Method for monitoring grouting amount of gravel pile

Abstract

The gravel pile grouting amount monitoring method comprises a vibratory hammer, a feeding opening, a pile pipe, a pile tip and gravel, the vibratory hammer is arranged at the top of the pile pipe, the feeding opening is formed in one side of the outer wall of the middle of the pile pipe, the bottom of the pile pipe is connected with the pile tip, and the gravel is poured into a gravel pile through the feeding opening; the device further comprises a distance measuring module, the distance measuring module comprises a laser, a camera, an installation mechanism and a differential GNSS module, the laser and the camera are arranged in the pile pipe, the light beam direction of the laser and the optical axis of the camera are located near the measured object and intersect, and the differential GNSS module is arranged at the top end of the outer side of the pile pipe. The relative height change of the end face of the gravel in the pile pipe is achieved through wireless distance measurement, direct measurement of the gravel filling amount is achieved, and errors caused by indirect measurement are avoided. Aiming at serious dust and rainwater shielding caused by a gravel dumping process in the pile pipe, a light beam image edge formed by a Tyndall effect can be acquired through a laser triangulation method, and the anti-interference capability is remarkable.

Description

Technical Field

[0001] The invention belongs to the technical field of gravel pile injection amount monitoring, and particularly relates to a gravel pile injection amount monitoring method. Background Art

[0002] The primary purpose of gravel pile construction is to reinforce sandy soil foundations, thereby increasing their bearing capacity and enhancing their resistance to liquefaction. During the construction process, a vibratory hammer is activated, squeezing the pile tube downward to form a pile hole. Once the designed depth is reached, gravel is poured in through the side opening of the pile tube. After the pile tube is raised to a certain height, the pile tip is pulled back by the weight of the gravel, leaving the gravel in the hole. Further downward squeezing of the pile tube is then performed to compact the remaining gravel. This process of pouring gravel, pulling out the pile, and then vibrating the pile tube repeatedly continues until the pile hole is densely packed with gravel. The construction process demonstrates that controlling the amount of gravel poured is a key factor in ensuring pile hole quality. Insufficient or excessive pouring can result in insufficient or excessive pile bearing capacity, compromising the stability and safety of the entire structure. Accurate metering and effective control of the pouring volume are crucial to ensuring project quality during gravel pile construction. Therefore, a series of measures must be implemented during construction to ensure that the pouring volume meets the design requirements.

[0003] Existing methods for measuring the amount of gravel poured typically rely on gravimetric measurement. This involves attaching a tension sensor to the gravel bucket cable to measure the change in bucket weight. However, moisture in the gravel and spillage during pouring into the feed port can cause measurement errors. Alternatively, volumetric measurement uses a plumb bob suspended from a rope to measure the height of the gravel pile. However, this method suffers from reliability issues due to complex mechanical structures like pulleys, cumbersome operation, and the potential for error.

[0004] Therefore, the present invention provides a method for monitoring the injection volume of a gravel pile to solve the problems raised by the above background technology. Summary of the Invention

[0005] In response to the problems raised by the above background technology, the purpose of the present invention is to provide a method for monitoring the injection volume of gravel piles, which realizes the relative height change of the end face of the gravel in the pile pipe through wireless ranging, realizes the direct measurement of the gravel injection volume, and avoids the error caused by indirect measurement.

[0006] In order to achieve the above technical objectives, the technical solutions adopted by the present invention are as follows:

[0007] A device for monitoring the injection volume of a gravel pile, the gravel pile comprising a vibrating hammer, a feeding port, a pile pipe, a pile tip, and gravel. The vibrating hammer is disposed on the top of the pile pipe, the feeding port is provided on one side of the outer wall of the middle portion of the pile pipe, the bottom of the pile pipe is connected to the pile tip, and the gravel is injected into the gravel pile through the feeding port.

[0008] It also includes a ranging module, which includes a laser, a camera, a mounting mechanism and a differential GNSS module. The laser and the camera are arranged inside the pile pipe, and the beam direction of the laser intersects with the optical axis of the camera near the object to be measured. The differential GNSS module is arranged at the top end of the outer side of the pile pipe.

[0009] It is further defined that the mounting mechanism is a base plate or a clamp.

[0010] A method for monitoring the injection volume of a gravel pile comprises the following steps:

[0011] S1: Install the laser and camera inside the pile pipe through a base plate or a clamp to form a triangulation distance measurement module to ensure that the height of the crushed stone end surface is always within the range of the triangulation distance measurement module;

[0012] S2: Based on S1, the relative position of the camera and the laser is fixed, and then the triangulation distance measurement module is calibrated. The purpose is to obtain the calculated relationship between the imaging position of the receiving element and the height of the gravel end face of the light spot image captured by the camera;

[0013] S3: Before construction begins, install the triangulation distance measurement module calibrated based on S1 and S2 at the top of the pile pipe. Fine-tune the direction to ensure that the laser beam is always perpendicular to the center of the gravel end face, and measure the radius r inside the pile pipe.

[0014] S4: During the continuous construction process, the differential GNSS and triangulation distance measurement results are collected in real time and synchronously to generate the crushed stone end face distance curve D and the pile pipe 105 top elevation curve H;

[0015] S5: Whenever the longitude and latitude of the differential GNSS module changes and becomes stable, when the elevation begins to drop, the pile driver is constructing a new pile point;

[0016] S6: For the elevation curve H during the construction of the new pile point, find the lowest point h of the elevation min and from h min Starting from the occurrence time, the differential curve H is obtained for the elevation curve diff , where the negative number represents the pile pulling action, and the pile pulling process is accompanied by gravel filling. Search and record H diff The starting and ending time of each consecutive negative moment in the , the i-th consecutive negative moment is recorded as (i start ,i end );

[0017] S7: For the distance measurement curve D, search (i start ,i end ) corresponds to the height value at the moment (p start ,p end ) and record the height difference Δd i =pstart -p end , and use this value as the height of the gravel filled during the pile extraction process during the i-th period;

[0018] S8: Accumulated from h min Starting from the moment of occurrence, record the height difference Δd of all crushed stones i The cumulative sum d is used as the final filling height of the crushed stone material, and then based on the pile pipe radius r obtained in step 3, the injection volume V=πr during the construction process of the pile point is obtained. 2 d.

[0019] It is further defined that S1 specifically includes the following steps:

[0020] S1.1: Measure the vertical distance from the top of the pile pipe to the pile tip and the feeding port respectively, which will serve as the farthest and closest measurement ranges of the triangulation distance measurement module;

[0021] S1.2: Set up a baffle as the measured surface. The baffle can move freely within the measurement range. Adjust the position of the laser on the base plate or fixture to ensure that the laser beam always shines in the center of the measured surface. After adjustment, fix the laser position.

[0022] S1.3: Fix the baffle to be measured in the middle of the measured range as a reference plane. Adjust the tilt angle of the camera relative to the laser on the base plate or fixture so that the camera optical axis intersects the laser beam on the measured plane. That is, the light spot is imaged in the middle of the camera receiving element. Then fix the camera position.

[0023] S1.4: Continue to move the measured plane so that it changes within the full measurement range. At the same time, adjust the focal length and aperture of the camera lens so that the light spot on the measured plane can always be clearly imaged on the camera receiving element. Finally, fix the focal length of the lens.

[0024] It is further defined that S2 specifically includes the following steps:

[0025] S2.1: Maintaining a rigid connection between the laser and the camera, and fixing the camera focal length and aperture, establish the following equation:

[0026]

[0027] Among them, L is the distance from the intersection of the laser beam and the camera optical axis to the camera lens, L' is the distance between the camera lens and the center point of the receiving element, and α is the angle between the laser beam and the camera optical axis. All of them are structural parameters of the laser triangulation measurement system and are fixed values. When the measured plane is displaced by a distance x, the imaging spot on the camera receiving element deviates from the position by x'.

[0028] S2.2: Simplify the structural parameters L, L', and α into two parameters k1 and k2:

[0029]

[0030] S2.3: Simplify the relationship between the measured distance x and the spot position x' into an expression containing only two parameters k1 and k2:

[0031]

[0032] S2.4: With the help of the object to be measured with known position and distance, multiple measurements are performed. Using multiple sets of known x and x', the least squares method is used to fit the parameters k1 and k2. The distance calculation relationship between the spot image position and the measured surface can be obtained.

[0033] Beneficial effects of the present invention:

[0034] (1) The present invention realizes the relative height change of the end face of the crushed stone in the pile pipe through wireless distance measurement, realizes the direct measurement of the amount of crushed stone poured, and avoids the error caused by indirect measurement.

[0035] (2) In view of the severe dust and rain obstruction caused by the dumping of gravel in the pile pipe, the laser rangefinder based on the time-of-flight method or the phase difference method will cause measurement errors due to the obstruction of the return light spot. However, the laser triangulation method can collect the edge of the light column image formed by the Tyndall effect, thus having significant anti-interference ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The present invention can be further illustrated by the non-limiting examples given in the accompanying drawings;

[0037] Figure 1 This is a structural schematic diagram of a method for monitoring the injection volume of a gravel pile during dynamic compaction construction according to an embodiment of the present invention;

[0038] Figure 2 The figure is a schematic diagram of the composition, adjustment and calibration of a triangulation distance measurement module in an embodiment of a method for monitoring the injection amount of a gravel pile according to the present invention.

[0039] The symbols of the main components are explained as follows: vibratory hammer 101 , laser 102 , camera 103 , feeding port 104 , pile pipe 105 , pile tip 106 , gravel 107 , mounting mechanism 108 , camera lens 109 , reference plane 110 , measured plane 111 , and receiving element 112 . DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the present invention, the technical solutions of the present invention are further described below in conjunction with the accompanying drawings and embodiments. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts are within the scope of protection of the present invention.

[0041] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0042] In addition, the descriptions of "first", "second", etc. in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention. It should be understood that the specific embodiments described here are only used to explain the present invention and are not used to limit the present invention.

[0043] like Figure 1 and Figure 2 As shown, a gravel pile injection amount monitoring device of the present invention comprises a gravel pile comprising a vibrating hammer 101, a feeding port 104, a pile pipe 105, a pile tip 106 and gravel 107. The vibrating hammer 101 is arranged at the top of the pile pipe 105, the feeding port 104 is opened on one side of the outer wall of the middle part of the pile pipe 105, the bottom of the pile pipe 105 is connected to the pile tip 106, and the gravel 107 is poured into the gravel pile through the feeding port 104.

[0044] It also includes a ranging module, which includes a laser 102, a camera 103, a mounting mechanism 108 and a differential GNSS module. The laser 102 and the camera 103 are arranged inside the pile pipe 105. The beam direction of the laser 102 intersects with the optical axis of the camera near the object to be measured. The differential GNSS module is arranged at the top end of the outer side of the pile pipe 105.

[0045] In practical applications of this embodiment, the mounting mechanism 108 is a base plate or a clamp.

[0046] A method for monitoring the injection volume of a gravel pile comprises the following steps:

[0047] S1: Install the laser 102 and the camera 103 inside the pile pipe 105 through a base plate or a clamp to form a triangulation distance measurement module to ensure that the height of the end surface of the crushed stone is always within the range of the triangulation distance measurement module;

[0048] S2: Based on S1, the relative positions of the camera 103 and the laser 102 are fixed, and then the triangulation distance measurement module is calibrated to obtain the calculated relationship between the imaging position of the light spot image captured by the camera 103 at the receiving element 112 and the height of the gravel end surface;

[0049] S3: Before construction begins, install the triangulation distance measurement module calibrated based on S1 and S2 at the top of the pile pipe 105. Fine-tune the direction to ensure that the laser beam is always perpendicular to the center of the gravel end face, and measure the radius r of the pile pipe 105.

[0050] S4: During the continuous construction process, the differential GNSS and triangulation distance measurement results are collected in real time and synchronously to generate the crushed stone end face distance curve D and the pile pipe 105 top elevation curve H;

[0051] S5: Whenever the longitude and latitude of the differential GNSS module changes and becomes stable, when the elevation begins to drop, the pile driver is constructing a new pile point;

[0052] S6: For the elevation curve H during the construction of the new pile point, find the lowest point h of the elevation min and from h min Starting from the occurrence time, the differential curve H is obtained for the elevation curve diff , where the negative number represents the pile pulling action, and the pile pulling process is accompanied by gravel filling. Search and record H diff The starting and ending time of each consecutive negative moment in the , the i-th consecutive negative moment is recorded as (i start ,i end );

[0053] S7: For the distance measurement curve D, search (i start ,i end ) corresponds to the height value at the moment (p start ,p end ) and record the height difference Δd i =p start -p end , and use this value as the height of the gravel filled during the pile extraction process during the i-th period;

[0054] S8: Accumulated from h min Starting from the moment of occurrence, record the height difference Δd of all crushed stones iThe cumulative sum d is used as the final filling height of the crushed stone material, and then based on the pile pipe radius r obtained in step 3, the injection volume V=πr during the construction process of the pile point is obtained. 2 d.

[0055] In the practical application of this embodiment, S1 specifically includes the following steps:

[0056] S1.1: Measure the vertical distance from the top of the pile tube 105 to the pile tip 106 and the feeding port 104, respectively, as the farthest and closest measurement ranges of the triangulation distance measurement module;

[0057] S1.2: Set a baffle as the measured surface 111. The baffle can move freely within the measurement range. Adjust the position of the laser 102 on the base plate or fixture to ensure that the laser beam always illuminates the center of the measured surface 111. After adjustment, fix the position of the laser 102.

[0058] S1.3: Fix the baffle to be measured in the middle of the measured range, which serves as reference plane 110. Adjust the tilt angle of camera 103 relative to laser 102 on a base plate or fixture so that the camera optical axis intersects the laser beam on measured plane 111. That is, the light spot is imaged in the middle of camera receiving element 112. Then fix the position of camera 103.

[0059] S1.4: Continue to move the measured plane 111 so that it changes within the full measurement range. At the same time, adjust the focal length and aperture of the camera lens 109 so that the light spot on the measured plane 111 can always be clearly imaged on the camera receiving element 112. Finally, fix the lens focal length.

[0060] In the practical application of this embodiment, S2 specifically includes the following steps:

[0061] S2.1: Maintaining a rigid connection between laser 102 and camera 103, and fixing the focal length and aperture of camera 103, establish the following equation:

[0062]

[0063] Among them, L is the distance from the intersection of the laser beam and the camera optical axis to the camera lens 109, L' is the distance between the camera lens 109 and the center point of the receiving element 112, and α is the angle between the laser beam and the camera optical axis. All of them are structural parameters of the laser triangulation measurement system and are fixed values. When the measured plane 111 is displaced by a distance x, the imaging spot on the camera receiving element 112 deviates from the position by x'.

[0064] S2.2: Simplify the structural parameters L, L', and α into two parameters k1 and k2:

[0065]

[0066] S2.3: Simplify the relationship between the measured distance x and the spot position x' into an expression containing only two parameters k1 and k2:

[0067]

[0068] S2.4: With the help of the object to be measured with known position and distance, multiple measurements are performed. Using multiple sets of known x and x', the least squares method is used to fit the parameters k1 and k2. The distance calculation relationship between the spot image position and the measured surface can be obtained.

[0069] During the pile construction process in this embodiment, the laser beam projected by laser 102 illuminates the end face of the gravel. As the relative height of the gravel end face changes during the pile sinking process, the image position of the reflected laser beam spot on camera receiving element 112 also changes accordingly. This change in the image position of the light spot on camera receiving element 112 can be used to calculate the distance between the gravel end face and laser 102, i.e., the height change of the gravel end face relative to pile pipe 105. Based on the cross-sectional area of ​​pile pipe 105, the real-time value of the gravel injection volume during the gravel pile construction process can be obtained. Finally, combined with the elevation changes of the differential GNSS module, the real-time pile sinking depth is obtained, and ultimately the gravel injection volume and filling coefficient of a single pile point are calculated.

[0070] In addition, this embodiment measures the height change of the end face of the filling material such as gravel in the pile pipe 105 by using a wireless distance measuring sensor composed of a laser 102 and a camera 103 inside the pile pipe 105; the wireless distance measuring sensor can also be a commercial large-range triangulation distance measuring sensor;

[0071] During the measurement process, the light beam projected by the triangulation measurement device can be laser or infrared light, and the end face of the light beam can be point-shaped or strip-shaped. The corresponding camera receiving element 112 can be a one-dimensional linear array or a two-dimensional area array, and the rigid optical principle of the receiving element 112 can be CCD, CMOS or PSD; the absolute height change of the top of the pile pipe 105 relative to the ground plane is obtained by positioning the antenna through the differential GNSS module, thereby obtaining the pile driving depth and the gravel pile.

[0072] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A gravel pile injection volume monitoring device, comprising a gravel pile, characterized in that: The gravel pile comprises a vibrating hammer (101), a feeding port (104), a pile pipe (105), a pile tip (106) and gravel (107), wherein the vibrating hammer (101) is arranged on the top of the pile pipe (105), the feeding port (104) is opened on one side of the outer wall of the middle part of the pile pipe (105), the bottom of the pile pipe (105) is connected to the pile tip (106), and the gravel (107) is poured into the gravel pile through the feeding port (104); The invention also includes a distance measurement module, which includes a laser (102), a camera (103), a mounting mechanism (108) and a differential GNSS module. The laser (102) and the camera (103) are arranged inside the pile pipe (105). The beam direction of the laser (102) and the optical axis of the camera intersect near the object to be measured. The differential GNSS module is arranged at the top end of the outer side of the pile pipe (105).

2. The method for monitoring the injection volume of a gravel pile according to claim 1, characterized in that: The mounting mechanism (108) is a base plate or a clamp.

3. A method for monitoring the injection volume of a gravel pile, characterized by: The steps include: S1: Installing the laser (102) and the camera (103) inside the pile pipe (105) through a base plate or a clamp to form a triangulation distance measurement module to ensure that the height of the end surface of the crushed stone is always within the range of the triangulation distance measurement module; S2: Based on S1, the relative positions of the camera (103) and the laser (102) are fixed, and then the triangulation distance measurement module is calibrated, so as to obtain the calculated relationship between the imaging position of the light spot image collected by the camera (103) at the receiving element (112) and the height of the gravel end surface; S3: Before construction begins, a triangulation distance measurement module calibrated based on S1 and S2 is installed at the top of the pile pipe (105). The direction is fine-tuned to ensure that the laser beam is always vertically irradiated at the middle position of the end face of the crushed stone, and the radius r inside the pile pipe (105) is measured. S4: During the continuous construction process, the differential GNSS and triangulation distance measurement results are collected in real time and synchronously to generate the crushed stone end face distance curve D and the pile pipe (105) top elevation curve H; S5: Whenever the longitude and latitude of the differential GNSS module changes and becomes stable, when the elevation begins to drop, the pile driver is constructing a new pile point; S6: For the elevation curve H during the construction of the new pile point, find the lowest point h of the elevation min and from h min Starting from the occurrence time, the differential curve H is obtained for the elevation curve diff , where the negative number represents the pile pulling action, and the pile pulling process is accompanied by gravel filling. Search and record H diff The starting and ending time of each consecutive negative moment in the , the i-th consecutive negative moment is recorded as (i start ,i end ); S7: For the distance measurement curve D, search (i start ,i end ) corresponds to the height value at the moment (p start ,p end ) and record the height difference Δd i =p start -p end , and use this value as the height of the gravel filled during the pile extraction process during the i-th period; S8: Accumulated from h min Starting from the moment of occurrence, record the height difference Δd of all crushed stones i The cumulative sum d is used as the final filling height of the crushed stone material, and then based on the pile pipe radius r obtained in step 3, the injection volume V=πr during the construction process of the pile point is obtained. 2 d.

4. A method for monitoring the injection volume of a gravel pile according to claim 3, characterized in that: The S1 specifically includes the following steps: S1.1: Measure the vertical distances from the top of the pile tube (105) to the pile tip (106) and the feeding port (104) respectively, as the farthest and closest measurement ranges of the triangulation distance measurement module; S1.2: A baffle is provided as the measured plane (111), wherein the baffle can move freely within the measuring range, and the position of the laser (102) on the base plate or the fixture is adjusted to ensure that the laser beam is always irradiated at the center of the measured plane (111). After the adjustment, the position of the laser (102) is fixed; S1.3: Fix the baffle to be measured in the middle of the measured range as a reference plane (110), adjust the tilt angle of the camera (103) relative to the laser (102) on the base plate or fixture so that the camera optical axis intersects the laser beam on the measured plane (111), that is, the light spot is imaged at the middle position of the camera receiving element (112), and then fix the position of the camera (103); S1.4: Continue to move the measured plane (111) so that it changes within the full measurement range, and at the same time adjust the focal length and aperture of the camera lens (109) so that the light spot on the measured plane (111) can always be clearly imaged on the camera receiving element (112), and finally fix the lens focal length.

5. The method for monitoring the injection volume of a gravel pile according to claim 3, characterized in that: The S2 specifically includes the following steps: S2.1: Maintaining a rigid connection between the laser (102) and the camera (103), and fixing the focal length and aperture of the camera (103), establish the following equation: Wherein, L is the distance from the intersection of the laser beam and the camera optical axis to the camera lens (109), L' is the distance between the camera lens (109) and the center point of the receiving element (112), and α is the angle between the laser beam and the camera optical axis, all of which are structural parameters of the laser triangulation measurement system and are fixed values; when the measured plane (111) is displaced by a distance x, the deviation position of the imaging spot on the camera receiving element (112) is x'; S2.2: Simplify the structural parameters L, L', and α into two parameters k1 and k2: S2.3: Simplify the relationship between the measured distance x and the spot position x' into an expression containing only two parameters k1 and k2: S2.4: With the help of the object to be measured with known position and distance, multiple measurements are performed. Using multiple sets of known x and x', the least squares method is used to fit the parameters k1 and k2. The distance calculation relationship between the spot image position and the measured surface can be obtained.

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