Karst area punching pile construction monitoring test device

Abstract

The utility model provides a karst area punching pile construction monitoring test device, which belongs to the field of karst pile foundation monitoring and comprises a test box, a prefabricated pipe pile, a hollow circular pipe, a karst cavity model box, an impact module, a first array type displacement meter and a second array type displacement meter. The first array type displacement meter is installed on the prefabricated pipe pile, the solution cavity model box and the hollow circular pipe are placed in the test box after being communicated, the second array type displacement meter extends into the test box and is located between the prefabricated pipe pile and the hollow circular pipe, the test box is filled with foundation filler, and the solution cavity model box is filled with solution cavity filler. The impact end of the impact module moves up and down in the hollow circular pipe and the solution cavity model box so as to repeatedly impact the solution cavity filler, and the first array type displacement meter and the second array type displacement meter monitor the influence of the foundation filler on the prefabricated pipe pile when the side wall of the solution cavity model box extrudes the foundation filler in the impact process.

Description

Technical Field

[0001] This utility model belongs to the field of karst pile foundation monitoring, and in particular relates to a test device for monitoring the construction of bored piles in karst areas. Background Technology

[0002] China is a country with diverse landforms, among which karst landforms are unique, also known as lava landforms. They are formed by the dissolution, precipitation, erosion, and deposition of soluble rocks by groundwater and surface water. Landforms are divided into two main categories: surface and underground. Surface features include karst pinnacles, solution channels, sinkholes, and sinkholes, while underground features include caves and underground rivers. The geological conditions in karst areas are complex. Due to the solubility of rocks, many caves are formed in karst areas. The existence of caves makes bridge pile foundation construction difficult. Therefore, it is necessary to conduct relevant research on pile foundation construction in karst areas.

[0003] Due to the complex geology of karst areas, there are a large number of caves of unknown size. For such projects, the conventional method is to use the backfilling method. In the backfilling method, after the hammer breaks through the cave wall, the mud will seep in. At this time, the cave is filled with a mixture of rubble, cement, clay and other materials in appropriate proportions. After repeated drilling, a stable protective wall is formed, and then the piles are poured.

[0004] In actual engineering, bridge pile foundations are often constructed in pairs, one after the other. If the construction of the first pile is completed and the construction of the next adjacent pile encounters a karst cave, the impact of the hammer on the rubble during the drilling process will produce a lateral soil squeezing effect, which will have a certain horizontal squeezing effect on the existing pile in front.

[0005] When simulating the above-mentioned pile foundation construction, the existing simulation device can only simulate and evaluate the forming process of a single pile. However, when adjacent piles are constructed, they will have a certain horizontal squeezing effect on the previous existing pile. The existing simulation device cannot simulate and evaluate this kind of horizontal squeezing effect. Utility Model Content

[0006] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a construction monitoring and testing device for bored piles in karst areas, which solves the problem that the existing technology can only simulate and evaluate the forming process of a single pile.

[0007] To achieve the above and other related objectives, this utility model provides a testing device for monitoring the construction of bored piles in karst areas, the testing device comprising:

[0008] The test chamber comprises a cavity filling material, precast pipe piles, hollow circular pipes, and a cavity model box simulating a karst cave. The test chamber is filled with foundation filling material, the precast pipe piles extend vertically into the foundation filling material, the cavity model box is embedded in the foundation filling material, the cavity filling material fills the cavity model box, and the hollow circular pipes penetrate the cavity model box from the foundation filling material and connect to the interior of the cavity model box. The central axis of the hollow circular pipes is parallel to the central axis of the precast pipe piles.

[0009] A punching unit, comprising an impact module, wherein the impact end of the impact module extends into a hollow circular tube and moves up and down within the hollow circular tube and the cavity model box to repeatedly impact the cavity filler.

[0010] The displacement measurement unit includes a displacement measurement module, and the measuring end of the displacement measurement module is fixedly installed on the precast pipe pile.

[0011] As an optional solution, the impact module includes a winch, a steel rope, and a hammer;

[0012] The fixed end of the winch is fixedly installed on the foundation fill material and located above the hollow circular tube. One end of the steel rope is fixedly connected to the rotating end of the winch, and the other end of the steel rope is fixedly connected to the impact hammer. Under the action of the winch, the impact hammer moves up and down in the hollow circular tube and the cavity model box to repeatedly impact the cavity fill material.

[0013] As an optional solution, the cavity filler is fitted to the side wall portion of the cavity model box.

[0014] As an optional solution, the displacement measurement module includes a first array of displacement gauges and mounting holes;

[0015] The precast pipe pile has an installation hole that penetrates the upper and lower end faces of the precast pipe pile, and the first array displacement gauge extends into the installation hole.

[0016] As an optional solution, the test apparatus also includes a second array of displacement gauges;

[0017] The second array displacement gauge extends vertically into the foundation fill.

[0018] The plane between the central axis of the precast pipe pile and the central axis of the hollow circular pipe is the first plane, and the central axis of the second array displacement gauge is located in the first plane.

[0019] As an optional solution, the lower end face of the first array displacement gauge is at the same height as the lower end face of the precast pipe pile, and the lower end face of the second array displacement gauge is at the same height as the lower end face of the first array displacement gauge.

[0020] As an optional solution, the horizontal height of the lower end face of the first array displacement gauge is not higher than the horizontal height of the lower end face of the cavity model box.

[0021] As an optional solution, the hollow circular tube is fixedly connected to the junction of the cavity model box.

[0022] As described above, the monitoring and testing device for bored pile construction in karst areas according to this utility model has at least the following beneficial effects:

[0023] 1. After a certain amount of cavity filler is filled into the cavity model box of this utility model, the impact end of the impact module moves up and down at a certain speed inside the hollow circular tube and the cavity model box to repeatedly impact the cavity filler, so as to form a stable protective wall inside the cavity model box, which facilitates subsequent casting into piles. During the impact process, the cavity filler squeezes the side wall of the cavity model box, and the side wall of the cavity model box squeezes the foundation filler. The displacement monitoring module monitors the horizontal squeezing effect of the foundation filler on the precast pipe pile when the side wall of the cavity model box squeezes the foundation filler, that is, whether the precast pipe pile is squeezed by the side wall of the cavity model box. Lateral displacement occurs due to the compression of the foundation filling material. If the precast pipe pile experiences lateral displacement, the test is restarted. During the test, the impact end of the impact module moves up and down at a lower speed than the previous time within the hollow circular tube and cavity model box, but still ensures that the cavity filling material is impacted and shaped. This continues until the impact end of the impact module moves up and down within the hollow circular tube and cavity model box at a speed that shapes the cavity filling material without causing lateral displacement of the precast pipe pile. The movement speed of the impact end of this impact module is recorded and applied to the actual project to ensure that during actual construction, the construction of the next pile will not cause lateral displacement of the previous existing pile.

[0024] 2. In the process of repeated impacts of the molten core material by the hammer driven by the winch at a certain speed, the first array displacement gauge collects the displacement data of the second array displacement gauge when the precast pipe pile begins to deviate laterally. Thus, during the actual construction, when the hammer repeatedly impacts the molten core material, the displacement of the array displacement gauge is kept within the recorded displacement data of the second array displacement gauge. That is, the displacement generated by the array displacement gauge does not exceed the displacement of the recorded displacement data of the second array displacement gauge, which ensures that the previously constructed pile will not deviate laterally during actual construction.

[0025] 3. The first array displacement gauge of this utility model can be inserted into the precast pipe pile. When the winch drives the hammer to repeatedly impact the cavity filling material, the precast pipe pile will be laterally displaced under the pressure of the side wall of the cavity model box on the foundation filling material. When the precast pipe pile is displaced, the first array displacement gauge will be synchronously displaced with the precast pipe pile, so as to reflect the pressure of the foundation filling material on the precast pipe pile in real time. Attached Figure Description

[0026] Figure 1 The diagram shown is a cross-sectional view of the structure of this utility model.

[0027] Figure 2 The image shown is a partial sectional view related to the mounting holes of this utility model.

[0028] In the diagram: 101, test chamber; 102, cavity filler; 103, foundation filler;

[0029] 201. Precast pipe piles;

[0030] 301. Hollow circular tube; 302. Melting cavity model box;

[0031] 401. Winch; 402. Steel rope; 403. Hammer;

[0032] 501. First array displacement gauge; 502. Mounting hole;

[0033] 601. Second array displacement meter. Detailed Implementation

[0034] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.

[0035] Please see Figures 1 to 2 It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of this invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and are not intended to limit the scope of this invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this invention.

[0036] The following embodiments are for illustrative purposes only. These embodiments can be combined and are not limited to the content shown in any single embodiment below.

[0037] Please see Figure 1 This utility model provides a testing device for monitoring the construction of bored piles in karst areas, the testing device comprising:

[0038] The test chamber 101, the cavity filling material 102, the precast pipe pile 201, the hollow circular pipe 301, and the cavity model box 302 simulating a karst cave are included. The test chamber 101 is filled with foundation filling material 103. The precast pipe pile 201 extends vertically into the foundation filling material 103. The cavity model box 302 is buried in the foundation filling material 103. The cavity filling material 102 fills the cavity model box 302. The hollow circular pipe 301 passes through the foundation filling material 103 and communicates with the interior of the cavity model box 302. The central axis of the hollow circular pipe 301 is parallel to the central axis of the precast pipe pile 201.

[0039] The punching unit includes an impact module. The impact end of the impact module extends into the hollow circular tube 301. The impact end of the impact module moves up and down within the hollow circular tube 301 and the cavity model box 302 to repeatedly impact the cavity filler 102.

[0040] The displacement measurement unit includes a displacement measurement module, and the measuring end of the displacement measurement module is fixedly installed on the precast pipe pile 201.

[0041] In this embodiment, the cavity model box 302 and the hollow circular tube 301 are first placed into the test chamber 101. The precast pipe pile 201 and the displacement measurement module are then vertically placed into the test chamber 101. Next, the foundation fill material 103 is laid and compacted layer by layer into the test chamber 101. The upper surface of the foundation fill material 103 after laying is not higher than the upper surfaces of the hollow circular tube 301 and the precast pipe pile 201. Then, an impact module is installed on the foundation fill material 103. Afterward, a certain amount of cavity fill material 102 is filled into the cavity model box 302 through the hollow circular tube 301. Finally, the impact end of the impact module is placed on the hollow circular tube 301. 1. The cavity model box 302 moves up and down to repeatedly impact the cavity filling material 102, so as to form a stable protective wall inside the cavity model box 302. During the impact, the cavity filling material 102 squeezes the side wall of the cavity model box 302, and the side wall of the cavity model box 302 squeezes the foundation filling material 103. The displacement monitoring module monitors the influence of the foundation filling material 103 on the precast pipe pile 201 when the side wall of the cavity model box 302 squeezes the foundation filling material 103, that is, whether the precast pipe pile 201 is laterally displaced under the squeezing of the foundation filling material 103 by the side wall of the cavity model box 302.

[0042] In this invention, after a certain amount of cavity filler 102 is filled into the cavity model box 302, the impact end of the impact module moves up and down at a certain speed within the hollow circular tube 301 and the cavity model box 302 to repeatedly impact the cavity filler 102, thereby forming a stable protective wall within the cavity model box 302, facilitating subsequent pile casting. During the impact process, the cavity filler 102 compresses the side wall of the cavity model box 302, which in turn compresses the foundation filler 103. The displacement monitoring module monitors the horizontal compression effect of the foundation filler 103 on the precast pipe pile 201 when the side wall of the cavity model box 302 compresses the foundation filler 103, i.e., whether the precast pipe pile 201 is within the cavity. The sidewall of the model box 302 causes lateral displacement under the pressure of the foundation fill 103. If the precast pipe pile 201 causes lateral displacement, the test is repeated. During the test, the speed at which the impact end of the impact module moves up and down in the hollow circular tube 301 and the cavity model box 302 is lower than the previous one, but it can still ensure that the cavity fill 102 is impacted and shaped. This continues until the speed at which the impact end of the impact module moves up and down in the hollow circular tube 301 and the cavity model box 302 is such that the precast pipe pile 201 does not cause lateral displacement while the cavity fill 102 is impacted and shaped. The movement speed of the impact end of this impact module is recorded and put into actual engineering to ensure that adjacent piles will not cause lateral displacement of the previous existing pile when the next pile is constructed during actual construction.

[0043] Please see Figure 1 The impact module includes a winch 401, a steel rope 402, and a hammer 403;

[0044] The fixed end of the winch 401 is fixedly installed on the foundation filler 103 and located above the hollow circular tube 301. One end of the steel rope 402 is fixedly connected to the rotating end of the winch 401, and the other end of the steel rope 402 is fixedly connected to the hammer 403. Under the action of the winch 401, the hammer 403 moves up and down in the hollow circular tube 301 and the cavity model box 302 to repeatedly impact the cavity filler 102.

[0045] In this embodiment, when the cavity filler 102 filled in the cavity model box 302 needs to be impact-formed, the winch 401 moves the hammer 403 up and down in the hollow tube 301 and the cavity model box 302 at a certain speed through the steel rope 402 to repeatedly impact the cavity filler 102. During the impact, the cavity filler 102 squeezes the side wall of the cavity model box 302, and the side wall of the cavity model box 302 squeezes the foundation filler 103. The displacement monitoring module monitors the horizontal squeezing effect of the foundation filler 103 on the precast pipe pile 201 when the side wall of the cavity model box 302 squeezes the foundation filler 103, that is, whether the precast pipe pile 201 is laterally deflected under the squeezing of the foundation filler 103 by the side wall of the cavity model box 302.

[0046] The hammer 403 of this invention can move up and down within the hollow tube 301 and the cavity model box 302 at a certain speed under the action of the winch 401, so that the hammer 403 repeatedly impacts the cavity filling material 102. During the impact molding process of the cavity filling material 102, the pressure of the cavity filling material 102 on the side wall of the cavity model box 302 will be converted into the lateral pressure of the side wall of the cavity model box 302 on the foundation filling material 103. The displacement monitoring module can monitor the horizontal compression effect of the foundation filling material 103 on the precast pipe pile 201. The structure is cleverly designed.

[0047] Please see Figure 1 The cavity filler 102 is attached to the side wall of the cavity model box 302.

[0048] In this embodiment, when the cavity filler 102 filled in the cavity model box 302 needs to be impact-formed, the hammer 403 impacts the cavity filler 102 in the opposite direction at a certain speed under the action of the winch 401, and the cavity filler 102 will fit against the side wall of the cavity model box 302.

[0049] When the hammer 403 of this invention repeatedly impacts the cavity filler 102 at a certain speed under the action of the winch 401, the cavity filler 102 will fit against the side wall of the cavity model box 302. This ensures that the cavity filler 102 will squeeze the side wall of the cavity model box 302 when the hammer 403 repeatedly impacts it. Only then will the side wall of the cavity model box 302 squeeze the foundation filler 103. The displacement monitoring module monitors the horizontal squeezing effect of the foundation filler 103 on the precast pipe pile 201 when the side wall of the cavity model box 302 squeezes the foundation filler 103.

[0050] Please see Figure 1 and Figure 2 The displacement measurement module includes a first array displacement meter 501 and a mounting hole 502;

[0051] The model of the first array displacement meter 501 is not limited here. The first array displacement meter 501 used in this embodiment is the ADM series flexible inclinometer. The ADM series flexible inclinometer has three dimensions (X, Y, Z) for measurement. The angle range of the ADM series flexible inclinometer is 0~360°, the monitoring point spacing is 0.3m, the acquisition frequency is 1Hz, and the working mode is MEMS microelectromechanical accelerometer.

[0052] The precast pipe pile 201 has an installation hole 502, which penetrates the upper and lower end faces of the precast pipe pile 201, and the first array displacement meter 501 extends into the installation hole 502.

[0053] In this embodiment, after the precast pipe pile 201 is placed into the test chamber 101, the first array displacement gauge 501 is inserted into the mounting hole 502. The cavity model box 302 and the hollow round pipe 301 are then placed into the test chamber 101 together. Then, the foundation filler 103 is laid and compacted layer by layer into the test chamber 101. The upper surface of the foundation filler 103 after laying is not higher than the upper surfaces of the hollow round pipe 301 and the precast pipe pile 201. A winch 401 is then installed on the foundation filler 103. A certain amount of cavity filler 102 is then filled into the cavity model box 302 through the hollow round pipe 301. The winch 401, at a certain speed, uses the steel rope 402 to cause the hammer 403 to move between the hollow round pipe 301 and the cavity model box 302. The device moves up and down within the cavity to repeatedly impact the cavity filling material 102. During the impact, the cavity filling material 102 compresses the side wall of the cavity model box 302, and the side wall of the cavity model box 302 compresses the foundation filling material 103. The first array displacement meter 501 monitors the horizontal compression effect of the foundation filling material 103 on the precast pipe pile 201 when the side wall of the cavity model box 302 compresses the foundation filling material 103, that is, whether the precast pipe pile 201 undergoes lateral displacement under the compression of the foundation filling material 103 by the side wall of the cavity model box 302. When the precast pipe pile 201 undergoes lateral displacement, the first array displacement meter 501 moves along with the precast pipe pile 201, and at the same time, the first array displacement meter 501 collects displacement data.

[0054] The first array displacement gauge 501 of this utility model can be inserted into the precast pipe pile 201. When the winch 401 drives the hammer 403 to repeatedly impact the cavity filling material 102, the precast pipe pile 201 will be laterally displaced under the pressure of the side wall of the cavity model box 302 on the foundation filling material 103. This will cause the first array displacement gauge 501 to move synchronously with the precast pipe pile 201 when the precast pipe pile 201 is displaced, so as to reflect the pressure of the precast pipe pile 201 on the foundation filling material 103 in real time.

[0055] Please see Figure 1The test apparatus also includes a second array displacement meter 601;

[0056] The model of the second array displacement meter 601 is not limited here. The second array displacement meter 601 used in this embodiment is the ADM series flexible inclinometer. The ADM series flexible inclinometer has three dimensions (X, Y, Z) for measurement. The angle range of the ADM series flexible inclinometer is 0~360°, the monitoring point spacing is 0.3m, the acquisition frequency is 1Hz, and the working mode is MEMS microelectromechanical accelerometer.

[0057] The second array displacement gauge 601 extends vertically into the foundation fill 103;

[0058] The plane between the central axis of the precast pipe pile 201 and the central axis of the hollow circular pipe 301 is the first plane, and the central axis of the second array displacement meter 601 is located in the first plane.

[0059] In this embodiment, the cavity model box 302 and the hollow circular pipe 301 are first placed into the test chamber 101. The precast pipe pile 201 and the first array displacement meter 501 are then vertically placed into the test chamber 101. The second array displacement meter 601 is also vertically placed into the test chamber 101, and the second array displacement meter 601 is located in the first plane. Then, the foundation filling material 103 is laid and compacted layer by layer into the test chamber 101. The upper surface of the foundation filling material 103 after it is laid is not higher than the upper surface of the hollow circular pipe 301 and the precast pipe pile 201. Then, a winch 401 is installed on the foundation filling material 103. After that, the cavity model box 302 is moved through the hollow circular pipe 301. A certain amount of cavity filler 102 is filled inside the cavity. When the winch 401 drives the hammer 403 to repeatedly impact the cavity filler 102 at a certain speed, the second array displacement gauge 601 will shift laterally along with the foundation filler 103 under the pressure of the side wall of the cavity model box 302. When the precast pipe pile 201 begins to shift laterally under the pressure of the side wall of the cavity model box 302 on the foundation filler 103, the displacement data of the second array displacement gauge 601 at this time is recorded. Then, the first array displacement gauge 501 and the second array displacement gauge 601 collect subsequent displacement data under the continued impact of the hammer 403.

[0060] This invention allows for the repeated impact of a winch 401 on the cavity filler 102 by a hammer 403 at a certain speed. When the first array displacement meter 501 detects the lateral displacement of the precast pipe pile 201, it records the displacement data of the second array displacement meter 601. This ensures that during actual construction, when the hammer 403 repeatedly impacts the cavity filler 102, the displacement of the array displacement meter remains within the recorded displacement data of the second array displacement meter 601. In other words, the displacement generated by the array displacement meter does not exceed the recorded displacement data of the second array displacement meter 601, thus guaranteeing that the previously constructed pile will not experience lateral displacement during actual construction.

[0061] Please see Figure 1 The lower end face of the first array displacement meter 501 is at the same height as the lower end face of the precast pipe pile 201, and the lower end face of the second array displacement meter 601 is at the same height as the lower end face of the first array displacement meter 501.

[0062] In this embodiment, the cavity model box 302 and the hollow circular tube 301 are first placed into the test chamber 101. The precast pipe pile 201 and the first array displacement meter 501 are then placed vertically into the test chamber 101. The second array displacement meter 601 is also placed vertically into the test chamber 101. When placing them, the lower end face of the first array displacement meter 501 is kept at the same height as the lower end face of the precast pipe pile 201, and the lower end face of the second array displacement meter 601 is kept at the same height as the lower end face of the first array displacement meter 501. Then, the foundation filling material 103 is laid and compacted layer by layer into the test chamber 101. The upper end face of the foundation filling material 103 after it is laid is not higher than the upper end face of the hollow circular tube 301 and the precast pipe pile 201, waiting for subsequent operations.

[0063] In the preparation of the test, the lower end face of the first array displacement meter 501, the lower end face of the second array displacement meter 601 and the lower end face of the precast pipe pile 201 are placed at the same horizontal height. This allows the first array displacement meter 501 to completely collect the lateral displacement of the entire precast pipe pile 201 during the process of the winch 401 driving the hammer 403 to repeatedly impact the cavity filling material 102 at a certain speed. The second array displacement meter 601 can also reflect the displacement data of the second array displacement meter 601 during the lateral displacement of the entire precast pipe pile 201.

[0064] Please see Figure 1 The horizontal height of the lower end face of the first array displacement gauge 501 is not higher than the horizontal height of the lower end face of the cavity model box 302.

[0065] In this embodiment, the cavity model box 302 and the hollow circular pipe 301 are first placed into the test chamber 101. The precast pipe pile 201 and the first array displacement meter 501 are then placed vertically into the test chamber 101. The second array displacement meter 601 is also placed vertically into the test chamber 101. When placing them, the lower end face of the first array displacement meter 501 is kept at the same height as the lower end face of the precast pipe pile 201, and the lower end face of the second array displacement meter 601 is kept at the same height as the lower end face of the first array displacement meter 501. The horizontal height of the lower end face of the cavity model box 302 is not lower than the horizontal height of the lower end face of the first array displacement meter 501. Then, the foundation filling material 103 is laid and compacted layer by layer into the test chamber 101. The upper end face of the foundation filling material 103 after it is laid is not higher than the upper end face of the hollow circular pipe 301 and the precast pipe pile 201, waiting for subsequent operations.

[0066] In this invention, during the test preparation, the horizontal height of the lower end face of the cavity model box 302 is set not lower than the horizontal height of the lower end face of the first array displacement meter 501. This ensures that during the repeated impact of the hammer 403 driven by the winch 401 on the cavity filling material 102 at a certain speed, when the side wall of the cavity model box 302 is squeezed by the cavity filling material 102 and thus squeezes the foundation filling material 103, the squeeze generated by the foundation filling material 103 will be laterally reflected in the acquisition range of the second array displacement meter 601 and the stress range of the precast pipe pile 201. As a result, the second array displacement meter 601 will acquire complete displacement data of the foundation filling material 103, and the first array displacement meter 501 will acquire the lateral displacement of the precast pipe pile 201 when the foundation filling material 103 squeezes the precast pipe pile 201.

[0067] Please see Figure 1 The hollow circular tube 301 is fixedly connected to the junction of the melting cavity model box 302.

[0068] The method of fixing the hollow circular tube 301 and the melting cavity model box 302 at the junction is not limited here; it can be welding, threaded connection, etc.

[0069] In this embodiment, before placing the cavity model box 302 and the hollow tube 301 together into the test chamber 101, the junction of the hollow tube 301 and the cavity model box 302 is welded together, so that the junction of the hollow tube 301 and the cavity model box 302 is fixedly connected together. Then, the welded cavity model box 302 and the hollow tube 301 are placed into the test chamber 101 together, with the hollow tube 301 positioned above the cavity model box 302.

[0070] This invention can simulate the sinkholes and punctures caused by impacts during actual construction by fixing the sinkhole model box 302 and the hollow round tube 301 together. The structure is ingeniously designed.

[0071] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A monitoring and testing device for bored pile construction in karst areas, characterized in that, The test apparatus includes: The test chamber comprises a cavity filling material, precast pipe piles, hollow circular pipes, and a cavity model box simulating a karst cave. The test chamber is filled with foundation filling material, the precast pipe piles extend vertically into the foundation filling material, the cavity model box is embedded in the foundation filling material, the cavity filling material fills the cavity model box, and the hollow circular pipes penetrate the cavity model box from the foundation filling material and connect to the interior of the cavity model box. The central axis of the hollow circular pipes is parallel to the central axis of the precast pipe piles. A punching unit, comprising an impact module, wherein the impact end of the impact module extends into a hollow circular tube and moves up and down within the hollow circular tube and the cavity model box to repeatedly impact the cavity filler. The displacement measurement unit includes a displacement measurement module, and the measuring end of the displacement measurement module is fixedly installed on the precast pipe pile.

2. The monitoring and testing device for bored pile construction in karst areas according to claim 1, characterized in that: The impact module includes a winch, a steel rope, and a hammer. The fixed end of the winch is fixedly installed on the foundation fill material and located above the hollow circular tube. One end of the steel rope is fixedly connected to the rotating end of the winch, and the other end of the steel rope is fixedly connected to the impact hammer. Under the action of the winch, the impact hammer moves up and down in the hollow circular tube and the cavity model box to repeatedly impact the cavity fill material.

3. The monitoring and testing device for bored pile construction in karst areas according to claim 1, characterized in that: The cavity filler is fitted to the side wall of the cavity model box.

4. The monitoring and testing device for bored pile construction in karst areas according to claim 2, characterized in that: The displacement measurement module includes a first array of displacement gauges and mounting holes; The precast pipe pile has an installation hole that penetrates the upper and lower end faces of the precast pipe pile, and the first array displacement gauge extends into the installation hole.

5. The monitoring and testing device for bored pile construction in karst areas according to claim 4, characterized in that: The test apparatus also includes a second array-type displacement meter; The second array displacement gauge extends vertically into the foundation fill. The plane between the central axis of the precast pipe pile and the central axis of the hollow circular pipe is the first plane, and the central axis of the second array displacement gauge is located in the first plane.

6. The monitoring and testing device for bored pile construction in karst areas according to claim 5, characterized in that: The lower end face of the first array displacement gauge is at the same height as the lower end face of the precast pipe pile, and the lower end face of the second array displacement gauge is at the same height as the lower end face of the first array displacement gauge.

7. The monitoring and testing device for bored pile construction in karst areas according to claim 6, characterized in that: The horizontal height of the lower end face of the first array displacement gauge is not higher than the horizontal height of the lower end face of the cavity model box.

8. The monitoring and testing device for bored pile construction in karst areas according to claim 1, characterized in that: The hollow circular tube is fixedly connected to the junction of the melt cavity model box.

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