In-situ standard penetration test device

Abstract

The utility model discloses an in-situ standard penetration test device, and relates to the field of standard penetration tests. The device comprises a penetrometer; the sleeve is connected with the penetrometer, and a guide groove is formed in the sleeve; the piercing hammer is positioned in the guide groove and can slide along the guide groove; the automatic unhooking mechanism is located in the guide groove and used for lifting the piercing hammer to a certain height and then releasing the piercing hammer; the hoisting mechanism is used for driving the automatic unhooking mechanism to move up and down; and the guide rod is vertically arranged in the guide groove and is used for ensuring that the piercing hammer is kept vertical in the falling process. The device has the beneficial effects that hammering energy is transmitted to a test soil layer through a rod piece system, and the connection time of rod pieces affects the test implementation efficiency; therefore, according to the scheme, the hammering device and the penetrometer are directly hoisted to the test position by adopting the flexible rope, so that the test installation time is saved.

Description

Technical Field

[0001] This utility model relates to the field of standard penetration testing, specifically to an in-situ standard penetration testing device. Background Technology

[0002] The standard penetration test (SPT) is a type of dynamic penetration test used to determine the bearing capacity of sandy or cohesive soil foundations in situ. This method is included in China's national standard, the "Code for Design of Foundations of Industrial and Civil Buildings." It utilizes a hammer (63.5 kg hammer weight, 76 cm drop height) to drive a split-tube penetrometer (51 mm outer diameter, 35 mm inner diameter, length greater than 457 mm, with a 76 mm long, 18°–20° cutting edge, and 1.6 mm thick cutting edge shoe at the lower end, and a drill rod at the upper end) into the soil at the bottom of the borehole. The penetration resistance in the soil is used to determine changes in the soil layers and the soil's engineering properties.

[0003] However, the lowering and raising of the penetrator in the existing standard penetration test takes a long time, resulting in low efficiency and increased testing costs. As the depth increases, the mass and number of joints in the force transmission system also increase. Affected by factors such as energy dissipation of the force transmission system, drilling verticality, and joint tightness, the N value exhibits significant dispersion.

[0004] Existing Chinese patent CN114894638A relates to a standard penetration test device. This device involves placing the standard penetration test apparatus within a sealed sleeve, with the standard penetration head located at the bottom of the sleeve. In use, a lifting mechanism first lowers the sealed sleeve and the standard penetration head to the bottom of the penetration hole; a conveying mechanism then lifts the mandrel, releasing it after it reaches a certain height, allowing it to fall freely onto the hammer pad. Its beneficial effect is to solve the problem in related technologies where most of the energy of the impact hammer is lost in the drill pipe, leading to inaccurate test results.

[0005] While existing technologies have solved the problem that most of the energy of current impact hammers is lost in the drill pipe, leading to inaccurate test results, they still require a lifting mechanism to place the sealing sleeve, and then a transmission mechanism located inside the sleeve to lift the mandrel. This increases the difficulty of manufacturing and maintenance, and also raises costs. Summary of the Invention

[0006] The purpose of this invention is to provide an in-situ standard penetration test device to address the problems in the existing technology, such as the long time required for lowering and raising the rod and the large dispersion of the N value when the rod is long.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: an in-situ standard penetration test device, comprising:

[0008] Penetrator,

[0009] A sleeve is connected to the penetrator, and a guide groove is provided inside the sleeve;

[0010] The through-hole hammer is located inside the guide groove and can slide along the guide groove;

[0011] An automatic unhooking mechanism, located in the guide groove, is used to lift the hammer to a certain height and then release it;

[0012] The winch mechanism is used to drive the automatic unhooking mechanism to move up and down;

[0013] The guide rod is vertically installed in the guide groove to ensure that the hammer remains vertical during its descent.

[0014] The sleeve and guide groove design ensure that the hammer maintains a stable track and orientation during the test, thereby improving the reliability of the test results.

[0015] The application of automatic unhooking and hoisting mechanisms makes the testing operation more automated, reduces the complexity of manual operation, and improves the efficiency of the test.

[0016] Furthermore, a through hole is provided on the center line of the hammer for the guide rod to pass through, and several vent holes are evenly provided on the outer wall of the hammer.

[0017] Furthermore, a hammer pad is installed at one end of the guide groove near the penetrator.

[0018] Furthermore, an end cap is installed at the top of the sleeve, and the end cap is provided with a lifting hole connected to the guide groove.

[0019] Furthermore, the hoisting mechanism includes

[0020] tripod;

[0021] The motor is mounted on the top of the tripod and serves as the power output terminal;

[0022] The rope is connected at both ends to a motor and an automatic unhooking mechanism, respectively.

[0023] A check block, installed on the rope, is used to limit the position of the automatic unhooking mechanism.

[0024] Furthermore, it also includes a distance measuring device for measuring the standard penetration depth, the distance measuring device comprising...

[0025] The roller is installed on the output end of the motor and rotates as the rope is wound up and down;

[0026] An angle recorder, mounted on the roller, is used to record the rotation angle of the roller;

[0027] The push-button switch, installed on the check block, is used to control the opening and closing of the angle recorder;

[0028] The processor, mounted on the tripod, is used to convert the data from the angle recorder into rope release and take-up lengths and record them.

[0029] The recording switch, installed on the inner wall of the sleeve, is used to control the processor to record data.

[0030] Furthermore, the recording switch is installed 76cm from the bottom of the guide groove. Each time the hammer strikes, the automatic disengagement mechanism will pass through this 76cm point.

[0031] Furthermore, the sleeve sidewall is provided with a maintenance window for maintaining the recording switch.

[0032] After adopting the above technical solution, the beneficial effects of this utility model are as follows:

[0033] The standard penetration test is conducted by simply placing the sleeve and lifting the mandrel using a winch mechanism. The simple structure makes maintenance easier.

[0034] The hammering energy is transferred to the test soil layer through the rod system, and the connection time of the rods affects the efficiency of the test. Therefore, this scheme uses flexible ropes to directly hoist the hammering device and penetrator to the test position to save test installation time.

[0035] As the test depth increases, the test energy applied to the soil and rock layer becomes unstable due to the tightness and verticality of the rod connections. This solution encloses the hammer in a sleeve with an automatic unhooking device inside, allowing the hammering energy to directly apply to the soil and rock layer at the test location, ensuring that the energy is equal for each test at different depths. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the structure of this utility model.

[0038] Figure 2 This is a schematic diagram of the sleeve structure in this utility model.

[0039] Figure 3 This is a cross-sectional schematic diagram of the sleeve in this utility model.

[0040] Figure 4 This is a schematic diagram of the mandrel in this utility model.

[0041] Explanation of reference numerals in the attached drawings: 1. Penetrator; 2. Sleeve; 21. End cap; 21. Lifting hole; 22. Inspection window; 23. Guide groove; 3. Through hammer; 31. Through hole; 32. Vent hole; 4. Automatic unhooking mechanism; 5. Hoisting mechanism; 51. Tripod; 52. Motor; 53. Rope; 54. Check block; 6. Guide rod; 7. Hammer pad; 8. Distance measuring device; 81. Roller; 82. Angle recorder; 83. Press switch; 84. Processor; 85. Recording switch. Detailed Implementation

[0042] See Figure 1-4 As shown, the technical solution adopted in this specific embodiment is: an in-situ standard penetration test device, which includes:

[0043] Penetrator 1,

[0044] Sleeve 2 is connected to penetrator 1, and guide groove 23 is provided inside sleeve 2; the length of guide groove 23 is greater than 90cm;

[0045] The hammer 3 is located in the guide groove 23 and can slide along the guide groove 23; the hammer 3 weighs 63.5 kg.

[0046] The automatic release mechanism 4, located in the guide groove 23, is used to lift the mandrel 3 to a height of 76cm from the bottom of the guide groove 23 and then release it; ensuring that the mandrel 3 is automatically released at a height of 76cm, thereby ensuring the accuracy and repeatability of the test;

[0047] The hoisting mechanism 5 is used to drive the automatic unhooking mechanism 4 to move up and down.

[0048] The guide rod 6 is vertically installed in the guide groove 23 to ensure that the hammer 3 remains vertical during its descent, thereby improving the accuracy of the test data.

[0049] The sleeve 2 and guide groove 23 are designed to ensure that the hammer 3 maintains a stable track and orientation during the test, thereby improving the reliability of the test results.

[0050] The application of the automatic unhooking mechanism 4 and the hoisting mechanism 5 makes the test operation more automated, reduces the complexity of manual operation, and improves the efficiency of the test.

[0051] In the specific process, the winch mechanism 5 is moved above the borehole, and then the sleeve 2 is hoisted to the test position. Then, the automatic release mechanism 4 moves downward to grab the mandrel 3 and brings it to a distance of 76cm from the bottom of the guide groove 23 before releasing the lock, allowing the mandrel 3 to fall and strike the sleeve 2. The distance measuring device 8 records the length of the rope 53 when the sleeve 2 is lowered to the test position and the distance the sleeve 2 is driven into the soil after each strike.

[0052] In a specific embodiment, a through hole 31 is provided on the center line of the hammer 3 for the guide rod 6 to pass through, which can ensure that the hammer 3 remains vertical during the fall and improve the accuracy of the test. Several exhaust holes 32 are evenly provided on the outer wall of the hammer 3, which helps to reduce the air resistance when the hammer 3 falls, thereby making the test data more accurate. It can also effectively prevent the influence of vacuum effect on the test data and ensure the reliability of the test results.

[0053] In a specific embodiment, a hammer pad 7 is installed at one end of the guide groove 23 near the penetrator 1. In standard penetration tests (SPTs), the hammer pad 7 is typically used as a damping and protective device. Located at the bottom of the guide groove 23, its main function is to reduce damage to the testing equipment during impact, while also mitigating the additional impact on the foundation. The hammer pad 7 helps to evenly distribute the impact force, reduce unnecessary vibration, and ensure the accuracy and reliability of the SPT.

[0054] In a specific embodiment, an end cap 21 is installed at the top of the sleeve 2, and the end cap 21 is provided with a lifting hole 211 that connects to the guide groove 23. The end cap 21 allows the user to easily install, disassemble, or adjust the automatic unhooking mechanism 4, improving the convenience and efficiency of operation.

[0055] In a specific embodiment, the hoisting mechanism 5 includes

[0056] Tripod 51; As the supporting part of the mechanism, tripod 51 can provide stable support, ensuring that the entire hoisting mechanism 5 will not shake or tilt during operation, thus improving safety and stability.

[0057] Motor 52 is installed at the top of tripod 51 as a power output end; as a power output end, motor 52 can provide sufficient power to rope 53 so that it can smoothly lift or lower heavy objects.

[0058] Rope 53, with its two ends connected to motor 52 and automatic unhooking mechanism 4 respectively;

[0059] The check block 54 is installed on the rope 53 to limit the position of the automatic unhooking mechanism 4. The setting of the check block 54 can limit the position of the rope 53, ensure safety during the lifting process, and prevent the sleeve 2 from colliding with the motor 52.

[0060] In the actual operation, the tripod 51 is moved above the borehole, and then the motor 52 rotates to lower the sleeve 2 to the test position. The motor 52 continues to run until the automatic release mechanism 4 grabs the mandrel 3. Then, the motor 52 reverses to lift the mandrel 3 upwards. When it reaches a certain height, the automatic release mechanism 4 releases its grip on the mandrel 3. The motor 52 then reverses again to grab the mandrel 3 from below, repeating the above steps until the standard penetration test is completed. After the standard penetration test is completed, the motor 52 reverses to lift the sleeve 2 from the test position until the check block 54 abuts against the motor 52.

[0061] In a specific embodiment, it further includes a distance measuring device 8 for measuring the standard penetration depth, the distance measuring device 8 comprising:

[0062] Roller 81 is installed on the output end of motor 52 and rotates as rope 53 is wound up and down;

[0063] An angle recorder 82 is mounted on the roller 81 to record the rotation angle of the roller 81;

[0064] The push switch 83, installed on the check block 54, is used to control the opening and closing of the angle recorder 82; it realizes the automated control of the measurement process, simplifies the operation process, and improves work efficiency.

[0065] The processor 84, mounted on the tripod 51, is used to convert the data from the angle recorder 82 into the length of the rope 53 and record it; it realizes the data processing and recording functions, which facilitates subsequent data analysis and management.

[0066] Recording switch 85, installed on the inner wall of sleeve 2, is used to control processor 84 to record data.

[0067] The roller 81 is installed at the output end of the motor 52 and rotates as the rope 53 is wound up and down. The rotation angle of the roller 81 is recorded by the angle recorder 82, which can accurately measure the winding and unwinding length of the rope 53 and improve the accuracy of the measurement.

[0068] In the specific process, the motor 52 activates the check block 54 to release its contact with the motor 52, and the push switch 83 activates the angle recorder 82. The angle recorder 82 transmits the data to the processor 84, which converts the data from the angle recorder 82 into the length of the rope 53 as it is lowered. When the automatic release mechanism 4 passes the recording switch 85, the processor 84 records the length of the rope 53 at that moment. Since each hammer blow to the automatic release mechanism 4 requires passing through the recording switch 85, and the recording switch 85 is installed on the inner wall of the sleeve 2, the recording switch 85 moves downward as the penetrometer 1 is driven into the soil, thus obtaining the depth of the penetrometer 1 driven into the soil with each hammer blow.

[0069] The distance measuring device 8 has the advantages of precise measurement, automated control, data processing and recording, convenient operation and comprehensive functions. It is suitable for various scenarios that require measuring the standard penetration depth, and improves the accuracy and efficiency of measurement.

[0070] In a specific embodiment, the recording switch 85 is installed 76cm from the bottom of the guide groove 23. Each time the automatic disengagement mechanism 4 is struck, it will pass through this 76cm distance.

[0071] In a specific embodiment, the sleeve 2 is provided with a maintenance window 22 for maintaining the recording switch 85.

[0072] The working principle of this utility model:

[0073] The first step is to move the in-situ standard penetration test device above the borehole and install the penetrator 1 on the sleeve 2.

[0074] The second step involves using a flexible rope 53 to lower the in-situ standard penetration test device to the test position, eliminating the need for a rod-based force transmission system between the drop hammer and the penetrometer 1, thus saving operation time associated with connecting the rods. During the lowering process, the check block 54 is disconnected from the motor 52, and the push-button switch 83 mounted on the check block 54 is activated. The angle recorder 82 begins recording the rotation angle of the roller 81 and transmits it to the processor 84, which converts the rotation angle into the length of the lowered rope 53.

[0075] In the third step, after the drill bit 1 reaches the bottom of the borehole, the automatic unhooking mechanism 4 continues to move downward along the sleeve 2. When the automatic unhooking mechanism 4 passes the recording switch 85, the recording switch 85 is turned on, and the processor 84 records the length of the rope 53 that has been lowered.

[0076] In the fourth step, the automatic unhooking mechanism 4 continues to descend along the sleeve 2 until it comes into contact with and grabs the hammer 3. Then, the motor 52 reverses to lift the automatic unhooking mechanism 4 and the hammer 3 to a predetermined height. Once the predetermined height is reached, the automatic unhooking mechanism 4 releases its lock on the hammer 3, and the hammer 3 falls freely to strike the sleeve 2. During the lifting process of the automatic unhooking mechanism 4, it will pass through the recording switch 85 again, and the processor 84 will record the length of the rope 53 as it descends.

[0077] Fifth, repeat the operation of step four until the penetrometer 1 is driven into the soil by 15cm, that is, the latest length of rope 53 recorded by processor 84 is 15cm longer than the first recorded length.

[0078] Step 6: Start recording the number of hammer blows for every 10cm penetration. The total number of hammer blows for a 30cm penetration is the standard penetration test hammer blow count N.

[0079] The above description is only used to illustrate the technical solution of this utility model and is not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solution of this utility model, as long as they do not depart from the spirit and scope of the technical solution of this utility model, should be covered within the scope of the claims of this utility model.

Claims

1. An in-situ standard penetration test apparatus, characterized in that: It includes Penetrator (1), Sleeve (2) is connected to penetrator (1), and guide groove (23) is provided inside sleeve (2); The through-hole hammer (3) is located in the guide groove (23) and can slide along the guide groove (23); An automatic unhooking mechanism (4) is located in the guide groove (23) and is used to lift the mandrel (3) to a certain height and then release it; The hoisting mechanism (5) is used to drive the automatic unhooking mechanism (4) to move up and down; The guide rod (6) is vertically set in the guide groove (23) to ensure that the hammer (3) remains vertical during the fall.

2. An in-situ standard penetration test apparatus according to claim 1, wherein: The center line of the hammer (3) is provided with a through hole (31) through which the guide rod (6) passes, and a number of exhaust holes (32) are evenly provided on the outer wall of the hammer (3).

3. An in-situ standard penetration test apparatus according to claim 1, wherein: A hammer pad (7) is installed at one end of the guide groove (23) near the penetrator (1).

4. An in-situ standard penetration test apparatus according to claim 1, wherein: The top of the sleeve (2) is fitted with an end cap (21), and the end cap (21) is provided with a lifting hole (211) that is connected to the guide groove (23).

5. An in-situ standard penetration test apparatus as claimed in claim 1, wherein: The hoisting mechanism (5) includes Tripod (51); The motor (52) is mounted on the top of the tripod (51) as the power output end; The rope (53) is connected at both ends to the motor (52) and the automatic unhooking mechanism (4); A check block (54) is installed on the rope (53) to limit the position of the automatic unhooking mechanism (4).

6. An in-situ standard penetration test apparatus as claimed in claim 1, wherein: It also includes a distance measuring device (8) for measuring the standard penetration depth, the distance measuring device (8) comprising: The roller (81) is installed on the output end of the motor (52) and rotates as the rope (53) is wound up and down; An angle recorder (82) is mounted on a roller (81) to record the rotation angle of the roller (81); A push switch (83) is installed on the check block (54) and is used to control the opening and closing of the angle recorder (82); A processor (84), mounted on a tripod (51), is used to convert and record the data from the angle recorder (82) into the length of the rope (53) for release and take-off. A recording switch (85) is installed on the inner wall of the sleeve (2) to control the processor (84) to record data.

7. An in-situ standard penetration test apparatus as claimed in claim 6, wherein: The recording switch (85) is installed 76 cm from the bottom of the guide groove (23).

8. An in-situ standard penetration test apparatus as claimed in claim 1, wherein: The sleeve (2) has a maintenance window (22) on its side wall for maintaining the recording switch (85).

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