A device and method for detecting the horizontal bearing capacity of a large-diameter high-pile foundation on water

Abstract

A device and method for testing the horizontal bearing capacity of large-diameter high-pile foundations on water, the device comprising at least a first loading cable, a second loading cable, a third loading cable, a force transmission cable, a marking cable, a first fixed pulley, a second fixed pulley, a first fixed pulley support, a second fixed pulley support, a first adjustable triangular bracket, a second adjustable triangular bracket, a marking cable support, a bottom support, a high-tonnage high-precision force gauge, a first test vessel, a first anchor chain, a second anchor chain, a first anchor claw, and a second anchor claw; one end of the loading cable is connected to the outer wall of the pile, and the other end of the force transmission cable is connected to the loading cables of each test pile, and the other end passes around the fixed pulley and connects to the high-tonnage high-precision force gauge and the marking cable, and then connects to a high-tonnage electric winch or a second backup test vessel. This invention avoids the need for reaction anchor piles, has a short testing cycle, low cost, convenient operation, and wide applicability; the testing device is reusable, further saving on engineering costs.

Description

Technical Field

[0001] This invention belongs to the field of pile foundation bearing capacity testing, specifically relating to a device and method for testing the horizontal bearing capacity of large-diameter high pile foundations on water, which is applicable to the testing of the horizontal bearing capacity of pile foundations on water and the assessment of their ultimate bearing capacity. Background Technology

[0002] Wind energy is one of the most promising renewable energy sources, and offshore wind energy, in particular, has gained widespread attention and favor due to its abundant resources, stable wind speeds, and low susceptibility to environmental noise. Offshore wind power projects are under construction at a rapid pace. Large-diameter monopile foundations, with their advantages of simple manufacturing, convenient installation, simple structure, and clear stress distribution, are widely used in nearshore wind power projects. Located in the extreme offshore environment, wind turbine foundations are subjected to long-term horizontal loads from wind, waves, and currents during their service life, causing significant angular and horizontal deformation. However, offshore wind turbines have high requirements for deformation control; excessive overall structural misalignment may cause blades to collide with the tower and the rotor to yaw, making it difficult for the control system to maintain constant power output, resulting in reduced power generation per unit. Therefore, conducting horizontal bearing capacity testing and ultimate bearing capacity assessment of the pile foundation is crucial for ensuring its safe service life.

[0003] Currently, most technologies for testing the horizontal bearing capacity of large-diameter high-pile foundations on water require driving reaction anchor piles near the test pile, applying horizontal loads to the test pile through a reaction device, and observing the deformation and failure of the pile foundation to assess its bearing capacity. This method is very traditional and reliable, but it also has significant limitations. First, it is costly, time-consuming, and labor-intensive. Driving reaction anchor piles and building loading devices and platforms requires a long period, and different reaction devices need to be rebuilt for different test piles, making the process cumbersome, time-consuming, and delaying construction. The testing costs can reach tens of millions of yuan, significantly increasing the economic cost of the testing work. Second, it cannot meet the enormous test reaction forces required for large-diameter pile foundations. With the improvement of offshore wind power construction, wind turbine capacity is increasing, and the corresponding pile diameter is also increasing. Some offshore wind farms have wind turbine pile diameters reaching 6.6 m. Traditional load testing methods using small-diameter anchor piles can no longer meet the test reaction forces required for large-diameter piles. Third, the stress point is too singular. Existing methods have a relatively singular location for the horizontal load application point, which may result in a small stress area on the pile body, excessive local pressure, and easy breakage or damage at the free end of the pile foundation, leading to test failure. Therefore, there is an urgent need to develop a device and method for testing the horizontal bearing capacity of large-diameter high pile foundations on water, simplifying the testing process, facilitating operation for testing personnel, and reducing testing costs and time. Summary of the Invention

[0004] The technical problem this invention aims to solve is to address the aforementioned shortcomings of existing pile foundation horizontal bearing capacity testing methods by providing a device and method for testing the horizontal bearing capacity of large-diameter high pile foundations on water. Using this invention, the horizontal bearing capacity testing of large-diameter high pile foundations on water can be performed without driving reaction anchor piles near the test pile to meet the required test reaction force for large-diameter pile foundations. This eliminates significant costs associated with the prefabrication, transportation, hoisting, and labor of reaction anchor piles, and avoids the problem of test failure due to pile damage caused by a single point of application of the horizontal force. Furthermore, the testing device is simple and quick to operate, saving considerable testing time, and the testing equipment can be reused, further reducing project costs.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0006] A device for testing the horizontal bearing capacity of large-diameter high-pile foundations on water, arranged near the pile to be tested, includes at least a first loading cable, a second loading cable, a third loading cable, a force transmission cable, a marking cable, a first fixed pulley, a second fixed pulley, a first fixed pulley support, a second fixed pulley support, a first adjustable triangular bracket, a second adjustable triangular bracket, a marking cable bracket, a bottom support, a high-tonnage high-precision force gauge, a first test vessel, a first anchor chain, a second anchor chain, a first anchor claw, and a second anchor claw. One end of the first, second, and third loading cables is connected to different points on the outer wall of the test pile, and the other ends of the first, second, and third loading cables converge and are connected to one end of the force transmission cable. The first fixed pulley is fixed to the upper end of the first fixed pulley support, and the first fixed pulley support is fixed to the top of the first adjustable triangular bracket. The second fixed pulley is fixed to the upper end of the second fixed pulley support, which is fixed to the top of the second adjustable triangular bracket. The bottom ends of the first and second adjustable triangular brackets are connected to the bottom support, which is installed on the hull of the first test vessel. The other end of the force transmission cable passes around the first and second fixed pulleys in sequence and is then connected to one end of the high-tonnage high-precision force gauge through a metal connecting buckle. The other end of the high-tonnage high-precision force gauge is connected to one end of the marking cable through the metal connecting buckle. The other end of the marking cable passes through the marking cable bracket and is connected to the high-tonnage electric winch or the second backup test vessel. The bow and stern of the first test vessel are respectively connected to the first anchor chain and the second anchor chain. The first anchor chain and the second anchor chain are respectively fixed to the seabed or riverbed by the first anchor claw and the second anchor claw.

[0007] According to the above scheme, three hook rings are pre-welded on the outer wall of the test pile. The three hook rings are on the same horizontal plane. One end of the first loading cable, the second loading cable and the third loading cable are respectively connected to the three hook rings through a metal connecting buckle. The three points are on the same horizontal plane.

[0008] According to the above scheme, the first loading cable and the third loading cable are both tangent to the outer wall of the test pile, and the extension line of the second loading cable passes through the center of the test pile on the same horizontal plane.

[0009] According to the above scheme, a central through-hole is reserved in the center of the marking cable bracket. The diameter of the through-hole is slightly larger than the diameter of the marking cable, so that the marking cable can pass through the marking cable bracket and ensure that the marking cable will not be resisted by the marking cable bracket during horizontal movement. The marking cable is marked with scale lines for directly reading the horizontal displacement of the marking cable at the central through-hole of the marking cable bracket.

[0010] According to the above scheme, the first loading cable, the second loading cable, the third loading cable, the force transmission cable, and the marking cable are all made of high-strength steel strands.

[0011] According to the above scheme, the first adjustable triangular bracket and the second adjustable triangular bracket are each equipped with three support legs. The projections of the three support legs on the horizontal plane form a 120° angle. The three support legs of the first adjustable triangular bracket fix the first fixed pulley support at different heights by opening or closing, so that the section of the force transmission cable passing through the first fixed pulley and connected to the first loading cable, the second loading cable, and the third loading cable remains horizontal. The three support legs of the second adjustable triangular bracket fix the second fixed pulley support at different heights by opening or closing, so that the large-tonnage high-precision force gauge and the marking cable also remain horizontal after being connected to the large-tonnage electric winch or the second backup test vessel. After fixing the opening angle of each support leg, the bottom end of the support leg is connected and fixed to the bottom support by bolts.

[0012] According to the above scheme, both the first fixed pulley support and the second fixed pulley support are circular. The first fixed pulley support has a reserved eccentric circular hole. The first fixed pulley is fixed at the center of the first fixed pulley support. The position of the eccentric circular hole is offset from the center of the first fixed pulley support, so that the force transmission cable passes through the eccentric circular hole after passing around the first fixed pulley. The eccentric circular hole is in the same vertical plane as one of the three support legs, and the other two support legs are distributed on both sides of the center of the first fixed pulley support.

[0013] According to the above scheme, the bottom support is fixed to the first test ship plate by bolts, the marking cable bracket is an alloy steel plate, and the marking cable bracket is welded and fixed to the bottom support.

[0014] The present invention also provides a method for testing the horizontal bearing capacity of pile foundations using the above-mentioned underwater large-diameter high pile foundation horizontal bearing capacity testing device, comprising the following steps:

[0015] (1) Preliminary preparation: Design a test plan and corresponding test equipment according to the specifications of the pile to be tested and the bearing capacity requirements. Prefabricate and prepare the following: first loading cable, second loading cable, third loading cable, force transmission cable, marking cable, first fixed pulley, second fixed pulley, first fixed pulley support, second fixed pulley support, first adjustable triangular bracket, second adjustable triangular bracket, marking cable bracket, bottom support, large-tonnage electric winch, large-tonnage high-precision force gauge, first test vessel, second spare test vessel, first anchor chain, second anchor chain, first anchor claw, second anchor claw;

[0016] (2) Docking of the test vessel: The testing device arranged on the first test vessel is transported to the vicinity of the water area to be tested using the first test vessel. According to the engineering requirements and the loading direction of the design, the first anchor chain, the second anchor chain and the first anchor claw and the second anchor claw are used to stably dock the first test vessel at a position 2-5 times the pile diameter away from the pile to be tested.

[0017] (3) Device Setup: First, the bottom support is fixed to the hull plate of the first test vessel using bolts. Then, one end of the first loading cable, the second loading cable, and the third loading cable are connected to the outer wall of the pile to be tested using the metal connecting buckle. One end of the force transmission cable is connected to the other end of the first loading cable, the second loading cable, and the third loading cable. The other end of the force transmission cable passes around the first fixed pulley and the second fixed pulley and is connected to the high-tonnage high-precision force gauge. The first adjustable triangular bracket is adjusted so that it passes through the first fixed pulley and connects with the first loading cable, The section connecting the second and third loading cables remains horizontal; the other end of the high-tonnage high-precision force gauge is connected to one end of the marking cable, and the other end of the marking cable passes through the center hole of the marking cable bracket and connects to the high-tonnage electric winch or the second backup test vessel. The second adjustable triangular bracket is adjusted so that the high-tonnage high-precision force gauge and the marking cable remain horizontal after being connected to the high-tonnage electric winch or the second backup test vessel; finally, the first and second adjustable triangular brackets are fixed to the bottom support with bolts.

[0018] (4) Start the test: After the detection device is set up, record the initial tension value of the large-tonnage high-precision force gauge and the initial scale value of the marking cable at the center of the marking cable bracket; start the test by opening the large-tonnage electric winch or starting the second backup test ship to tension the marking cable to provide the horizontal force required for the test, and perform progressively graded loading, while recording the horizontal tension value measured by the large-tonnage high-precision force gauge and the scale value of the marking cable at the through hole of the marking cable bracket under each load level;

[0019] (5) Follow-up work: After the test, process the raw data obtained from the test. The horizontal tension measured by the large-tonnage high-precision force gauge is the horizontal force on the test pile. The difference in the scale value of the marking cable is the horizontal displacement of the test pile. Plot and analyze the load-displacement curve, evaluate the ultimate bearing capacity of the pile foundation, recover the equipment, and complete the test of the horizontal bearing capacity of the marine pile foundation.

[0020] According to the above scheme, in step (3), the large-tonnage electric winch and the second backup test vessel are used to provide horizontal force for the test pile. For test piles with low bearing capacity, the large-tonnage electric winch is used to provide horizontal force, and for test piles with high bearing capacity, the second backup test vessel is used to provide horizontal force.

[0021] Compared with traditional methods for testing the horizontal bearing capacity of pile foundations, the beneficial effects of the present invention's device and method for testing the horizontal bearing capacity of large-diameter high pile foundations on water are as follows:

[0022] 1. When conducting static load tests using the waterborne large-diameter high pile foundation horizontal bearing capacity testing device of the present invention, it is not necessary to drive one or more reaction anchor piles near the test pile to meet the test reaction force required for large-diameter pile foundations. This saves a lot of costs for the prefabrication, transportation, hoisting and labor of reaction anchor piles. In addition, the testing device is simple and quick to operate, saving a lot of testing time. Furthermore, the testing equipment can be reused, further saving the project economy.

[0023] 2. Most of the testing and detection devices of this invention are deployed on the test ship. The deployment and installation of the devices are convenient, and the acquisition of the horizontal force and the resulting displacement of the test pile is also relatively simple and ingenious. In addition, the traditional testing method of applying thrust to the test pile using a reaction device is changed to directly applying tension to the test pile using a large-tonnage electric winch or the test ship, which is more convenient for the test personnel to operate.

[0024] 3. When conducting static load tests using the waterborne large-diameter high pile foundation horizontal bearing capacity testing device of the present invention, three loading cables are used to apply horizontal force to the test pile, which avoids the situation where the test fails due to pile wall damage caused by a single point of force application on the test pile.

[0025] 4. The present invention has at least two embodiments of the horizontal bearing capacity testing device for large-diameter high pile foundations on water. For pile foundations with smaller pile diameters and smaller ultimate bearing capacity, the load can be applied directly using a large-tonnage electric winch in the testing device. For pile foundations with larger pile diameters and larger ultimate bearing capacity, the load can be applied using a second backup test vessel in the testing device. This ingeniously makes full use of the unique geographical advantages and resources on water. The two embodiments also make the device of the present invention more widely applicable.

[0026] 5. In addition, the testing and experimental devices of this invention are all set up on the test ship, which greatly reduces the space requirements and can be applied to a wider range of water construction environments. It also avoids the need to drive more anchor piles in the seabed and reduces pollution to the marine environment and impact on marine life. Attached Figure Description

[0027] Figure 1 This is an overall schematic diagram of Embodiment 1 of the present invention, which is a device for detecting the horizontal bearing capacity of large-diameter high pile foundations on water.

[0028] Figure 2 This is an overall schematic diagram of Embodiment 2 of the present invention, which is a test device for the horizontal bearing capacity of large-diameter high pile foundations on water.

[0029] Figure 3 This is a partial top view of the connection points between the test pile and each loading cable in this invention;

[0030] Figure 4 This is a partial top view of the test device on the bottom support in this invention;

[0031] Figure 5 This is a partial top view of the first fixed pulley support device in this invention;

[0032] Figure 6 This is a partial side view of the cable support in this invention;

[0033] In the diagram: 1-Test pile, 2-First loading cable, 3-Second loading cable, 4-Third loading cable, 5-Force transmission cable, 6-Marking cable, 7-First fixed pulley, 8-Second fixed pulley, 9-First fixed pulley support, 10-Second fixed pulley support, 11-First adjustable triangular bracket, 12-Second adjustable triangular bracket, 13-Marking cable bracket, 14-Bottom support, 15-Large-tonnage electric winch, 16-Large-tonnage high-precision force gauge, 17-Metal connecting buckle, 18-First test vessel, 19-Second spare test vessel, 20-First anchor chain, 21-Second anchor chain, 22-First anchor claw, 23-Second anchor claw, 24-Eccentric circular hole, 25-Bolt, 26-Through circular hole. Detailed Implementation

[0034] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0035] Reference Figures 1-2 As shown, the present invention discloses a device for testing the horizontal bearing capacity of a large-diameter high-pile foundation on water, comprising a first loading cable 2, a second loading cable 3, a third loading cable 4, a force transmission cable 5, a marking cable 6, a first fixed pulley 7, a second fixed pulley 8, a first fixed pulley support 9, a second fixed pulley support 10, a first adjustable triangular bracket 11, a second adjustable triangular bracket 12, a marking cable bracket 13, a bottom support 14, a large-tonnage electric winch 15, a large-tonnage high-precision force gauge 16, a metal connecting buckle 17, a first test vessel 18, and a second fixed pulley 9. The second backup test vessel 19, the first anchor chain 20, the second anchor chain 21, the first anchor claw 22 and the second anchor claw 23, the first loading cable 2, the second loading cable 3 and the third loading cable 4 are respectively connected to different points on the outer wall of the test pile through metal connecting buckles 17, the other ends of the first loading cable 2, the second loading cable 3 and the third loading cable 4 converge and are connected to one end of the force transmission cable 5; the first fixed pulley 7 is fixed to the upper end of the first fixed pulley support 9, the first fixed pulley support 9 is fixed to the top of the first adjustable triangular bracket 11, and the second fixed pulley 8. The first adjustable triangular bracket 11 and the second adjustable triangular bracket 12 are fixed to the top of the second fixed pulley support 10. The bottom ends of the first adjustable triangular bracket 11 and the second adjustable triangular bracket 12 are connected to the bottom support 14. The bottom support 14 is fixedly installed on the hull plate of the first test ship 18 by bolts 25. The other end of the force transmission cable 5 passes through the first fixed pulley 7 and the second fixed pulley 8 in sequence, and then connects to one end of the high-tonnage high-precision force gauge 16 through a metal connecting buckle 17. The other end of the high-tonnage high-precision force gauge 16 is connected to the bottom support 14. One end of the marker cable 6 is connected to the metal connecting buckle 17, and the other end of the marker cable 6 passes through the through hole of the marker cable bracket 13 and is connected to the large-tonnage electric winch 15 or the second backup test vessel 19. The marker cable bracket 13 is made of alloy steel plate and is welded and fixed to the bottom support 14. The bow and stern of the first test vessel 18 are respectively connected to the first anchor chain 20 and the second anchor chain 21. The first anchor chain 20 and the second anchor chain 21 are fixed in the seabed by the first anchor claw 22 and the second anchor claw 23 respectively (the seabed is used as an example in this embodiment, but it can also be a riverbed).

[0036] Reference Figures 2-6As shown, three hook rings are pre-welded to the outer wall of the test pile 1. These three hook rings are on the same horizontal plane. One end of the first loading cable 2, the second loading cable 3, and the third loading cable 4 are connected to the three hook rings on the outer wall of the test pile 1 via a metal connecting buckle 17. The first loading cable 2 and the third loading cable 4 are tangent to the outer wall of the test pile 1, and the extension of the second loading cable 3 passes through the center of the test pile 1 on the same horizontal plane. In actual testing, depending on special circumstances, the angle between the lines connecting the two outer hook rings and the center can be selected to be 90°~150°. The first adjustable triangular bracket 11 and the second adjustable triangular bracket 12 are each provided with three support legs. The projections of the three support legs on the horizontal plane form a 120° angle. The three support legs of the first adjustable triangular bracket 11 fix the first fixed pulley support 9 at different heights by opening or closing, so that the section of the force transmission cable 5 passing through the first fixed pulley 7 and connected to the first loading cable 2, the second loading cable 3, and the third loading cable 4 remains horizontal. The three support legs of the second adjustable triangular bracket 12 fix the second fixed pulley support 10 at different heights by opening or closing, so that the large-tonnage high-precision force gauge 16 and the marking cable 6 also remain horizontal after being connected to the large-tonnage electric winch 15 or the second backup test vessel 19. After fixing the opening angle of each support leg, the bottom end of the support leg is connected and fixed to the bottom support 14 by bolts. Both the first fixed pulley support 9 and the second fixed pulley support 10 are circular. The first fixed pulley 7 is fixed at the center of the first fixed pulley support 9. The first fixed pulley support 9 has an eccentric circular hole 24. The position of the eccentric circular hole 24 is slightly off from the center of the first fixed pulley support 9, so that the force transmission cable 5 passes through the eccentric circular hole 24 after passing over the first fixed pulley 7. The circular hole 24 is in the same vertical plane as one of the three support legs, and the other two support legs are distributed on the first fixed pulley support. On both sides of the center of the 9th cable (to ensure greater stability under tension); a through hole 26 is also reserved in the center of the marking cable bracket 13; the diameter of the eccentric hole 24 is slightly larger than the diameter of the force transmission cable 5, and the diameter of the through hole 26 is slightly larger than the diameter of the marking cable 6, so that the respective cables can pass through and ensure that they will not be resisted by the wall of the hole during cable movement; the marking cable 6 is also marked with scale lines, and the horizontal displacement of the marking cable 6 can be read directly at the through hole 26 of the marking cable bracket 13.

[0037] The first loading cable 2, the second loading cable 3, the third loading cable 4, the force transmission cable 5, and the marking cable 6 are all made of high-strength steel strand and can be braided into cables of different diameters. Based on the ultimate bearing capacity of the test piles in the project, the ultimate tensile strength of the cables is calculated, and cables of the corresponding diameters are prefabricated.

[0038] The large-tonnage electric winch 15 and the second backup test vessel 19 are used to provide horizontal force for the test pile 1. The large-tonnage electric winch 15 is used to provide horizontal force for the test pile 11 with low bearing capacity, while the second backup test vessel 19 is used to provide horizontal force for the test pile 11 with high bearing capacity.

[0039] The first anchor chain 20, the second anchor chain 21, the first anchor claw 22, and the second anchor claw 23 are all made of heavy anchors selected according to the specifications of the test vessel, to ensure that the first test vessel 18 is stably moored at sea.

[0040] Example 1:

[0041] For pile foundations with smaller pile diameters and lower ultimate bearing capacities, a method for testing the horizontal bearing capacity of pile foundations using a large-tonnage electric winch in the testing device and the aforementioned underwater large-diameter high pile foundation horizontal bearing capacity testing device includes the following steps:

[0042] (1) Preliminary preparation: Design test scheme and corresponding test equipment according to the specifications of the pile to be tested and the bearing capacity requirements. Prefabricate and prepare the corresponding first loading cable 2, second loading cable 3, third loading cable 4, force transmission cable 5, marking cable 6, first fixed pulley 7, second fixed pulley 8, first fixed pulley support 9, second fixed pulley support 10, first adjustable triangular bracket 11, second adjustable triangular bracket 12, marking cable bracket 13, bottom support 14, large tonnage electric winch 15, large tonnage high precision force gauge 16, first test ship 18, first anchor chain 20, second anchor chain 21, first anchor claw 22, second anchor claw 23 and other test equipment;

[0043] (2) Docking of the test vessel: In this embodiment, taking the sea area as an example, the first test vessel 18 is used to transport the testing device to the vicinity of the test pile 1. According to the engineering requirements and the loading direction of the design, the first anchor chain 20, the second anchor chain 21, the first anchor claw 22, and the second anchor claw 23 are used to steadily dock the first test vessel 18 at a distance of 5 times the pile diameter from the test pile 1.

[0044] (3) Device setup: First, the bottom support 14 is fixed to the hull plate of the first test vessel 18 by bolts 25. Then, one end of the first loading cable 2, the second loading cable 3, and the third loading cable 4 are connected to the outer wall of the pile to be tested 1 by metal connecting buckles 17. One end of the force transmission cable 5 is connected to the first loading cable 2, the second loading cable 3, and the third loading cable 4, and the other end passes through the first fixed pulley 7 and the second fixed pulley 8 and is connected to the high-tonnage high-precision force gauge 16. The first adjustable triangular bracket 11 is adjusted so that it passes through the first fixed pulley 7 and is connected to the first loading cable 16. The section connecting the load cable 2, the second load cable 3, and the third load cable 4 remains horizontal; the other end of the high-tonnage high-precision force gauge 16 is connected to one end of the marking cable 6, and the other end of the marking cable 6 passes through the center hole of the marking cable bracket 13 and is connected to the high-tonnage electric winch 15. The second adjustable triangular bracket 12 is adjusted so that the high-tonnage high-precision force gauge 16 and the marking cable 6 remain horizontal after being connected to the high-tonnage electric winch 15; finally, the first adjustable triangular bracket 11 and the second adjustable triangular bracket 12 are fixed to the bottom support 14 by bolts 25.

[0045] (4) Start the test: After the testing device is set up, record the initial tension value of the high-precision force gauge 16 and the initial scale value of the marker cable 6 at the center of the marker cable bracket 13; start the test by opening the high-precision electric winch 15 to tension the marker cable 6 to provide the horizontal force required for the test, and gradually load it in stages. At the same time, record the horizontal tension value measured by the high-precision force gauge 16 under each load level and the scale value of the marker cable 6 at the through hole 26 of the marker cable bracket 13.

[0046] (5) Follow-up work: After the test, process the raw data obtained from the test. The horizontal tension measured by the high-tonnage high-precision force gauge 16 is the horizontal force on the test pile 1. The difference in the scale value of the marked cable 6 is the horizontal displacement generated by the tension point of the test pile 1. Draw and analyze the load-displacement curve, evaluate the ultimate bearing capacity of the pile foundation, recover the equipment, and complete the test of the horizontal bearing capacity of the marine pile foundation.

[0047] Example 2:

[0048] For pile foundations with very large pile diameters and large ultimate bearing capacities, another method for testing the horizontal bearing capacity of pile foundations using the aforementioned floating large-diameter high pile foundation horizontal bearing capacity testing device, with the second backup test vessel in the testing apparatus applying the load, includes the following steps:

[0049] (1) Preliminary preparation: Design a test plan and corresponding test equipment according to the specifications of the pile to be tested and the bearing capacity requirements. Prefabricate and prepare the following test equipment: first loading cable 2, second loading cable 3, third loading cable 4, force transmission cable 5, marking cable 6, first fixed pulley 7, second fixed pulley 8, first fixed pulley support 9, second fixed pulley support 10, first adjustable triangular bracket 11, second adjustable triangular bracket 12, marking cable bracket 13, bottom support 14, large tonnage high precision force gauge 16, first test vessel 18, second spare test vessel 19, first anchor chain 20, second anchor chain 21, first anchor claw 22, second anchor claw 23, etc.

[0050] (2) Docking of the test vessel: In this embodiment, the sea area is still taken as an example. The first test vessel 18 is used to transport the testing device to the vicinity of the test pile 1. According to the engineering requirements and the loading direction of the design, the first anchor chain 20, the second anchor chain 21, the first anchor claw 22, and the second anchor claw 23 are used to steadily dock the first test vessel 18 at a distance of 3 times the pile diameter from the test pile 1.

[0051] (3) Device setup: First, the bottom support 14 is fixed to the hull plate of the first test vessel 18 by bolts 25. Then, one end of the first loading cable 2, the second loading cable 3, and the third loading cable 4 are respectively connected to the outer wall of the pile to be tested 1 by metal connecting buckles 17. One end of the force transmission cable 5 is connected to the first loading cable 2, the second loading cable 3, and the third loading cable 4, and the other end passes around the first fixed pulley 7 and the second fixed pulley 8 and is connected to the high-tonnage high-precision force gauge 16. The first adjustable triangular bracket 11 is adjusted so that it passes through the first fixed pulley 7 and is connected to the first fixed pulley 8. The section connecting loading cable 2, second loading cable 3, and third loading cable 4 is kept horizontal; the other end of the high-tonnage high-precision force gauge 16 is connected to one end of the marking cable 6, and the other end of the marking cable 6 passes through the center hole of the marking cable bracket 13 and is connected to the second backup test vessel 19. The second adjustable triangular bracket 12 is adjusted so that the high-tonnage high-precision force gauge 16 and the marking cable 6 are also kept horizontal after being connected to the second backup test vessel 19; finally, the first adjustable triangular bracket 11 and the second adjustable triangular bracket 12 are fixed to the bottom support 14 by bolts 25.

[0052] (4) Start the test: After the testing device is set up, record the initial tension value of the high-precision force gauge 16 and the initial scale value of the marker cable 6 at the center of the marker cable bracket 13; start the test by activating the second backup test ship 19 to tension the marker cable 6 to provide the horizontal force required for the test, and perform progressive loading. At the same time, record the horizontal tension value measured by the high-precision force gauge 16 under each load level and the scale value of the marker cable 6 at the through hole 26 of the marker cable bracket 13.

[0053] (5) Follow-up work: After the test, process the raw data obtained from the test. The horizontal tension measured by the high-tonnage high-precision force gauge 16 is the horizontal force on the test pile 1. The difference in the scale value of the marked cable 6 is the horizontal displacement generated by the tension point of the test pile 1. Draw and analyze the load-displacement curve, evaluate the ultimate bearing capacity of the pile foundation, recover the equipment, and complete the test of the horizontal bearing capacity of the marine pile foundation.

[0054] This invention is not limited to the applications listed in the specification and embodiments. For those skilled in the art, various corresponding modifications and variations can be made according to this invention, and all such modifications and variations fall within the protection scope of the claims of this invention.

Claims

1. A device for testing the horizontal bearing capacity of large-diameter high pile foundations on water, arranged near the pile to be tested, characterized in that, The system includes at least a first loading cable, a second loading cable, a third loading cable, a force transmission cable, a marking cable, a first fixed pulley, a second fixed pulley, a first fixed pulley support, a second fixed pulley support, a first adjustable triangular bracket, a second adjustable triangular bracket, a marking cable support, a bottom support, a high-tonnage high-precision force gauge, a first test vessel, a first anchor chain, a second anchor chain, a first anchor claw, and a second anchor claw. One end of the first, second, and third loading cables is connected to different points on the outer wall of the test pile, and the other ends of the first, second, and third loading cables converge and are connected to one end of the force transmission cable. The first fixed pulley is fixed to the upper end of the first fixed pulley support, the first fixed pulley support is fixed to the top of the first adjustable triangular bracket, and the second fixed pulley is fixed to the second fixed pulley support. At the upper end of the base, the second fixed pulley support is fixed to the top of the second adjustable triangular bracket. The bottom ends of the first and second adjustable triangular brackets are connected to the bottom support, which is installed on the hull of the first test vessel. The other end of the force transmission cable passes around the first and second fixed pulleys in sequence and is then connected to one end of the high-tonnage high-precision force gauge through a metal connecting buckle. The other end of the high-tonnage high-precision force gauge is connected to one end of the marking cable through the metal connecting buckle. The other end of the marking cable passes through the marking cable bracket and is connected to the high-tonnage electric winch or the second backup test vessel. The bow and stern of the first test vessel are respectively connected to the first anchor chain and the second anchor chain. The first anchor chain and the second anchor chain are respectively fixed to the seabed or riverbed by the first anchor claw and the second anchor claw.

2. The device for testing the horizontal bearing capacity of large-diameter high pile foundations on water according to claim 1, characterized in that, Three hook rings are pre-welded to the outer wall of the test pile. The three hook rings are on the same horizontal plane. One end of the first loading cable, the second loading cable, and the third loading cable are respectively connected to the three hook rings through a metal connecting buckle. The three points are on the same horizontal plane.

3. The device for testing the horizontal bearing capacity of large-diameter high pile foundations on water according to claim 1, characterized in that, The first and third loading cables are both tangent to the outer wall of the test pile, and the extension of the second loading cable passes through the center of the test pile on the same horizontal plane.

4. The device for testing the horizontal bearing capacity of large-diameter high pile foundations on water according to claim 1, characterized in that, The center of the marking cable bracket has a pre-drilled circular hole, the diameter of which is slightly larger than the diameter of the marking cable, so that the marking cable can pass through the marking cable bracket and ensure that the marking cable will not be subject to resistance from the marking cable bracket during horizontal movement; the marking cable is marked with scale lines for directly reading the horizontal displacement of the marking cable at the circular hole of the marking cable bracket.

5. The device for testing the horizontal bearing capacity of large-diameter high pile foundations on water according to claim 1, characterized in that, The first loading cable, the second loading cable, the third loading cable, the force transmission cable, and the marking cable are all made of high-strength steel strand.

6. The device for testing the horizontal bearing capacity of large-diameter high pile foundations on water according to claim 1, characterized in that, The first and second adjustable triangular supports are each equipped with three support legs, and the projections of the three support legs on the horizontal plane form a 120° angle. The three support legs of the first adjustable triangular support fix the first fixed pulley support at different heights by opening or closing, so that the section of the force transmission cable passing through the first fixed pulley and connected to the first loading cable, the second loading cable, and the third loading cable remains horizontal. The three support legs of the second adjustable triangular support fix the second fixed pulley support at different heights by opening or closing, so that the large-tonnage high-precision force gauge and the marking cable also remain horizontal after being connected to the large-tonnage electric winch or the second backup test vessel. After fixing the opening angle of each support leg, the bottom end of the support leg is connected and fixed to the bottom support by bolts.

7. The device for testing the horizontal bearing capacity of large-diameter high pile foundations on water according to claim 1, characterized in that, Both the first and second fixed pulley supports are circular. The first fixed pulley support has an eccentric circular hole. The first fixed pulley is fixed at the center of the first fixed pulley support. The position of the eccentric circular hole is offset from the center of the first fixed pulley support, so that the force transmission cable passes through the eccentric circular hole after passing around the first fixed pulley. The eccentric circular hole is in the same vertical plane as one of the three support legs, and the other two support legs are distributed on both sides of the center of the first fixed pulley support.

8. The device for testing the horizontal bearing capacity of large-diameter high pile foundations on water according to claim 1, characterized in that, The bottom support is fixed to the first test vessel's hull plate by bolts, and the marking cable bracket is made of alloy steel plate and is welded and fixed to the bottom support.

9. A method for testing the horizontal bearing capacity of a large-diameter high pile foundation on water using the testing device for testing the horizontal bearing capacity of a pile foundation on water as described in any one of claims 1 to 8, characterized in that, Includes the following steps: (1) Preliminary preparation: Design a test plan and corresponding test equipment according to the specifications of the pile to be tested and the bearing capacity requirements. Prefabricate and prepare the following: first loading cable, second loading cable, third loading cable, force transmission cable, marking cable, first fixed pulley, second fixed pulley, first fixed pulley support, second fixed pulley support, first adjustable triangular bracket, second adjustable triangular bracket, marking cable bracket, bottom support, large-tonnage electric winch, large-tonnage high-precision force gauge, first test vessel, second spare test vessel, first anchor chain, second anchor chain, first anchor claw, second anchor claw; (2) Docking of the test vessel: The testing device arranged on the first test vessel is transported to the vicinity of the water area to be tested using the first test vessel. According to the engineering requirements and the loading direction of the design, the first anchor chain, the second anchor chain and the first anchor claw and the second anchor claw are used to stably dock the first test vessel at a position 2-5 times the pile diameter away from the pile to be tested. (3) Device Setup: First, the bottom support is fixed to the hull plate of the first test vessel using bolts. Then, one end of the first loading cable, the second loading cable, and the third loading cable are connected to the outer wall of the pile to be tested using the metal connecting buckle. One end of the force transmission cable is connected to the other end of the first loading cable, the second loading cable, and the third loading cable. The other end of the force transmission cable passes around the first fixed pulley and the second fixed pulley and is connected to the high-tonnage high-precision force gauge. The first adjustable triangular bracket is adjusted so that it passes through the first fixed pulley and connects with the first loading cable, The section connecting the second and third loading cables remains horizontal; the other end of the high-tonnage high-precision force gauge is connected to one end of the marking cable, and the other end of the marking cable passes through the center hole of the marking cable bracket and connects to the high-tonnage electric winch or the second backup test vessel. The second adjustable triangular bracket is adjusted so that the high-tonnage high-precision force gauge and the marking cable remain horizontal after being connected to the high-tonnage electric winch or the second backup test vessel; finally, the first and second adjustable triangular brackets are fixed to the bottom support with bolts. (4) Start the test: After the detection device is set up, record the initial tension value of the large-tonnage high-precision force gauge and the initial scale value of the marking cable at the center of the marking cable bracket; start the test by opening the large-tonnage electric winch or starting the second backup test ship to tension the marking cable to provide the horizontal force required for the test, and perform progressively graded loading, while recording the horizontal tension value measured by the large-tonnage high-precision force gauge and the scale value of the marking cable at the through hole of the marking cable bracket under each load level; (5) Follow-up work: After the test, process the raw data obtained from the test. The horizontal tension measured by the large-tonnage high-precision force gauge is the horizontal force on the test pile. The difference in the scale value of the marking cable is the horizontal displacement of the test pile. Plot and analyze the load-displacement curve, evaluate the ultimate bearing capacity of the pile foundation, recover the equipment, and complete the test of the horizontal bearing capacity of the marine pile foundation.

10. A method for testing the horizontal bearing capacity of large-diameter high pile foundations on water using a testing device according to claim 9, characterized in that, In step (3), the large-tonnage electric winch and the second backup test vessel are used to provide horizontal force for the test pile. For test piles with low bearing capacity, the large-tonnage electric winch is used to provide horizontal force, and for test piles with high bearing capacity, the second backup test vessel is used to provide horizontal force.

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