Measuring instrument for low-strain detection of pile foundation and use method
By designing a measuring instrument for low-strain detection of pile foundations, the problem of inconsistent hitting position of the monitor's handheld force hammer is solved, and more accurate detection results are achieved, suitable for pile foundations of different diameters and sizes.
Patent Information
- Application Number
- CN202411799190.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-09
- Publication Date
- 2025-03-28
AI Technical Summary
When detecting the strength of foundation piles under roads and bridge piers, the monitor's hand-held hammer strike may cause inconsistent positions of each strike, affecting the accuracy of the detection results.
A measuring instrument for low-strain detection of pile foundations is designed, including a pile dynamic measuring instrument, a speed sensor and a hammer mechanism. The hammer mechanism passes through the frame and the strike column, using the drive assembly and control system, ensuring that the strike column hits the pile foundation three times apart at the same position.
By ensuring the consistent position of each knock, the accuracy of the detection results is improved, artificial errors are reduced, and the adaptability to pile foundations of different diameters is enhanced.
Smart Images
Figure CN119715202A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of pile foundation detection, and in particular to a measuring instrument and a use method for low-strain detection of pile foundations. Background Art
[0002] The low-strain detection of pile foundation refers to applying a dynamic force (dynamic load) to the top of the pile. The dynamic force can be a transient impact force or a steady-state exciting force. The pile-soil system produces a dynamic response under the action of the dynamic force. The dynamic response signal is received by the pile dynamic measuring instrument. The structural integrity of the pile body is judged through time domain analysis or transfer function analysis of the signal. In order to ensure the accuracy of the pile foundation data monitoring results, the same pile foundation needs to be hammered three times, and the three waveform curves formed by the three hammerings should be basically consistent in shape, amplitude and phase to be qualified.
[0003] Before the test, the monitoring personnel will stick the velocity sensor connected to the pile dynamic tester on the pile in turn, and then manually hold the force hammer and make the force hammer fall and hit the top of the pile at a certain length. The stress wave generated by this propagates downward along the pile body at a wave speed C. When the stress wave passes through the interface where the pile impedance z (Z:AC) changes (such as shrinkage, foreign matter, concrete segregation or expansion), part of the stress wave is reflected and propagated upward, and the other part of the stress wave is transmitted and propagated downward to the pile end, where it is reflected again. The reflected wave signal is received by the velocity sensor, and the acceleration time history curve is obtained after the signal is amplified and processed by the pile dynamic tester. The impedance change position or pile length can be determined from the curve morphology characteristics, and the strength grade of the concrete can be estimated from the average wave velocity.
[0004] However, when monitoring the strength of piles under the piers of roads and bridges that have been in use for a period of years, the monitoring personnel need to stick the speed sensor on the pier above the ground. At this time, the monitoring personnel need to use a handheld hammer to hit the pier above the speed sensor to generate dynamic force. Since the pile foundation detection requires hammering the same position of the pier three times, but the monitoring personnel need to lift the hammer to hit the pier, the monitoring personnel may hit a different position each time, resulting in inaccurate monitoring results and shortcomings. Summary of the invention
[0005] In order to improve the problem of inconsistent tapping positions each time by monitoring personnel, the present application provides a measuring instrument for low-strain detection of pile foundations and a method for use.
[0006] In the first aspect, the present application provides a pile foundation low strain detection measuring instrument, which adopts the following technical solution: A measuring instrument for low-strain detection of pile foundations, comprising a pile foundation dynamic measuring instrument, a velocity sensor and a hammering mechanism for striking the pile foundation, wherein the velocity sensor is electrically connected to the pile foundation dynamic measuring instrument, and the hammering mechanism comprises a frame and a striking column, wherein the frame is provided with a fixing member, wherein the fixing member is used to fix the frame on the circumferential outer side wall of the pile foundation, the striking column is slidably arranged on the frame, and the frame is provided with a driving component for driving the striking column to strike the pile foundation.
[0007] By adopting the above technical solution, the inspection personnel first fix the frame to the outer wall of the pile foundation through the fixing parts, and then paste the speed sensor on the pile foundation under the frame, and then electrically connect the speed sensor with the pile foundation dynamic measuring instrument, and finally drive the knocking column through the driving component to knock the pile foundation three times at intervals to generate dynamic force. The speed sensor feeds back the signal to the pile foundation dynamic measuring instrument, and then the inspection personnel observe whether the three waveform curves obtained are consistent.
[0008] Optionally, the fixing member includes a shaft rod rotatably mounted on the frame, a tensioning motor electrically connected to the control system is mounted on the frame, the shaft rod is coaxially mounted on the output shaft of the tensioning motor, a pull rope is wound around the shaft rod, a hanging ring is mounted on the pull rope, a hook is mounted on the side of the frame facing away from the shaft rod, and the hanging ring is sleeved on the hook.
[0009] By adopting the above technical solution, the inspector starts the tensioning motor through the control system, and the tensioning motor drives the shaft rod to rotate in the reverse direction to unwind the pull rope. The inspector wraps the hook on the pull rope around the pile foundation once and puts it on the hook, and then starts the tensioning motor again. The tensioning motor drives the shaft rod to rotate forward to rewind the pull rope. The friction between the frame and the pile foundation fixes the frame on the pile foundation, which is beneficial to improve the adaptability to pile foundations of different diameters.
[0010] Optionally, the driving assembly includes a guide column arranged on the frame, an intermediate tube is provided on the sliding sleeve of the guide column, the cross-section of the guide column is polygonal, a connecting rod is provided between the knocking column and the intermediate tube, a power compression spring is supported between the impact end of the intermediate tube facing away from the knocking column and the frame, and a sliding member for driving the intermediate tube to move is provided on the frame.
[0011] By adopting the above technical solution, the sliding member drives the striking column away from the pile foundation through the intermediate tube and the connecting rod. At this time, the intermediate tube continuously squeezes the power compression spring, and the power compression spring is deformed and accumulates elastic potential energy.
[0012] Optionally, the sliding member includes a screw rotatably arranged on the frame, a rotating motor electrically connected to the control system is arranged on the frame, the screw is coaxially arranged on the output shaft of the rotating motor, the axis of the screw is parallel to the axis of the guide column, a guide tube coaxial with the screw is arranged on the frame, a driving block with a circular cross-section is threadedly connected to the screw, the circumferential outer side wall of the driving block abuts against the circumferential inner side wall of the guide tube, the driving block is provided with a rod, and the inner and outer sides of the guide tube are connected An escape groove for the sliding of the along rod is opened between the walls along the axial direction of the guide tube, a shift rod is rotatably arranged on the along rod, a torsion spring is arranged between the shift rod and the along rod, the shift rod is used to push the middle tube away from one end of the power compression spring, a disengagement groove communicating with the escape groove is opened between the inner and outer walls of the guide tube along the radial direction of the axis of the guide tube, the disengagement groove is slidably matched with the along rod, and when the along rod slides to the end of the disengagement groove, the shift rod is disengaged from the middle tube.
[0013] By adopting the above technical solution, the control system starts the rotating motor, and the output shaft of the rotating motor drives the screw to rotate. Due to the restrictive relationship between the along rod and the avoidance slot, the driving block slides along the axial direction of the guide tube. At the same time, the driving block drives the lever along the rod to push the intermediate tube to squeeze the power compression spring. The power compression spring is deformed and accumulates elastic potential energy until it slides along the rod to the connection point between the avoidance slot and the disengagement slot. As the rotating motor continues to drive the screw to rotate, the screw drives the driving block to rotate around the axis of the guide tube, and the driving block drives the along rod to slide on the disengagement slot to the disengagement slot. The lever is then separated from the middle tube, the power compression spring recovers its deformation and pushes the middle tube close to the pile foundation, the middle tube drives the striking column to hit the pile foundation through the connecting rod and generates dynamic force, and then the control system starts the rotating motor again, the rotating motor drives the driving block to reset through the screw rod, during this process, the lever is driven along the rod to abut against the middle tube, the lever rotates, the torsion spring deforms, until the lever is separated from the bottom of the middle tube, the torsion spring recovers its deformation, the lever rotates and resets and is ready to push the bottom of the middle tube again, and the operation is repeated three times.
[0014] Optionally, an anti-heavy impact rod is provided on the frame, a push ring plate is coaxially slidably provided on the guide column, and a push ring plate is provided on the push ring plate, and the push rod is used to abut against the intermediate tube, and a rebound compression spring is supported between the push ring plate on the side facing away from the intermediate tube and the frame, and an arc plate is provided on the intermediate tube, and there is a spacing between the arc plate and the push ring plate, and between the arc plate and the anti-heavy impact rod, and the anti-heavy impact rod is provided with a locking groove, and a locking block is slidably provided in the locking groove, and a locking compression spring is supported between the locking block and the closed end of the locking groove, and the locking block is used to abut against the side of the push ring plate toward the intermediate tube, and a guide inclined surface is provided on the locking block, and the arc plate is used to abut and slide with the guide inclined surface, and the guide inclined surface is inclinedly arranged toward the intermediate tube along the direction from the intermediate tube to the push ring plate, and the side of the push ring plate facing the intermediate tube is used to abut against the along rod.
[0015] By adopting the above technical scheme, when the knocking column hits the pile foundation, the middle tube drives the arc piece to abut against the guide inclined surface on the locking block, and the locking block continuously squeezes the locking compression spring until the arc piece separates the locking block from the push ring plate. At this time, the rebound compression spring restores its deformation and pushes the push rod close to the middle tube through the push ring plate. At the same time, the knocking column rebounds and moves away from the pile foundation after hitting the pile foundation, and the power compression spring is compressed again until the knocking column approaches the pile foundation again. At this time, the push rod will press against the end of the middle tube under the action of the rebound compression spring, and the knocking column will continuously move back and forth through the middle tube under the action of the rebound compression spring and the power compression spring until it stops, thereby preventing the knocking column from hitting the pile foundation again during one knocking process, which is beneficial to improving the accuracy of the detection results.
[0016] Optionally, an adjusting ring tube is provided on the outer coaxial sliding sleeve of the guide tube, and an adjusting groove is provided on the adjusting ring tube for the sliding of the along rod, and a plurality of gear grooves are provided between the inner and outer side walls of the adjusting ring tube, each of which is communicated with the adjusting groove, and the gear groove cooperates with the sliding of the along rod, and a plurality of avoidance grooves are provided on the guide tube, and the avoidance grooves correspond to the gear grooves one by one, and an electric cylinder electrically connected to a control system is provided on the frame, and the adjusting ring tube is provided on the piston rod of the electric cylinder. When the adjusting ring tube slides, only one group of corresponding avoidance grooves coincides with the gear groove at the same time.
[0017] By adopting the above technical solution, when the inspector needs different sizes of impact force to impact the pile foundation, the inspector starts the electric cylinder through the control system, and the piston rod of the electric cylinder drives the adjusting ring tube to slide, so that the gear grooves at different positions on the adjusting ring tube coincide with the avoidance grooves on the guide tube, so that the power compression spring obtains different sizes of compression potential energy, thereby changing the size of the impact force of the knocking column, which is conducive to improving the adaptability to pile foundations with different performances.
[0018] Optionally, the striking end of the striking column is detachably provided with a striking plate.
[0019] By adopting the above technical solution, inspectors can extend the service life of the knocking column by replacing the damaged impact plate.
[0020] Optionally, a friction pad is detachably provided on the frame, and the friction pad is used to abut against the outer side wall of the pile foundation.
[0021] By adopting the above technical solution, the friction between the frame and the pile foundation is increased, which is beneficial to improving the accuracy of the impact position of the knocking column on the frame.
[0022] In a second aspect, the present application provides a method for using a measuring instrument for low-strain detection of pile foundations, which adopts the following technical solution: A method for using a measuring instrument for low-strain detection of pile foundations comprises the following steps: S1. The monitoring personnel fix the frame to the outer side wall of the pile foundation through the fixing member; S2, pasting the speed sensor on the outer side wall of the pile foundation below the frame, and then electrically connecting the speed sensor and the pile foundation dynamic measuring instrument; S3, driving the knocking column to knock the pile foundation to generate dynamic force through the driving component, and obtaining a waveform curve through the pile foundation dynamic measuring instrument; S4, making the knocking column knock the pile foundation repeatedly three times, and obtaining corresponding waveform curves, and analyzing whether the three waveform curves are consistent.
[0023] By adopting the above technical solution, the striking column can generate multiple impact forces of the same magnitude at the same position on the pile foundation, which is beneficial to improving the accuracy of the detection results.
[0024] In summary, the present application includes at least one of the following beneficial technical effects: 1. The inspector first fixes the frame to the outer wall of the pile foundation through the fixings, then pastes the speed sensor on the pile foundation below the frame, and then electrically connects the speed sensor to the pile foundation dynamic tester. Finally, the driving component drives the knocking column to knock the pile foundation three times to generate dynamic force. The speed sensor feeds back the signal to the pile foundation dynamic tester, and then the inspector observes whether the three waveform curves obtained are consistent; 2. The control system starts the rotating motor, and the output shaft of the rotating motor drives the screw to rotate. Due to the restriction relationship between the rod and the avoidance slot, the driving block slides along the axis direction of the guide tube. At the same time, the driving block drives the lever along the rod to push the middle tube to squeeze the power compression spring. The power compression spring deforms and accumulates elastic potential energy until it slides along the rod to the connection between the avoidance slot and the disengagement slot. As the rotating motor continues to drive the screw to rotate, the screw drives the driving block to rotate around the axis of the guide tube. The driving block drives the rod along the disengagement slot to slide on the disengagement slot to the end of the disengagement slot facing away from the avoidance slot. At this time, the lever is separated from the middle tube, and the power compression spring recovers its deformation and pushes the middle tube close to the pile foundation. The middle tube drives the striking column to hit the pile foundation through the connecting rod and generates dynamic force. 3. When the knocking column hits the pile foundation, the middle tube drives the arc piece to abut against the guide inclined surface on the locking block, and the locking block continuously squeezes the locking compression spring until the arc piece separates the locking block from the push ring plate. At this time, the rebound compression spring recovers its deformation and pushes the push rod close to the middle tube through the push ring plate. At the same time, the knocking column rebounds and moves away from the pile foundation after hitting the pile foundation, and the power compression spring is compressed again until the knocking column approaches the pile foundation again. At this time, the push rod will press against the end of the middle tube under the action of the rebound compression spring, and the knocking column will continuously move back and forth through the middle tube under the action of the rebound compression spring and the power compression spring until it stops. In this way, the knocking column is prevented from hitting the pile foundation again during one knocking process, which is beneficial to improve the accuracy of the detection results. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 It is a schematic diagram of the structure of an embodiment of the present application.
[0026] Figure 2 It is a schematic structural diagram of the positional relationship among the adjusting ring tube, the guide tube and the knocking column in the embodiment of the present application.
[0027] Figure 3 It is a cross-sectional view of the positional relationship among the adjusting ring tube, the locking block and the driving block in the embodiment of the present application.
[0028] Description of the accompanying drawings: 0, pile foundation; 1, pile dynamic measuring instrument; 2, speed sensor; 3, hammer mechanism; 31, frame; 32, knock column; 33, fixing member; 331, shaft; 332, tensioning motor; 333, pull rope; 334, hanging ring; 335, hook; 34, driving assembly; 341, guide column; 342, intermediate tube; 343, connecting rod; 344, power compression spring; 345, sliding member; 3451, screw; 3452, rotating motor; 3453, guide Toward tube; 3454, driving block; 3455, along rod; 3456, avoidance slot; 3457, shift rod; 3458, torsion spring; 3459, disengagement slot; 4, anti-heavy impact rod; 5, push ring plate; 6, push rod; 7, rebound compression spring; 8, arc plate; 9, locking slot; 10, locking block; 11, locking compression spring; 12, guide ramp; 13, adjustment ring tube; 14, adjustment slot; 15, gear slot; 16, electric cylinder; 17, impact plate; 18, friction pad; 19, winding wheel. DETAILED DESCRIPTION
[0029] The following is combined with Figure 1-3 This application is described in further detail.
[0030] Example 1 The embodiment of the present application discloses a measuring instrument for low-strain detection of pile foundations.
[0031] Reference Figure 1 A measuring instrument for low-strain detection of pile foundations includes a pile foundation dynamic measuring instrument 1, a velocity sensor 2 and a hammer mechanism 3 for hammering the pile foundation 0, the velocity sensor 2 is used to be bonded to the circumferential outer wall of the pile foundation 0, the velocity sensor 2 is electrically connected to the pile foundation dynamic measuring instrument 1, and the hammer mechanism 3 includes a frame 31 and a hammering column 32 slidably arranged on the frame 31.
[0032] Reference Figure 1 , Figure 2 and Figure 3 A friction pad 18 is bonded to the frame 31, and the friction pad 18 can be made of rubber material. The friction pad 18 is used to abut against the outer wall of the pile foundation 0. The impact end of the knocking column 32 is bolted with a metal impact plate 17. The frame 31 is arranged with a fixing part 33 for fixing the frame 31 on the circumferential outer wall of the pile foundation 0.
[0033] Reference Figure 1 , Figure 2 and Figure 3The fixing part 33 includes a shaft rod 331 rotatably connected to the frame 31, a tensioning motor 332 electrically connected to the control system is bolted to the frame 31, the shaft rod 331 is coaxially welded to the output shaft of the tensioning motor 332, a winding wheel 19 is welded to the shaft rod 331, a pull rope 333 is wound on the winding wheel 19, the pull rope 333 can be made of a stainless steel wire rope in the prior art, a hanging ring 334 is welded to the pull rope 333, a hook 335 is arranged on the side of the frame 31 facing away from the shaft rod 331, and the hanging ring 334 is sleeved on the hook 335.
[0034] The inspector places the frame 31 on the pile foundation 0, and then starts the tensioning motor 332 through the control system. The tensioning motor 332 can adopt the forward and reverse motor in the prior art. The output shaft of the tensioning motor 332 drives the shaft 331 to rotate in the opposite direction, and the winding wheel 19 unwinds the pull rope 333. Another inspector puts the hanging ring 334 on the pull rope 333 around the pile foundation 0 and then puts it on the hook 335, and then starts the tensioning motor 332 again. The tensioning motor 332 drives the shaft 331 to rotate forward.
[0035] The winding wheel 19 reels the pull rope 333, and the friction pad 18 is squeezed and deformed by the frame 31 and the pile foundation 0. The friction between the friction pad 18 and the pile foundation 0 fixes the frame 31 on the pile foundation 0. Then the inspection personnel sticks the speed sensor 2 on the pile foundation 0 under the frame 31, and then connects the speed sensor 2 to the pile foundation dynamic measuring instrument 1 through a wire.
[0036] Reference Figure 1 , Figure 2 and Figure 3 A driving assembly 34 for driving the knocking column 32 to knock the pile foundation 0 is arranged on the frame 31. The driving assembly 34 includes a guide column 341 bolted to the frame 31 and having a polygonal cross-section. An intermediate tube 342 is slidably sleeved on the guide column 341. A connecting rod 343 is welded between the knocking column 32 and the intermediate tube 342. A power compression spring 344 is supported between the side of the impact end of the intermediate tube 342 facing away from the knocking column 32 and the frame 31. The power compression spring 344 is sleeved on the guide column 341. A sliding member 345 for driving the intermediate tube 342 to move is arranged on the frame 31.
[0037] Reference Figure 1 , Figure 2 and Figure 3 The sliding member 345 includes a screw rod 3451 rotatably connected to the frame 31, the axis of the screw rod 3451 is parallel to the axis of the guide column 341, a rotating motor 3452 electrically connected to the control system is bolted to the frame 31, the rotating motor 3452 can adopt the forward and reverse motor in the prior art, the screw rod 3451 is coaxially welded to the output shaft of the rotating motor 3452, and a guide tube 3453 coaxial with the screw rod 3451 and sleeved on the screw rod 3451 is bolted to the frame 31.
[0038] Reference Figure 1 , Figure 2 and Figure 3 A driving block 3454 with a circular cross-section is threadedly connected to the screw rod 3451, and the circumferential outer wall of the driving block 3454 abuts against the circumferential inner wall of the guide tube 3453. An along rod 3455 is welded to the driving block 3454, and an avoidance groove 3456 for sliding of the along rod 3455 is provided between the inner and outer walls of the guide tube 3453 along the axial direction of the guide tube 3453. A shifting rod 3457 is rotatably connected to the along rod 3455, and a torsion spring 3458 is arranged between the shifting rod 3457 and the along rod 3455.
[0039] Reference Figure 1 , Figure 2 and Figure 3 The lever 3457 is used to push one end of the intermediate tube 342 away from the power compression spring 344, and a disengagement slot 3459 communicating with the avoidance slot 3456 is provided between the inner and outer walls of the guide tube 3453 along the radial direction of the axis of the guide tube 3453. The disengagement slot 3459 is slidably matched with the along rod 3455. When the along rod 3455 slides to the end of the disengagement slot 3459, the lever 3457 is disengaged from the end of the intermediate tube 342.
[0040] Reference Figure 1 , Figure 2 and Figure 3 An adjusting ring tube 13 is coaxially slidingly sleeved outside the guide tube 3453, and an adjusting slot 14 for sliding along the rod 3455 is opened between the inner and outer walls of the adjusting ring tube 13 along the axial direction of the adjusting ring tube 13, and a plurality of gear slots 15 that are in communication with the adjusting slot 14 are opened between the inner and outer walls of the adjusting ring tube 13 along the radial direction of the axis of the adjusting ring tube 13, and the plurality of gear slots 15 are arranged along the axial direction of the adjusting ring tube 13.
[0041] Reference Figure 1 , Figure 2 and Figure 3 The gear slot 15 is slidably matched with the rod 3455, and a plurality of avoidance slots 3456 are provided along the axial direction of the guide tube 3453. The avoidance slots 3456 correspond to the gear slots 15 one by one. An electric cylinder 16 electrically connected to the control system is bolted to the frame 31, and the adjusting ring tube 13 is bolted to the piston rod of the electric cylinder 16. When the adjusting ring tube 13 slides, at the same time, there is only one set of corresponding avoidance slots 3456 and the gear slot 15 that can overlap.
[0042] The inspector selects different sizes of impact force to impact the pile foundation 0 according to the type of the pile foundation 0. The inspector starts the electric cylinder 16 through the control system. The piston rod of the electric cylinder 16 drives the adjusting ring tube 13 to slide, so that the gear slots 15 at different positions on the adjusting ring tube 13 can coincide with the avoidance slots 3456 on the guide tube 3453. Then the rotating motor 3452 is started through the control system. The output shaft of the rotating motor 3452 drives the screw 3451 to rotate in the forward direction.
[0043] Due to the restriction of the avoidance slot 3456 on the rod 3455, the driving block 3454 slides along the axial direction of the guide tube 3453, and the driving block 3454 drives the lever 3457 along the rod 3455 to push the intermediate tube 342 to continuously squeeze the power compression spring 344. The power compression spring 344 is deformed and accumulates elastic potential energy until it slides along the rod 3455 to the overlap of the gear slot 15 and the disengagement slot 3459. As the rotating motor 3452 continues to drive the screw 3451 to rotate, the screw 3451 drives the driving block 3454 to rotate around the axis of the guide tube 3453.
[0044] The driving block 3454 drives the rod 3455 to slide on the overlap of the disengagement slot 3459 and the gear slot 15 until the rod 3455 slides to the end of the avoidance slot 3456 that is opposite to the disengagement slot 3459. At this time, the lever 3457 is separated from the middle tube 342, and the power compression spring 344 restores its deformation and pushes the middle tube 342 close to the pile foundation 0. The middle tube 342 drives the impact plate 17 on the knocking column 32 to impact the pile foundation 0 through the connecting rod 343 and generate dynamic force.
[0045] Reference Figure 1 , Figure 2 and Figure 3 An anti-heavy impact rod 4 is bolted to the frame 31, a push ring plate 5 is coaxially slidingly sleeved on the guide column 341, a push rod 6 is welded to the side of the push ring plate 5 facing the middle tube 342, the push rod 6 is used to abut against the middle tube 342, a rebound compression spring 7 is supported between the side of the push ring plate 5 facing away from the middle tube 342 and the frame 31, and an arc piece 8 with a C-shaped cross section is bolted to the middle tube 342.
[0046] Reference Figure 1 , Figure 2 and Figure 3 The length of the arc piece 8 is longer than the length of the push rod 6. There is a distance between the C-shaped inner side of the arc piece 8 and the outer side of the push ring plate 5, and between the C-shaped outer side of the arc piece 8 and the anti-heavy impact rod 4. A locking groove 9 is opened on the anti-heavy impact rod 4, and a locking block 10 is slidably arranged in the locking groove 9. A locking compression spring 11 is supported between the locking block 10 and the closed end of the locking groove 9.
[0047] Reference Figure 1 , Figure 2 and Figure 3The locking block 10 is used to abut against the side of the push ring plate 5 toward the middle tube 342. A guide slope 12 is provided on the locking block 10. The arc piece 8 is used to abut and slide with the guide slope 12. The guide slope 12 is arranged obliquely toward the middle tube 342 along the direction from the middle tube 342 to the push ring plate 5. The side of the push ring plate 5 toward the middle tube 342 is used to abut against the rod 3455.
[0048] When the knocking column 32 drives the impact plate 17 to impact the pile foundation 0, the middle tube 342 drives the arc piece 8 to abut against the guide slope 12 on the locking block 10. Under the action of the guide slope 12, the locking block 10 continuously squeezes the locking compression spring 11 until the arc piece 8 separates the locking block 10 from the push ring plate 5. At this time, the locking block 10 is separated from the push ring plate 5, and the rebound compression spring 7 restores its deformation and drives the push rod 6 to approach the middle tube 342 through the push ring plate 5. At this time, the impact plate 17 on the knocking column 32 hits the pile foundation 0.
[0049] After hitting the pile foundation 0, the knocking column 32 rebounds and drives the impact plate 17 away from the pile foundation 0. The power compression spring 344 is compressed again until the knocking column 32 approaches the pile foundation 0 again. At this time, the push rod 6 will press against the end of the middle tube 342 under the action of the rebound compression spring 7. The knocking column 32 moves back and forth continuously through the middle tube 342 under the action of the rebound compression spring 7 and the power compression spring 344 until it stops.
[0050] During this process, the locking compression spring 11 recovers its deformation and pushes the locking block 10 to reset, thereby completing a knocking test process and preventing the knocking column 32 from hitting the pile foundation 0 again in a knocking test. Then the control system starts the rotating motor 3452 again, and the output shaft of the rotating motor 3452 drives the screw 3451 to rotate in the opposite direction, and the screw 3451 drives the driving block 3454 to reset, and the driving block 3454 drives the lever 3457 along the rod 3455 to approach the middle tube 342.
[0051] During this process, the lever 3455 drives the lever 3457 to gradually abut against the middle tube 342, the lever 3457 rotates, and the torsion spring 3458 deforms until the lever 3457 is separated from the bottom of the middle tube 342, and the torsion spring 3458 recovers its deformation, and the lever 3457 rotates and resets. As the driving block 3454 drives the lever 3455 to continue to approach the push ring plate 5, the push ring plate 5 is pushed and squeezes the rebound compression spring 7, and the rebound compression spring 7 deforms until the edge of the push ring plate 5 abuts against the guide slope 12 on the locking block 10.
[0052] The locking block 10 continuously squeezes the locking compression spring 11 until the edge of the push ring plate 5 is separated from the locking block 10. At this time, the locking compression spring 11 restores its deformation and pushes the locking block 10 to re-lock the push ring plate 5. The control system stops supplying power to the rotating motor 3452, and then starts the rotating motor 3452 again through the control system to drive the screw 3451 to rotate forward. Repeat the operation three times.
[0053] The implementation principle of Example 1 is as follows: the inspector places the frame 31 on the pile foundation 0, and then starts the tensioning motor 332 through the control system. The output shaft of the tensioning motor 332 drives the shaft 331 to rotate in the opposite direction, and the winding wheel 19 unwinds the pull rope 333. Another inspector puts the hanging ring 334 on the pull rope 333 around the pile foundation 0 and then puts it on the hook 335, and then starts the tensioning motor 332 again. The tensioning motor 332 drives the shaft 331 to rotate forward.
[0054] The winding wheel 19 reels the pull rope 333, and the friction pad 18 is squeezed and deformed by the frame 31 and the pile foundation 0. The friction between the friction pad 18 and the pile foundation 0 fixes the frame 31 on the pile foundation 0. Then the inspection personnel sticks the speed sensor 2 on the pile foundation 0 under the frame 31, and then connects the speed sensor 2 to the pile foundation dynamic measuring instrument 1 through a wire.
[0055] The inspector selects different sizes of impact force to impact the pile foundation 0 according to the type of the pile foundation 0. The inspector starts the electric cylinder 16 through the control system. The piston rod of the electric cylinder 16 drives the adjusting ring tube 13 to slide, so that the gear slots 15 at different positions on the adjusting ring tube 13 can coincide with the avoidance slots 3456 on the guide tube 3453. Then the rotating motor 3452 is started through the control system. The output shaft of the rotating motor 3452 drives the screw 3451 to rotate in the forward direction.
[0056] Due to the restriction of the avoidance slot 3456 on the rod 3455, the driving block 3454 slides along the axial direction of the guide tube 3453, and the driving block 3454 drives the lever 3457 along the rod 3455 to push the intermediate tube 342 to continuously squeeze the power compression spring 344. The power compression spring 344 is deformed and accumulates elastic potential energy until it slides along the rod 3455 to the overlap of the gear slot 15 and the disengagement slot 3459. As the rotating motor 3452 continues to drive the screw 3451 to rotate, the screw 3451 drives the driving block 3454 to rotate around the axis of the guide tube 3453.
[0057] The driving block 3454 drives the rod 3455 to slide on the overlap of the disengagement slot 3459 and the gear slot 15 until the rod 3455 slides to the end of the avoidance slot 3456 that is opposite to the disengagement slot 3459. At this time, the lever 3457 is separated from the middle tube 342, and the power compression spring 344 restores its deformation and pushes the middle tube 342 close to the pile foundation 0. The middle tube 342 drives the impact plate 17 on the knocking column 32 to impact the pile foundation 0 through the connecting rod 343 and generate dynamic force.
[0058] When the knocking column 32 drives the impact plate 17 to impact the pile foundation 0, the middle tube 342 drives the arc piece 8 to abut against the guide slope 12 on the locking block 10. Under the action of the guide slope 12, the locking block 10 continuously squeezes the locking compression spring 11 until the arc piece 8 separates the locking block 10 from the push ring plate 5. At this time, the locking block 10 is separated from the push ring plate 5, and the rebound compression spring 7 restores its deformation and drives the push rod 6 to approach the middle tube 342 through the push ring plate 5. At this time, the impact plate 17 on the knocking column 32 hits the pile foundation 0.
[0059] After hitting the pile foundation 0, the knocking column 32 rebounds and drives the impact plate 17 away from the pile foundation 0. The power compression spring 344 is compressed again until the knocking column 32 approaches the pile foundation 0 again. At this time, the push rod 6 will press against the end of the middle tube 342 under the action of the rebound compression spring 7. The knocking column 32 moves back and forth continuously through the middle tube 342 under the action of the rebound compression spring 7 and the power compression spring 344 until it stops.
[0060] During this process, the locking compression spring 11 recovers its deformation and pushes the locking block 10 to reset, thereby completing a knocking test process and preventing the knocking column 32 from hitting the pile foundation 0 again in a knocking test. Then the control system starts the rotating motor 3452 again, and the output shaft of the rotating motor 3452 drives the screw 3451 to rotate in the opposite direction, and the screw 3451 drives the driving block 3454 to reset, and the driving block 3454 drives the lever 3457 along the rod 3455 to approach the middle tube 342.
[0061] During this process, the lever 3455 drives the lever 3457 to gradually abut against the middle tube 342, the lever 3457 rotates, and the torsion spring 3458 deforms until the lever 3457 is separated from the bottom of the middle tube 342, and the torsion spring 3458 recovers its deformation, and the lever 3457 rotates and resets. As the driving block 3454 drives the lever 3455 to continue to approach the push ring plate 5, the push ring plate 5 is pushed and squeezes the rebound compression spring 7, and the rebound compression spring 7 deforms until the edge of the push ring plate 5 abuts against the guide slope 12 on the locking block 10.
[0062] The locking block 10 continuously squeezes the locking compression spring 11 until the edge of the push ring plate 5 is separated from the locking block 10. At this time, the locking compression spring 11 restores its deformation and pushes the locking block 10 to re-lock the push ring plate 5. The control system stops supplying power to the rotating motor 3452, and then starts the rotating motor 3452 again through the control system to drive the screw 3451 to rotate forward. Repeat the operation three times.
[0063] Example 2 Embodiment 2 of the present application discloses a method for using a measuring instrument for low-strain detection of pile foundations, comprising the following steps: S1. The monitoring personnel places the frame 31 on the outer wall of the pile foundation 0, and then starts the tensioning motor 332 through the control system. The tensioning motor 332 first drives the winding wheel 19 to rotate forward to unwind the pull rope 333. The detection personnel wraps the hanging ring 334 on the pull rope 333 around the pile foundation 0 and then puts it on the hook 335. Then, the output shaft of the tensioning motor 332 drives the winding wheel 19 to rotate reversely to rewind the pull rope 333, so as to fix the frame 31. S2, stick the speed sensor 2 on the outer wall of the pile foundation 0 below the frame 31, and then electrically connect the speed sensor 2 to the pile foundation dynamic measuring instrument 1; S3, the electric cylinder 16 is started by the control system, and the piston rod of the electric cylinder 16 makes the gear slots 15 at different positions on the adjustment ring tube 13 coincide with the avoidance notch 3456 on the guide tube 3453, so as to select the appropriate gear; S4, the rotating motor 3452 is started through the control system, and the rotating motor 3452 drives the knocking column 32 to knock the pile foundation 0 to generate dynamic force through the mechanical structure inside the frame 31, and a waveform curve is obtained through the pile foundation dynamic measuring instrument 1; S5, making the knocking column 32 repeatedly knock the pile foundation 0 three times, and obtaining corresponding waveform curves, and analyzing whether the three waveform curves are consistent.
[0064] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.
Claims
1. A measuring instrument for low-strain detection of pile foundations, comprising a pile foundation dynamic measuring instrument (1), a velocity sensor (2) and a hammer mechanism (3) for striking a pile foundation (0), wherein the velocity sensor (2) is electrically connected to the pile foundation dynamic measuring instrument (1), and is characterized in that: The hammer mechanism (3) comprises a frame (31) and a knocking column (32); a fixing member (33) is arranged on the frame (31); the fixing member (33) is used to fix the frame (31) on the circumferential outer side wall of the pile foundation (0); the knocking column (32) is slidably arranged on the frame (31); and a driving component (34) is arranged on the frame (31) for driving the knocking column (32) to knock the pile foundation (0).
2. A pile foundation low strain detection measuring instrument according to claim 1, characterized in that: The fixing member (33) comprises a shaft (331) rotatably arranged on the frame (31); a tensioning motor (332) electrically connected to a control system is arranged on the frame (31); the shaft (331) is coaxially arranged on an output shaft of the tensioning motor (332); a pull rope (333) is wound around the shaft (331); a hanging ring (334) is arranged on the pull rope (333); a hook (335) is arranged on a side of the frame (31) facing away from the shaft (331); and the hanging ring (334) is sleeved on the hook (335).
3. The measuring instrument for low strain detection of pile foundation according to claim 1, characterized in that: The driving assembly (34) comprises a guide column (341) arranged on the frame (31), an intermediate tube (342) being slidably sleeved on the guide column (341), the cross section of the guide column (341) being polygonal, a connecting rod (343) being arranged between the knocking column (32) and the intermediate tube (342), a power compression spring (344) being supported between the side of the impact end of the intermediate tube (342) facing away from the knocking column (32) and the frame (31), and a sliding member (345) for driving the intermediate tube (342) to move is arranged on the frame (31).
4. The measuring instrument for low strain detection of pile foundation according to claim 3, characterized in that: The sliding member (345) includes a screw rod (3451) rotatably arranged on the frame (31); a rotating motor (3452) electrically connected to a control system is arranged on the frame (31); the screw rod (3451) is coaxially arranged on the output shaft of the rotating motor (3452); the axis of the screw rod (3451) is parallel to the axis of the guide column (341); a guide tube (3453) coaxial with the screw rod (3451) is arranged on the frame (31); a driving block (3454) having a circular cross section is threadedly connected to the screw rod (3451); the circumferential outer side wall of the driving block (3454) abuts against the circumferential inner side wall of the guide tube (3453); a rod (3455) is arranged on the driving block (3454); and a groove (3456) is formed between the inner and outer walls of the guide tube (3453) and the guide tube (3453). A shimming slot (3456) for sliding along the rod (3455) is provided in the axial direction of the guide tube (3453), a lever (3457) is rotatably provided on the rod (3455), a torsion spring (3458) is provided between the lever (3457) and the rod (3455), the lever (3457) is used to push the middle tube (342) away from one end of the power compression spring (344), a disengagement slot (3459) communicating with the shimming slot (3456) is provided between the inner and outer side walls of the guide tube (3453) in the radial direction of the axis of the guide tube (3453), the disengagement slot (3459) is slidably matched with the rod (3455), and when the rod (3455) slides to the end of the disengagement slot (3459), the lever (3457) is disengaged from the middle tube (342).
5. The measuring instrument for low strain detection of pile foundation according to claim 4, characterized in that: The frame (31) is provided with an anti-heavy impact rod (4), the guide column (341) is coaxially slidably provided with a push ring plate (5), the push ring plate (5) is provided with a push rod (6), the push rod (6) is used to abut against the intermediate tube (342), a rebound compression spring (7) is supported between the push ring plate (5) and the frame (31) on the side facing away from the intermediate tube (342), the intermediate tube (342) is provided with an arc plate (8), there is a distance between the arc plate (8) and the push ring plate (5), and between the arc plate (8) and the anti-heavy impact rod (4), the anti-heavy impact rod (4) is provided with a locking groove (9), and a sliding device (2) is provided in the locking groove (9). A locking block (10) is provided, and a locking compression spring (11) is supported between the locking block (10) and the closed end of the locking groove (9). The locking block (10) is used to abut the side of the push ring plate (5) facing the intermediate tube (342). A guide slope (12) is provided on the locking block (10), and the arc plate (8) is used to abut and slide with the guide slope (12). The guide slope (12) is arranged obliquely toward the intermediate tube (342) along the direction from the intermediate tube (342) to the push ring plate (5), and the side of the push ring plate (5) facing the intermediate tube (342) is used to abut against the along rod (3455).
6. The measuring instrument for low strain detection of pile foundation according to claim 4, characterized in that: An adjusting ring tube (13) is coaxially slidably sleeved outside the guide tube (3453). An adjusting notch (14) is provided on the adjusting ring tube (13) for the sliding movement of the along rod (3455). A plurality of gear slots (15) are provided between the inner and outer side walls of the adjusting ring tube (13) and are in communication with the adjusting notch (14). The gear slots (15) are slidably matched with the along rod (3455). A plurality of avoidance slots (3456) are provided on the guide tube (3453). The avoidance slots (3456) correspond to the gear slots (15) one by one. An electric cylinder (16) electrically connected to a control system is provided on the frame (31). The adjusting ring tube (13) is provided on the piston rod of the electric cylinder (16). When the adjusting ring tube (13) slides, only one set of corresponding avoidance slots (3456) overlaps with the gear slots (15) at the same time.
7. The measuring instrument for low strain detection of pile foundation according to claim 1, characterized in that: The striking end of the striking column (32) is detachably provided with a striking plate (17).
8. The measuring instrument for pile foundation low strain detection according to claim 1, characterized in that: The frame (31) is detachably provided with a friction pad (18), and the friction pad (18) is used to abut against the outer side wall of the pile foundation (0).
9. A method for using the pile foundation low strain detection measuring instrument according to any one of claims 1 to 8, characterized in that: The steps include: S1. A monitoring staff fixes the frame (31) to the outer wall of the pile foundation (0) through the fixing member (33); S2, pasting the speed sensor (2) on the outer wall of the pile foundation (0) below the frame (31), and then electrically connecting the speed sensor (2) and the pile foundation dynamic measuring instrument (1); S3, driving the knocking column (32) to knock the pile foundation (0) to generate dynamic force through the driving component (34), and obtaining a waveform curve through the pile foundation dynamic measuring instrument (1); S4, causing the knocking column (32) to repeatedly knock the pile foundation (0) three times, and obtaining corresponding waveform curves, and analyzing whether the three waveform curves are consistent.