripods 110. Each tripod 110 includes a horizontal beam 11 horizontally provided along a first axis, a load-bearing beam 12 welded to the horizontal beam, and a support beam 13. The load-bearing beam and the support beam are welded together at one end away from the horizontal beam. The two tripods 110 are connected together via a cross plate 131. The surface of each load-bearing beam 12 tilted upwards forms a support surface 121 perpendicular to the anchor rod 50 to be inspected. The support surfaces 121 of the two load-bearing beams are coplanar. The support surfaces of the two load-bearing beams together form an inspection surface, on which the hollow hydraulic jack 45 is supported. An anchor rod passage 15 is formed between the two tripods. A clamping member 14 extending downward in a vertical direction is welded to the lower side of the horizontal beam. The inspection frame is clamped on the pressure platform via the clamping member. In this embodiment, corresponding to each longitudinal beam 21 of the frame base, two clamping members 14 are welded on the lower side of each horizontal beam, and the two clamping members are respectively located on both sides of the longitudinal beam in the direction of the first axis.

[0045] The two tripods of the same detection frame are spaced apart along the second axis so that the anchor rod passage 15 extends along the first axis. The anchor rod to be detected in this embodiment extends obliquely along the first axis so that the anchor rod to be detected can pass through the anchor rod passage 15 smoothly.

[0046] In this embodiment, the horizontal beam, the load-bearing beam and the support beam are all made of H-steel. The anchor rod 50 to be tested can pass through the anchor rod passage and the anchor rod passage in sequence and then be lifted by the hollow hydraulic jack.

[0047] In order to improve the stability of the detection frame on the pressure platform, an upper pin hole 111 is provided on the horizontal beam 11 of the detection frame, and a lower pin hole 211 is provided on the longitudinal beam of the pressure platform. The pin 112 can pass through the upper pin hole and the lower pin hole in sequence from top to bottom. It is understood that in another embodiment, the screw rod can also be inserted into the upper pin hole and the lower pin hole at the same time. Depending on the convenience of operation, the nut can be screwed on the screw rod or not. Since the detection frame is subjected to pressure in the inclined direction during the detection process, the pressure platform is subjected to the pressure in the vertical direction and the thrust in the horizontal direction of the detection frame, but is not subjected to tension. There is no need for pins or screw rods to provide tension, and only shear force needs to be borne. However, when the screw rod is passed through the lower pin hole and the upper pin hole in sequence from bottom to top, the nut still needs to be screwed on the upper end of the screw rod to prevent the screw rod from falling off.

[0048] The detection module includes a pressure gauge 47 for detecting the pressure of the hollow hydraulic jack and a deformation detection unit for detecting the deformation of the anchor rod. In this embodiment, the pressure gauge 47 is installed on the hydraulic pipe 46 of the hollow hydraulic jack. The deformation detection unit includes an instrument bracket 41 inserted in the foundation, a micrometer 43 installed on the instrument bracket, and a reference plate 44 fixed on the anchor rod 50 to be detected. The reference plate 44 is located between the hollow hydraulic jack 45 and the micrometer 43. The side of the reference plate 44 facing the micrometer forms a reference surface. The pointer of the micrometer contacts the reference surface of the reference plate, and the reference surface is perpendicular to the anchor rod to be detected. In this embodiment, the instrument bracket includes a vertical pole 411 inserted vertically in the foundation and an inclined rod 412 fixed to the vertical pole 411 with a fastener. It can be understood that in another embodiment, the instrument bracket can also use a bent steel pipe or weld the vertical pole and the inclined rod together.

[0049] In the present application, the detection piece is supported on the pressure platform by a clamping piece, and the detection frame is connected to the pressure platform by pins or bolts. After the pins and bolts are removed, the detection frame can be removed from the pressure platform and recycled. The pressure platform is supported on the top of the steel pile through a guide seat, and the pressure platform is only supported on the steel pile through a cover plate. There is no fixed connection between the pressure platform and the steel pile. By lifting the pressure platform upward, the pressure platform can be directly removed from the top of the steel pile and recycled. That is, there is no non-detachable connection between any two of the steel pile, the pressure platform and the detection frame, so that when the pull-out test device is disassembled, the pressure platform and the detection frame can be quickly and conveniently detached and recycled, and then the steel pile can be pulled out and recycled.

[0050] In this embodiment, two detection racks are arranged on a pressure platform. It can be understood that in other embodiments, only one detection rack, or three or four detection racks can be arranged on a pressure platform. Considering the convenience of disassembly and transfer, it is preferred to arrange two or three detection racks on a pressure platform, taking into account both the detection efficiency and the installation and disassembly efficiency of the pull-out test device.

[0051] In order to make the pull-out test device in this application clearer, the specific steps for testing the pull-out performance of the inclined anchor rod are described below. The specific steps are as follows:

[0052] (1) The pressure-bearing platform 20 is arranged in the area of ​​the anchor rod 50 to be inspected which has been completed, so that the anchor rod to be inspected passes upward through the anchor rod passage 25.

[0053] (2) Using the pile hole 224 of the guide seat 22 as a guide hole, sink the steel pile 30 into the foundation, then fix the cover plate 26 to the top plate 221 with anchor bolts 27, and make the cover plate be located at the top of the pile hole, with the steel pile 30 pressed against the cover plate.

[0054] During actual construction, the top of each steel pile must be at least flush with the top of the guide seat so that the top of the steel pile can press against the cover plate. The height to which the steel pile extends above the guide seat can vary. By adjusting the length of the anchor bolts, each cover plate can press against the top of the steel pile. In the accompanying figure, the top of the steel pile extends upward beyond the top of the guide seat.

[0055] (3) Place the test frame 10 on the pressure platform 20. The clamping pieces on the lower side of the pressure platform are clamped on both sides of the longitudinal beam 21. Then, insert the pins 112 from top to bottom into the upper pin holes 111 and the lower pin holes 211 to keep the test frame stably on the pressure platform. The anchor rod to be tested is passed upward through the anchor rod passage 15.

[0056] Connect the hollow hydraulic jack to the anchor rod to be tested and support it on the test surface. Adjust the position of the hollow hydraulic jack so that the stretching direction of the hollow hydraulic jack extends along the axial direction of the anchor rod to be tested. At the same time, complete the installation of the detection module.

[0057] (4) Start the hollow hydraulic jack to test the pullout bearing capacity of the anchor rod to be tested. Use the detection module to measure the tension of the hollow hydraulic jack and the pull-out displacement of the anchor cable 50 to be tested, obtain a load-pull-out curve, and obtain the pull-out bearing capacity of the anchor rod to be tested based on the load-pull-out curve. The tension of the hollow hydraulic jack is detected by the pressure gauge 47, and the pull-out displacement of the anchor cable 50 to be tested is detected by the micrometer 43.

[0058] (5) After the inspection is completed, the hollow hydraulic jack, inspection frame and pressure platform are removed in sequence and moved to a testing location; the steel piles are pulled out and recycled.

Claims

1. A pull-out test device for an inclined anchor rod of a photovoltaic flexible support, characterized in that: The system includes a detection module, several steel piles, a pressure platform and a detection frame. The pressure platform is supported on the top of the steel piles, and the detection frame is clamped on the pressure platform. The pressure platform is supported on the steel piles only by gravity. The pressure platform can be lifted upward and removed directly from the top of the steel piles. The detection frame has a detection surface perpendicular to the anchor rod to be detected, and a hollow hydraulic jack is arranged on the detection surface; a downwardly extending clamping piece is provided on the lower side of the detection frame, and the detection frame is clamped on the pressure platform by the clamping piece; An anchor passage is provided on the pressure platform, and an anchor passage is provided on the inspection frame. The anchor rod to be inspected can pass through the anchor passage and the anchor passage in sequence and then be stretched and inspected by a hollow hydraulic jack; a pile hole is provided on the pressure platform corresponding to each steel pile, and the steel pile can be sunk into the foundation through the corresponding pile hole; The detection module includes a pressure gauge and a deformation detection part. The pressure gauge is used to detect the pressure of the hollow hydraulic jack, and the deformation detection part is used to detect the deformation of the anchor rod. The deformation detection part includes an instrument bracket inserted in the foundation, a dial indicator installed on the instrument bracket, and a reference plate fixed on the anchor rod to be detected. The reference plate is located between the hollow hydraulic jack and the dial indicator. The side of the reference plate facing the dial indicator forms a reference surface, and the pointer of the dial indicator contacts the reference surface of the reference plate.

2. The pull-out test device according to claim 1, characterized in that: The pressure platform includes a frame base, on which pile holes are arranged, and a cover plate is installed on the top of the pile hole. After the steel pile is completely sunk, the cover plate is detachably installed on the frame base via anchor bolts, and the top of the steel pile can be pressed against the cover plate.

3. The pull-out test device according to claim 2, characterized in that: On the frame base, a guide seat is provided corresponding to at least one pile hole. The pile hole is provided in the guide seat. Guide plates are provided around the pile hole. The guide seat is welded to the frame base.

4. The pull-out test device according to claim 1, characterized in that: The detection frame includes two spaced-apart tripods, each of which includes a horizontal beam, a load-bearing beam welded to the horizontal beam, and a support beam, wherein the load-bearing beam and the support beam are welded together at one end away from the horizontal beam, and the two tripods are connected together via a transverse plate; the surface of each load-bearing beam inclined upward forms a support surface perpendicular to the anchor rod to be detected, and the support surfaces of the two load-bearing beams are coplanar, and the support surfaces of the two load-bearing beams together form a detection surface; a passage for the anchor rod to pass through is formed between the two tripods; The holders are welded to the underside of the horizontal beam.

5. The pull-out test device according to claim 1, characterized in that: The reference surface of the reference plate is perpendicular to the extension direction of the anchor rod to be tested.

6. The pull-out test device according to claim 1, characterized in that: An upper pin hole is provided on the detection frame, and a lower pin hole is provided on the pressure platform. Pins or screws can be passed through the upper pin hole and the lower pin hole.

7. The pull-out test device according to claim 1, characterized in that: After the test was completed, the steel pile was pulled out and recovered.

8. The pull-out test device according to claim 1, characterized in that: 1-5 testing racks are set on the same pressure platform.

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