A rotary drilling hole forming mode monitoring method based on a rotary drilling hole forming mode monitoring device

Abstract

The application discloses a rotary drilling hole-forming shape monitoring method based on a rotary drilling hole-forming shape monitoring device, which comprises a monitoring device support fixed on a drill bit, a sensor for measuring the posture of the drill bit, a data storage module for storing the posture data of the drill bit and a data transmission module for uploading the posture data of the drill bit stored in the data storage module to a server, which are all packaged and fixed in the monitoring device support. The rotary drilling hole-forming shape monitoring device designed in the application can be quickly installed on the drill bit, has small volume, does not affect the hole digging work of the drill bit, has the structural characteristics of signal transmission, vibration resistance, impact resistance, deep water pressure resistance and detachability. The posture of the drill bit can be measured in real time through the sensor, and the posture of the drill bit at different depths can be obtained by matching the footage depth data and the time stamp of the rotary drilling equipment, the hole wall shape is reflected through the posture of the drill bit, and the hole-forming shape of the hole dug by the drill bit can be fitted in real time. The hole-forming shape can be monitored in real time, and the hole-forming quality and the perpendicularity are ensured.

Description

Technical Field

[0001] This invention relates to the field of drilling and grouting construction equipment technology, specifically to a method for monitoring the borehole morphology of rotary drilling based on a rotary drilling borehole morphology monitoring device. Background Technology

[0002] Drilled pile construction is a foundation treatment technology widely used in bridge and railway engineering. Rotary drilling of bored piles is a new type of pile foundation drilling construction method that has developed the fastest in recent years. It uses the rotation of the drill rod and drill bucket, with the drill bucket's own weight plus hydraulic pressure as the drilling pressure, to fill the drill bucket with soil cuttings and then lift the drill bucket out of the soil. The hole is formed by repeatedly rotating the drill bucket, digging, lifting, unloading the soil and using mud to protect the wall.

[0003] However, in the construction process of rotary drilling cast-in-place piles, the inspection operation can only be carried out after the hole is formed. Currently, because it is impossible to monitor the hole shape in real time, the hole shape is prone to deviation, which affects the construction effect. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the above-mentioned background technology and provide a rotary drilling borehole morphology monitoring device and method that can monitor the borehole morphology in real time during the construction of rotary drilling cast-in-place piles to ensure that the borehole morphology meets the construction requirements.

[0005] To achieve this objective, the rotary drilling borehole morphology monitoring device designed in this invention includes a monitoring device bracket that can be fixed to the drill bit. The monitoring device bracket encapsulates and fixes a sensor for measuring the drill bit's attitude, a data storage module for storing the drill bit's attitude data, and a data transmission module for uploading the drill bit's attitude data stored in the data storage module to a server.

[0006] Furthermore, the monitoring device bracket also encapsulates and fixes a battery for supplying power to the data transmission module.

[0007] Preferably, the sensor is a three-axis fiber optic gyroscope sensor that integrates the data storage module.

[0008] Furthermore, the rotary drilling borehole morphology monitoring method based on the aforementioned rotary drilling borehole morphology monitoring device includes the following steps:

[0009] Step 1: Install and fix the monitoring device bracket to the top of the drill bit;

[0010] Step 2: Lower the drill bit to excavate the current hole section. The sensor collects the drill bit attitude at a fixed frequency f1 and stores the drill bit attitude data within a fixed time period T in the data storage module. The data storage module transmits the drill bit attitude data stored in the data storage module to the data transmission module at a fixed frequency f2. The data transmission module is continuously connected to the server.

[0011] Step 3: After the drill bit completes the excavation of the current hole section, let the drill bit stand still for the set time T1, then lift it up;

[0012] Step 4: Calculate the inclination shape of the current hole section based on the drill bit excavation timestamp, drill bit depth, and drill bit attitude data;

[0013] Step 5: Repeat steps 2 to 4 to fit the tilt shape of all hole segments to obtain the current hole shape. Determine whether the current hole shape meets the verticality requirement until a complete hole shape is obtained.

[0014] Furthermore, the drill bit attitude data in step two includes the drill bit tilt angle in the X direction, the drill bit tilt angle in the Y direction, and the drill bit rotation angle.

[0015] Furthermore, the tilt shape of the current hole segment in step four is the tilt shape when the drill bit completes the excavation of the current hole segment and is stationary at the maximum depth position of the current hole segment.

[0016] Furthermore, the method for calculating the inclination shape of the current hole segment in step four based on the drill bit excavation timestamp, drill bit depth, and drill bit attitude data is as follows: Multiple drill bit attitude data points within a distance L from the maximum depth of the current hole segment are selected. The variance of the drill bit's inclination angle in the X direction and its inclination angle in the Y direction within a time interval T1 / 2 before and after each drill bit attitude data point is calculated. The inclination shape of the drill bit when it is at the maximum depth of the current hole segment is calculated based on the drill bit attitude data corresponding to the minimum variance sum. Since it is impossible to determine from which timestamp the drill bit stops after reaching the maximum depth, this invention uses the maximum depth of the current hole segment as a basis, selects data within a certain range from the maximum depth of the current hole segment for variance calculation, and the drill bit remains stationary within T1 / 2 before and after the data with the minimum variance sum, i.e., the total time T1. This requires not only calculating the variance sum when the drill bit is at its maximum depth, but also calculating the variance sum of data within a certain range from the maximum hole depth to avoid the influence of the sensor on the results during the interval of drill bit attitude acquisition (the drill bit may jump up and down, and when the drill bit jumps up, it happens to be within the interval acquisition time of the sensor, and when the drill bit reaches the maximum hole depth, the sensor just acquires the drill bit attitude at this time).

[0017] Furthermore, the step of calculating the tilt pattern of the drill bit when it is at the maximum depth position of the current hole segment based on the minimum variance and the corresponding drill bit attitude data includes: calculating the spatial tilt angle and tilt direction of the drill bit when it is at the maximum depth position of the current hole segment.

[0018] Furthermore, the method for calculating the spatial inclination angle when the drill bit is at the maximum depth position of the current hole segment is as follows: Where θ is the spatial tilt angle of the drill bit when it is at the maximum depth position of the current hole section, α is the tilt angle of the drill bit in the X direction of the minimum variance and the corresponding drill bit attitude data, and β is the tilt angle of the drill bit in the Y direction of the minimum variance and the corresponding drill bit attitude data.

[0019] Furthermore, the method for calculating the tilt direction of the drill bit when it is at the maximum depth position of the current hole segment is as follows: Where φ is the tilt direction of the drill bit when it is at the maximum depth position of the current hole section, α is the tilt angle of the drill bit in the X direction of the minimum variance and the corresponding drill bit attitude data, β is the tilt angle of the drill bit in the Y direction of the minimum variance and the corresponding drill bit attitude data, and γ is the rotation angle of the drill bit in the minimum variance and the corresponding drill bit attitude data.

[0020] The beneficial effects of this invention are as follows: The rotary drilling borehole morphology monitoring device designed in this invention can be quickly installed on the drill bit, is small in size, does not affect the drilling operation, and has structural features such as signal transmission capability, vibration resistance, impact resistance, deep water pressure resistance, and detachability. Through sensors, the drill bit attitude can be measured in real time, and the drill bit attitude at different depths can be obtained by matching the drilling depth data and timestamps of the rotary drilling equipment. By reflecting the borehole wall morphology through the drill bit attitude, the borehole morphology can be fitted in real time. Real-time monitoring of the borehole morphology can ensure borehole quality and verticality. Attached Figure Description

[0021] Figure 1 This is a three-dimensional view of the rotary drilling borehole morphology monitoring device installed on the drill bit in this invention;

[0022] Figure 2 This is a front view of the rotary drilling borehole morphology monitoring device installed on the drill bit in this invention.

[0023] Figure 3 This is a schematic diagram of the internal structure of the rotary drilling borehole morphology monitoring device in this invention;

[0024] Figure 4 This is a schematic diagram of the drilling state of the drill bit in this invention;

[0025] Figure 5 This is a front view of the hole morphology fitting in this invention;

[0026] Figure 6 This is a three-dimensional image of the hole morphology fitting in this invention;

[0027] Among them, 1—drill bit, 2—monitoring device bracket (2.1—base, 2.2—cover, 2.3—cover plate, 2.4—long bolt), 3—sensor, 4—battery. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0029] like Figure 1 As shown in Figure 3, the rotary drilling borehole morphology monitoring device designed in this invention includes a monitoring device support 2, which contains a three-axis fiber optic gyroscope sensor (sensor 3), a lithium battery (battery 4), and a DTU network module (data transmission module). The three-axis fiber optic gyroscope sensor and the data storage module are packaged together.

[0030] like Figure 1 As shown in Figure 2, the monitoring device support 2 is a cylindrical structure, which is installed and fixed in a concealed place near the center of the upper surface of the drill bit 1 to minimize the impact of rock impact and drill bit vibration on the monitoring device.

[0031] like Figure 3 As shown, the monitoring device bracket 2 comprises three parts: a metal base 2.1, a cover plate 2.3, and an acrylic sleeve 2.2. Bolt holes are provided on the base plate of the base 2.1, allowing it to be fixed to the drill bit 1. Sealing rings are added to the contact points between the base 2.1, the cover 2.3, and the sleeve 2.2 to enhance sealing. The sleeve 2.2 prevents electromagnetic signal shielding and is made of thickened acrylic sheet to resist impact and pressure. The cover 2.3 is fixedly connected to the base 2.1 by three long bolts 2.4. The three-axis fiber optic gyroscope sensor and data storage module are packaged together and fixed to the base 2.1 with bolts. The packaging must ensure that there is no relative displacement between the sensor 3 and the drill bit 1. The lithium battery and DTU network module are placed in the middle of the sleeve 2.2, which is filled with bubble wrap to buffer the impact and vibration of the drill bit.

[0032] The measurement principle of the aforementioned rotary drilling borehole morphology monitoring device is as follows:

[0033] During rotary drilling, the borehole wall is shaped by drill bit 1. Therefore, the posture of drill bit 1 within the hole reflects the shape of the borehole wall. By measuring the tilt and rotation angles of drill bit 1 at different depths, the complete shape of the rotary-drilled borehole can be approximated. Since drill bit 1 is deeply embedded in the hole, signals cannot be transmitted within the hole, and sensor 3 can only measure drill bit posture, not its depth. Therefore, the data storage module saves and updates the drill bit posture data for half an hour (time period T) in real time, while the DTU network module continuously maintains data transmission. When drill bit 1 is lifted to the ground, the data is successfully uploaded to the server. Simultaneously, the server receives and saves the drilling depth data uploaded by the rotary drilling rig. By matching the drill bit posture data with the drilling depth using the timestamps of these two sets of data, the morphological data of the borehole wall at different depths can be obtained, such as... Figure 4 As shown in Figure 6, the complete pore morphology can be obtained by fitting the pore morphology of each segment.

[0034] The specific fitting method is as follows: starting from the center of the hole top, fitting is performed section by section downwards. The depth of the center point of each section is the depth corresponding to the hole wall morphology data of that section, and the spatial inclination angle of the line connecting the center point of each section to the center point of the previous section is the spatial inclination angle of the hole wall morphology of that section. The horizontal eccentricity distance and eccentricity direction between the center of the bottom of the hole and the center of the top of the hole at the current deepest point are calculated through the fitted hole morphology. The ratio of the eccentricity distance to the current hole depth is used to obtain the current hole verticality. If the verticality exceeds the threshold required for construction, the server sends a verticality alarm message to the operator. The alarm message includes the current hole verticality, the eccentricity distance at the bottom of the hole, and the eccentricity direction, so that the operator can correct the hole excavation morphology in a timely manner.

[0035] Since the three-axis fiber optic gyroscope sensor needs to be stationary to accurately measure the drill bit's attitude, and the drill bit 1 is always in motion during rotary drilling, the drill bit 1 is left stationary for a time T1 before each soil extraction and before the drill is lifted. After the data is uploaded, the server calculates the sum of variances of the data within the time interval T1 / 2 before and after each data point, and selects the data corresponding to the minimum sum of variances. This data is the data when the drill bit 1 remains stationary for a continuous time interval T1 when the depth is the deepest.

[0036] The specific steps for monitoring the borehole morphology of rotary drilling are as follows:

[0037] Step 1: Before the rotary drilling rig starts the pile foundation drilling construction, ensure that the battery 4 has enough power to meet the measurement requirements, calibrate the sensor 3, and install the monitoring device bracket 2 on the middle of the upper surface of the drill bit 1.

[0038] Step 2: During the drill bit lowering and excavation process, the three-axis fiber optic gyroscope sensor continuously collects the azimuth and inclination angles of drill bit 1 at a frequency of 0.2Hz (i.e., f1). The data storage module receives and saves the data from sensor 3, and sends the data received in the most recent half hour (i.e., time period T) to the DTU network module at a frequency of 0.2Hz (i.e., f2).

[0039] Step 3: Before the rotary drilling rig reaches the excavation position for each cycle and prepares to lift the drill bit, keep drill bit 1 stationary for 30 seconds (i.e., time period T1), and then lift the drill bit.

[0040] Step 4: The DTU network module always maintains a data transmission state. When drill bit 1 emerges from the ground, the DTU network module successfully sends the data to the server. After the server obtains the drill bit attitude data, it matches the timestamp with the rotary drilling footage depth data. First, it filters out the data within 5-10cm (i.e., L) of the maximum depth. Then, it calculates the sum of the variances of the X-direction tilt angle and Y-direction tilt angle within 15s (i.e., time period T1 / 2) before and after each data point. The data with the smallest variance is selected, which is the data when drill bit 1 remains stationary for 30 consecutive seconds at the deepest depth. This yields the local borehole wall tilt pattern at that depth.

[0041] Step 5: Fit the current hole wall morphology with the previously measured hole wall morphology to obtain the current hole morphology. Calculate the horizontal eccentricity distance and eccentricity direction between the center of the bottom and the center of the top of the hole at the current deepest point using the hole morphology. Calculate the ratio of the eccentricity distance to the current hole depth to obtain the current hole verticality. If the verticality exceeds the construction requirement threshold, the server will send a verticality alarm message to the operator. The alarm message includes the current hole verticality, the hole bottom eccentricity distance, and the eccentricity direction.

[0042] Step 6: Repeat steps 2 to 5 until the hole is formed. The complete hole shape can be fitted by these local hole wall morphologies.

[0043] Specific examples are as follows:

[0044] As shown in Table 1, the collected data on the X-direction tilt angle, Y-direction tilt angle, and rotation angle of drill bit 1 were matched with the hole depth using timestamps. The deepest hole depth in this rotary drilling cycle was 34.01m. Data within 10cm of 34.01m were first selected, i.e., data between 39.91m and 34.01m, including 10 data points between 51 minutes 59 seconds and 52 minutes 44 seconds. The variance of the tilt angle within 15 seconds before and after each of the 10 data points was calculated using formula (1) (the sampling frequency was 0.2 Hz, and the data within 15 seconds before and after each data point consisted of 7 data points, from the first 3 to the last 3). The calculation results are shown in Table 2. The variance sum was smallest at 52 minutes and 29 seconds. The data at this moment was the data when drill bit 1 remained stationary for 30 seconds at the deepest point. At this moment, the tilt angles of drill bit 1 in the X direction and Y direction were 0.4 degrees and 0.25 degrees, respectively. The spatial tilt angle θ and tilt direction of drill bit 1 were calculated using formulas (2) and (3), respectively. The measured inclination angle of the borehole wall at a depth of 34.01m at that moment was 0.47 degrees, and the inclination direction was 357.27 degrees.

[0045] (1)

[0046] In the formula, Sn is the sum of the variances of the tilt angles in the X and Y directions within 15 seconds before and after the nth data acquisition, αn is the tilt angle in the X direction of the nth acquisition, and βn is the tilt angle in the Y direction of the nth acquisition. and These are the average values ​​of the X-direction tilt angle and the Y-direction tilt angle, respectively, collected from the (n-3)th to the (n+3)th time.

[0047] (2)

[0048] (3)

[0049] Table 1 Data collected during the hole forming process

[0050] time X tilt angle α / degree Y tilt angle β / degree Rotation angle γ / degree Drill depth / m 20231010145124 0.03 1.91 324.34 33.74 20231010145129 1.44 1.99 320.96 33.77 20231010145134 0.95 2.17 321.21 33.79 20231010145139 1.31 2.42 320.81 33.82 20231010145144 0.37 4.8 321.42 33.85 20231010145149 1.45 -1.13 320.11 33.88 20231010145154 1.38 -5.71 320.86 33.90 20231010145159 -0.43 0.23 323.94 33.93 20231010145204 2.56 0.68 324.42 33.96 20231010145209 2.03 0.71 318.38 33.99 20231010145214 0.79 1.7 322.67 34.01 20231010145219 0.89 0.73 324.27 34.01 20231010145224 0.58 2.42 325.32 34.01 20231010145229 0.4 0.25 325.26 34.01 20231010145234 0.33 1.11 325.29 34.01 20231010145239 0.34 0.83 325.32 34.01 20231010145244 0.37 0.75 325.22 34.01 20231010145249 1.44 1.9 325.30 33.90 20231010145254 0.95 1.92 325.29 32.81 20231010145259 1.31 1.79 325.21 31.12

[0051] Table 2 Variance Calculation Results

[0052] time X tilt angle α / degree Y tilt angle β / degree Sum of variances within 30 seconds 20231010145159 -0.43 0.23 9.534 20231010145204 2.56 0.68 6.108 20231010145209 2.03 0.71 6.949 20231010145214 0.79 1.7 1.434 20231010145219 0.89 0.73 1.111 20231010145224 0.58 2.42 0.763 20231010145229 0.4 0.25 0.496 20231010145234 0.33 1.11 0.635 20231010145239 0.34 0.83 0.674 20231010145244 0.37 0.75 0.578

[0053] In summary, the rotary drilling hole morphology monitoring device designed in this invention can be quickly installed on the drill bit 1, is small in size, does not affect the drilling operation, and has structural features such as signal transmission capability, vibration resistance, impact resistance, deep water pressure resistance, and detachability. The drill bit attitude can be measured in real time via sensor 3, and the drill bit attitude at different depths can be obtained by matching the drilling depth data and timestamps of the rotary drilling equipment. By reflecting the hole wall morphology through the drill bit attitude, the hole morphology can be fitted in real time. Real-time monitoring of the hole morphology ensures hole quality and verticality.

[0054] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the structure of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A method for monitoring the borehole morphology of rotary drilling based on a rotary drilling borehole morphology monitoring device, characterized in that: The rotary drilling borehole morphology monitoring device includes a monitoring device bracket (2) that can be fixed on the drill bit (1). The monitoring device bracket (2) contains a sensor (3) for measuring the drill bit attitude, a data storage module for storing drill bit attitude data, and a data transmission module for uploading the drill bit attitude data stored in the data storage module to the server. The method for monitoring the borehole morphology of rotary drilling based on a rotary drilling borehole morphology monitoring device includes the following steps: Step 1: Install and fix the monitoring device bracket (2) on the top of the drill bit (1); Step 2: Lower the drill bit (1) to excavate the current hole section. The sensor (3) collects the drill bit posture at a fixed frequency f1 and stores the drill bit posture data within a fixed time period T in the data storage module. The data storage module transmits the drill bit posture data stored in the data storage module to the data transmission module at a fixed frequency f2. The data transmission module is continuously connected to the server. Step 3: After the drill bit (1) completes the excavation of the current hole section, the drill bit (1) is left to stand for a set time T1 before being lifted. Step 4: Calculate the inclination shape of the current hole section based on the drill bit excavation timestamp, drill bit depth, and drill bit attitude data; Step 5: Repeat steps 2 to 4 to fit the inclination shape of all hole segments to obtain the current hole shape. Determine whether the current hole shape meets the verticality requirement until a complete hole shape is obtained. The method for calculating the inclination shape of the current hole segment in step four based on the drill bit excavation timestamp, drill bit depth, and drill bit attitude data is as follows: multiple drill bit attitude data within L of the maximum depth of the current hole segment are selected, and the variance of the inclination angle of the drill bit (1) in the X direction and the inclination angle of the drill bit (1) in the Y direction within the T1 / 2 time period before and after each drill bit attitude data is calculated. The inclination shape of the drill bit (1) when it is at the maximum depth position of the current hole segment is calculated based on the drill bit attitude data corresponding to the minimum variance.

2. The rotary drilling borehole morphology monitoring method based on the rotary drilling borehole morphology monitoring device as described in claim 1, characterized in that: The monitoring device bracket (2) also contains a battery (4) for supplying power to the data transmission module.

3. The rotary drilling borehole morphology monitoring method based on a rotary drilling borehole morphology monitoring device as described in claim 1 or 2, characterized in that: The sensor (3) is a three-axis fiber optic gyroscope sensor that integrates the data storage module.

4. The method for monitoring the borehole morphology of rotary drilling based on a borehole morphology monitoring device as described in claim 1, characterized in that: The drill bit attitude data in step two includes the tilt angle of the drill bit (1) in the X direction, the tilt angle of the drill bit (1) in the Y direction, and the rotation angle of the drill bit (1).

5. The rotary drilling borehole morphology monitoring method based on the rotary drilling borehole morphology monitoring device as described in claim 4, characterized in that: The inclination shape of the current hole segment in step four is the inclination shape when the drill bit (1) completes the excavation of the current hole segment and is placed at the maximum depth position of the current hole segment.

6. The rotary drilling borehole morphology monitoring method based on the rotary drilling borehole morphology monitoring device as described in claim 1, characterized in that: The calculation of the tilt pattern of the drill bit (1) at the maximum depth position of the current hole section based on the minimum variance and the corresponding drill bit attitude data includes: calculating the spatial tilt angle and tilt direction of the drill bit (1) at the maximum depth position of the current hole section.

7. The rotary drilling borehole morphology monitoring method based on the rotary drilling borehole morphology monitoring device as described in claim 6, characterized in that: The method for calculating the spatial inclination angle when the drill bit (1) is at the maximum depth position of the current hole section is: , where θ is the spatial tilt angle of the drill bit (1) when it is at the maximum depth position of the current hole section, α is the tilt angle of the drill bit (1) in the X direction of the minimum variance and the corresponding drill bit attitude data, and β is the tilt angle of the drill bit (1) in the Y direction of the minimum variance and the corresponding drill bit attitude data.

8. The method for monitoring the borehole morphology of rotary drilling based on a borehole morphology monitoring device as described in claim 6, characterized in that: The method for calculating the tilt direction of the drill bit (1) when it is at the maximum depth position of the current hole section is as follows: , where φ is the tilt direction of the drill bit (1) when it is at the maximum depth position of the current hole section, α is the tilt angle of the drill bit (1) in the X direction of the minimum variance and the corresponding drill bit attitude data, β is the tilt angle of the drill bit (1) in the Y direction of the minimum variance and the corresponding drill bit attitude data, and γ is the rotation angle of the drill bit (1) in the minimum variance and the corresponding drill bit attitude data.

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