Square tube anti-pulling test device

Abstract

The utility model discloses a square pipe pile tensile test device is provided, technical scheme is as follows: including solid square pile and its upward extension and the multiple anchor rod of square arrangement, the upper portion of multiple anchor rod is connected with the equal force board, the anchor rod inside and outside area of equal force board evenly is provided with a plurality of outer pull rod and inner pull rod, the lower extreme of outer pull rod is connected with the fixed square hoop outside solid square pile outside synchronous arrangement, the top of outer pull rod and inner pull rod is fixed through the upper roof and counterforce beam connection, the both ends lower part of counterforce beam is supported on the support base through the hydraulic oil jar, the utility model through the synergies of equal force board, outer pull rod and inner pull rod and square hoop, has realized to the uniform distribution and effective transmission of resistance to tensile force, avoided the damage of traditional welding mode to anchor rod structure, has the advantages such as improving test security, guaranteeing structural integrity, realizing uniform stress distribution and accurate simulation composite stress state.

Description

Technical Field

[0001] This utility model relates to the field of pipe pile pull-out resistance, specifically to a square pipe pile pull-out resistance testing device. Background Technology

[0002] Square pipe piles, as a new type of foundation construction material, are widely used in various engineering projects due to their excellent compressive strength and bearing capacity. During construction, after the pipe piles are inserted into the ground by excavation equipment, backfilling is required. This construction method may cause the pipe piles to be subjected to pull-out moments, so pull-out tests must be conducted to verify their structural stability and bearing capacity.

[0003] Traditional pull-out testing methods have significant drawbacks: First, the method of directly welding the tie rod to the anchor rod of the square pile compromises the original structural integrity of the anchor rod, and stress concentration easily occurs in the heat-affected zone. Second, welding quality is difficult to guarantee, and safety hazards such as weld breakage may occur during the test. Third, the single anchor rod connection method leads to uneven stress distribution, which can easily cause excessive local stress in the square pile and damage it during the test. In addition, existing testing devices lack effective force transmission and equalization mechanisms, making it impossible to accurately simulate the complex stress state in actual engineering projects, thus affecting the reliability of test data. These technical defects not only reduce the safety of the test but also restrict the accurate assessment of pull-out performance. Therefore, existing technologies urgently need improvement to address these problems. Utility Model Content

[0004] To address the aforementioned problems, this utility model provides a square pipe pile pull-out test device.

[0005] This utility model is achieved through the following technical solution:

[0006] This application provides a square pipe pile pull-out test device, the technical solution of which is as follows: it includes a solid square pile and multiple anchor rods extending upward and arranged in a square shape. The upper part of the multiple anchor rods is connected to a force equalizing plate. Multiple outer tie rods and inner tie rods are evenly arranged in the inner and outer areas of the anchor rods on the force equalizing plate. The lower end of the outer tie rod is simultaneously connected to a square clamp fixed to the outside of the solid square pile. The top of the outer tie rod and the inner tie rod are connected and fixed to a reaction beam through an upper top plate. The lower parts of both ends of the reaction beam are supported on a support base by hydraulic cylinders.

[0007] Furthermore, this application also proposes that a plurality of the outer tie rods and inner tie rods are arranged in a square shape along the inner and outer sides of the anchor rod, and the outer tie rods and inner tie rods are connected to the lower part of the force equalizing plate by limiting nuts.

[0008] Furthermore, this application also proposes that the square clamp is composed of two C-shaped frame frames connected by multiple bolts and clamped to the outside of the solid square pile. The two sides of the square clamp are fixed with pull plates for passing through the outer tie rod, and the lower part of the pull plate is provided with a limiting nut that is threadedly connected to the outer tie rod.

[0009] Furthermore, this application also proposes that the upper part of the anchor rod is engaged with a pull-out clamp located at the top of the force equalization plate.

[0010] Furthermore, this application also proposes that an upper top plate is placed at the upper center of the reaction beam, and limiting plates that are fixed on the outer sides of the reaction beam are fixed on both sides of the upper top plate.

[0011] Furthermore, this application also proposes that the outer tie rod passes upward through the upper top plate and is connected and fixed by a limiting nut, and the inner tie rod is connected and fixed by a plurality of through slots on the reaction beam and a limiting nut provided on the upper top plate.

[0012] Furthermore, this application also proposes that the hydraulic cylinder is connected to a hydraulic pump via an oil line pipe.

[0013] Compared with existing technologies, the advantages of this utility model are: through the synergistic effect of the force equalizing plate, the outer tie rod, the inner tie rod, and the square clamp, this utility model achieves the uniform distribution and effective transmission of the pull-out force, avoids the damage to the anchor structure caused by traditional welding methods, and has the advantages of improving test safety, ensuring structural integrity, achieving uniform force distribution, and accurately simulating the composite force state. Attached Figure Description

[0014] Figure 1 This is a three-dimensional structural schematic diagram of the present invention;

[0015] Figure 2 yes Figure 1 Enlarged schematic diagram of a local structure;

[0016] Figure 3 This is a schematic diagram of the arrangement of anchor bolts, external tie rods, and internal tie rods in a force-equalizing frame.

[0017] In the diagram: 1. Solid square pile; 2. Anchor rod; 201. Pull-out clamp; 3. Force equalizing plate; 4. Square clamp; 41. Pull plate; 42. Limiting nut; 5. Outer tie rod; 6. Inner tie rod; 7. Top plate; 8. Limiting plate; 9. Reaction beam; 10. Through slot; 11. Hydraulic cylinder; 12. Support base. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments:

[0019] like Figure 1-3As shown, this application proposes a square pipe pile pull-out test device, including a solid square pile and multiple anchor rods extending upward and arranged in a square shape. The upper part of the multiple anchor rods is connected to a force equalizing plate. Multiple outer tie rods and inner tie rods are evenly arranged in the inner and outer regions of the anchor rods on the force equalizing plate. The lower end of the outer tie rod is simultaneously connected to a square clamp fixed to the outside of the solid square pile. The top of the outer tie rod and the inner tie rod are connected and fixed to the reaction beam through an upper top plate. The lower parts of both ends of the reaction beam are supported on the support base by hydraulic cylinders.

[0020] The force-equalizing plate can be made of steel plate, with a thickness of 30-50mm designed according to the stress requirements. The outer and inner tie rods can be made of threaded steel with a diameter range of 20-40mm. The square clamp consists of two C-shaped frames connected by bolts, preferably 4-8 bolts. The hydraulic cylinder's working pressure is adjustable from 10-50MPa, with a stroke of 100-300mm. The support base can be made of cast concrete, and its dimensions are determined according to the span of the reaction beam.

[0021] This technical solution achieves uniform load distribution by using a force-equalizing plate, and the square clamp connected to the lower part of the outer tie rod prevents localized stress concentration. The synergistic effect of the outer and inner tie rods effectively transmits tensile force, and the square clamp is fixed to the solid square pile without welding, protecting the structural integrity of the pile. A hydraulic cylinder applies controllable tensile force through a reaction beam, enabling accurate measurement of the pull-out resistance of the pipe pile. Compared to existing technologies, this device offers advantages such as structural stability, high testing accuracy, and safe operation, solving the problem of traditional welding methods damaging the anchor structure and achieving non-destructive testing.

[0022] Furthermore, this application also proposes that multiple outer tie rods and inner tie rods are arranged in a square along the inner and outer sides of the anchor rod, and the outer tie rods and inner tie rods are connected to the lower limit of the force equalizing plate by limit nuts.

[0023] Specifically, the square arrangement of the outer and inner tie rods can be either evenly spaced or staggered. Evenly spaced arrangement ensures uniform stress distribution, while staggered arrangement enhances structural stability. The limiting nuts can be standard hexagonal nuts or lock nuts with anti-loosening mechanisms.

[0024] Therefore, this technical solution effectively solves the anchor bolt damage problem caused by traditional welded connections by designing the tie rod system as an inner and outer double-layer square array structure, combined with the mechanical fixing method of the limiting nuts. The square arrangement allows the tie rods to form a cooperative force-bearing system, which can evenly transfer the load to the entire pile body; the limiting nut connection not only avoids the heat-affected zone of welding, but also allows for precise control of the tie rod preload by adjusting the nut position. Compared with the single welded connection in the prior art, this structure significantly improves the safety of the test device and the reliability of the test data, while also facilitating disassembly and maintenance.

[0025] Furthermore, this application also proposes that the square clamp is composed of two C-shaped frame frames connected by multiple bolts and clamped to the outside of the solid square pile. The two sides of the square clamp are fixed with pull plates for passing through the outer tie rod, and the lower part of the pull plate is provided with a limiting nut that is threadedly connected to the outer tie rod.

[0026] Specifically, the square clamp adopts a split structure design, with two C-shaped frames fastened together by bolts to form a closed loop structure, facilitating on-site installation and disassembly. Tie plates are welded and fixed to both sides of the clamp. As a preferred embodiment, the C-shaped frames can be forged from high-strength steel as a single piece, with anti-slip textured inner surfaces to enhance friction with the solid square pile. The tie plates can be cut from steel plates, with their thickness designed according to the tensile force requirements of the outer tie rod.

[0027] Furthermore, this application also proposes that the upper part of the anchor bolt is engaged with a pull-out clamp located at the top of the equalizing plate.

[0028] The pull-out clamp adopts a split snap-fit ​​structure, consisting of two symmetrical clamping blocks fastened together by high-strength bolts. The inner side of each clamping block is machined with a groove matching the outer contour of the anchor bolt; the surface of the groove can be provided with anti-slip textures or a rubber pad. As a preferred embodiment, the clamping blocks are made of hardened 40Cr alloy steel, and their clamping surfaces can be machined with a serrated structure to enhance friction.

[0029] This solution achieves non-destructive clamping of anchor bolts by installing a dedicated clamp above the force-equalizing plate. Specifically, during pull-out tests, the pull-out clamp securely fixes the top of the anchor bolt through a mechanical snap-fit, avoiding the damage to the anchor bolt structure caused by traditional welding methods. The symmetrical design of the clamp ensures that the force is evenly distributed to the force-equalizing plate, preventing localized stress concentration. The modular structure allows for easy replacement of clamping blocks for anchor bolts of different diameters, improving the adaptability of the device. Compared to welded connections, this clamp is reusable and does not suffer from material property degradation due to the heat-affected zone of welding, significantly improving the safety and accuracy of the test.

[0030] Furthermore, this application also proposes that an upper top plate is placed at the upper center of the reaction beam, and limiting plates that are fixed on the outer sides of the reaction beam are fixed on both sides of the upper top plate.

[0031] Specifically, the upper top plate, acting as a connecting component, is positioned at the upper center of the reaction beam to transmit tensile force. Limiting plates are fixed to both sides of the upper top plate, their shape matching the outer side of the reaction beam, allowing them to effectively engage with it. This is a preferred embodiment.

[0032] To address this issue, this technical solution effectively solves the problem of unstable connection between the upper plate and the reaction beam in traditional testing devices by incorporating a limiting plate structure. The locking design of the limiting plate prevents lateral displacement of the upper plate under load, ensuring the stability of tensile force transmission. Compared to existing technologies, this structure eliminates the need for welding, avoiding damage to the reaction beam structure, and also simplifies installation and disassembly. During testing, the tight fit between the limiting plate and the reaction beam ensures even force distribution, improving the accuracy of test data.

[0033] Furthermore, this application also proposes that the outer tie rod passes upward through the upper top plate and is connected and fixed by a limiting nut, and the inner tie rod is connected and fixed by a number of through slots on the reaction beam and a limiting nut set on the upper top plate.

[0034] This technical solution achieves a multi-point uniform force loading method by using through-type connection structures for the outer and inner tie rods. The outer tie rod is directly fixed by passing through the upper top plate, while the inner tie rod is positioned using through-holes in the reaction beam. Both are ultimately fixed synchronously by limiting nuts on the upper top plate. This connection method avoids the quality risks associated with welding processes and ensures uniform force distribution on each tie rod through mechanical connection. Specifically, the through-hole design allows the position of the inner tie rod to be adjusted according to actual needs, improving installation flexibility. Thus, this structure not only solves the anchor rod damage problem caused by traditional welding methods but also effectively improves the force distribution through an adjustable connection method.

[0035] Furthermore, this application also proposes that the hydraulic cylinder is connected to the hydraulic pump via an oil line.

[0036] The hydraulic cylinder, acting as the actuator, is powered by pressurized oil supplied by a hydraulic pump. The hydraulic lines utilize high-pressure hydraulic hoses or rigid pipes, connected to the hydraulic pump outlet and cylinder inlet via quick-connect couplings. This technical solution achieves smooth lifting of the reaction beam through a hydraulic transmission system. The hydraulic pump provides a stable and controllable pressure source, the hydraulic lines transmit power, and the hydraulic cylinder converts hydraulic energy into mechanical energy.

[0037] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A square pipe pile pull-out test device, comprising a solid square pile (1) and a plurality of anchor rods (2) extending upward and arranged in a square shape, characterized in that: Multiple anchor rods (2) are connected to a force equalizing plate (3) on their upper part. Multiple outer tie rods (5) and inner tie rods (6) are evenly arranged in the inner and outer areas of the anchor rods (2) of the force equalizing plate (3). The lower end of the outer tie rod (5) is simultaneously connected to a square clamp (4) fixed on the outside of the solid square pile (1). The top of the outer tie rod (5) and the inner tie rod (6) are connected and fixed to the reaction beam (9) through the upper top plate (7). The lower ends of the reaction beam (9) are supported on the support base (12) by hydraulic cylinders (11).

2. The square pipe pile pull-out test device according to claim 1, characterized in that: Multiple outer tie rods (5) and inner tie rods (6) are arranged in a square shape along the inner and outer sides of the anchor rod (2). The outer tie rods (5) and inner tie rods (6) are connected to the lower part of the force equalizing plate (3) by limiting nuts (42).

3. The square pipe pile pull-out test device according to claim 1, characterized in that: The square clamp (4) is made of two C-shaped frames connected by multiple bolts and clamped to the outside of the solid square pile (1). The square clamp (4) has pull plates (41) fixed on both sides for passing through the outer tie rod (5). The lower part of the pull plate (41) is provided with a limiting nut (42) that is threadedly connected to the outer tie rod (5).

4. The square pipe pile pull-out test device according to claim 2, characterized in that: The upper part of the anchor rod (2) is engaged with a pull-out clamp (201) located on top of the force equalization plate (3).

5. The square pipe pile pull-out test device according to claim 1, characterized in that: An upper top plate (7) is placed on the upper center of the reaction beam (9), and limiting plates (8) that are fixed on the outside of the reaction beam (9) are fixed on both sides of the upper top plate (7).

6. The square pipe pile pull-out test device according to claim 3, characterized in that: The outer tie rod (5) passes upward through the upper top plate (7) and is connected and fixed by the limiting nut (42). The inner tie rod (6) passes through several through slots (10) on the reaction beam (9) and is connected and fixed by the limiting nut (42) on the upper top plate (7).

7. The square pipe pile pull-out test device according to claim 1, characterized in that: The hydraulic cylinder (11) is connected to the hydraulic pump via an oil line.

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