Dynamic sounding device for testing bearing capacity of deep soil layer
By using a guiding mechanism and a closed-loop control system, the problems of energy loss and drop distance error caused by probe deflection were solved, enabling efficient and accurate testing of the bearing capacity of deep soil layers.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA RAILWAY SEVENTH GRP CO LTD
- Filing Date
- 2026-02-11
- Publication Date
- 2026-04-10
AI Technical Summary
In existing technologies, the low energy transfer efficiency and poor drop height control accuracy caused by excessively long probes affect the accuracy and reliability of deep soil bearing capacity testing.
The system employs a guiding mechanism and a closed-loop control system. The guide wheel of the guiding mechanism works in conjunction with the pre-embedded guide tube to ensure the verticality of the probe rod. Combined with a laser rangefinder sensor, it achieves precise control of the drop distance, thereby improving energy transfer efficiency and testing accuracy.
It effectively improves energy transfer efficiency, ensures the reliability and repeatability of test data, and reduces the labor intensity and safety risks for operators.
Smart Images
Figure CN121827301A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of geotechnical engineering investigation technology, and in particular to a dynamic penetration test device for testing the bearing capacity of deep soil layers. Background Technology
[0002] Dynamic penetration testing (DPPT) is an important in-situ testing method used in geotechnical engineering investigation to determine the mechanical properties of soil layers. A heavy dynamic penetration test typically consists of a probe, a penetration rod, and a hammer. During the test, a 63.5 kg hammer is raised to a fixed height of 0.76 m and then allowed to fall freely, striking the penetration rod and transferring the impact energy to the soil layer. The bearing capacity of the soil layer is evaluated based on the number of blows required for the probe to penetrate to a certain depth.
[0003] However, when the testing depth is large, existing technologies face two prominent technical bottlenecks: First, there is the problem of a sharp decline in energy transfer efficiency due to the excessive length of the probe system. This problem stems from two aspects: First, the unavoidable theoretical attenuation, meaning that when impact energy is transmitted as stress waves in a long probe, it naturally attenuates due to internal material friction. Second, and more seriously, unnecessary losses: in deep holes, slender probes are prone to bending and tilting due to their own weight and the unevenness of the soil layers, leading to continuous collisions and friction between the probe and the borehole wall. This non-ideal tilt not only consumes a large amount of impact energy but also severely exacerbates the scattering and distortion of stress waves, resulting in the effective energy ultimately acting on the probe being far lower than the initial hammer impact energy. This leads to a significantly higher measured hammer impact count, severely underestimating the actual bearing capacity of deep soil layers and posing a significant threat to engineering safety.
[0004] Secondly, there is the issue of the accuracy of drop height control. Traditional methods often rely on manual visual inspection or the use of mechanical stops to control the drop height of the hammer, which inevitably introduces human error and mechanical clearance error. Deviations in drop height directly lead to non-standard and inconsistent impact energy input, resulting in poor repeatability and comparability of test results, failing to meet the requirements of precise geotechnical investigation.
[0005] Therefore, there is an urgent need in the field for a dynamic penetration test device for testing the bearing capacity of deep soil layers to solve the above-mentioned technical problems. Summary of the Invention
[0006] The purpose of this invention is to provide a dynamic cone penetration test device for testing the bearing capacity of deep soil layers, so as to solve the two core technical problems in the prior art: low impact energy transmission efficiency due to excessively long probe rods and easy deflection, and poor drop distance accuracy due to manual control.
[0007] To achieve the above objectives, the present invention provides the following solution: The present invention provides a dynamic cone penetration test device for testing the bearing capacity of deep soil layers, comprising: The above-ground structure includes a support component and a drive component. The support component is disposed on the ground and is positioned corresponding to the borehole, while the drive component serves as the power source for the device. A probe rod is located in the borehole. A positioning component and a hammering component are provided at the top of the probe rod. The driving component is connected to the hammering component to provide the probe rod with probing power. The guiding mechanism includes a U-shaped seat sleeved on the probe rod, and a plurality of guide wheels arranged axially at equal intervals on the U-shaped seat. The guide wheels make rolling contact with the inner wall of the guide tube pre-embedded in the borehole.
[0008] Preferably, the guiding mechanism further includes a support block fixed to the probe rod, and the U-shaped seat is fixed to the probe rod through the support block, so that the guide wheel moves synchronously with the probe rod.
[0009] Preferably, the U-shaped seat is provided with an arc-shaped groove, and a rotating shaft is provided in the arc-shaped groove. The guide wheel is mounted on the rotating shaft through the rotating shaft.
[0010] Preferably, the probe rod is provided with an oil box, which is correspondingly arranged with the U-shaped seat to provide lubrication for the plurality of guide wheels.
[0011] Preferably, the hammering assembly includes a fixed outer cylinder fixed to the upper part of the probe rod, and a through hammer is sleeved on the portion of the probe rod located on the fixed outer cylinder. The through hammer is connected to the driving assembly for driving and lifting the through hammer. After the through hammer falls, it falls to the bottom of the inner cavity of the fixed outer cylinder.
[0012] Preferably, a hammer pad is provided at the bottom of the inner cavity of the fixed outer cylinder, the hammer pad is fixedly connected to the probe rod, and the falling through-hole hammer strikes the hammer pad.
[0013] Preferably, the positioning component includes a laser rangefinder sensor mounted on the top of the fixed outer cylinder, the laser rangefinder sensor being used to monitor the position of the hammer.
[0014] Preferably, the drive assembly includes a main winch and an auxiliary winch mounted on the ground. The wire rope of the main winch is drivenly connected to the probe rod to control the depth of the probe rod in the borehole. The wire rope of the auxiliary winch is drivenly connected to the mandrel to lift the mandrel.
[0015] Preferably, the support assembly includes a main support frame erected on the ground, the main support frame being correspondingly arranged with respect to the borehole; the main support frame is provided with a plurality of pulleys, and the steel wires of the main winch and the auxiliary winch are respectively reversed through the pulleys.
[0016] Preferably, a probe is provided at the bottom end of the probe rod.
[0017] Compared with existing technologies, this invention has the following advantages and technical effects: This invention discloses a dynamic penetration testing device for testing the bearing capacity of deep soil layers, mainly composed of a ground structure, a probe rod, and a guiding mechanism. It solves the problems of energy loss and accuracy in deep soil penetration testing, improving energy transfer efficiency and the reliability of test data. The ground structure includes a support component and a drive component. The support component is arranged corresponding to the borehole, providing stable support and a solid working foundation for the drive component and probe rod system, reducing test errors caused by equipment shaking during penetration and improving the overall operational reliability of the device. The drive component, as a power source, is connected to the hammering component at the top of the probe rod, providing power for the penetration operation. The probe rod is placed inside the borehole, with a positioning component and a hammering component at its top. The hammering component receives power from the drive component, realizing the hammering penetration of the probe rod. The core of the guiding mechanism is a U-shaped seat fitted onto the probe rod. The U-shaped seat has several axially equidistant guide wheels. These guide wheels roll in contact with the inner wall of the pre-embedded guide tube inside the borehole, replacing the traditional sliding friction and collision between the probe rod and the borehole wall. This constrains the lateral displacement of the probe rod, avoids stress wave scattering and distortion caused by probe rod deflection, and improves the efficiency of impact energy transmission to the probe. The axially equidistant arrangement of the guide wheels forms a stable guiding constraint, preventing the probe rod from bending or tilting in deep soil layers due to its own weight or uneven soil layers. This ensures that the probe always penetrates the soil layer vertically, allowing the test data to accurately reflect the bearing capacity of the deep soil layers. Attached Figure Description
[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 This is a schematic diagram of the dynamic penetration test device of the present invention used for testing the bearing capacity of deep soil layers; Figure 2 This is a schematic diagram of the main support of the present invention; Figure 3 This is a schematic diagram of the guide wheel of the present invention; Figure 4 This is a schematic diagram of the probe structure of the present invention; Figure 5 This is a schematic diagram of the hammer structure of the present invention; In the diagram: 1. Main winch; 2. Main support; 3. Pulley; 4. Auxiliary winch; 5. Ground control box; 6. Laser rangefinder sensor; 7. Fixed outer cylinder; 8. Through-hole hammer; 9. Hammer pad; 10. Guide wheel; 11. Probe rod; 12. Oil box; 13. Rotating shaft; 14. U-shaped seat; 15. Rotating shaft; 16. Support block; 17. Arc groove; 18. Probe. Detailed Implementation
[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0021] Reference Figures 1 to 5 As shown, this embodiment provides a dynamic penetration test device for testing the bearing capacity of deep soil layers, comprising: The above-ground structure includes a support component and a drive component. The support component is set on the ground and is positioned corresponding to the borehole, while the drive component serves as the power source for the device. The probe rod 11 is located in the borehole. The top of the probe rod 11 is equipped with a positioning component and a hammering component. The drive component is connected to the hammering component to provide the probe rod 11 with the probing power. The guiding mechanism includes a U-shaped seat 14 sleeved on the probe rod 11, and a number of guide wheels 10 arranged axially at equal intervals on the U-shaped seat 14. The guide wheels 10 make rolling contact with the inner wall of the guide tube pre-embedded in the borehole.
[0022] This invention discloses a dynamic penetration test device for testing the bearing capacity of deep soil layers. It mainly consists of a surface structure, a probe rod 11, and a guiding mechanism. The device addresses the energy loss and accuracy issues in deep soil penetration testing, improving energy transfer efficiency and test data reliability. The surface structure includes a support assembly and a drive assembly. The support assembly is positioned corresponding to the borehole, providing stable support and a solid working foundation for the drive assembly and probe rod 11 system. This reduces testing errors caused by equipment shaking during penetration testing and improves the overall operational reliability of the device. The drive assembly, as a power source, is connected to a hammering assembly at the top of the probe rod 11, providing power for the penetration operation. The probe rod 11 is placed inside the borehole, with a positioning assembly and a hammering assembly at its top. The hammering assembly receives power from the drive assembly, enabling hammer penetration testing of the probe rod 11. The core of the guiding mechanism is a U-shaped seat 14 fitted onto the probe rod 11. The U-shaped seat 14 has several axially equidistant guide wheels 10. These guide wheels 10 roll in contact with the inner wall of the pre-embedded guide tube inside the borehole, replacing the traditional sliding friction and collision between the probe rod 11 and the borehole wall. This constrains the lateral displacement of the probe rod 11, preventing stress wave scattering and distortion caused by probe rod 11 deflection, and improving the efficiency of impact energy transmission to the probe 18. The axially equidistant arrangement of the guide wheels 10 forms a stable guiding constraint, preventing the probe rod 11 from bending or tilting in deep soil layers due to its own weight or uneven soil distribution. This ensures that the probe 18 always penetrates the soil layer vertically, allowing the test data to accurately reflect the bearing capacity of the deep soil layers.
[0023] In one embodiment of the present invention, at least one set of guiding mechanisms is provided on the lower part of the probe rod 11 and the section above the probe 18.
[0024] Further optimizing the design, the guiding mechanism also includes a support block 16 fixed to the probe rod 11. The U-shaped seat 14 is fixed to the probe rod 11 via the support block 16, allowing the guide wheel 10 to move synchronously with the probe rod 11. An arc-shaped groove 17 is provided on the U-shaped seat 14, and a rotating shaft 15 is installed in the arc-shaped groove 17. The guide wheel 10 is mounted on the rotating shaft 15 via a rotating shaft 13. At the lower part of the probe rod 11, the U-shaped seat 14 is fixed by the support block 16. The arc-shaped groove 17 is formed on the U-shaped seat 14, and the rotating shaft 15 is installed in the arc-shaped groove 17. The guide wheel 10 is mounted on the rotating shaft 15 via the rotating shaft 13. The guide wheel 10 cooperates with the guide tube pre-filled in the borehole to form a guiding structure for the inclination measurement ceremony. This effectively constrains the lateral displacement of the lower part of the probe rod 11, ensuring its vertical state, thereby minimizing the collision and friction between the probe rod 11 and the borehole wall, and reducing unnecessary loss of impact energy.
[0025] In one embodiment of the present invention, the guiding mechanism preferably provides two sets of guide wheels 10, which are arranged in a staggered manner as high wheels and low wheels, respectively, to provide a more stable guiding effect.
[0026] In a further optimized design, an oil box 12 is installed on the probe rod 11, corresponding to the U-shaped seat 14, to provide lubrication for several guide wheels 10. The oil box 12 is used to lubricate the guiding mechanism, reduce friction, and ensure smooth guiding.
[0027] Further optimizing the design, the hammering assembly includes a fixed outer cylinder 7 fixed to the upper part of the probe rod 11. A through-hammer 8 is sleeved on the portion of the probe rod 11 located on the fixed outer cylinder 7. The through-hammer 8 is connected to the drive assembly for lifting the through-hammer 8. After falling, the through-hammer 8 lands at the bottom of the inner cavity of the fixed outer cylinder 7. A hammer pad 9 is provided at the bottom of the inner cavity of the fixed outer cylinder 7. The hammer pad 9 is fixed to the probe rod 11, and the falling through-hammer 8 strikes the hammer pad 9. The upper part of the probe rod 11 is rigidly connected to the fixed outer cylinder 7 by welding. A hammer pad 9 is rigidly installed on the bottom inner side of the fixed outer cylinder 7 as the impact reference surface for the falling through-hammer 8, used to withstand the impact of the through-hammer 8. One output end of the drive assembly is connected to the fixed outer cylinder 7, which can drive the entire underground part to rise and fall in the guide cylinder; while the other output end of the drive assembly is connected to the through-hammer 8 for lifting the height of the through-hammer 8, and then releasing it to fall freely, striking the hammer pad 9.
[0028] Further optimization of the scheme involves a positioning component including a laser rangefinder 6 mounted on the top of the fixed outer cylinder 7. The laser rangefinder 6 monitors the position of the hammer 8. Simultaneously, both the laser rangefinder 6 and the auxiliary winch 4 are connected to the ground control box 5, forming a closed-loop control system for the drop distance of the hammer 8. The specific control process is as follows: first, the hammer 8 is lowered to the hammer pad 9 to zero, and the laser reading S1 is recorded; then, based on the target drop distance H (e.g., 0.76m), the target value S = S1 + H is calculated; finally, the auxiliary winch 4 is controlled to lift the hammer 8, and when the laser reading reaches S, it is braked and released, achieving precise control of the drop distance and ensuring consistent and standardized input of impact energy for each impact.
[0029] Further optimizing the design, the drive assembly includes a main winch 1 and an auxiliary winch 4 mounted on the ground. The wire rope on the main winch 1 is connected to the probe rod 11 for controlling the depth of the probe rod 11 in the borehole. The wire rope on the auxiliary winch 4 is connected to the mandrel 8 for lifting the mandrel 8. The drive assembly includes the main winch 1 and the auxiliary winch 4. The main winch 1 controls the lifting and lowering of the probe rod 11 and the fixed outer cylinder 7 as a whole system, and its wire rope is connected to the top of the system via a pulley 3 at the top of the main support 2. The auxiliary winch 4 is specifically used to lift the mandrel 8, and its wire rope is connected to the mandrel 8.
[0030] Further optimization of the design includes a support structure comprising a main support 2 erected on the ground, corresponding to the borehole. Several pulleys 3 are installed on the main support 2, through which the wire ropes of the main winch 1 and the auxiliary winch 4 are redirected. The main support 2 is an A-type steel structure, primarily used for supporting and fixing the equipment, while also providing space for the raising and lowering of the probe rod 11. The pulleys 3 are mainly used to redirect the wire ropes of the main winch 1 and the auxiliary winch 4.
[0031] To further optimize the design, a probe 18 is installed at the bottom of the probe rod 11. The probe 18, located at the bottom of the probe rod 11, plays a primary detection role.
[0032] During operation, the guide tube is first pre-placed into the soil. The main winch 1 is started, lowering the probe rod 11 and the guide mechanism so that the guide wheel 10 enters the guide tube and adheres tightly to the inner wall. During testing, the ground control box 5 controls the auxiliary winch 4 to raise the mandrel 8, with the laser rangefinder 6 monitoring in real time. Once the set height is reached, the mandrel 8 is released, falling freely to impact the hammer pad 9, completing one standard hammer strike. This process is repeated, and the probe rod 11 is intermittently lowered by the main winch 1, enabling fully automated deep soil layer testing.
[0033] In one embodiment of the present invention, the guiding mechanism of this embodiment may also adopt a spring-pressed guide wheel, which can also achieve similar guiding and close-fitting functions to the pipe wall, and can be used as an alternative to the fixed guide wheel 10 in this embodiment.
[0034] In one embodiment of the present invention, for drop distance measurement, other non-contact distance sensors may also be considered, provided that accuracy and reliability are guaranteed.
[0035] In summary, compared with the prior art, the technical advantages of the present invention are as follows: 1. Effectively improve energy transfer efficiency: Through the cooperation of the guide mechanism at the bottom of the probe rod 11 and the pre-embedded guide tube, the verticality of the probe rod 11 in the deep soil layer is forcibly guaranteed, which fundamentally eliminates the unnecessary energy loss caused by the deviation of the probe rod 11, so that the impact energy can be transferred to the probe 18 more effectively, and the test data more realistically reflects the bearing capacity of the deep soil layer.
[0036] 2. Achieve precise automated control of drop distance: Through a closed-loop control system consisting of laser rangefinder 6 and drive components, millimeter-level precision control of the drop distance of the hammer 8 is achieved, completely eliminating human error and ensuring the standardization of testing and the comparability of results.
[0037] 3. High degree of automation and convenient operation: The main and auxiliary dual winch system realizes the automated coordinated operation of probe rod 11 penetration / lifting and hammering 8, which greatly improves work efficiency and reduces the labor intensity and safety risks of operators.
[0038] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.
[0039] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.
Claims
1. A dynamic cone penetration test device for testing the bearing capacity of deep soil layers, characterized in that, include: The above-ground structure includes a support component and a drive component. The support component is disposed on the ground and is positioned corresponding to the borehole, while the drive component serves as the power source for the device. The probe (11) is located in the borehole. The top of the probe (11) is provided with a positioning component and a hammering component. The driving component is connected to the hammering component for providing the probe (11) with the probing power. The guiding mechanism includes a U-shaped seat (14) sleeved on the probe rod (11), and a number of guide wheels (10) are provided on the U-shaped seat (14) at equal axial intervals. The guide wheels (10) roll in contact with the inner wall of the guide tube pre-embedded in the borehole.
2. The dynamic cone penetration test device for testing the bearing capacity of deep soil layers according to claim 1, characterized in that: The guiding mechanism also includes a support block (16) fixed to the probe rod (11). The U-shaped seat (14) is fixed to the probe rod (11) through the support block (16), so that the guide wheel (10) moves synchronously with the probe rod (11).
3. The dynamic cone penetration test device for testing the bearing capacity of deep soil layers according to claim 1, characterized in that: The U-shaped seat (14) is provided with an arc groove (17), and a rotating shaft (15) is provided in the arc groove (17). The guide wheel (10) is installed on the rotating shaft (15) through the rotating shaft (13).
4. The dynamic cone penetration test device for testing the bearing capacity of deep soil layers according to claim 1, characterized in that: An oil box (12) is provided on the probe rod (11), and the oil box (12) is correspondingly provided with the U-shaped seat (14) to provide lubrication for a number of guide wheels (10).
5. The dynamic cone penetration test device for testing the bearing capacity of deep soil layers according to claim 1, characterized in that: The hammering assembly includes a fixed outer cylinder (7) fixed to the upper part of the probe rod (11). A through hammer (8) is sleeved on the part of the probe rod (11) located on the fixed outer cylinder (7). The through hammer (8) is connected to the drive assembly for driving and is used to lift the through hammer (8). After the through hammer (8) falls, it falls to the bottom of the inner cavity of the fixed outer cylinder (7).
6. The dynamic cone penetration test device for testing the bearing capacity of deep soil layers according to claim 5, characterized in that: A hammer pad (9) is provided at the bottom of the inner cavity of the fixed outer cylinder (7). The hammer pad (9) is fixedly connected to the probe rod (11). The falling hammer (8) strikes the hammer pad (9).
7. The dynamic cone penetration test device for testing the bearing capacity of deep soil layers according to claim 5, characterized in that: The positioning component includes a laser range sensor (6) mounted on the top of the fixed outer cylinder (7), which is used to monitor the position of the hammer (8).
8. The dynamic cone penetration test device for testing the bearing capacity of deep soil layers according to claim 5, characterized in that: The drive assembly includes a main winch (1) and an auxiliary winch (4) mounted on the ground. The wire on the main winch (1) is connected to the probe rod (11) for controlling the depth of the probe rod (11) in the borehole. The wire on the auxiliary winch (4) is connected to the mandrel (8) for lifting the mandrel (8).
9. The dynamic cone penetration test device for testing the bearing capacity of deep soil layers according to claim 8, characterized in that: The support assembly includes a main support (2) erected on the ground, which is corresponding to the borehole; the main support (2) is provided with several pulleys (3), and the steel wires of the main winch (1) and the auxiliary winch (4) are reversed through the pulleys (3).
10. The dynamic cone penetration test device for testing the bearing capacity of deep soil layers according to claim 1, characterized in that: The probe (18) is provided at the bottom end of the probe rod (11).