Device and method for testing bearing performance of foundation grouting connection section of offshore wind power jacket

Abstract

The invention provides an offshore wind power jacket foundation grouting connection section bearing performance test device and method, and the method comprises the steps: controlling a movable cross beam to carry out preloading through a PC controller, observing the difference value of the strain on the symmetric surface of a grouting connection section model, guaranteeing that the test loading does not have the eccentric problem, and carrying out the testing of the bearing performance of the grouting connection section model; observing whether the loading condition of the testing machine is normal or not and whether the data change of resistance strain gauges at all measuring points of the grouting connection section model is normal or not; after all conditions are ensured to be normal, the PC controller controls the movable cross beam to carry out formal loading until the grouting connection section model is damaged; and exporting the strain change data of each measuring point in the test process from the data acquisition computer, and analyzing the stress condition of each measuring point in the formal loading process. Through the method, the strain of a plurality of measuring points can be measured at the same time, the grouting thickness of the grouting connection section model or the diameter and the wall thickness of a steel pipe are changed, and bearing performance tests can be carried out on grouting connection section models of different sizes.

Description

Technical Field

[0001] The present invention relates to the technical field of offshore wind power, and particularly to a bearing performance test device and method for the grouting connection section of an offshore wind power jacket foundation. Background Art

[0002] Wind energy is a renewable and pollution-free green energy source, and wind power generation is one of the important ways to address current global climate change and achieve energy transformation. With the advancement of offshore wind power development, offshore resources are gradually saturated, and deep-sea areas have become the focus of development. The coupled action of complex loads such as wind, waves, and currents in deep-sea wind farms poses higher requirements for the support structures of wind turbines. The jacket foundation, with its characteristics of high strength, light weight, and adaptability to deep-water environments, has become the main choice for the construction of deep-sea wind farms. The grouting connection section is an indispensable part in the installation process of the jacket foundation, and its bearing performance will affect the safety and stability of the entire jacket wind power.

[0003] Currently, existing test devices and methods for jacket wind turbines mainly study the mechanical properties of the upper steel structure of the jacket foundation, and there is little physical test research on the grouting connection section. Based on this, it is necessary to propose a bearing performance test device and method for the grouting connection section of an offshore wind power jacket foundation to provide a test basis for the design of the jacket foundation. Summary of the Invention

[0004] In view of this, the present invention proposes a bearing performance test device and method for the grouting connection section of an offshore wind power jacket foundation to solve the technical problems raised in the above background art, namely, there is little physical test research on the grouting connection section and it is impossible to provide a test basis for the design of the jacket foundation.

[0005] The technical solution of the present invention is implemented as follows:

[0006] In the first aspect, the present invention provides a bearing performance test method for the grouting connection section of an offshore wind power jacket foundation, including:

[0007] Combined with the maximum adjustment range of the vertical test space of the pressure testing machine and the maximum applied load value, calculate the scale ratio conversion according to the original scale of the grouting connection section and the principles of geometric, kinematic, and dynamic similarity, and fabricate a grouting connection section model;

[0008] Place the grouting connection section model at the center of the loading plate, arrange resistance strain gauges on the grouting connection section model, record the measuring point numbers corresponding to all resistance strain gauges, and connect the resistance strain gauges and the static strain test system through wires;

[0009] The static strain test system is connected to the data acquisition computer for data transmission. After turning on the power, zero the values of the resistance strain gauges;

[0010] Control the moving crossbeam through the PC controller for preloading, observe the difference in strain on the symmetry plane of the grouting connection section model, ensure that there is no eccentricity problem in the test loading, and observe whether the loading condition of the testing machine is normal and whether the data of the resistance strain gauges at all measuring points of the grouting connection section model changes normally;

[0011] After ensuring that everything is normal, control the moving crossbeam through the PC controller for formal loading until the grouting connection section model fails;

[0012] Export the strain change data of each measuring point during the test process from the data acquisition computer, and analyze the force-bearing conditions of each measuring point during the formal loading process.

[0013] On the basis of the above technical solutions, preferably, the control of the moving crossbeam through the PC controller for preloading includes: the preloading adopts force control loading and is loaded to 10% of the calculated ultimate bearing capacity of the grouting connection section model.

[0014] On the basis of the above technical solutions, preferably, the control of the moving crossbeam through the PC controller for formal loading includes: in the early stage, it is force control loading, and when the load reaches 80% of the calculated ultimate bearing capacity, it is changed to displacement control loading. The loading rate of the displacement control loading is 0.1 mm / min. After the grouting connection section model fails, continue to use displacement control loading to observe the mechanical performance of the grouting connection section model in the plastic stage, and the test ends after the load drops to 70% of the ultimate bearing capacity.

[0015] On the basis of the above technical solutions, preferably, the analysis of the force-bearing conditions of each measuring point during the formal loading process includes: the load-displacement data during the test loading can be exported from the PC controller. According to the strain change data and load-displacement data of each measuring point, analyze the force-bearing conditions of each measuring point during the formal loading process and draw the load-strain curve.

[0016] On the basis of the above technical solutions, preferably, the calculated ultimate bearing capacity is calculated according to the following formula:

[0017]

[0018] In formula (1), s is the distance between two adjacent shear keys on the same side, n is the number of shear keys, γ m is a material parameter, which is taken as 2.0 when calculating the ultimate bearing state of the circular grouting connection with shear keys and 1.5 when calculating the fatigue bearing state, f bk is the shear bearing capacity of the contact surface of the grouting connection with shear keys, and its value is the smaller value of the calculation results of formula (2) and formula (3);

[0019]

[0020] In Formulas (2) and (3), D JL is the diameter of the inner pipe of the grouting connection, h is the shear key height, k is the radial stiffness coefficient of the grouting connection, and f ck is the cube compressive strength of the grouting material;

[0021] k = [(2R p / t p ) + (2R JL / t JL )] -1 + (E g / E)[(2R JL - 2t JL ) / t g )] -1 (4);

[0022] In Formula (4), R P and t P are the radius and wall thickness of the outer pipe of the grouting connection, R JL and t JL are the radius and wall thickness of the inner pipe of the grouting connection, E g is the elastic modulus of the grouting material, E is the elastic modulus of the grouting material, and t g is the grout thickness.

[0023] On the basis of the above technical solutions, preferably, before the PC controller controls the moving crossbeam for formal loading, it further includes: aligning a high-speed camera with the grouting connection section model and recording the appearance changes of the grouting connection section model during the formal loading process.

[0024] On the basis of the above technical solutions, preferably, the calculation of the conversion scale ratio according to the original scale of the grouting connection section and the principles of geometric, kinematic, and dynamic similarity includes: calculating that the conversion scale ratio is 11:75, and manufacturing a grouting connection section model according to this conversion scale ratio.

[0025] In a second aspect, the present invention provides a test device for the bearing performance of a grouting connection section of an offshore wind power jacket foundation, including a pressure testing machine, a PC controller, a static strain testing system, a data acquisition computer, a grouting connection section model, resistance strain gauges, and a high-speed camera, wherein:

[0026] The pressure testing machine includes a frame, a loading plate, a moving crossbeam, and a main actuator; the frame includes a base, a top plate, and connecting columns, and the connecting columns are connected between the base and the top plate; the loading plate is arranged on the base and is used to place the grouting connection section model; the moving crossbeam slides inside the connecting columns; the main actuator is installed on the top plate and is connected to the moving crossbeam;

[0027] The PC controller is electrically connected to the main actuator;

[0028] The static strain test system is used to collect the strain change data during the test;

[0029] The data acquisition computer is connected to the static strain test system;

[0030] The grouting connection section model includes an outer pipe, an inner pipe, and grouting material. The outer pipe is sleeved outside the inner pipe and they are coaxial. The grouting material is filled between the outer pipe and the inner pipe;

[0031] The resistance strain gauges are installed on the outer pipe, the inner pipe, and in the grouting material, and are connected to the static strain test system through wires;

[0032] The high-speed camera is aligned with the grouting connection section model and is used to record the appearance changes of the grouting connection section model during the formal loading process.

[0033] Based on the above technical solutions, preferably, the top of the inner pipe is higher than the top of the outer pipe. The grouting connection section model further includes a bearing plate and two end plates. The two end plates are respectively connected to the bottom of the outer pipe and the top of the inner pipe. The bearing plate is arranged on the top of the upper end plate. A first reinforcing rib is provided between the outer wall of the outer pipe and the lower end plate, and a second reinforcing rib is provided between the outer wall of the inner pipe and the upper end plate.

[0034] Based on the above technical solutions, preferably, it further includes a mounting bracket. The resistance strain gauges arranged in the grouting material are installed on the mounting bracket, and the mounting bracket is inserted into the grouting material.

[0035] The bearing performance test device and method for the grouting connection section of the offshore wind turbine jacket foundation of the present invention have the following beneficial effects compared with the prior art:

[0036] (1) By arranging resistance strain gauges on the grouting connection section model and recording the measuring point numbers corresponding to all the resistance strain gauges; controlling the moving crossbeam to perform preloading through a PC controller, after ensuring that everything is normal, controlling the moving crossbeam to perform formal loading through the PC controller until the grouting connection section model fails; exporting the strain change data of each measuring point during the test process from the data acquisition computer and analyzing the stress conditions of each measuring point during the formal loading process; through the above methods, the strain of multiple measuring points can be measured simultaneously. By changing the grouting thickness, steel pipe diameter, or wall thickness of the grouting connection section model, the bearing performance tests can be carried out on grouting connection section models of different sizes. The grouting connection section model is made by calculating the scale ratio according to the maximum adjustment range of the vertical test space and the maximum applied load value of the pressure testing machine, as well as the original scale, geometric, kinematic, and dynamic similarity principles of the grouting connection section, making the accuracy of the test data closer to the actual situation and improving the reliability of the test results;

[0037] (2) Force control loading is adopted for preloading, loading to 10% of the calculated ultimate bearing capacity of the grouting connection section model. The data of the resistance strain gauges will change, which can facilitate observing whether the strain differences on the symmetry plane of the grouting connection section model are consistent, ensuring that there is no eccentricity problem in the test loading and that the loading force will not be too large to cause the grouting connection section model to fail due to large strain;

[0038] (3) During formal loading, force control loading is adopted in the early stage until the load reaches 80% of the calculated ultimate bearing capacity, then it is changed to displacement control loading. The loading rate of displacement control loading is 0.1 mm / min. After the grouting connection section model fails, displacement control loading is continued to observe the mechanical performance of the plastic stage of the grouting connection section model. The test ends after the load drops to 70% of the ultimate bearing capacity; adopting force control loading in the early stage and displacement control loading in the later stage can obtain more linear strain data, making the measurement results more accurate and reliable;

[0039] (4) Align a high-speed camera with the grouting connection section model to record the appearance changes of the grouting connection section model during the formal loading process, which is convenient for subsequent correspondence between the strain and appearance changes during the loading process and provides reliable visual data for recording the test results;

[0040] (5) By installing the resistance strain gauges on the outer pipe, inner pipe, and grouting material, the strain data at different positions of the grouting connection section model can be measured, making the collected data more reliable and real, closer to the strain change situation of the actual grouting connection section, and improving the reliability of the test results. Description of the Drawings

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0042] Figure 1 It is a schematic flow chart of the test method for the bearing capacity of the grouting connection section of the offshore wind turbine jacket foundation in the embodiment of the present invention;

[0043] Figure 2 It is a schematic structural diagram of the test device for the bearing capacity of the grouting connection section of the offshore wind turbine jacket foundation in the embodiment of the present invention;

[0044] Figure 3 It is a schematic structural diagram of the grouting connection section model in the embodiment of the present invention;

[0045] Figure 4 It is a partial cross-sectional view of the grouting connection section model in the embodiment of the present invention;

[0046] Figure 5 It is a schematic structural diagram of the mounting bracket and the resistance strain gauge in the embodiment of the present invention;

[0047] Figure 6 It is a curve graph of load-strain at a certain measuring point in the embodiment of the present invention.

[0048] Explanation of reference numerals: 1 - pressure testing machine, 2 - PC controller, 3 - static strain testing system, 4 - data acquisition computer, 5 - USB data cable, 6 - wire, 7 - high-speed camera, 8 - grouting connection section model, 9 - resistance strain gauge, 10 - loading plate, 11 - frame, 12 - base, 111 - top plate, 112 - connecting column, 13 - moving crossbeam, 14 - main actuator, 15 - inner tube, 16 - outer tube, 17 - grouting material, 18 - end plate, 19 - first reinforcing rib, 20 - second reinforcing rib, 21 - bearing plate, 22 - mounting bracket. Specific embodiments

[0049] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0050] Refer to Figure 1As shown in the figure, an embodiment of the first aspect of the present invention provides a test method for the bearing performance of the grouting connection section of an offshore wind power jacket foundation, including:

[0051] Step S1: Combining the maximum adjustment range of the vertical test space of the pressure testing machine 1 and the maximum applied load value, calculate the scaling ratio according to the original scale of the grouting connection section and the principles of geometric, kinematic, and dynamic similarity, and fabricate the grouting connection section model 8;

[0052] In step S1, the maximum adjustment range of the vertical test space of the pressure testing machine 1 is 20 cm, and the maximum applied load value is 10,000 kN; the grouting connection section model 8 includes an outer pipe 16, an inner pipe 15, and grouting material 17. The outer pipe 16 is sleeved outside the inner pipe 15 and the two are coaxial. The grouting material 17 is filled between the outer pipe 16 and the inner pipe 15; resistance strain gauges 9 on the wall of the inner pipe 15 are arranged in advance during the model fabrication stage, and the surface is coated with epoxy resin for protection. The wires 6 pass through holes drilled in the wall of the outer pipe 16. The installation bracket 22 is fabricated in advance to fix the resistance strain gauges 9 in the reverse direction and connect one end of the wires 6. The bracket is placed during the model grouting, and the grouting material 17 seeps in to measure the strain during loading;

[0053] Step S2: Place the grouting connection section model 8 at the center of the loading plate 10, arrange resistance strain gauges 9 on the grouting connection section model 8, record the measuring point numbers corresponding to all the resistance strain gauges 9, and connect the resistance strain gauges 9 and the static strain test system 3 through the wires 6;

[0054] In step S2, the grouting connection section model 8 is placed at the center of the loading plate 10 by a crane, and the resistance strain gauges 9 are arranged according to the pre-designed test plan. For example, shear keys are provided on the outer wall of the outer pipe 16, and the resistance strain gauges 9 are arranged at positions corresponding to the shear keys. Four measuring points are arranged on each shear key, namely 0°, 90°, 180°, and 270°. One circumferential and one longitudinal strain gauge are arranged at each measuring point. For example, the spacing between the shear keys is 51 mm, so the vertical spacing between the resistance strain gauges 9 is 51 mm;

[0055] Step S3: The static strain test system 3 is connected to the data acquisition computer 4 for data transmission. After the power is turned on, zero the values of the resistance strain gauges 9;

[0056] In step S3, the static strain test system 3 is connected to the data acquisition computer 4 through a USB data cable 5, and the values of the resistance strain gauges 9 are zeroed, that is, the measuring points are balanced so that the initial values of the resistance strain gauges 9 at each measuring point are all zero;

[0057] Step S4: Control the moving crossbeam 13 through the PC controller 2 to perform preloading, observe the difference in strain on the symmetry plane of the grouting connection section model 8, ensure that there is no eccentricity problem in the test loading, and observe whether the loading condition of the testing machine is normal and whether the data of all measuring points' resistance strain gauges 9 on the grouting connection section model 8 changes normally;

[0058] In step S4, the PC controller 2 inputs the operation of preloading to check whether the moving crossbeam 13 and the main actuator 14 of the testing machine can normally descend to apply load to the specimen, eliminate equipment failure problems, and check the display of the data acquisition computer 4 connected to the static strain measurement system 3. The strain of the measuring points on the symmetry plane of the same shear key should be approximately the same, and the numerical change trends of all measuring points during the loading process should be approximately the same, eliminating problems such as poor contact of the wire 6 or failure of the static strain measurement system 3 that cause inability to collect data;

[0059] Step S5: After ensuring that everything is normal, control the moving crossbeam 13 through the PC controller 2 to perform formal loading until the grouting connection section model 8 fails;

[0060] Step S6: Export the strain change data of each measuring point during the test process from the data acquisition computer 4 and analyze the force conditions of each measuring point during the formal loading process.

[0061] It should be noted that when simulating the force-bearing process of the grouting connection section, only by changing the pasting position of the resistance strain gauge 9 in step S3, the strain change data at different positions of the grouting connection section can be obtained. According to the size of the fabricated grouting connection section model 8 and the calculated ultimate bearing capacity, the critical load values in the preloading and formal loading stages can be changed.

[0062] The test method for the bearing capacity of the grouting connection section of the offshore wind turbine jacket foundation proposed in this embodiment arranges resistance strain gauges 9 on the grouting connection section model 8 and records the measuring point numbers corresponding to all resistance strain gauges 9; controls the moving crossbeam 13 through the PC controller 2 to perform preloading, and after ensuring that everything is normal, controls the moving crossbeam 13 through the PC controller 2 to perform formal loading until the grouting connection section model 8 fails; exports the strain change data of each measuring point during the test process from the data acquisition computer 4 and analyzes the force conditions of each measuring point during the formal loading process; through the above method, the strain of multiple measuring points can be measured simultaneously. By changing the grouting thickness or the diameter and wall thickness of the steel pipe of the grouting connection section model 8, the bearing capacity test can be carried out on the grouting connection section models 8 of different sizes. The grouting connection section model 8 is made by calculating the scale ratio according to the maximum vertical test space adjustment range and the maximum applied load value of the pressure testing machine 1, as well as the original scale, geometric, kinematic, and dynamic similarity principles of the grouting connection section. The accuracy of the test data is closer to the actual situation, improving the reliability of the test results.

[0063] In some embodiments, in step S4, the preloading of the moving crossbeam 13 by the PC controller 2 includes: the preloading is carried out by force control loading until it reaches 10% of the calculated ultimate bearing capacity of the grouting connection section model 8. By preloading in the above manner, the data of the resistance strain gauge 9 will change, which can facilitate observing whether the difference in strain on the symmetry plane of the grouting connection section model 8 is consistent, ensuring that there is no eccentricity problem in the test loading, and the loading force will not be too large to cause large strain and failure of the grouting connection section model 8.

[0064] In some embodiments, in step S5, the formal loading of the moving crossbeam 13 by the PC controller 2 includes: in the early stage, it is force control loading until the load reaches 80% of the calculated ultimate bearing capacity, then it is changed to displacement control loading, and the loading rate of the displacement control loading is 0.1 mm / min. After the grouting connection section model 8 fails, continue to use displacement control loading to observe the mechanical performance of the grouting connection section model 8 in the plastic stage. The test ends after the load drops to 70% of the ultimate bearing capacity. During formal loading, force control loading in the early stage and displacement control loading in the later stage can obtain more linear strain data, making the measurement results more accurate and reliable.

[0065] In some embodiments, in step S6, the analysis of the force conditions of each measuring point during formal loading includes: the load-displacement data during the test can be exported from the PC controller 2. According to the strain change data and load-displacement data of each measuring point, analyze the force conditions of each measuring point during formal loading and draw the load-strain curve. The load-strain curve of one of the measuring points is as Figure 6 shown.

[0066] In some embodiments, the calculated ultimate bearing capacity is calculated according to the following formula:

[0067]

[0068] In formula (1), s is the distance between two adjacent shear keys on the same side, n is the number of shear keys, γ m is a material parameter, which takes 2.0 when calculating the ultimate bearing state of the circular grouting connection with shear keys and 1.5 when calculating the fatigue bearing state, and f bk is the shear bearing capacity of the contact surface of the grouting connection with shear keys, and its value is the smaller value of the calculation results of formula (2) and formula (3);

[0069]

[0070] In formulas (2) and (3), D JL is the diameter of the inner pipe of the grouting connection, h is the height of the shear key, k is the radial stiffness coefficient of the grouting connection, and f ckis the cube compressive strength of the grouting material;

[0071] k = [(2R p / t p ) + (2R JL / t JL )] -1 + (E g / E)[(2R JL - 2t JL ) / t g )] -1 (4);

[0072] In formula (4), R P and t P are the radius and wall thickness of the outer tube of the grouting connection, R JL and t JL are the radius and wall thickness of the inner tube of the grouting connection, E g is the elastic modulus of the grouting material, E is the elastic modulus of the grouting material, and t g is the thickness of the grout body.

[0073] In some embodiments, before the moving crossbeam 13 is formally loaded by the PC controller 2, it further includes: aligning the high-speed camera 7 with the grouting connection section model 8 to record the appearance changes of the grouting connection section model 8 during the formal loading process. Recording the appearance changes of the grouting connection section model 8 during the formal loading process by the high-speed camera 7 facilitates subsequent correspondence between the strain and appearance changes during the loading process, providing reliable and intuitive data for recording the test results.

[0074] In some embodiments, the calculation of the conversion scale ratio according to the original scale of the grouting connection section and the principles of geometric, kinematic, and dynamic similarity includes: calculating that the conversion scale ratio is 11:75, and manufacturing the grouting connection section model 8 according to this conversion scale ratio. Manufacturing the grouting connection section model 8 according to the calculated conversion scale ratio of 11:75 makes the obtained model closer to the actual grouting connection section, improving the accuracy and reliability of the test results.

[0075] Based on the same concept, the second aspect embodiment of the present invention, as shown in reference to Figures 2 - 6 provides a test device for the bearing capacity of the grouting connection section of an offshore wind turbine jacket foundation, including a pressure testing machine 1, a PC controller 2, a static strain testing system 3, a data acquisition computer 4, a grouting connection section model 8, a resistance strain gauge 9, and a high-speed camera 7, wherein:

[0076] The pressure testing machine 1 includes a frame 11, a loading plate 10, a moving crossbeam 13, and a main actuator 14; the frame 11 includes a base 12, a top plate 111, and connecting columns 112, and the connecting columns 112 are connected between the base 12 and the top plate 111; the loading plate 10 is arranged on the base 12 for placing the grouting connection section model 8; the moving crossbeam 13 slides inside the connecting columns 112; the main actuator 14 is installed on the top plate 111 and connected to the moving crossbeam 13;

[0077] The PC controller 2 is electrically connected to the main actuator 14; the way and amplitude of applying load during the test of the pressure testing machine 1 are controlled by the PC controller 2, and the load-displacement data can be exported from the PC controller 2 after the test;

[0078] The static strain testing system 3 is used to collect the strain change data during the test. The static strain testing system 3 is connected to the resistance strain gauges 9 through wires 6 and is used to measure the strain changes that occur in the pipe wall and grouting material 17 during the compression of the grouting connection section model 8;

[0079] The data acquisition computer 4 is connected to the static strain testing system 3 through a USB data cable 5 and is used to record the strain change data during the test;

[0080] The grouting connection section model 8 includes an outer pipe 16, an inner pipe 15, and grouting material 17. The outer pipe 16 is sleeved outside the inner pipe 15 and the two are coaxial, and the grouting material 17 is filled between the outer pipe 16 and the inner pipe 15;

[0081] The resistance strain gauges 9 are installed on the outer pipe 16, the inner pipe 15, and in the grouting material 17 and are conductively connected to the static strain testing system 3; the surfaces of the resistance strain gauges 9 for measuring the strain changes of the pipe walls of the inner pipe 15 and the outer pipe 16 are coated with epoxy resin for protection; the resistance strain gauges 9 on the wall of the inner pipe 15 are arranged in advance during the model making stage and the surfaces are coated with epoxy resin for protection, and the wires 6 pass through holes drilled in the wall of the outer pipe 16;

[0082] The high-speed camera 7 is aligned with the grouting connection section model 8 and is used to record the appearance changes of the grouting connection section model 8 during the formal loading process.

[0083] In some embodiments, the top of the inner pipe 15 is higher than the top of the outer pipe 16. The grouting connection section model 8 further includes a bearing plate 21 and two end plates 18. The two end plates 18 are respectively connected to the bottom of the outer pipe 16 and the top of the inner pipe 15. The bearing plate 21 is arranged on the top of the upper end plate 18. A first reinforcing rib 19 is provided between the outer wall of the outer pipe 16 and the lower end plate 18, and a second reinforcing rib 20 is provided between the outer wall of the inner pipe 15 and the upper end plate 18.

[0084] In some embodiments, the bearing performance test device for the grouting connection section of the offshore wind power jacket foundation further includes an installation bracket 22. The resistance strain gauges 9 disposed in the grouting material 17 are installed on the installation bracket 22, and the installation bracket 22 is inserted into the grouting material 17. Before grouting, the resistance strain gauges 9 are pre-distributed along the length direction of the installation bracket 22. During grouting, the installation bracket 22 is inserted into the grouting material 17. The installation bracket 22 is parallel to the axis of the grouting connection section, ensuring that the strain gauges are arranged along the axis direction of the grouting connection section model 8, so that the measured strain results are convenient for statistics.

[0085] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. Test method for bearing performance of grouting connection section of jacket foundation for offshore wind power, characterized in that, Including: Combined with the maximum adjustment range of the vertical test space of the pressure testing machine and the maximum applied load value, the conversion scale ratio is calculated according to the original scale of the grouting connection section and the principles of geometric, kinematic and dynamic similarity, and the grouting connection section model is fabricated. Place the grouting connection section model at the center of the loading plate, arrange resistance strain gauges on the grouting connection section model, record the measuring point numbers corresponding to all the resistance strain gauges, and connect the resistance strain gauges and the static strain testing system through wires. The static strain testing system is connected to the data acquisition computer for data transmission. After turning on the power, zero the values of the resistance strain gauges. Control the moving crossbeam through the PC controller for preloading, observe the difference in strain on the symmetry plane of the grouting connection section model to ensure that there is no eccentricity problem in the test loading, and observe whether the loading condition of the testing machine is normal and whether the data of the resistance strain gauges at all measuring points of the grouting connection section model change normally. After ensuring that everything is normal, control the moving crossbeam through the PC controller for formal loading until the grouting connection section model fails. Export the strain change data of each measuring point during the test process from the data acquisition computer, and analyze the force conditions of each measuring point during the formal loading process.

2. The test method for the bearing performance of the grouting connection section of the offshore wind power jacket foundation according to claim 1, characterized in that The control of the moving crossbeam through the PC controller for preloading includes: the preloading adopts force control loading, and the loading is up to 10% of the calculated ultimate bearing capacity of the grouting connection section model.

3. The test method for the bearing performance of the grouting connection section of the offshore wind power jacket foundation according to claim 2, characterized in that, The control of the moving crossbeam through the PC controller for formal loading includes: in the early stage, it is force control loading, and when the load reaches 80% of the calculated ultimate bearing capacity, it is changed to displacement control loading. The loading rate of the displacement control loading is 0.1 mm / min. After the grouting connection section model fails, continue to use displacement control loading to observe the mechanical performance of the grouting connection section model in the plastic stage, and the test ends after the load drops to 70% of the ultimate bearing capacity.

4. The test method for the bearing performance of the grouting connection section of the offshore wind power jacket foundation according to claim 3, wherein, The analysis of the force conditions of each measuring point during the formal loading process includes: the load-displacement data during the test loading can be exported from the PC controller. According to the strain change data and the load-displacement data of each measuring point, analyze the force conditions of each measuring point during the formal loading process and draw the load-strain curve.

5. The test method for the bearing performance of the grouting connection section of the offshore wind power jacket foundation according to claim 4, wherein, The calculated ultimate bearing capacity is calculated according to the following formula: In formula (1), s is the distance between two adjacent shear keys on the same side, n is the number of shear keys, and γ m is a material parameter, which is taken as 2.0 when calculating the ultimate bearing capacity of the circular grouted connection with shear keys and 1.5 when calculating the fatigue bearing capacity. f bk is the shear bearing capacity of the contact surface of the grouted connection with shear keys, and its value is the smaller of the calculation results of formula (2) and formula (3); In Formulas (2) and (3), D JL is the diameter of the inner pipe of the grouting connection, h is the shear key height, k is the radial stiffness coefficient of the grouting connection, and f ck is the cube compressive strength of the grouting material; k = [(2R p / t p ) + (2R JL / t JL )] -1 + (E g / E)[(2R JL - 2t JL ) / t g )] -1 (4); In formula (4), R P and t P are the radius and wall thickness of the outer tube of the grouting connection, R JL and t JL are the radius and wall thickness of the inner tube of the grouting connection, E g is the elastic modulus of the grouting material, E is the elastic modulus of the grouting material, t g is the thickness of the grout body.

6. The test method for the bearing performance of the grouting connection section of the offshore wind turbine jacket foundation according to claim 1, characterized in that, Before the control of the moving crossbeam through the PC controller for formal loading, it also includes: aiming the high-speed camera at the grouting connection section model and recording the appearance changes of the grouting connection section model during the formal loading process.

7. The test method for the bearing performance of the grouting connection section of the offshore wind power jacket foundation according to claim 1, characterized in that The calculation of the conversion scale ratio according to the original scale of the grouting connection section and the principles of geometric, kinematic and dynamic similarity includes: the calculated conversion scale ratio is 11:75, and the grouting connection section model is fabricated according to this conversion scale ratio.

8. Test device for bearing capacity of grouting connection section of jacket foundation for offshore wind power, characterized in that, Including a pressure testing machine, a PC controller, a static strain testing system, a data acquisition computer, a grouting connection section model, resistance strain gauges and a high-speed camera, where: The pressure testing machine includes a frame, a loading plate, a moving crossbeam, and a main actuator; the frame includes a base, a top plate, and connecting columns, and the connecting columns are connected between the base and the top plate; the loading plate is arranged on the base and is used for placing the grouting connection section model; the moving crossbeam slides inside the connecting columns; the main actuator is installed on the top plate and is connected to the moving crossbeam; The PC controller is electrically connected to the main actuator; The static strain testing system is used to collect the strain change data during the test; The data acquisition computer is connected to the static strain testing system; The grouting connection section model includes an outer pipe, an inner pipe, and grouting material. The outer pipe is sleeved outside the inner pipe and the two are coaxial. The grouting material is filled between the outer pipe and the inner pipe; The resistance strain gauges are installed on the outer pipe, the inner pipe, and in the grouting material, and are connected to the static strain testing system through wires; The high-speed camera is aligned with the grouting connection section model and is used to record the appearance changes of the grouting connection section model during the formal loading process.

9. The bearing performance test device for the grouting connection section of the jacket foundation of offshore wind turbines according to claim 8, characterized in that The top of the inner pipe is higher than the top of the outer pipe. The grouting connection section model further includes a bearing plate and two end plates. The two end plates are respectively connected to the bottom of the outer pipe and the top of the inner pipe. The bearing plate is arranged on the top of the upper end plate. A first reinforcing rib is provided between the outer wall of the outer pipe and the lower end plate, and a second reinforcing rib is provided between the outer wall of the inner pipe and the upper end plate.

10. The bearing performance test device for the grouting connection section of the offshore wind power jacket foundation according to claim 9, characterized in that, It further includes a mounting bracket. The resistance strain gauges arranged in the grouting material are installed on the mounting bracket, and the mounting bracket is inserted into the grouting material.

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