Cement-soil mixing pile intelligent drilling system and drilling method based on spontaneous mixing resistance monitoring

Abstract

The invention discloses a cement-soil mixing pile intelligent drilling system and drilling method based on spontaneous mixing resistance monitoring, and belongs to the field of cement-soil mixing pile construction equipment. A plurality of groups of stirring blades are arranged on the drill bit body, a strain gauge is arranged at the joint of the end part of each stirring blade and the drill bit body, the strain gauges are connected with a wireless sensor, and the wireless sensor is responsible for collecting signals of the strain gauges, converting the signals into wireless signals and transmitting the wireless signals to a ground receiving system; the equipment can accurately monitor the hardness change of the soil layer in real time and reflect the distribution condition of the soil layer, and is particularly suitable for areas with complicated interbed distribution of soil layers such as the yellow flood area. The equipment analyzes the soil layer distribution of each depth position in real time and outputs optimal process parameters, intelligent construction is achieved, it is ensured that the process parameters can be adjusted in real time in the drill lifting process, and the construction effect is optimized.

Description

Technical Field

[0001] This invention designs a smart drilling system and drilling method for cement-soil mixing piles based on spontaneous mixing resistance monitoring, belonging to the field of cement mixing pile construction equipment. Background Technology

[0002] In geologically complex areas such as the Yellow River floodplain, strata often exhibit a significant interbedded distribution, with different lithological layers such as loess, silty clay, and clay alternating. These strata not only show significant differences in soil hardness but also exhibit high levels of deep-seated stress. Traditional cement-soil mixing pile construction technology struggles to adapt key process parameters such as drilling, mixing, and shotcreting to these complex geological conditions in real-time and dynamically, resulting in poor pile quality and severely limiting the improvement of pile bearing capacity and overall foundation stability.

[0003] To address the aforementioned issues, existing technologies disclose methods for construction control by monitoring apparent parameters of the mixing pile machine during the penetration process, such as drive current or tension. While data acquisition is relatively convenient, these parameters are affected by various factors such as penetration depth, mechanical efficiency decay, and system losses, making it difficult to establish a stable and direct correspondence with actual soil mechanical parameters, resulting in inherent limitations in identification accuracy. Furthermore, existing technologies also disclose some intelligent mixing pile control devices that install additional static penetration probes or strain gauges at the drill bit tip or drill rod head. These devices analyze the pile end resistance and side friction resistance during penetration to determine soil hardness and adjust construction parameters. However, such external probes are typically structurally complex and difficult to meet the stringent requirements of actual engineering projects for long-term reliability, structural durability, and ease of maintenance in harsh engineering environments. Summary of the Invention

[0004] To address this issue, this invention proposes a smart drilling system and method for cement-soil mixing piles based on spontaneous mixing resistance monitoring. This system can monitor soil hardness changes in real time and accurately reflect soil layer distribution, making it particularly suitable for areas with complex interlayered soil layers, such as the Yellow River floodplain.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a smart drilling system for cement-soil mixing piles based on spontaneous mixing resistance monitoring, including a drill bit, mixing blades, strain gauges, wireless sensors, signal conditioners, wireless receivers, a data processing system, and an electrical control system; The drill bit is equipped with multiple sets of stirring blades, and a strain gauge is provided at the connection between the end of each stirring blade and the drill bit. The strain gauge is connected to a wireless sensor. The wireless sensor is responsible for acquiring the signal from the strain gauge and converting it into a wireless signal for transmission to the ground receiving system; the signal conditioner is used to amplify the signal from the strain gauge and perform filtering and analog-to-digital conversion. The wireless receiver is used to receive wireless signals from the drill bit and decode them into processable data; The data processing system is responsible for processing and analyzing the signals received by the wireless receiver, and monitoring changes in mixing resistance and soil hardness in real time. The electrical control system receives signals processed by the data processing system, obtains optimal construction parameters, and adjusts the parameters at each position during the drilling process based on the optimal construction parameters.

[0006] As a further technical solution, a relay node is also included, which is located on the drill pipe and is used to enhance the transmission range of wireless signals by receiving signals from the drill bit and forwarding them.

[0007] As a further technical solution, a battery is also provided on the drill bit body, which is powered by the wireless sensor and signal conditioner.

[0008] As a further technical solution, a groove is made at the connection between the stirring blade and the drill bit body, and a strain gauge is installed at the grooved position.

[0009] As a further technical solution, the wireless receiver is installed on the ground.

[0010] As a further technical solution, the data processing system is located on the ground.

[0011] Secondly, the present invention also provides a monitoring method for a smart drilling system for cement-soil mixing piles based on spontaneous mixing resistance monitoring, as follows: Before construction, a calibration model for ground stress and strain signals is established, and the optimal construction parameters for each type of soil layer are obtained. The drill bit is started, and the mixing blades begin to rotate and cut and mix the soil layer. During drilling, the resistance generated by the interaction between the mixing blades and the soil layer is captured in real time by strain gauges. The signal is transmitted through a wireless sensor, amplified by a relay node, and then transmitted to a wireless receiver. The wireless receiver sends the signal to the ground data processing system. After receiving the signal, the ground data processing system calculates the mixing resistance in real time and, in conjunction with a calibration model of ground stress and strain signals, corrects for the influence of ground stress and estimates the current soil layer hardness and type. The system automatically matches the optimal grouting pressure and drilling speed and adjusts relevant construction parameters through the electrical control system.

[0012] As a further technical solution, based on the geological survey report, the soil layer type, distribution and depth of the construction area are determined, and preliminary tests are carried out; by drilling and stirring representative soil layer samples, the correspondence between strain gauge output signals and actual depths is recorded, and a calibration model of geostress and strain signals is established. As a further technical solution, the relationship model between the geostress and the strain gauge signal is as follows;

[0013] in, The output signal of the acquired strain gauge, is the coefficient to be calibrated, F is the actual stirring resistance, and h is the drilling depth.

[0014] As a further technical solution, the grouting pressure decreases as the formation hardness decreases, while the drilling speed increases as the formation hardness increases.

[0015] The beneficial effects of this invention are as follows: This invention discloses a smart drilling system for cement-soil mixing piles based on spontaneous mixing resistance monitoring. By installing strain gauges at the key connection between the mixing blades and the drill bit body, it monitors in real time the dynamic resistance experienced by the mixing blades during the cutting and mixing of the strata, thus reflecting the hardness and distribution characteristics of the soil layer. As the mixing resistance increases, it can be determined that the soil layer is gradually hardening, and construction parameters can be automatically adjusted during the upward grouting process, achieving intelligent construction. This invention abandons the technical approach of adding an external independent probe, instead seamlessly integrating the sensing function into the structure of the construction drill bit body. This not only fundamentally avoids the problems of complex, easily damaged, and poorly adaptable structures of additional probes, but also significantly improves the system's engineering applicability and reliability. By directly sensing the resistance generated by the interaction between the mixing blades and the soil layer, the acquired resistance signal is highly correlated with the immediate mechanical state of the strata currently being mixed, achieving precise correspondence between strata parameter identification and construction parameter control, greatly improving control accuracy. The introduction of this smart drill bit can not only effectively improve the quality of cement-soil mixing pile construction, but also significantly improve construction efficiency. Especially in complex soil environments, it can provide more accurate soil hardness data and adjust process parameters in real time through data processing and electrical control systems, thereby avoiding the inherent problems in quality control of traditional methods and existing smart solutions. Attached Figure Description

[0016] Figure 1 This is a top view of the intelligent drilling system for cement-soil mixing piles based on spontaneous mixing resistance monitoring proposed in this invention. Figure 2 A front view of a smart drilling system for cement-soil mixing piles based on spontaneous mixing resistance monitoring; Figure 3A side view of a smart drilling system for cement-soil mixing piles based on spontaneous mixing resistance monitoring; Figure 4 A schematic diagram of strain gauge installation in a smart drilling system for cement-soil mixing piles based on spontaneous mixing resistance monitoring. Figure 5 Construction drawings for a smart drilling system for cement-soil mixing piles based on spontaneous mixing resistance monitoring; Figure 6 A diagram outlining the mechanism of a smart drilling system for cement-soil mixing piles based on spontaneous mixing resistance monitoring. In the diagram: 1. Stirring blade; 2. Strain gauge; 3. Wireless sensor; 5. Battery; 4. Signal conditioner; 6. Wireless receiver; 7. Relay node; 8. Data processing system; 9. Electrical control system; 10. Drill bit. Detailed Implementation The intelligent drilling system for cement-soil mixing piles based on spontaneous mixing resistance monitoring disclosed in this invention will be described in detail below with reference to the accompanying drawings; The intelligent drilling system for cement-soil mixing piles based on spontaneous mixing resistance monitoring disclosed in this embodiment can monitor soil hardness changes in real time and accurately, reflecting the soil layer distribution. It is particularly suitable for areas with complex interlayered soil layers, such as the Yellow River floodplain. The equipment analyzes the soil layer distribution at each depth in real time and outputs the optimal process parameters to achieve intelligent construction and ensure that process parameters can be adjusted in real time during the drilling process to optimize the construction effect. Specifically, such as Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, the intelligent drilling system for cement-soil mixing piles based on spontaneous mixing resistance monitoring includes a drill bit 10, mixing blades 1, four sets of strain gauges 2, wireless sensors 3, signal conditioner 4, battery 5, wireless receiver 6, relay node 7, data processing system 8, and electrical control system 9. Among them, the stirring blade 1 generates stirring resistance by rotating and stirring the soil layer. The blade is usually made of wear-resistant and corrosion-resistant alloy material. It is connected to the body of the drill bit 10. A groove is made at the connection between the blade and the body of the drill bit 10 and a strain gauge 2 is placed there. Strain gauge 2 is used to measure the compressive force at the connection between the mixing blade 1 and the drill bit 10. By sensing the stress change, the soil hardness information is obtained. Four sets of strain gauges 2 are evenly distributed at the connection to ensure comprehensive monitoring of the mixing process. The resistance of the strain gauge 2 changes with the pressure. Through this change, the mixing resistance data can be obtained in real time. The mixing resistance data is transmitted by the wireless sensor 3. Wireless sensor 3 is responsible for collecting the signals from strain gauge 2 and converting them into wireless signals for transmission to the ground receiving system. The signal conditioner 4 is used to amplify the signal transmitted from the strain gauge 2, and to perform filtering and analog-to-digital conversion to ensure the stability and accuracy of the signal and avoid the influence of environmental noise on the data. Battery 5 provides power to the entire system, especially the wireless sensors 3 and signal conditioner 4. It typically uses high-capacity lithium batteries, which can operate stably underground for extended periods, ensuring the system's power needs are met. The batteries require high temperature resistance and corrosion resistance. The wireless receiver 6 is mounted on the ground to receive wireless signals from the drill bit 10 and decode them into processable data. It maintains communication with the wireless sensor 3 on the drill bit 10 through wireless communication technology to ensure that the ground control system can receive and process the stirring resistance data from the drill bit 10 in real time. The relay node 7 is located on the drill pipe and is used to enhance the transmission range of wireless signals. By receiving signals from the drill bit 10 and forwarding them, it ensures that the signals can be transmitted to the ground receiver, thereby enhancing the coverage of the system, which is especially suitable for deep drilling. The data processing system is located on the ground and is responsible for processing and analyzing the signals received by the wireless receiver, and monitoring the changes in mixing resistance and soil hardness in real time. After the data processing system processes the data, the electrical control system obtains the optimal construction parameters. Based on the optimal construction parameters, the electrical control system adjusts parameters such as grouting pressure and drilling speed at various locations during the drilling process, thereby ensuring the quality of cement-soil mixing piles in complex strata. The equipment can acquire and analyze the soil layer distribution at various depths in real time and output the optimal process parameters to achieve intelligent construction and ensure that process parameters can be adjusted in real time during the drilling process to optimize the construction effect.

[0017] In this embodiment, the stirring resistance monitoring of the drill bit 10 during the drilling process is achieved by the stirring blade 1 spontaneously squeezing the strain gauge 2 located at the intersection of the stirring blade 1 and the drill rod due to the soil resistance during the drilling stirring process.

[0018] Furthermore, the aforementioned mixing blade 2 generates mixing resistance by rotating and mixing the soil layer. The blade is typically made of wear-resistant and corrosion-resistant alloy material. It is connected to the drill rod, and a groove is cut at the connection point to place a strain gauge. The strain gauge is in close contact with the end of the mixing blade. When the mixing blade encounters resistance during construction, it compresses the strain gauge. The mixing blade is fixed to the drill bit with bolts to ensure that the mixing blade does not undergo relative displacement during construction. The strain gauge is used to measure the compressive force at the connection point between the mixing blade and the drill rod. By sensing the stress change, information on the soil hardness is obtained. Four sets of strain gauges are evenly distributed at the connection point to ensure comprehensive monitoring of the mixing process. The resistance of the strain gauge changes with the pressure. Through this change, mixing resistance data can be obtained in real time. The mixing resistance data is transmitted by a wireless sensor. Furthermore, a pressure calibration algorithm is employed to address the interference caused by ground stress due to increased depth. The ground stress experienced by drill bit 10 increases with depth. Previous experiments have verified that depth and ground stress have a certain impact on the optimal construction parameters under different soil layers, which can interfere with the parameter decision-making system. Through actual tests at different depths and under different soil layer conditions, a relationship model between ground stress and strain gauge 2 signals is established, and errors caused by ground stress are calibrated in real time.

[0019]

[0020] in, The output signal of strain gauge 2 is collected. The coefficient to be calibrated is F, the actual stirring resistance is h, and the drilling depth is h. Before on-site construction, based on geological survey data, a pre-test was conducted in the same soil layer (assuming the actual stirring resistance remains unchanged). The output signal of strain gauge 2 and the relationship with the depth were recorded to obtain the calibration coefficient. Thus, the relationship between the actual stirring resistance and the output signal of strain gauge 2 was obtained, which solved the measurement interference caused by the increase in ground stress when the depth increased.

[0021] Furthermore, to enhance the transmission range of wireless signals and avoid signal data loss due to wireless signal attenuation, a relay node 7 is installed at the midpoint of the drill pipe, especially in cases of large drilling depth and complex soil layers, to extend the signal transmission distance and improve signal stability.

[0022] Furthermore, after receiving the mixing resistance data from drill bit 10, the data processing system processes the data using a built-in algorithm. Based on the real-time acquired mixing resistance data, the system can calculate the hardness or type of the current soil layer.

[0023] Furthermore, based on the database of optimal construction parameters for different soil layers established through preliminary tests, the data processing system queries the corresponding optimal construction parameters by comparing real-time collected soil layer information. Key construction parameters mainly include grouting pressure and drilling speed. If the soil layer is identified as hard, the system can automatically select a higher grouting pressure and a lower drilling speed to enhance the mixing effect; if the soil layer is soft, the system may select a lower grouting pressure and a higher drilling speed. The grouting pressure ranges from 5 MPa to 20 MPa; the drilling speed ranges from 20 cm / min to 100 cm / min.

[0024] Furthermore, once the data processing system determines the properties of the current soil layer and extracts the optimal construction parameters, the electrical control system will adjust the operation of the drill bit 10 based on these parameters.

[0025] Furthermore, all data throughout the construction process (such as mixing resistance, grouting pressure, and drilling speed) is recorded and can be used for later analysis. By analyzing the parameters and results of each construction operation, the system can gradually optimize the matching between soil layer type and construction parameters, thereby continuously improving construction efficiency and pile quality.

[0026] The specific monitoring methods are as follows: Before construction, based on the geological survey report, the soil layer type, distribution, and depth of the construction area were determined, and pre-tests were conducted. Through drilling and mixing representative soil samples, the correspondence between the output signal of strain gauge 2 and the actual depth was recorded, a calibration model of in-situ stress and strain signals was established, and the optimal construction parameters (including grouting pressure and drilling speed) for each type of soil layer were obtained. The smart drill bit 10 was connected to the drill rod, ensuring that the four sets of strain gauges 2 were accurately installed at the slotted positions where the mixing blade 1 connected to the drill rod. The connection and power of the wireless sensor 3, signal conditioner 4, and high-capacity lithium battery were checked to ensure the communication module and relay node were properly configured. After the drill bit 10 was started, the mixing blade 1 began to rotate and cut and mix the soil layer. During drilling, the resistance generated by the interaction between the mixing blade 1 and the soil layer was captured in real time by the strain gauge 2. The signal was transmitted through the wireless sensor 3, amplified by the relay node, and then transmitted to the ground wireless receiver. After receiving the signal, the ground data processing system calculated the mixing resistance in real time and, combined with the depth-stress model established in the pre-tests, corrected for the influence of in-situ stress, and estimated the current soil layer hardness and type. The system automatically matches the optimal grouting pressure and drilling speed, and adjusts relevant construction parameters through the electrical control system.

[0027] The aforementioned grouting pressure decreases as the soil hardness decreases, while the drilling speed increases as the soil hardness increases. For example, when the soil hardness is detected to increase, the system automatically adjusts the grouting pressure to 15MPa and reduces the drilling speed to 30cm / min; when the soil softens, the system adjusts the grouting pressure to 8MPa and increases the drilling speed to 80cm / min.

[0028] The drill bit 10 incorporates strain gauges 2 at the critical connection between the mixing blades 1 and the drill bit body to monitor the dynamic resistance experienced by the mixing blades 1 during cutting and mixing of the strata in real time, thereby reflecting the hardness and distribution characteristics of the soil layer. As the mixing resistance increases, it can be determined that the soil layer is gradually hardening, and construction parameters can be automatically adjusted during the upward grouting process, achieving intelligent construction. This invention abandons the technical approach of adding an external independent probe, instead seamlessly integrating the sensing function into the structure of the construction drill bit 10. This not only fundamentally avoids the problems of complex, easily damaged, and poorly adaptable structures associated with additional probes, but also significantly improves the system's engineering applicability and reliability. By directly sensing the resistance generated by the interaction between the mixing blades 1 and the soil layer, the acquired resistance signal is highly correlated with the immediate mechanical state of the strata facing the current mixing operation, achieving precise correspondence between strata parameter identification and construction parameter control, greatly improving control accuracy. The introduction of this smart drill bit 10 can not only effectively improve the quality of cement-soil mixing pile construction, but also significantly improve construction efficiency. Especially in complex soil environments, it can provide more accurate soil hardness data and adjust process parameters in real time through data processing and electrical control system, thereby avoiding the inherent problems in quality control of traditional methods and existing smart solutions.

Claims

1. A smart drilling system for cement-soil mixing piles based on spontaneous mixing resistance monitoring, characterized in that, Includes drill bits, stirring blades, strain gauges, wireless sensors, signal conditioners, wireless receivers, data processing systems, and electrical control systems; The drill bit is equipped with multiple sets of stirring blades, and a strain gauge is provided at the connection between the end of each stirring blade and the drill bit. The strain gauge is connected to a wireless sensor. The wireless sensor is responsible for acquiring the signal from the strain gauge and converting it into a wireless signal for transmission to the ground receiving system; the signal conditioner is used to amplify the signal from the strain gauge and perform filtering and analog-to-digital conversion. The wireless receiver is used to receive wireless signals from the drill bit and decode them into processable data; The data processing system is responsible for processing and analyzing the signals received by the wireless receiver, and monitoring changes in mixing resistance and soil hardness in real time. The electrical control system receives signals processed by the data processing system, obtains optimal construction parameters, and adjusts the parameters at each position during the drilling process based on the optimal construction parameters.

2. The intelligent drilling system for cement-soil mixing piles based on spontaneous mixing resistance monitoring as described in claim 1, characterized in that, It also includes relay nodes located on the drill pipe to enhance the transmission range of wireless signals by receiving and forwarding signals from the drill bit.

3. The intelligent drilling system for cement-soil mixing piles based on spontaneous mixing resistance monitoring as described in claim 1, characterized in that, A battery is also provided on the drill bit body, which powers the wireless sensor and signal conditioner.

4. The intelligent drilling system for cement-soil mixing piles based on spontaneous mixing resistance monitoring as described in claim 1, characterized in that, A slot is made at the connection between the stirring blade and the drill bit body, and strain gauges are installed at the slotted position.

5. The intelligent drilling system for cement-soil mixing piles based on spontaneous mixing resistance monitoring as described in claim 1, characterized in that, The wireless receiver is installed on the ground.

6. The intelligent drilling system for cement-soil mixing piles based on spontaneous mixing resistance monitoring as described in claim 1, characterized in that, The data processing system is located on the ground.

7. The drilling method of the intelligent drilling system for cement-soil mixing piles based on spontaneous mixing resistance monitoring as described in any one of claims 1-6, characterized in that, as follows: Before construction, a calibration model for ground stress and strain signals is established, and the optimal construction parameters for each type of soil layer are obtained. The drill bit is started, and the mixing blades begin to rotate and cut and mix the soil layer; during the drilling process, the resistance generated by the interaction between the mixing blades and the soil layer is captured by strain gauges in real time. The signal is transmitted through a wireless sensor, amplified by a relay node, and then transmitted to a wireless receiver. The wireless receiver sends signals to the ground data processing system. After receiving the signals, the ground data processing system calculates the mixing resistance in real time and, in conjunction with the calibration model of ground stress and strain signals, corrects the influence of ground stress and calculates the current soil layer hardness and type. The system automatically matches the optimal grouting pressure and drilling speed and adjusts relevant construction parameters through the electrical control system.

8. The monitoring method for a smart drilling system for cement-soil mixing piles based on spontaneous mixing resistance monitoring as described in claim 7, characterized in that, Based on the geological survey report, the soil layer type, distribution and depth of the construction area were determined, and preliminary tests were carried out. By drilling and stirring representative soil layer samples, the correspondence between strain gauge output signals and actual depths was recorded, and a calibration model of geostress and strain signals was established.

9. The monitoring method for a smart drilling system for cement-soil mixing piles based on spontaneous mixing resistance monitoring as described in claim 7, characterized in that, The relationship model between the geostress and the strain gauge signal is as follows; in, The output signal of the acquired strain gauge, is the coefficient to be calibrated, F is the actual stirring resistance, and h is the drilling depth.

10. The monitoring method for a smart drilling system for cement-soil mixing piles based on spontaneous mixing resistance monitoring as described in claim 7, characterized in that, The grouting pressure decreases as the formation hardness decreases, while the drilling speed increases as the formation hardness increases.

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