A test device for a pile-diameter-expanded anchor rod composite foundation structure

Abstract

The application provides a test device for a pile-diameter-expanded anchor rod composite foundation structure, belonging to the technical field of load test of the pile-diameter-expanded anchor rod composite foundation structure, and comprising: a support arranged above a model box and connected with the model box, serving as a bearing and counterforce structure of the whole device, ensuring that a vertical loading device and a horizontal loading device can be stably installed, ensuring the rigidity and stability of the whole device, and preventing the test precision from being affected by the shaking of the support during the loading process. The test device is simple to operate, has a wide application range, and can flexibly perform unidirectional loading test or combined loading test through the setting of the mutually independent vertical loading device and the horizontal loading device, synchronously or step by step applies vertical and horizontal loads to the foundation structure model, loads the foundation structure model on the same test device, can simulate the complex stress state borne by the composite foundation structure in actual engineering, has high practicability, does not need to replace other test equipment, and accelerates the test process.

Description

Technical Field

[0001] This application belongs to the technical field of load testing of pile-expanded diameter anchor composite foundation structures, specifically relating to a test device for pile-expanded diameter anchor composite foundation structures. Background Technology

[0002] With the continuous development of power engineering construction in my country, the number of transmission line projects is constantly increasing, and power tower foundations are widely used in engineering construction. During operation, power tower foundations must simultaneously withstand various complex loads, such as wind loads, conductor tension, overturning moments, and uplift loads. These diverse load types and complex mechanisms place higher demands on the foundation's bearing capacity and stability. Existing traditional pile foundations often exhibit insufficient bearing capacity, poor uplift resistance, and complex failure modes when subjected to combined loads, making them unsuitable for the use of high tower foundations under complex stress conditions. To improve the foundation's stress performance, a pile-expanded diameter anchor composite foundation structure has been proposed. By adding an expanded diameter section and anchor structure to the pile end or side, the foundation's bearing capacity and uplift resistance can be effectively improved.

[0003] However, research on the stress characteristics of pile-expanded diameter anchor composite foundations under combined vertical and horizontal loads remains limited. Existing test devices mostly focus on unidirectional loading, making it difficult to comprehensively reflect the true stress state of pile-expanded diameter anchor composite foundations under complex load conditions. Utility Model Content

[0004] This utility model aims to solve at least one of the technical problems existing in the prior art or related technologies.

[0005] In view of this, according to an embodiment of this application, a test apparatus for a pile-expanded diameter anchor composite foundation structure is proposed, comprising: The basic structural model is vertically embedded in the medium model inside the model box, with the top of the basic structural model extending out of the medium model. The support frame is positioned above the model box and is connected to the model box. A vertical loading device, the first end of which is connected to the foundation structure model, and the second end of which is connected to the support frame; A horizontal loading device, the first end of which extends horizontally and is connected to the top of the foundation structure model, and a weight is suspended on the second end of the horizontal loading device.

[0006] In one feasible implementation, the infrastructure model includes: The pile model is arranged vertically, with the top of the pile model protruding outside the medium model; An anchor bolt assembly model, which includes several anchor bolt models, is vertically arranged below the pile model and is fixedly connected to the bottom of the pile model.

[0007] In one feasible implementation, the medium model includes a rock mass model and a soil model, with the rock mass model arranged at the bottom of the model box and the soil model arranged above the rock mass model. The anchor bolt model is embedded in the rock mass model, and the pile model is embedded in the soil model.

[0008] In one feasible implementation, the vertical loading device includes: The reaction plate is horizontally arranged above the foundation structure model and is fixedly connected to the support frame. The pressure sensor is mounted on the reaction plate. The jack is arranged vertically, and its fixed end is in contact with the pressure sensor. The frame is placed above the basic structure model, and is wrapped around the outside of the reaction plate, with a gap between the frame and the reaction plate. The first end of the frame abuts against the telescopic end of the jack, and the second end of the frame abuts against the top of the foundation structure model, so as to transfer the vertical load provided by the jack to the foundation structure model through the frame.

[0009] In one feasible implementation, the test apparatus for the pile-expanded diameter anchor composite foundation structure further includes: Hydraulic pump; The hydraulic hose has one end connected to the hydraulic pump and the other end connected to the jack to provide power to the jack. A pressure gauge is installed on the hydraulic pump to monitor the pressure of the hydraulic pump.

[0010] In one feasible implementation, the horizontal loading device includes: The first end of the pull rope is connected to the basic structural model. The first fixed pulley is mounted on the bracket. The pull rope passes around the bottom of the first fixed pulley to guide the pull rope and make the first end of the pull rope extend horizontally. The second fixed pulley is arranged above the first fixed pulley and is mounted on a bracket. The pull rope passes over the second fixed pulley from the top of the second fixed pulley and is guided by the second fixed pulley and the pull rope so that the second end of the pull rope hangs down naturally. The weight box contains weights and is connected to the second end of the pull rope to transfer horizontal loads to the foundation structure model.

[0011] In one feasible implementation, the test apparatus for the pile-expanded diameter anchor composite foundation structure further includes: The pull ring is located at the center of the top of the basic structure model, and the first end of the pull rope is connected to the pull ring.

[0012] In one feasible implementation, the test apparatus for the pile-expanded diameter anchor composite foundation structure further includes: Metal sheets are arranged horizontally and are fixedly connected to the top end face of the base structure model. The first end of the metal sheet extends vertically. The first link, the first end of the first link is connected to the bracket; A vertical displacement dial indicator is installed at the second end of the first connecting rod. The probe of the vertical displacement dial indicator contacts the first end of the metal plate to detect the displacement of the metal plate in the vertical direction.

[0013] In one feasible implementation, the second end of the metal sheet extends horizontally, and the test apparatus for the pile-expanded diameter anchor composite foundation structure further includes: The second link, the first end of the second link is connected to the bracket; A horizontal displacement dial indicator is installed at the second end of the second connecting rod. The probe of the horizontal displacement dial indicator contacts the second end of the metal plate to detect the displacement of the metal plate in the horizontal direction.

[0014] In one feasible implementation, the test apparatus for the pile-expanded diameter anchor composite foundation structure further includes: Strain gauges are arranged at equal intervals along the length of the foundation structure model on the side wall of the foundation structure model.

[0015] The experimental device for a pile-expanded diameter anchor composite foundation structure disclosed in this application has the following advantages compared with the prior art: The test apparatus for pile-expanded diameter anchor composite foundation structures provided in this application includes a foundation structure model, a support frame, a vertical loading device, and a horizontal loading device. The support frame is arranged above and connected to the model box, serving as the load-bearing and reaction structure of the entire apparatus. This ensures the stable installation of the vertical and horizontal loading devices, guaranteeing the rigidity and stability of the entire apparatus and preventing the test accuracy from being affected by the swaying of the support frame during loading. The test apparatus is easy to operate and has a wide range of applications. By setting up independent vertical and horizontal loading devices, testers can flexibly conduct unidirectional or combined loading tests, applying vertical and horizontal loads to the foundation structure model simultaneously or in stages. Loading the foundation structure model on the same test apparatus can simulate the complex stress state of composite foundation structures in actual engineering projects. It is highly practical, requires no replacement of other test equipment, and accelerates the simulation test process. Attached Figure Description

[0016] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A schematic structural diagram of a test apparatus for a pile-expanded diameter anchor composite foundation structure according to an embodiment of this application; Figure 2 A schematic structural diagram of the foundation structure model of the test device for a pile-expanded diameter anchor composite foundation structure according to an embodiment of this application, showing the first angle of the foundation structure model. Figure 3 A schematic structural diagram of the foundation structure model of the test device for a pile-expanded diameter anchor composite foundation structure according to an embodiment of this application, taken from a second angle. Figure 4 A schematic structural diagram of the strain gauge arrangement of a test device for a pile-expanded diameter anchor composite foundation structure according to an embodiment of this application; Figure 5 A schematic structural diagram of a second arrangement of strain gauges for a test device of a pile-expanded diameter anchor composite foundation structure according to an embodiment of this application; in, Figures 1 to 5 The correspondence between the reference numerals and component names in the attached drawings is as follows: 11. Basic structural model; 12. Model box; 13. Support frame; 14. Vertical loading device; 15. Horizontal loading device; 16. Hydraulic pump; 17. Hydraulic pipe; 18. Pressure gauge; 19. Pull ring; 20. Metal sheet; 21. First connecting rod; 22. Vertical displacement dial gauge; 23. Second connecting rod; 24. Horizontal displacement dial gauge; 25. Strain gauge; 26. Rock mass model; 27. Soil model; 111. Pile model; 112. Anchor bolt assembly model; 141. Reaction plate; 142. Pressure sensor; 143. Jack; 144. Frame; 151. Pull rope; 152. First fixed pulley; 153. Second fixed pulley; 154. Weight box; 155. Weights. Detailed Implementation

[0017] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0018] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0019] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0020] The preferred embodiments of this application are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit this application.

[0021] like Figure 1 As shown in the embodiment of this application, a test device for a pile-expanded diameter anchor composite foundation structure is proposed, comprising: a foundation structure model 11, a support 13, a vertical loading device 14, and a horizontal loading device 15; the foundation structure model 11 is vertically embedded in a medium model inside a model box 12, with the top end of the foundation structure model 11 extending outside the medium model; the support 13 is arranged above the model box 12 and connected to the model box 12; the first end of the vertical loading device 14 is connected to the foundation structure model 11, and the second end of the vertical loading device 14 is connected to the support 13, and the vertical loading device 14 applies a vertical load to the foundation structure model 11; the first end of the horizontal loading device 15 extends horizontally and is connected to the top end of the foundation structure model 11, and a weight is suspended on the second end of the horizontal loading device 15 to apply a horizontal load to the foundation structure model 11.

[0022] The test apparatus for the pile-expanded diameter anchor composite foundation structure provided in this application includes a foundation structure model 11, a support 13, a vertical loading device 14, and a horizontal loading device 15. The support 13 is arranged above and connected to the model box 12, serving as the load-bearing and reaction structure of the entire apparatus. This ensures that the vertical loading device 14 and the horizontal loading device 15 can be stably installed, guaranteeing the rigidity and stability of the entire apparatus and preventing the test accuracy from being affected by the swaying of the support 13 during loading. The test apparatus is easy to operate and has a wide range of applications. By setting up independent vertical loading devices 14 and horizontal loading devices 15, testers can flexibly conduct unidirectional loading tests or combined loading tests, applying vertical and horizontal loads to the foundation structure model 11 synchronously or stepwise. Loading the foundation structure model 11 on the same test apparatus can simulate the complex stress state borne by the composite foundation structure in actual engineering. It is highly practical, requires no replacement of other test equipment, and accelerates the simulation test process.

[0023] It is understandable that by using the vertical loading device 14 in conjunction with the horizontal loading device 15, it is possible to simulate the uplift load and horizontal load from the superstructure, groundwater, soil expansion, wind load, earthquake and temporary load, thereby providing more comprehensive data support for the application of the basic structure model 11 in engineering.

[0024] like Figures 1 to 3 As shown in the figure, in one feasible implementation, the basic structure model 11 includes: a pile model 111 and an anchor bolt assembly model 112; the pile model 111 is arranged vertically, and the top of the pile model 111 is exposed outside the medium model; the anchor bolt assembly model 112 includes a plurality of anchor bolt models, which are arranged vertically below the pile model 111, and the anchor bolt models are fixedly connected to the bottom end of the pile model 111.

[0025] In this technical solution, the pile model 111 is vertically arranged and mainly bears the lateral earth pressure, bending moment, and shear force. The anchor assembly model 112 is arranged below the pile model 111 and fixedly connected to it, improving the bearing capacity and pull-out resistance of the foundation. The top of the pile model 111 protrudes outside the medium model, increasing the contact area between the foundation structure model 11 and the vertical loading device 14 and the horizontal loading device 15, ensuring the stability of the contact between the vertical loading device 14 and the horizontal loading device 15 and the foundation structure model 11, thereby ensuring the accuracy of the test data.

[0026] In some instances, four anchor bolt models are set up, and the four anchor bolt models are symmetrically arranged at the bottom of the pile model 111.

[0027] like Figure 1As shown, in one feasible implementation, the medium model includes a rock mass model 26 and a soil model 27. The rock mass model 26 is arranged at the bottom of the model box 12, and the soil model 27 is arranged above the rock mass model 26. The anchor bolt model is embedded in the rock mass model 26, and the pile model 111 is embedded in the soil model 27.

[0028] In this technical solution, the rock mass model 26 is arranged at the bottom of the model box 12 to provide a high-strength, high-anchorage bearing layer for the anchor bolt model, simulating the situation in actual engineering where the anchor bolt model is anchored into bedrock or hard soil layers; the soil model 27 simulates the overburden soil layer or soft soil layer traversed by the foundation pile model 111; by combining soil layer simulation and rock layer simulation, common foundation conditions in actual engineering are reproduced, so that the test can observe the anchorage mechanism of the anchor bolt model in the rock mass and the load transfer law of the pile model 111 in the soil mass respectively, ensuring the reliability of the simulation test results, and effectively simulating the overall working performance and failure mode of the pile-expanded diameter anchor bolt model composite foundation structure under real geological conditions.

[0029] In some examples, 6mm diameter threaded steel bars are used as the non-expanded diameter anchor bolt model, and 12mm diameter threaded steel bars are used as the expanded diameter pile model 111. The pile model 111 is welded to the anchor bolt model to form the foundation structure model 11. The pile model 111 is made by concrete casting. After the anchor bolt model is installed and the rock concrete has initially solidified, the pile model 111 is cast. Uniform sandy soil is used as the soil model 27 to simulate the soil, and concrete is used as the rock model 26 to simulate the rock mass. A 610mm×610mm×350mm wooden template is used to construct the lower part of the model box 12 for pouring concrete rock mass model 26; a 600mm×600mm×350mm acrylic template is used to construct the upper part of the model box 12 for filling soil mass model 27, so as to facilitate observation of changes in soil mass model 27. The foundation structure model 11 is placed in the center of the model box 12. The distance between the foundation structure model 11 and the inner wall of the model box 12 is more than 2.82 times the size of the foundation structure model 11, so the influence of boundary effect can be ignored.

[0030] First, the lower rock mass model 26 is poured. Sand, cement, talcum powder, and gypsum powder are thoroughly mixed and poured into the model box 12. Concrete samples are collected after each pour for testing. A layered pouring process is used, with each layer controlled to a thickness of 10cm, and each layer is thoroughly compacted and vibrated using a rubber mallet. The pouring process is continuous, with strict control over the interval between layers. Once the concrete reaches the predetermined height, the foundation structure model 11 is placed in the designated position, and subsequent pouring continues. For 12 hours after pouring, the concrete is covered with plastic film to maintain moisture, and then sprayed with water every 12 hours to ensure it remains moist. The upper soil model 27 is filled with sand in layers of 10cm thickness and compacted with a rubber hammer and wooden board. After each layer is filled, it is tamped and leveled. This process is repeated until the soil model reaches the same height as the top of the pile. After the soil model 27 is filled, a heavy object is placed on top of the soil model 27 and left to stand for 3 days to compact the soil model 27.

[0031] like Figure 1 As shown, in one feasible embodiment, the vertical loading device 14 includes: a reaction plate 141, a pressure sensor 142, a jack 143, and a frame 144; the reaction plate 141 is horizontally arranged above the foundation structure model 11, and the reaction plate 141 is fixedly connected to the support 13; the pressure sensor 142 is disposed on the reaction plate 141; the jack 143 is vertically arranged, and the fixed end of the jack 143 is in contact with the pressure sensor 142; the frame 144 is arranged above the foundation structure model 11, and the frame 144 is wrapped around the outside of the reaction plate 141, with a gap between the frame 144 and the reaction plate 141; the first end of the frame 144 abuts against the telescopic end of the jack 143, and the second end of the frame 144 abuts against the top of the foundation structure model 11, so as to transmit the vertical load provided by the jack 143 to the foundation structure model 11 through the frame 144.

[0032] In this technical solution, the reaction plate 141 is horizontally arranged and fixedly connected to the bracket 13. The reaction plate 141 serves as the supporting structure for the jack 143. The jack 143 lifts the frame 144 upward, and the frame 144 generates a vertical upward tension on the foundation structure model 11, simulating the vertical load on the pile-expanded diameter anchor composite foundation structure. This ensures the stability and controllability of the vertical load application and avoids the problem of easy swaying in traditional pull-out loading. There is a gap between the frame 144 and the reaction plate 141 so that the frame 144 and the reaction plate 141 do not contact each other, thereby enabling the frame 144 to transfer the load more accurately. When the jack 143 is lifted, it is subjected to the reaction force of the frame 144. The pressure sensor 142 is set between the reaction plate 141 and the jack 143. The pressure sensor 142 measures the reaction force applied by the jack 143 to the reaction plate 141 in real time. According to Newton's third law, the reaction force is equal to the vertical load applied to the foundation structure model 11, thereby realizing the accurate measurement of the loading force, so as to facilitate the real-time and accurate measurement of the load applied in the vertical direction and obtain reliable test data.

[0033] Furthermore, the frame 144 includes a bottom frame, a top frame, and four connecting rods. The bottom frame abuts against the foundation structure model 11, the top frame abuts against the top surface of the jack 143, and the connecting rods are vertically arranged to connect the top frame and the bottom frame to form a stable frame 144 structure.

[0034] Understandably, the vertical load applied to the foundation structure model 11 can be calculated by converting the readings of the pressure sensor 142, and the calculation formula is: F=PA.

[0035] like Figure 1 As shown, in one feasible embodiment, the test device for the pile-expanded diameter anchor composite foundation structure further includes: a hydraulic pump 16, a hydraulic pipe 17, and a pressure gauge 18; the first end of the hydraulic pipe 17 is connected to the hydraulic pump 16, and the second end of the hydraulic pipe 17 is connected to the jack 143 to provide power to the jack 143 through the hydraulic pipe 17; the pressure gauge 18 is installed on the hydraulic pump 16 to monitor the pressure of the hydraulic pump 16.

[0036] In this technical solution, the hydraulic pump 16 is connected to the jack 143 through the hydraulic pipe 17, providing the jack 143 with continuous and stable hydraulic power; the pressure gauge 18 is installed on the hydraulic pump 16, and the pressure gauge 18 monitors the output pressure of the hydraulic pump 16. The pressure gauge 18 provides the test personnel with a real-time load monitoring window, and the value of the pressure gauge 18 can be cross-verified with the value of the pressure sensor 142, which is beneficial to improving the accuracy of vertical load application.

[0037] like Figure 1As shown, in one feasible embodiment, the horizontal loading device 15 includes: a pull rope 151, a first fixed pulley 152, a second fixed pulley 153, and a weight box 154; the first end of the pull rope 151 is connected to the foundation structure model 11; the first fixed pulley 152 is mounted on the bracket 13, and the pull rope 151 passes around the bottom of the first fixed pulley 152 to guide the pull rope 151 through the first fixed pulley 152, so that the first end of the pull rope 151 extends in the horizontal direction; the second fixed pulley 152, the first fixed pulley 152, the second fixed pulley 153, and the weight box 154; the first end of the pull rope 151 is connected to the foundation structure model 11; the first fixed pulley 152 is mounted on the bracket 13, and the pull rope 151 passes around the bottom of the first fixed pulley 152 to guide the pull rope 151 through the first fixed pulley 152, so that the first end of the pull rope 151 extends in the horizontal direction; the second fixed pulley 152, the first fixed pulley 153, and the second fixed pulley 154. Two fixed pulleys 153 are arranged above the first fixed pulley 152. The second fixed pulley 153 is mounted on the bracket 13. The pull rope 151 passes over the second fixed pulley 153 from the top of the second fixed pulley 153 to guide the pull rope 151 through the second fixed pulley 153, so that the second end of the pull rope 151 hangs down naturally. The weight box 154 contains weights 155. The weight box 154 is connected to the second end of the pull rope 151 to transfer the horizontal load to the foundation structure model 11 through the pull rope 151.

[0038] In this technical solution, the first fixed pulley 152 and the second fixed pulley 153 are used to change the direction of the pull rope 151, thereby changing the direction of the force. The first fixed pulley 152 is mounted on the support 13, and the pull rope 151 passes around the bottom of the first fixed pulley 152. By changing the direction of the force through the first fixed pulley 152, the weight of the weight box 154 is converted into a horizontal tension acting on the basic structural model 11. The pull rope 151 passes around the top of the second fixed pulley 153, ensuring that the weight box 154 can hang naturally, avoiding collisions between the weight box 154 and the model box 12 or other components, reducing fluctuations in the horizontal load value. By adding or removing standard weights 155, high-precision, graded loading of the horizontal load can be achieved. The operation is simple and the cost is low. At the same time, the fixed pulley group structure can reduce the friction force on the pull rope 151, so that the horizontal load value applied to the basic structural model 11 is close to the weight of the weights 155, making the loading amount of the horizontal load easier to control and helping to speed up the test process.

[0039] It should be noted that vertical loading is generally performed first, followed by horizontal loading; different combined loading methods are selected as follows: first keep the vertical loading unchanged, and adjust the loading amount of the horizontal loading device 15.

[0040] It is understandable that when applying a horizontal load to the foundation structure model 11, the weight of the applied weight 155 is used, and the friction between the rope 151 and the two fixed pulleys can be ignored. The calculation formula is: F=mg.

[0041] like Figure 1 and Figure 2 As shown, in one feasible embodiment, the test device for the pile-expanded diameter anchor composite foundation structure further includes: a pull ring 19, which is set at the center of the top of the foundation structure model 11, and the first end of the pull rope 151 is connected to the pull ring 19.

[0042] In this technical solution, the pull ring 19 structure ensures the firmness of the pull rope 151 connection; by setting the pull ring 19 at the center position of the top of the foundation structure model 11, it ensures that the point of application of the horizontal load passes through the axis of the foundation structure model 11, preventing additional torque from being generated at the top of the foundation structure model 11 due to load eccentricity, which facilitates subsequent theoretical analysis and model verification.

[0043] like Figure 1 As shown, in one feasible embodiment, the test device for the pile-expanded diameter anchor composite foundation structure further includes: a metal sheet 20, a first connecting rod 21, and a vertical displacement dial gauge 22; the metal sheet 20 is arranged horizontally and is fixedly connected to the end face of the top of the foundation structure model 11, with the first end of the metal sheet 20 extending in the vertical direction; the first end of the first connecting rod 21 is connected to the support 13; the vertical displacement dial gauge 22 is set at the second end of the first connecting rod 21, and the probe of the vertical displacement dial gauge 22 contacts the first end of the metal sheet 20 to detect the displacement of the metal sheet 20 in the vertical direction.

[0044] In this technical solution, the metal sheet 20 is pasted and fixed to the end face of the top of the base structure model 11. The metal sheet 20 serves as a reference plate for displacement measurement, transmitting the displacement of the base structure model 11. The first connecting rod 21 is connected to the bracket 13 to ensure that the support structure of the vertical displacement dial gauge 22 is independent and stable, and is not affected by the deformation of the base structure model 11. The probe of the vertical displacement dial gauge 22 is in contact with the vertical end of the metal sheet 20 to measure the vertical displacement of the metal sheet 20. That is, the vertical displacement of the base structure model 11 is monitored in real time and continuously, which increases the device's ability to monitor the vertical displacement of the base structure model 11.

[0045] Furthermore, a clearance opening is provided on the metal sheet 20, through which the pull ring 19 passes to prevent the horizontal tension of the pull rope 151 from acting on the metal sheet, ensuring that the horizontal load acts directly on the foundation structure model 11.

[0046] like Figure 1 As shown, in one feasible embodiment, the second end of the metal sheet 20 extends horizontally, and the test device for the pile-expanded diameter anchor composite foundation structure further includes: a second connecting rod 23 and a horizontal displacement dial gauge 24; the first end of the second connecting rod 23 is connected to the bracket 13; the horizontal displacement dial gauge 24 is disposed at the second end of the second connecting rod 23, and the probe of the horizontal displacement dial gauge 24 contacts the second end of the metal sheet 20 to detect the displacement of the metal sheet 20 in the horizontal direction.

[0047] In this technical solution, the second connecting rod 23 is connected to the bracket 13 to ensure that the support structure of the horizontal displacement dial gauge 24 is independent and stable and is not affected by the deformation of the foundation structure model 11; the probe of the horizontal displacement dial gauge 24 is in contact with the horizontal end of the metal plate 20 to measure the horizontal displacement of the metal plate 20, that is, to monitor the horizontal displacement of the foundation structure model 11 in real time and continuously, thereby increasing the device's ability to monitor the horizontal displacement of the foundation structure model 11.

[0048] like Figure 4 and Figure 5 As shown, in one feasible implementation, the test device for the pile-expanded diameter anchor composite foundation structure further includes: strain gauges 25, and a plurality of strain gauges 25 are arranged on the side wall of the foundation structure model 11 along the length direction of the foundation structure model 11.

[0049] In this technical solution, the data measured by multiple strain gauges 25 can be used to draw bending moment distribution diagrams, stress distribution diagrams, etc. of the foundation structure model 11, thereby intuitively showing the load transfer path in the foundation structure model 11, determining the location of the maximum bending moment point, and analyzing the area where cracks may develop in the foundation structure model 11, providing a theoretical basis for the internal stress mechanism of the foundation structure model 11, verification and optimization design.

[0050] Furthermore, strain gauges 25 are arranged at equal intervals along the length of the foundation structure model 11 on the sidewall of the foundation structure model 11 to measure the strain variation of the foundation structure model 11 with depth.

[0051] In some examples, strain gauges 25 at the same axial position of the foundation structure model 11 are arranged symmetrically around the circumference of the foundation structure model 11 to measure the strain in different directions of the same cross section in order to calculate the bending moment of the cross section.

[0052] It will be readily understood by those skilled in the art that the above embodiments can be freely combined and superimposed without conflict.

[0053] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application. The above are merely preferred embodiments of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this application, and these improvements and modifications should also be considered within the protection scope of this application.

Claims

1. A test apparatus for a pile-expanded diameter anchor composite foundation structure, characterized in that, The test apparatus for the pile-expanded diameter anchor composite foundation structure includes: A basic structural model, wherein the basic structural model is vertically embedded in the medium model inside the model box, and the top of the basic structural model extends out of the medium model; A support frame is arranged above the model box and connected to the model box. A vertical loading device, wherein the first end of the vertical loading device is connected to the foundation structure model, and the second end of the vertical loading device is connected to the support; A horizontal loading device, wherein the first end of the horizontal loading device extends in a horizontal direction and is connected to the top of the basic structure model, and a weight is suspended on the second end of the horizontal loading device.

2. The test device for a pile-expanded diameter anchor composite foundation structure according to claim 1, characterized in that, The basic structure model includes: A pile model, wherein the pile model is arranged vertically and the top of the pile model protrudes outside the medium model; An anchor bolt assembly model, comprising several anchor bolt models, which are vertically arranged below the pile model and fixedly connected to the bottom end of the pile model.

3. The test device for a pile-expanded diameter anchor composite foundation structure according to claim 2, characterized in that, The medium model includes a rock mass model and a soil mass model. The rock mass model is arranged at the bottom of the model box, and the soil mass model is arranged above the rock mass model. The anchor bolt model is embedded in the rock mass model, and the pile model is embedded in the soil mass model.

4. The test device for a pile-expanded diameter anchor composite foundation structure according to claim 1, characterized in that, The vertical loading device includes: A reaction plate, which is horizontally arranged above the foundation structure model and is fixedly connected to the support; A pressure sensor is disposed on the reaction plate; A jack, wherein the jack is arranged vertically and the fixed end of the jack is in contact with the pressure sensor; A frame is arranged above the basic structure model, the frame is wrapped around the outside of the reaction plate, and a gap is left between the frame and the reaction plate. The first end of the frame abuts against the telescopic end of the jack, and the second end of the frame abuts against the top of the foundation structure model, so as to transmit the vertical load provided by the jack to the foundation structure model through the frame.

5. The test device for a pile-expanded diameter anchor composite foundation structure according to claim 4, characterized in that, The test apparatus for the pile-expanded diameter anchor composite foundation structure also includes: Hydraulic pump; A hydraulic pipe, the first end of which is connected to the hydraulic pump and the second end of which is connected to the jack, so as to provide power to the jack through the hydraulic pipe; A pressure gauge is mounted on the hydraulic pump to monitor the pressure of the hydraulic pump.

6. The test device for a pile-expanded diameter anchor composite foundation structure according to claim 1, characterized in that, The horizontal loading device includes: A pull rope, the first end of which is connected to the basic structure model; A first fixed pulley is mounted on the bracket, and the pull rope passes around the bottom of the first fixed pulley to guide the pull rope so that the first end of the pull rope extends in a horizontal direction. The second fixed pulley is arranged above the first fixed pulley and is mounted on the bracket. The pull rope passes over the second fixed pulley from the top of the second fixed pulley and is guided by the second fixed pulley and the pull rope so that the second end of the pull rope hangs down naturally. A weight box containing weights is provided, and the weight box is connected to the second end of the pull rope to transfer horizontal loads to the foundation structure model via the pull rope.

7. The test device for a pile-expanded diameter anchor composite foundation structure according to claim 6, characterized in that, The test apparatus for the pile-expanded diameter anchor composite foundation structure also includes: A pull ring is provided at the center of the top of the basic structure model, and the first end of the pull rope is connected to the pull ring.

8. A test apparatus for a pile-expanded diameter anchor composite foundation structure according to any one of claims 1 to 7, characterized in that, The test apparatus for the pile-expanded diameter anchor composite foundation structure also includes: A metal sheet, the metal sheet being arranged horizontally, the metal sheet being fixedly connected to the end face of the top of the basic structure model, and the first end of the metal sheet extending in a vertical direction; The first link, the first end of the first link being connected to the bracket; A vertical displacement dial indicator is installed at the second end of the first connecting rod. The probe of the vertical displacement dial indicator contacts the first end of the metal sheet to detect the displacement of the metal sheet in the vertical direction.

9. The test device for a pile-expanded diameter anchor composite foundation structure according to claim 8, characterized in that, The second end of the metal sheet extends horizontally, and the test device for the pile-expanded diameter anchor composite foundation structure further includes: The second link, the first end of which is connected to the bracket; A horizontal displacement dial indicator is installed at the second end of the second connecting rod. The probe of the horizontal displacement dial indicator contacts the second end of the metal sheet to detect the displacement of the metal sheet in the horizontal direction.

10. The test device for a pile-expanded diameter anchor composite foundation structure according to claim 9, characterized in that, The test apparatus for the pile-expanded diameter anchor composite foundation structure also includes: Strain gauges, a plurality of strain gauges are arranged at equal intervals along the length of the foundation structure model on the side wall of the foundation structure model.

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