A test device and test method for simulating pile driving on reef limestone

Abstract

The application provides a test device for simulating pile driving on reef limestone, which comprises a detachably connected upper support and a lower support, the lower support is provided with a plurality of mounting positions, a test box for simulating marine environment is arranged below the upper support, a brake for providing power for a test pile is arranged on the upper support, the brake comprises a jack for providing static pressure power and a vibration exciter for providing vibration power, the jack and the vibration exciter are arranged along the direction of the plurality of mounting positions, so that the jack or the vibration exciter can correspondingly perform static pressure pile sinking or vibration pile sinking test with the test box when the upper support is mounted at different mounting positions. The test device is a static pressure and vibration integrated device, by changing the relative position of the upper support and the lower support, the jack corresponds to the test box or the vibration exciter corresponds to the test box, so that the test device has the ability of static pressure pile sinking and vibration pile sinking test.

Description

Technical Field

[0001] This invention relates to the field of offshore piling technology, specifically to a test device and test method for simulating piling on reef limestone. Background Technology

[0002] Marine construction technology is an essential component, and the field of marine civil engineering requires more advanced and sophisticated construction techniques. When it comes to structures such as offshore platforms and land reclamation, marine pile foundations are a key element.

[0003] Currently, my country's technology for driving piles on coral reefs is not yet mature, and pile driving on coral reef limestone is difficult to control. To solve these problems, tests are usually conducted on pile driving test devices to obtain valuable data to guide on-site pile driving. At present, most of the existing pile driving test devices in China are used for land-based simulations, and pile driving test devices with different power sources are not integrated, making disassembly and assembly cumbersome, replacing brakes inconvenient, and resulting in low pile driving efficiency. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a test device for simulating pile driving on reef limestone. This test device is an integrated static pressure and vibration device. By changing the relative positions of the upper and lower supports, the jacks or vibrators can be aligned with the test chamber, enabling the test device to perform both static pressure pile driving and vibration pile driving tests.

[0005] This invention provides a test device for simulating pile driving on reef limestone, comprising a detachably connected upper support and a lower support. The lower support has multiple mounting positions. A test chamber for simulating a marine environment is disposed below the upper support. A brake for providing power to the test pile is disposed on the upper support. The brake includes a jack for providing static pressure power and a vibrator for providing vibration power. The jack and vibrator are arranged along the direction of the multiple mounting positions, so that when the upper support is installed in different mounting positions, the jack or vibrator corresponds with the test chamber to conduct static pressure pile driving or vibratory pile driving tests.

[0006] By setting up detachable upper and lower supports, the jack and vibrator are installed on the upper support. By changing the relative positions of the upper and lower supports, the jack or vibrator can be aligned with the test chamber, enabling the test device to perform static pressure pile driving and vibration pile driving tests, and making it easy to operate.

[0007] Furthermore, the lower support includes a first lower support and a second lower support arranged in parallel. The top of the first lower support and the second lower support have multiple sets of corresponding mounting holes along the length direction. Each set of corresponding mounting holes forms a mounting position. The upper support is detachably mounted on the top of the first lower support and the second lower support through the mounting holes.

[0008] By setting multiple sets of mounting holes on the lower support, the installation position of the upper support can be changed, thus achieving the correspondence between the jack and the test chamber or the vibrator and the test chamber.

[0009] Furthermore, a pressure plate is provided at the bottom of the lower support, and the test chamber is mounted on the pressure plate. The lower support and the pressure plate are an integral structure.

[0010] By setting up a pressure plate and mounting the test chamber on the pressure plate, the stability of the test chamber is improved, preventing the test chamber from moving or shaking during the test. Integrating the lower support with the pressure plate as a whole improves the overall stability of the test device, further ensuring the stability of the test chamber during the test and helping to reduce test errors.

[0011] Furthermore, the upper support includes two columns mounted on the lower support through mounting holes, a base rod and a reaction rod are connected between the two columns, the reaction rod is arranged parallel above the base rod, the brake is mounted on the reaction rod through a reaction plate, a reaction rod support is provided between the reaction rod and the base rod, and the reaction rod support is arranged directly below the reaction plate.

[0012] The function of the reaction plate is to connect the jack and the vibrator into a whole and to evenly transmit the reaction force to the upper support. By setting up the abutment rod and the reaction rod support and arranging the reaction rod support directly below the reaction plate, the abutment rod and the reaction rod support can directly support the reaction rod, so that the reaction rod will not undergo large deformation, shaking or twisting due to the power of the brake during the test.

[0013] Furthermore, limiting rings are provided on both sides of the bottom rod to restrict the horizontal movement of the test pile.

[0014] The limiting ring is placed outside the test pile to restrict its horizontal movement and ensure the reliability of the test results.

[0015] Furthermore, the top of the reaction plate is provided with multiple plate-shaped stiffening ribs, the stiffening ribs are perpendicular to the reaction plate, and the height of the stiffening ribs gradually decreases from the center to both ends.

[0016] Stiffening ribs are installed on the upper part of the reaction plate to resist bending. The stiffening ribs can resist the reaction force of the brake and prevent the reaction plate from bending upward.

[0017] Furthermore, the jack and the vibrator are connected to the reaction plate through the first connecting plate and the second connecting plate, respectively. Both the first connecting plate and the second connecting plate are L-shaped. The reaction rod is disposed between the first connecting plate and the second connecting plate, and the portions of the first connecting plate and the second connecting plate perpendicular to the reaction plate abut against the reaction rod.

[0018] By setting up symmetrical L-shaped first connecting plate and L-shaped second connecting plate, and abutting the first connecting plate and the second connecting plate against the reaction rod, after the first connecting plate or the second connecting plate is subjected to the upward reaction force of the brake, the second connecting plate or the first connecting plate can support the reaction plate through the part perpendicular to the reaction plate, which further reduces the swaying and deformation of the reaction plate.

[0019] Furthermore, it includes a dynamic pile driving tester, which includes an intelligent sensor box connected to a sensor. The intelligent sensor box is installed on the reaction rod support, and the sensor can be installed on the test pile connected to a jack or vibrator.

[0020] The smart sensor box is placed on the reaction rod support located between the jack and the vibrator, so that the sensor can be easily installed on the test pile on the side of the jack or the side of the vibrator when conducting static pressure pile driving or vibratory pile driving tests.

[0021] Furthermore, the test chamber is made of transparent material, and a PIV camera and a sheet light source are mounted on the lower support. The PIV camera is used for image acquisition.

[0022] The test chamber is made of transparent material, which facilitates direct observation of the damage and deformation of the reef limestone. Using PIV full-field displacement image testing technology, images of the reef limestone are collected to obtain velocity information and velocity vector field, thereby obtaining the flow state of the reef limestone particles during the test and studying the foundation settlement and deformation during reef limestone pile driving.

[0023] Furthermore, the test chamber is provided with multiple independent grooves, and the PIV camera can capture images of multiple grooves.

[0024] By setting up multiple grooves, the settlement and deformation of the reef limestone foundation can be directly compared after the pile driving test is completed in each groove, and the test results are clear and intuitive.

[0025] This invention also provides a test method for simulating pile driving on reef limestone, comprising:

[0026] S1. Arrange the test chamber according to the set test conditions, install the upper support on a certain installation position of the lower support, so that the jack is directly above the test chamber, install the test pile on the jack, and install the sensor in the upper part of the test pile.

[0027] S2. Start the jacks to drive the piles, and record the test data using a dynamic pile driving tester and a PIV camera.

[0028] S3. Disassemble the upper support and install the upper support on another mounting position of the lower support so that the vibrator is directly above the test chamber; rearrange the test chamber under the same test conditions, install another test pile on the vibrator, and install the sensor in the upper part of the other test pile;

[0029] S4. Turn on the vibrator to drive the pile, and record the test data using a dynamic pile driving tester and a PIV camera.

[0030] S5. Using experimental data and similarity theory, calculate the prototype stress and prototype load of the original pile during actual construction, and determine whether pile driving is feasible under both static pile driving and vibratory pile driving schemes.

[0031] By changing the mounting position of the upper bracket, the corresponding brake of the test chamber can be quickly changed, thereby realizing the rapid switching between static pile driving and vibratory pile driving methods and improving test efficiency.

[0032] Further, step S5 includes:

[0033] Based on the similarity between simulation experiments and actual engineering projects Find α σ ,in α σ Let α be the stress similarity constant. γ Let α be the density similarity constant. l γ is the geometric similarity constant. p For the prototype bulk density, γ m For the model's bulk density, l p For the prototype geometry, l m These are the geometric dimensions of the model;

[0034] According to stress similarity constants Find σ p , where σ p For the prototype stress, σ m For model stress;

[0035] Based on the similarity constant of elastic modulus and load similarity constants Find p y E y E is the prototype elastic modulus. s p is the elastic modulus of the model. y For the prototype load, p s For model loads;

[0036] Compare the prototype load p calculated under static pile driving and vibratory pile driving schemes. y .

[0037] By analyzing and calculating the test data using the principle of similarity, the load on the pile foundation during actual construction can be obtained. Combined with the results recorded by the PIV camera, it is possible to determine whether static pile driving or vibratory pile driving is feasible under this condition.

[0038] Furthermore, step S1 includes multiple sets of test conditions. The differences between these test conditions are simply changing the laying order of hard, medium, and soft reef limestone in the test chamber, or changing the laying order of reef limestone of different structural types in the test chamber, or changing the laying angle of the reef limestone in the test chamber, or whether seawater is added to the test chamber, or changing the type of test pile.

[0039] This experimental method simulates and compares various working conditions of pile driving on reef limestone, more realistically reproducing the marine pile driving environment. It simulates pile driving on reef limestone in a marine environment and scales it up to infer the actual marine pile driving situation, which has high reference value for actual construction.

[0040] The beneficial effects of this invention are as follows: the test device is an integrated static pressure and vibration device. By changing the relative positions of the upper and lower supports, the jacks or vibrators can be aligned with the test chamber, enabling the test device to perform static pressure pile driving and vibration pile driving tests, and it is easy to operate. The test device can simulate and compare various working conditions of pile driving in reef limestone, more realistically restoring the marine pile driving environment and having higher reference value. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the structure of the present invention;

[0042] Figure 2 This is a schematic diagram of the connection structure between the upper support and the lower support of the present invention;

[0043] Figure 3 This is a schematic diagram of the upper support structure of the present invention;

[0044] Figure 4 This is a schematic diagram of the lower support structure of the present invention;

[0045] Figure 5 This is a schematic diagram of the structure of the pressure plate of the present invention;

[0046] Figure 6 This is a schematic diagram of the structure of the smart sensor box of the present invention;

[0047] Figure 7 This is a schematic diagram of the connection structure between the brake and the reaction plate of the present invention;

[0048] Figure 8This is a schematic diagram of the connection structure between the upper support and the brake of the present invention;

[0049] Figure 9 This is a schematic diagram of the structure of the PDA system host of the present invention;

[0050] Figure 10 This is a schematic diagram of the first type of reef limestone paving structure in an embodiment of the present invention;

[0051] Figure 11 This is a schematic diagram of the first type of reef limestone paving structure in an embodiment of the present invention;

[0052] Figure 12 This is a schematic diagram of the third type of reef limestone paving structure in an embodiment of the present invention.

[0053] Reference numerals: Upper support 1; Lower support 2; Test chamber 3; Jack 4; Vibrator 5; First lower support 6; Second lower support 7; Mounting hole 8; Bearing plate 9; Column 10; Base rod 11; Reaction rod 12; Reaction rod support column 13; Limiting ring 14; Stiffening rib 15; First connecting plate 16; Second connecting plate 17; PDA system host 18; Smart sensor box 19; Sensor 20; PIV camera 21; Sheet light source 22; Test pile 23; Groove 24; Reaction plate 25. Detailed Implementation

[0054] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0055] like Figure 1 , 2 As shown, the experimental device includes an upper support 1 and a lower support 2. The lower support 2 houses a test chamber 3, which has a groove 24. The groove 24 can be filled with reef limestone and seawater to simulate a marine environment. The test chamber 3 is made of resin material and is transparent in appearance. A PIV camera 21 is installed on one side of the lower support 2 to collect images of the test pile 23 and reef limestone during construction. A sheet light source 22 is installed on the adjacent side. A brake is installed on the upper support 1. The brake includes a jack 4 for providing static pressure power and a vibrator 5 for providing vibration power. The jack 4 and the vibrator 5 are respectively arranged on both sides of the upper support 1.

[0056] It should be noted that multiple grooves 24 can be set. After the experiment is completed in each groove 24, the settlement and deformation of the reef limestone foundation under different working conditions in each groove 24 can be compared more intuitively. The test results are clear and intuitive. In this embodiment, only one groove 24 is set in the middle of the test chamber 3.

[0057] like Figure 4 As shown, the lower support 2 includes a first lower support 6 and a second lower support 7 arranged in parallel. Both the first lower support 6 and the second lower support 7 include two lower pillars and a crossbeam. Multiple sets of mounting holes 8 are opened on the top of the first lower support 6 and the second lower support 7, i.e., on the crossbeam. The multiple sets of mounting holes 8 are arranged along the length of the crossbeam. The lower pillars and the crossbeam are welded together.

[0058] like Figure 3 As shown, the upper support 1 includes two parallel vertically arranged columns 10. The bottom of the two columns 10 is fixedly connected to the lower support 2 by bolts passing through the mounting holes 8 of the lower support 2. By connecting the two columns 10 to different sets of mounting holes 8, the position of the upper support 1 along the length of the crossbeam of the lower support 2 can be changed, so that the jack 4 or vibrator 5 corresponds to the test chamber 3, thereby realizing the integration of static pressure pile driving and vibratory pile driving tests of the test device.

[0059] A base rod 11 and a reaction rod 12 are connected between the two support pillars. The base rod 11 is arranged parallel to the reaction rod 12 directly below it. A reaction rod support 13 is welded between the base rod 11 and the reaction rod 12. The reaction rod support 13 is perpendicular to the base rod 11 and the reaction rod 12. The combination of the base rod 11, the reaction rod 12 and the reaction rod support 13 ensures the stable operation of the brake.

[0060] like Figure 5 As shown, the test device includes a pressure plate 9, which is disposed between the first lower support 6 and the second lower support 7. The pressure plate 9 can be welded to the first lower support 6 and the second lower support 7 or connected by bolts.

[0061] like Figure 6 , 9 As shown, the experimental setup includes a dynamic pile driving tester, which comprises an intelligent sensor box 19 connected to a sensor 20 mounted on the test pile 23. Vibratory pile driving tests are conducted using a PDA system host, while static pressure pile driving tests are conducted using a ZBL-Q500A static load tester. The intelligent sensor box 19 is wirelessly connected to the PDA system host 18 and the ZBL-Q500A static load tester. The dynamic pile driving tester can measure the real-time pile stress, hammer energy, penetration depth, pile integrity, and bearing capacity of the test pile 23, enabling real-time measurement and evaluation during pile driving, providing data support for test result analysis.

[0062] like Figure 7 , 8As shown, the top of the jack 4 is fixed to the lower surface of the reaction plate 25 via the first connecting plate 16, and the top of the vibrator 5 is fixed to the lower surface of the reaction plate 25 via the second connecting plate 17. The reaction plate 25 is welded to the upper surface of the reaction rod 12. The cross-sections of the first connecting plate 16 and the second connecting plate 17 are both L-shaped. The reaction rod 12 is located between the first connecting plate 16 and the second connecting plate 17. The portions of the first connecting plate 16 and the second connecting plate 17 perpendicular to the reaction plate 25 abut against the reaction rod 12. The portions of the first connecting plate 16 and the second connecting plate 17 perpendicular to the reaction plate 25 are fixedly connected to the reaction rod 12 by bolts or welding. The bottom ends of the jack 4 and the vibrator 5 are connected to the test pile 23. The test pile 23 can be connected to the jack 4 or the vibrator 5 by bolts or welding. Two parallel plate-shaped stiffening ribs 15 are arranged on the top of the reaction rod 12. The stiffening ribs 15 are perpendicular to the reaction plate 25, and the height of the stiffening ribs 15 gradually decreases from the center to both ends.

[0063] Understandably, when jack 4 is working, it pushes the test pile 23 downward into the reef limestone. Jack 4 will be subjected to an upward reaction force, which will be transmitted to the reaction plate 25, causing the reaction plate 25 to tend to rotate. At this time, the part of the second connecting plate 17 perpendicular to the reaction plate 25 will support the reaction plate 25. In addition, the reaction force on the reaction plate 25 will also cause the part of the reaction plate 25 located on the side of jack 4 to tend to bend upward, and the bending moment is greater closer to the center of the reaction plate 25. By setting plate-shaped stiffening ribs 15 with a high center and low ends, the bending of the reaction plate 25 can be effectively prevented, ensuring the stability of the structure and thus ensuring the reliability of the experimental results.

[0064] The reaction rod support 13 has a hollow structure, and a smart sensor box 19 is installed inside. The sensor 20 of the smart sensor box 19 can be installed on the test pile 23 of the jack 4 or the test pile 23 of the vibrator 5 according to the test conditions. There is no need to change the position of the smart sensor box 19, so the installation is convenient and quick.

[0065] The bottom rod 11 is connected to the limit rings 14 on both sides by connecting rods. The limit rings 14 are sleeved on the outside of the test pile 23, which can limit the horizontal sway of the test pile 23 and reduce the eccentric load of the test pile 23.

[0066] The method for conducting pile driving tests on reef limestone using this experimental apparatus is as follows:

[0067] S1. Set multiple test conditions to divide the internal space of the groove 24 into three layers: the first layer is the bottom layer, the second layer is the middle layer, and the third layer is the top layer.

[0068] like Figure 10 As shown, test condition one: hard, soft, and hard types of reef limestone were placed in the first, second, and third layers, respectively;

[0069] Experimental condition 2: Soft, hard, and soft types of reef limestone were placed in the first, second, and third layers, respectively;

[0070] Experimental condition three: Hard, medium, and soft types of reef limestone were placed in the first, second, and third layers, respectively.

[0071] Experimental condition four: Soft, medium, and hard types of reef limestone were placed in the first, second, and third layers, respectively;

[0072] Experimental condition 5: The first and second layers are filled with hard and soft reef limestone, respectively, and the third layer is filled with seawater;

[0073] Experimental Condition Six: The first and second layers are filled with soft and hard reef limestone, respectively, and the third layer is filled with coral reefs and seawater, vividly simulating the marine piling environment, i.e., environmental similarity.

[0074] Test Condition Seven: Based on Test Conditions One through Six, a comparative test was conducted using open-ended piles and closed-ended piles.

[0075] In test conditions one through seven, the contact surfaces of the first and second layers are inclined, while the contact surfaces of the second and third layers are horizontal.

[0076] Test conditions one, two, three, and four simulate the effects of pile driving under different reef limestone layers on the piles and observe the damage to the rock layers.

[0077] In addition to the above objectives, test conditions five and six also simulated the marine piling environment, i.e., the environmental similarity, making the results more meaningful.

[0078] Test condition seven simulated the similarity of the effects of open and closed piles and the possibility of soil plugging effect on reef limestone.

[0079] like Figure 11 As shown, test condition eight is to change the contact surface of the first and second layers in test conditions one to seven to a horizontal surface.

[0080] like Figure 12 As shown, the internal space of the groove 24 can also be divided into four layers. The contact surface between the first and second layers is an inclined surface, the contact surface between the second and third layers is a horizontal surface, and the contact surface between the third and fourth layers is an inclined surface.

[0081] Furthermore, the experimental conditions can be altered by changing the structural type or weathering degree of the reef limestone. The structural types of reef limestone include massive, gravelly, clastic, gravelly sandy, sandy, and granular structures. Weathering degrees include strongly weathered and completely weathered reef limestone.

[0082] Arrange the groove 24 of the test chamber 3 according to a certain test condition, install the upper bracket 1 on a certain installation position of the lower bracket 2, so that the jack 4 is located directly above the test chamber 3, install the test pile 23 on the jack 4, and install the sensor 20 in the upper part of the test pile 23.

[0083] S2. Start the jack 4 to drive the pile. Use the dynamic pile driving test instrument to monitor the real-time pile stress, pile hammer energy, penetration, pile integrity and bearing capacity of the test pile 23. Use the PIV camera 21 to collect images, speed and velocity vector field when driving the test pile 23 to obtain the flow state of the reef limestone particles and then study the foundation settlement and deformation when driving the reef limestone pile.

[0084] S3. Disassemble the upper support 1 and install the upper support 1 on another mounting position of the lower support 2, so that the vibrator 5 is located directly above the test chamber 3; rearrange the test chamber 3 under the same test conditions, install another test pile 23 on the vibrator 5, and install the sensor 20 in the upper part of the other test pile 23.

[0085] S4. Turn on the vibrator 5 to drive the pile, and use the dynamic pile driving tester and PIV camera 21 to record the test data.

[0086] S5. Using experimental data and similarity theory, calculate the prototype stress and prototype load of the original pile during actual construction, and determine whether pile driving is feasible under both static pile driving and vibratory pile driving schemes.

[0087] The calculation process is as follows: based on the similarity between the simulation experiment and the actual engineering... Find α σ ,in α σ Let α be the stress similarity constant. γ Let α be the density similarity constant. l γ is the geometric similarity constant. p For the prototype bulk density, γ m For the model's bulk density, l p For the prototype geometry, l m These are the geometric dimensions of the model;

[0088] According to stress similarity constants Find σ p , where σ p For the prototype stress, σ m For model stress;

[0089] Based on the similarity constant of elastic modulus and load similarity constants Find p y E y E is the prototype elastic modulus. sp is the elastic modulus of the model. y For the prototype load, p s The load is the model load; the model is the test pile 23.

[0090] Compare the prototype load p calculated under static pile driving and vibratory pile driving schemes. y .

[0091] The criteria for judging whether pile driving is feasible need to be judged from two aspects: from the perspective of quality: whether the test pile 23 has experienced pile slippage, tilting, or soil jamming effect; from the perspective of bearing capacity: the model load of the test pile 23 is measured by the dynamic testing instrument, and the prototype load of the field pile is calculated to see if it meets the bearing capacity requirements of the upper part of the field pile.

[0092] This experimental device realistically replicates the marine piling environment. It can combine the feasibility of piling with the settlement and deformation of reef limestone to comprehensively consider which piling method, static piling or vibratory piling, is the better option under different test conditions, thus providing a basis for actual engineering design and construction.

[0093] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A test device for simulating pile driving on reef limestone, characterized in that: The device includes a detachably connected upper support (1) and a lower support (2). The lower support (2) has multiple mounting positions. A test chamber (3) for simulating a marine environment is provided below the upper support (1). A brake for providing power to the test pile (23) is provided on the upper support (1). The brake includes a jack (4) for providing static pressure power and a vibrator (5) for providing vibration power. The jack (4) and vibrator (5) are arranged along the direction of the multiple mounting positions so that when the upper support (1) is installed in different mounting positions, the jack (4) or vibrator (5) and the test chamber (3) can perform static pressure pile driving or vibration pile driving tests respectively.

2. The experimental apparatus for simulating pile driving on reef limestone according to claim 1, characterized in that: The lower bracket (2) includes a first lower bracket (6) and a second lower bracket (7) arranged in parallel. The top of the first lower bracket (6) and the second lower bracket (7) has multiple sets of corresponding mounting holes (8) along the length direction. Each set of corresponding mounting holes (8) forms a mounting position. The upper bracket (1) is detachably mounted on the top of the first lower bracket (6) and the second lower bracket (7) through the mounting holes (8).

3. The experimental apparatus for simulating pile driving on reef limestone according to claim 2, characterized in that: The upper support (1) includes two columns (10) installed on the lower support (2) through mounting holes (8). A bottom rod (11) and a reaction rod (12) are connected between the two columns (10). The reaction rod (12) is arranged parallel above the bottom rod (11). The brake is installed on the reaction rod (12) through a reaction plate (25). A reaction rod support column (13) is provided between the reaction rod (12) and the bottom rod (11). The reaction rod support column (13) is arranged directly below the reaction plate (25).

4. The experimental apparatus for simulating pile driving on reef limestone according to claim 3, characterized in that: The bottom rod (11) is provided with limiting rings (14) on both sides to restrict the horizontal movement of the test pile (23).

5. The experimental apparatus for simulating pile driving on reef limestone according to claim 3, characterized in that: The reaction plate (25) is provided with a plurality of plate-shaped stiffening ribs (15) on its top. The stiffening ribs (15) are perpendicular to the reaction plate (25), and the height of the stiffening ribs (15) gradually decreases from the center to both ends.

6. The experimental apparatus for simulating pile driving on reef limestone according to claim 3, characterized in that: The jack (4) and the vibrator (5) are connected to the reaction plate (25) through the first connecting plate (16) and the second connecting plate (17), respectively. The first connecting plate (16) and the second connecting plate (17) are both L-shaped. The reaction rod (12) is set between the first connecting plate (16) and the second connecting plate (17). The portions of the first connecting plate (16) and the second connecting plate (17) perpendicular to the reaction plate (25) abut against the reaction rod (12).

7. The experimental apparatus for simulating pile driving on reef limestone according to claim 1, characterized in that: The test chamber (3) is made of transparent material, and a PIV camera (21) and a sheet light source (22) are provided on the lower support (2). The PIV camera (21) is used for image acquisition.

8. The experimental apparatus for simulating pile driving on reef limestone according to claim 7, characterized in that: The test chamber (3) is provided with multiple independent grooves (24), and the PIV camera (21) acquires images of the multiple grooves (24).

9. A test method for simulating pile driving on reef limestone, characterized in that: include: S1. Arrange the test chamber (3) according to the set test conditions, install the upper support (1) on a certain installation position of the lower support (2), so that the jack (4) is located directly above the test chamber (3), install the test pile (23) on the jack (4), and install the sensor (20) in the upper part of the test pile (23); S2. Turn on the jack (4) to drive the pile, and use the dynamic pile driving tester and PIV camera (21) to record the test data. S3. Remove the upper bracket (1) and install the upper bracket (1) on another mounting position of the lower bracket (2) so that the vibrator (5) is located directly above the test chamber (3); rearrange the test chamber (3) under the same test conditions, install another test pile (23) on the vibrator (5), and install the sensor (20) in the upper part of the other test pile (23); S4. Turn on the vibrator (5) to drive the pile, and use the dynamic pile driving tester and PIV camera (21) to record the test data. S5. Using experimental data and similarity theory, calculate the prototype stress and prototype load of the original pile during actual construction, and determine whether pile driving is feasible under both static pile driving and vibratory pile driving schemes.

10. The test method for simulating pile driving on reef limestone according to claim 9, characterized in that: Step S5 includes: Based on the similarity between simulation experiments and actual engineering projects Find ,in , , Let be the stress similarity constant. Let be the density similarity constant. Let be the geometric similarity constant. Based on the original density, For the model's bulk density, Based on the prototype's geometric dimensions, These are the geometric dimensions of the model; According to stress similarity constants Find ,in, For prototype stress, For model stress; Based on the similarity constant of elastic modulus and load similarity constants Find ,in, For the prototype elastic modulus, The elastic modulus of the model; For prototype loads, For model loads; Comparison of prototype loads calculated under static pile driving and vibratory pile driving schemes .

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