CN111551356A - An expanded head anchor bolt group anchor test device and test method thereof - Google Patents

Abstract

An enlarged head anchor bolt group anchor test device, comprising a transparent test box, a plurality of enlarged head anchor rod models arranged in the test chamber in a horizontal direction, and a second servo hydraulic pressure for drawing the multiple enlarged head anchor rod models Loading device, the first servo-hydraulic loading device that vertically pressurizes the soil; the box is filled with soil, the anchoring section model is buried in the middle of the soil, and is in close contact with the front side wall of the test box; the enlarged head anchor The free section model of the rod is connected with a first displacement gauge and a tension pressure sensor, and the anchor section model is connected with a second displacement gauge; the right ends of the free section models of multiple enlarged head anchor rods are connected in parallel through steel plates, and a digital camera is installed on the front side of the test box. , the digital camera is electrically connected to the computer. The present invention also provides a test method of the enlarged head anchor rod group anchor test device. The invention can simulate the construction process of uplift resistance of the enlarged head anchor rod in the laboratory, so as to understand the influence law of the single and multiple enlarged head anchor rods on the deformation of the surrounding soil in the use stage.

Description

An expanded head anchor bolt group anchor test device and test method thereof

technical field

The invention relates to the field of geotechnical engineering, in particular to a test device and a test method for expanding head bolt group anchors.

Background technique

In the soft soil area along the southeast coast, due to the low strength of the foundation soil, the ultimate pullout resistance of the ordinary bolt is small, which restricts its application in the soft soil foundation. In order to improve the pullout resistance of the bolt in the soft soil foundation, the engineers developed the enlarged head bolt. The bolt adopts a high-pressure rotary jetting process, and a cylindrical anchoring section with a larger diameter is formed within a certain range at the bottom of the bolt, which significantly improves the pull-out resistance of the bolt.

The use of enlarged head anchor rod has the advantages of fast construction speed, excellent quality, little impact on the surrounding environment, and can effectively improve the pull-out resistance of the anchor body. However, because the mechanism of action of the enlarged head bolt is still unclear, it is still in the stage of empirical design. In addition, bolts generally appear in foundation pits and tunnel projects in the form of multiple roots. Arranging multiple anchor rods within a certain range will make the anchor rods influence each other and restrict each other, resulting in the failure to achieve the expected pullout resistance and causing engineering hidden dangers. The arrangement of bolts with reasonable spacing has a positive effect on the safety, stability and economic rationality of the project. It is of great significance to expand the safe application and promotion of head bolts to further study the action mechanism of the bolt group through indoor model tests.

SUMMARY OF THE INVENTION

In order to overcome the above problems, the present invention provides an enlarged head anchor bolt group anchor test device and a test method with a simple structure and convenient operation.

A first aspect of the present invention provides an enlarged head anchor rod group anchor test device, including a test box, a plurality of enlarged head anchor rod models arranged in the test box in a horizontal direction, and a plurality of enlarged head anchor rod models are drawn. The second servo hydraulic loading device, the first servo hydraulic loading device for vertically pressurizing the soil, the first displacement gauge, the second displacement gauge, the tension pressure sensor, the digital camera and the computer;

The enlarged head anchor rod model is divided into a free segment model and an anchored segment model. The free segment model is a threaded rod. The part of the threaded rod located inside the test chamber is sleeved with a threaded rod for separating the threaded rod and the soil. The first casing, the left end of the free segment model is connected with the anchoring segment model, the anchoring segment model is a semi-cylindrical structure, the semi-cylindrical structure has a longitudinal section, and the longitudinal section is a rectangular surface; the enlarged head anchor rod model is horizontal Arranged in the box, a plurality of enlarged head anchor rod models are stacked and arranged in intervals along the vertical direction;

The test box includes a transparent box body, the top surface of the box body is provided with an opening for filling the soil, and a cover plate is closely fitted at the opening; a first servo hydraulic loading device extending downward to apply pressure to the cover plate, the bottom end of the first servo hydraulic loading device is in contact with the upper surface of the cover plate;

The box body is provided with a soil body and an enlarged head anchor rod model embedded in the soil body, and the left and right side walls of the box body are symmetrically arranged in sequence along the vertical direction with multiple pairs of through holes for the expansion head anchor rod model to pass through. , the right side of the box body is the drawing end; the through hole is set close to the front side of the box body, so that when the expansion head anchor rod model is inserted into the through hole, the rectangular surface of the anchoring section model is close to the box body The front side wall of the box body; a plurality of marking points are evenly arranged on the front side wall of the box;

The enlarged head anchor rod model is horizontally penetrated into the box body from the through hole on the right side of the box body along the direction of the central axis of the through hole, and the anchoring section model is buried in the middle of the soil body; the right part of the free section model is exposed in the box. Outside the box, the right ends of the free segment models of multiple enlarged head anchor models are connected together by steel plates; the plane where the steel plates are located is perpendicular to the axial direction of the enlarged head anchor model, and the steel plate corresponds to the positions of the multiple enlarged head anchor models There are a plurality of connecting holes, and a plurality of expansion head anchor rod models are penetrated in the connection holes and fixedly connected with the steel plate; the right side of the steel plate is connected with a second servo hydraulic loading device for horizontally drawing the expansion head anchor rod model; free The part of the segment model located outside the box is provided with a first displacement gauge for measuring the elastic displacement information of the free segment model and a tension pressure sensor for measuring the horizontal tension of the expanded head anchor model. The first displacement gauge is connected with the small iron piece. Threaded rod connections for free segment models;

The left end of the anchoring segment model is connected with one end of the metal wire, and the other end of the metal wire is connected with the second displacement meter for measuring the horizontal displacement information of the enlarged head anchor rod model through the through hole located on the left side of the box body. The part located in the box is sleeved with a second sleeve for isolating the wire and the soil;

The front side of the test box is provided with a digital camera for taking pictures of soil displacement, and the digital camera is electrically connected to the computer to transmit the taken displacement pictures to the computer;

The first displacement meter, the second displacement meter, and the tension pressure sensor are respectively electrically connected to the computer, so as to transmit the detected elastic displacement information, horizontal displacement information, and horizontal tensile force to the computer;

The first servo hydraulic loading device and the second servo hydraulic loading device are respectively electrically connected with the computer, and the computer controls the first servo hydraulic loading device and the second servo hydraulic loading device.

Further, the plurality of marking points are arranged in a matrix, and the distance between adjacent marking points is 10 cm.

Further, the box body is made of tempered glass material.

Further, the outer surface of the anchor segment model is coated with an epoxy resin layer.

Further, the cover plate is a steel plate.

Further, the anchoring segment model is made of cement or rubber material.

A second aspect of the present invention provides a test method for an enlarged head bolt group anchor test device, comprising the following steps:

Step 1, connect the free segment threaded rod and the anchor segment to form an enlarged head anchor rod model;

Step 2: Use the sand rain method to fill the soil into the box layer by layer, fill it with a certain thickness and then compact it to ensure that the filling is uniform; when the filling height is close to the small hole of the box, the soil surface is flattened;

Step 3: Embed the pre-prepared enlarged head anchor rod model to ensure the level of the anchor rod; insert a single enlarged head anchor rod model from the through hole on the right side of the box body along the axial direction of the through hole to the box body to make the free segment model The threaded rod of the free segment model passes through the through hole horizontally, and the threaded rod of the free segment model is located in the part of the box body with a first sleeve; the surface of the anchor segment model of the semi-cylindrical structure should be close to the tempered glass of the front side wall of the box body; Multiple enlarged head anchor rod models to ensure that the distance between each enlarged head anchor rod model meets the test requirements; use steel sheets to connect the right ends of each enlarged head anchor rod model, and the steel sheets need to be perpendicular to the second servo hydraulic loading device to ensure that each The root expansion head anchor model is uniformly stressed;

Step 4, the left end of the anchoring segment model is connected to the metal wire, and the metal wire is horizontally passed through the through hole on the left side of the box body, and a second sleeve is sleeved on the outside of the metal wire;

Step 5: Continue to fill the box with a predetermined amount of soil and compact it, and cover the cover;

Step 6, connect the first displacement gauges on the multiple enlarged head anchor rod models in parallel, and connect the second displacement gauges with wires;

Step 7, the threaded rod is connected with the tension pressure sensor, the right end of the steel plate is connected with the second servo hydraulic loading device, and the first servo hydraulic loading device is connected with the cover plate;

Step 8, the first servo hydraulic loading device controls the upper load to be loaded to the set value;

Step 9: Make sure that the enlarged head anchor model keeps close to the tempered glass during the loading process. The second servo hydraulic loading device adopts the oil pump to pressurize the loading, which is automatically loaded by the computer control. The actual loading amount is recorded by the tension and pressure sensor, and the two sides are recorded. Displacement meter readings, digital cameras take pictures after each stage of loading, and soil deformation is recorded to simulate the process of the extended head bolt pullout test.

Step 10: Analyze relevant data, use software to process soil deformation images, observe soil changes before and after each level of loading, and prepare for subsequent research.

The beneficial effects of the invention are that the structure is simple, the operation is convenient, fits the reality, and can realize the simulation of various working conditions. The construction process of the expansion head bolt can be simulated in the laboratory, so as to understand the influence law of the single and multiple expansion head bolts on the surrounding soil deformation during the use stage. The enlarged head bolt model composed of threaded rod and cement block is more realistic and the simulation effect is more accurate.

Description of drawings

Figure 1 is a schematic diagram of the structure of the enlarged head bolt group anchor test device.

Figure 2 is a schematic view of the structure of the enlarged head anchor rod.

FIG. 3 is a schematic diagram of the matching structure of the second displacement gauge and the metal wire.

FIG. 4 is a schematic diagram of the cooperation structure of the first displacement gauge and the free segment model.

Description of reference numerals: 1. Box body; 2. Front side wall of box body; 3. Cover plate; 4. Reaction frame; 5. First servo hydraulic loading device; 6. Marking point; 7. Anchoring segment model; 8. First casing; 9. Free segment model; 10. Upright pole; 11. Small iron piece; 12. First displacement gauge; 13. Metal wire; 14. Second displacement gauge; 15. Second casing; 16. Second servo hydraulic loading device; 17. Pull pressure sensor; 18. Tripod; 19. Digital camera; 20. Computer.

Detailed ways

The technical solutions of the patent of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that when the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" appear. The orientation or positional relationship indicated by ” and the like is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, a specific orientation, and a specific orientation. The orientation configuration and operation of the device should not be construed as a limitation of the present invention. Furthermore, the terms "first," "second," and "third," as they appear, are for descriptive purposes only and should not be construed to indicate or imply relative importance.

In the description of the present invention, it should be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection or a Removable connection, or integral connection; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be internal communication between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

Referring to the accompanying drawings, an enlarged head anchor rod group anchor test device includes a test box, a plurality of enlarged head anchor rod models arranged in the test box in a horizontal direction, and a second extended head anchor rod model for drawing the plurality of enlarged head anchor rod models. Servo hydraulic loading device 16, first servo hydraulic loading device 5 for vertically pressurizing the soil, first displacement gauge 12, second displacement gauge 14, tension and pressure sensor 17, digital camera 19 and computer 20;

The enlarged head anchor rod model is divided into a free segment model 9 and an anchoring segment model 7. The free segment model 9 is a threaded rod, and the part of the threaded rod located inside the test box is sleeved with a threaded rod for separating the threaded rod and the anchor rod. The first casing 8 of the soil body, the left end of the free segment model 9 is connected with the anchoring segment model, the anchoring segment model 7 is a semi-cylindrical structure, the semi-cylindrical structure has a longitudinal section, and the longitudinal section is a rectangular surface; the anchoring section The model 7 is made of cement or rubber material, the outer surface of the anchoring section model 7 is coated with an epoxy resin layer, and the soil particles are pasted on the outer surface of the anchoring section model 7 . The enlarged head anchor rod models are horizontally arranged in the box, and a plurality of enlarged head anchor rod models are stacked and arranged in intervals along the vertical direction;

The test box includes a transparent box body 1, and the box body 1 is made of tempered glass. The top surface of the box body 1 is provided with an opening for filling in the soil, and the opening is closely fitted with a cover plate 3, which is a steel plate; the top of the box body 1 is provided with a reaction force frame 4, which is provided with a first servo hydraulic loading device 5 extending vertically downward to apply pressure to the cover plate, and the bottom end of the first servo hydraulic loading device 5 is in contact with the upper surface of the cover plate 3;

The box body 1 is provided with a soil body and an enlarged head anchor rod model embedded in the soil body. The left and right side walls of the box body 1 are symmetrically arranged in sequence along the vertical direction with a plurality of pairs for the expansion head anchor rod model to pass through. A through hole, the right side of the box body 1 is the drawing end; the through hole is set at a position close to the front side of the box body 1, so that when the expansion head anchor rod model is inserted in the through hole, the rectangular surface of the anchoring section model 7 It is closely attached to the front side wall 2 of the box body; a plurality of marking points 6 are evenly arranged on the front side wall 2 of the box body, and the marking points 6 are arranged in a matrix, and the distance between the adjacent marking points 6 is 10cm.

The enlarged head anchor rod model is horizontally penetrated into the box body 1 from the through hole on the right side of the box body along the direction of the central axis of the through hole, and the anchoring section model 7 is buried in the middle of the soil body; The right part is exposed outside the box, and the right ends of the free segment models 9 of the multiple enlarged head anchor models are connected together by steel plates; the plane where the steel plates are located is perpendicular to the axial direction of the enlarged head anchor model, and the steel plates correspond to multiple enlarged heads A plurality of connecting holes are opened at the position of the anchor rod model, and a plurality of enlarged head anchor rod models are penetrated in the connecting holes to be fixedly connected with the steel plate; the right side of the steel plate is connected with a second servo for horizontally drawing the enlarged head anchor rod model. The hydraulic loading device 16 and the second servo hydraulic loading device 16 are supported by the vertical rod 10; the part of the free segment model 9 located outside the box is provided with a first displacement gauge 12 for measuring the elastic displacement information of the free segment model 9 and a first displacement gauge 12 for measuring The tension and pressure sensor for expanding the horizontal tension of the head anchor model, the first displacement gauge 12 is connected with the threaded rod of the free segment model 9 through the small iron piece 11;

The left end of the anchoring segment model 7 is connected to one end of the metal wire 13, and the other end of the metal wire 13 passes through the through hole on the left side of the box body 1 and is used for measuring the horizontal displacement information of the enlarged head anchor rod model. The second displacement meter 14 is connected, and the part of the wire inside the box is sleeved with a second sleeve 15 for isolating the wire and the soil;

The front side of the test box is provided with a digital camera 19 for taking pictures of soil displacement, the digital camera 19 is supported by a tripod 18, and the digital camera 19 is electrically connected to the computer 20 to transmit the photographed displacement pictures to the computer 20;

The first displacement gauge 12, the second displacement gauge 14, and the tension pressure sensor 17 are respectively electrically connected to the computer 20, so as to transmit the detected elastic displacement information, horizontal displacement information, and horizontal tensile force to the computer 20;

The first servo hydraulic loading device 5 and the second servo hydraulic loading device 16 are respectively electrically connected to the computer 20 , and the computer 20 controls the first servo hydraulic loading device 5 and the second servo hydraulic loading device 16 .

A test method for an enlarged head bolt group anchor test device, comprising the following steps:

Step 1, connect the free segment threaded rod and the anchor segment to form an enlarged head anchor rod model;

Step 2: Use the sand rain method to fill the soil into the box layer by layer, fill it with a certain thickness and then compact it to ensure that the filling is uniform; when the filling height is close to the small hole of the box, the soil surface is flattened;

Step 3: Embed the pre-prepared enlarged head anchor rod model to ensure the level of the anchor rod; insert a single enlarged head anchor rod model from the through hole on the right side of the box body along the axial direction of the through hole to the box body to make the free segment model The threaded rod of the free segment model passes through the through hole horizontally, and the threaded rod of the free segment model is located in the part of the box body with a first sleeve; the surface of the anchor segment model of the semi-cylindrical structure should be close to the tempered glass of the front side wall of the box body; Multiple enlarged head anchor rod models to ensure that the distance between each enlarged head anchor rod model meets the test requirements; use steel sheets to connect the right ends of each enlarged head anchor rod model, and the steel sheets need to be perpendicular to the second servo hydraulic loading device to ensure that each The root expansion head anchor model is uniformly stressed;

Step 4, the left end of the anchoring segment model is connected to the metal wire, and the metal wire is horizontally passed through the through hole on the left side of the box body, and a second sleeve is sleeved on the outside of the metal wire;

Step 5: Continue to fill the box with a predetermined amount of soil and compact it, and cover the cover;

Step 6, connect the first displacement gauges on the multiple enlarged head anchor rod models in parallel, and connect the second displacement gauges with wires;

Step 7, the threaded rod is connected with the tension pressure sensor, the right end of the steel plate is connected with the second servo hydraulic loading device, and the first servo hydraulic loading device is connected with the cover plate;

Step 8, the first servo hydraulic loading device controls the upper load to be loaded to the set value;

Step 9: Make sure that the enlarged head anchor model keeps close to the tempered glass during the loading process. The second servo hydraulic loading device adopts the oil pump to pressurize the loading, which is automatically loaded by the computer control. The actual loading amount is recorded by the tension and pressure sensor, and the two sides are recorded. Displacement meter readings, digital cameras take pictures after each stage of loading, and soil deformation is recorded to simulate the process of the extended head bolt pullout test.

Step 10: Analyze relevant data, use software to process soil deformation images, observe soil changes before and after each level of loading, and prepare for subsequent research.

The content described in the embodiments of the present specification is only an enumeration of the realization forms of the inventive concept, and the protection scope of the present invention should not be regarded as limited to the specific forms stated in the embodiments, and the protection scope of the present invention also extends to those skilled in the art. Equivalent technical means that can be conceived by a person based on the inventive concept.

Claims (7)

1. an enlarged head anchor bolt group anchor test device is characterized in that: comprising a test chamber, a plurality of enlarged head anchor rod models arranged in the test chamber in a horizontal direction, a plurality of enlarged head anchor rod models being drawn a second servo hydraulic loading device, a first servo hydraulic loading device for vertically pressurizing the soil, a first displacement gauge, a second displacement gauge, a tension pressure sensor, a digital camera and a computer; The enlarged head anchor rod model is divided into a free segment model and an anchored segment model. The free segment model is a threaded rod. The part of the threaded rod located inside the test chamber is sleeved with a threaded rod for separating the threaded rod and the soil. The first casing, the left end of the free segment model is connected with the anchoring segment model, the anchoring segment model is a semi-cylindrical structure, the semi-cylindrical structure has a longitudinal section, and the longitudinal section is a rectangular surface; the enlarged head anchor rod model is horizontal Arranged in the box, a plurality of enlarged head anchor rod models are stacked and arranged in intervals along the vertical direction; The test box includes a transparent box body, the top surface of the box body is provided with an opening for filling the soil, and a cover plate is closely fitted at the opening; a first servo hydraulic loading device extending downward to apply pressure to the cover plate, the bottom end of the first servo hydraulic loading device is in contact with the upper surface of the cover plate; The box body is provided with a soil body and an enlarged head anchor rod model embedded in the soil body, and the left and right side walls of the box body are symmetrically arranged in sequence along the vertical direction with multiple pairs of through holes for the expansion head anchor rod model to pass through. , the right side of the box body is the drawing end; the through hole is set close to the front side of the box body, so that when the expansion head anchor rod model is inserted into the through hole, the rectangular surface of the anchoring section model is close to the box body The front side wall of the box body; a plurality of marking points are evenly arranged on the front side wall of the box; The enlarged head anchor rod model is horizontally penetrated into the box body from the through hole on the right side of the box body along the direction of the central axis of the through hole, and the anchoring section model is buried in the middle of the soil body; the right part of the free section model is exposed in the box. Outside the box, the right ends of the free segment models of multiple enlarged head anchor models are connected together by steel plates; the plane where the steel plates are located is perpendicular to the axial direction of the enlarged head anchor model, and the steel plate corresponds to the positions of the multiple enlarged head anchor models There are a plurality of connecting holes, and a plurality of expansion head anchor rod models are penetrated in the connection holes and fixedly connected with the steel plate; the right side of the steel plate is connected with a second servo hydraulic loading device for horizontally drawing the expansion head anchor rod model; free The part of the segment model located outside the box is provided with a first displacement gauge for measuring the elastic displacement information of the free segment model and a tension pressure sensor for measuring the horizontal tension of the expanded head anchor model. The first displacement gauge is connected with the small iron piece. Threaded rod connections for free segment models; The left end of the anchoring segment model is connected with one end of the metal wire, and the other end of the metal wire is connected with the second displacement meter for measuring the horizontal displacement information of the enlarged head anchor rod model through the through hole located on the left side of the box body. The part located in the box is sleeved with a second sleeve for isolating the wire and the soil; The front side of the test box is provided with a digital camera for taking pictures of soil displacement, and the digital camera is electrically connected to the computer to transmit the taken displacement pictures to the computer; The first displacement meter, the second displacement meter, and the tension pressure sensor are respectively electrically connected to the computer, so as to transmit the detected elastic displacement information, horizontal displacement information, and horizontal tensile force to the computer; The first servo hydraulic loading device and the second servo hydraulic loading device are respectively electrically connected with the computer, and the computer controls the first servo hydraulic loading device and the second servo hydraulic loading device. 2 . The enlarged head bolt group anchor test device according to claim 1 , wherein the plurality of marking points are arranged in a matrix, and the distance between adjacent marking points is 10 cm. 3 . 3 . The enlarged head bolt group anchor test device according to claim 1 , wherein the box body is made of tempered glass material. 4 . 4 . The enlarged head anchor bolt group anchor test device according to claim 1 , wherein the outer surface of the anchoring segment model is coated with an epoxy resin layer. 5 . 5 . The enlarged head bolt group anchor test device according to claim 1 , wherein the cover plate is a steel plate. 6 . 6 . The enlarged head bolt group anchor test device according to claim 1 , wherein the anchoring section model is made of cement or rubber material. 7 . 7. the test method of a kind of expansion head bolt group anchor test device as described in any one of claim 1-6, is characterized in that, comprises the following steps: Step 1, connect the free segment threaded rod and the anchor segment to form an enlarged head anchor rod model; Step 2: Use the sand rain method to fill the soil into the box layer by layer, fill it with a certain thickness and then compact it to ensure that the filling is uniform; when the filling height is close to the small hole of the box, the soil surface is flattened; Step 3: Embed the pre-prepared enlarged head anchor rod model to ensure the level of the anchor rod; insert a single enlarged head anchor rod model from the through hole on the right side of the box body along the axial direction of the through hole to the box body to make the free segment model The threaded rod of the free-segment model passes through the through hole horizontally, and the threaded rod of the free-segment model is located in the part of the box body with a first sleeve; the rectangular surface of the anchoring-section model of the semi-cylindrical structure needs to be close to the tempered glass of the front side wall of the box; Put in multiple enlarged head anchor rod models to ensure that the distance between each enlarged head anchor rod model meets the test requirements; use steel sheets to connect the right ends of each enlarged head anchor rod model, and the steel sheets must be perpendicular to the second servo hydraulic loading device. Ensure that the force of each enlarged head anchor model is uniform; Step 4, the left end of the anchoring segment model is connected to the metal wire, and the metal wire is horizontally passed through the through hole on the left side of the box body, and a second sleeve is sleeved on the outside of the metal wire; Step 5: Continue to fill the box with a predetermined amount of soil and compact it, and cover the cover; Step 6, connect the first displacement gauges on the multiple enlarged head anchor rod models in parallel, and connect the second displacement gauges with wires; Step 7, the threaded rod is connected with the tension pressure sensor, the right end of the steel plate is connected with the second servo hydraulic loading device, and the first servo hydraulic loading device is connected with the cover plate; Step 8, the first servo hydraulic loading device controls the upper load to be loaded to the set value; Step 9: Make sure that the enlarged head anchor model keeps close to the tempered glass during the loading process. The second servo hydraulic loading device adopts the oil pump to pressurize the loading, which is automatically loaded by the computer control. The actual loading amount is recorded by the tension and pressure sensor, and the two sides are recorded. Displacement meter readings, digital cameras take pictures after each stage of loading, and soil deformation is recorded to simulate the process of the extended head bolt pullout test. Step 10: Analyze relevant data, use software to process soil deformation images, observe soil changes before and after each level of loading, and prepare for subsequent research.

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