Pipe jacking construction resistance identification and jacking force early warning system and method

Abstract

A pipe jacking construction resistance recognition and jacking force early warning system and method comprises a jack arranged on a supporting wall, a jacking force sensor arranged on the jack, jacking iron connected with the jack and a pipe jacking machine, a supporting frame arranged at the lower end of the jacking iron, a pipe jacking machine head located at the front end of the pipe jacking machine, and a one-way valve arranged on an inner wall hole of a pipe joint of the pipe jacking machine. The plurality of sensor mounting mark positions are arranged on a pipe joint of the pipe jacking machine; in order to overcome the defects of calculation of jacking resistance and jacking force parameters in pipe jacking construction, jacking force early warning is given through dynamic recognition of jacking resistance and jacking force in the pipe jacking construction process, so that a construction scheme is adjusted in time, the construction process control quality is improved, and the project progress and construction safety are guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of pipe network construction, and relates to a pipe jacking construction resistance identification and jacking force early warning system and method. Background Art

[0002] As a trenchless pipeline laying technology for underground projects, pipe jacking construction has been widely used in underground pipe network construction projects in recent years because of its advantages such as no damage to the road surface, small construction disturbance, and protection of urban landscape. Jacking resistance is an important construction parameter that must be determined in pipe jacking construction. It directly affects the calculation of jacking force, and then affects the selection of indicators such as the back design of the working well and the strength requirements of the pipe section. There are many existing methods for calculating jacking resistance, generally theoretical formula calculation and empirical formula inference. Although there are many theoretical formulas, it is difficult to consider the influence of factors such as soil changes on resistance, resulting in unclear applicable conditions, large differences in calculation results, and confusion in actual construction applications. Although the empirical formula is simple and clear, it can only be applied to certain specific conditions such as soil quality, pipe diameter, and jacking length, and cannot adapt to the dynamic jacking process with constantly changing resistance. It can be seen that the calculation of jacking force based on the resistance calculated by the existing method does not conform to the dynamic change of resistance during the jacking process. Smaller or larger jacking forces cannot guarantee the construction progress and construction quality, which is easy to lead to failure to jack or cause "back soil effect". Therefore, real-time understanding of the resistance and force of the jacking process is of great practical significance for achieving real-time control of the jacking force.

[0003] At present, there have been relevant studies on the analysis of pipe jacking construction resistance and the prediction of jacking force. Jin Lianghai et al. proposed an automatic identification method for pipe jacking friction resistance, aiming to improve the safety and smooth progress of pipe jacking construction. Zhang Shuyuan et al. conducted a systematic study on the jacking resistance in pipe jacking technology, and analyzed the resistance characteristics of horizontal pipe jacking, curved pipe jacking and vertical pipe jacking. The results showed that the jacking force was greatly affected by factors such as geological conditions and construction level, and it was difficult to accurately predict. Zhou Zaiyan proposed a friction resistance calculation method for large-section rectangular jacking pipes and predicted the jacking force. This method has strong practicality and has been widely used in parameter design before subway construction. Saeed Rahjoo et al. compared different trenchless pipe jacking loading models and emphasized the need for more research to improve the accuracy of jacking force estimation. HaoZhou et al. proposed a machine learning model for predicting jacking force in pipe jacking construction, among which the PSO-SVR model performed better than the PSO-BPNN model. MIPeerun et al. summarized the application of advanced technologies such as discrete element simulation (DEM) and 3D printing in improving the prediction of pipeline jacking force in underground pipeline construction.

[0004] The above studies show that the analysis and prediction of pipe jacking construction resistance and jacking force are important key links in pipe jacking construction, which directly affect the progress and quality of pipe jacking construction and have important practical significance for engineering practice. However, existing studies have certain limitations in practical applications and do not conform to the dynamic changes of resistance during jacking. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a system and method for identifying resistance and jacking force warning in pipe jacking construction. In view of the deficiencies in the calculation of jacking resistance and jacking force parameters in pipe jacking construction, a jacking force warning is given by dynamically identifying the jacking resistance and jacking force during the pipe jacking construction process, so as to timely adjust the construction plan, improve the process control quality of the construction, and ensure the project progress and construction safety.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a pipe jacking construction resistance identification and jacking force warning system, which includes a jack arranged on a supporting wall, a jacking force sensor arranged on the jack, a jacking iron connecting the jack and the pipe jacking machine, a support frame arranged at the lower end of the jacking iron, a pipe jacking machine head located at the front end of the pipe jacking machine, a one-way valve arranged on the inner wall hole of the pipe section of the pipe jacking machine, and multiple sensor installation marking positions arranged on the pipe section of the pipe jacking machine; wherein the first marking position is located one meter away from the pipe jacking machine head, the second marking position is located at one-third of the pipe section of the pipe jacking machine, and the third marking position is located at two-thirds of the pipe section of the pipe jacking machine.

[0007] A pressure sensor is installed in the one-way valve, a signal converter is connected to the pressure sensor, and a data collector is connected to the signal converter.

[0008] A base bracket is arranged below the data collector, a cable is connected to the pressure sensor, and a communication cable is connected to the data collector and the console.

[0009] There are two jacking force sensors, and six pressure sensors are arranged on the pipe segment circle where each marking position is located. The pressure sensors are fixed on the lifting column and connected to the lifting column cable.

[0010] The data collector is associated with a data converter, and the data collector conditions the electrical signals output by the pressure sensor and the top force sensor to improve the quality and accuracy of the signals.

[0011] The resistance and top force data processed by the data collector are transmitted to the control console via a communication cable.

[0012] The method for constructing the pipe jacking construction resistance identification and jacking force warning system as described above comprises the following steps: S1, determine the installation area of ​​the pipe jacking resistance sensor, and divide the soil disturbance during the pipe jacking construction into zones through theoretical mechanical force analysis to ensure the effectiveness of the resistance sensor installation position; S2, installing the resistance sensor and the jacking force sensor, respectively installing the resistance sensor and the jacking force sensor to the determined positions; before installing the resistance sensor, mark the installation position of the resistance sensor on the pipe section of the pipe jacking machine, set three marking positions, and set 6 resistance sensor installation holes at each marking position on the pipe section, and the size of the hole position must match the size of the resistance sensor; S3, install the resistance and top force data converter and data acquisition device. The data converter is associated with the data acquisition device. The data acquisition device conditions the electrical signals output by the resistance and top force sensors in the signal conditioning circuit to improve the quality and accuracy of the signals. The sampling frequency must satisfy the Nyquist sampling theorem, that is, the sampling frequency should be at least twice the highest frequency of the signal. The data acquisition device converts the amplitude value of the sampled signal into a finite discrete value and introduces a quantization error to complete the quantization processing of the sampled signal. The quantized discrete value is converted into a binary code for computer processing and storage. Noise or interference in the signal is removed by filtering.

[0013] S4, build a resistance and top force console, and the data collector transmits the processed resistance and top force data to the console through a communication cable; support human-computer interaction UI interface, interact with visualization software by creating data tables and custom charts, complete resistance and top force data processing and visualization, and realize automatic identification of resistance and top force; S5, set up a resistance and top force warning system, determine the warning values ​​of resistance and top force, and perform system alarm control on the warning values.

[0014] In S1, it specifically includes: S1-1, the soil disturbed by pipe jacking construction is divided into several disturbance zones, namely: extrusion disturbance zone, shear disturbance zone, unloading disturbance zone, grouting shear disturbance zone and consolidation zone; S1-2, during the jacking process, friction resistance is generated between the casing and the surrounding soil. As a result of this force, a shear disturbance zone is generated in the soil around the casing of the tunnel boring machine. The range of this zone is smaller than that of other zones. S1-3, when no grouting is done, the soil in the grouting shear disturbance zone is subject to the shear friction resistance between the pipeline and the surrounding soil, and will repeatedly move forward and backward along the pipeline axis during the construction process. After grouting, the mud converts the dry friction between the pipeline and the soil into wet friction, reducing the friction resistance, while supporting the surrounding soil and reducing the soil deformation caused by the pipe jacking construction; S1-4, determine the installation position of the jacking force sensor; through finite element analysis, install the jacking force sensor on the thrust transmission path of the jack, that is, on the piston rod or thrust plate of the jack, so as to achieve the effect of accurately measuring the jacking force; S1-5. During the installation of the resistance and jacking force sensors, the installation position of the sensors should ensure their stability to avoid being affected by vibration or other external forces during the jacking process. The resistance and jacking force sensors should be firmly fixed to avoid loosening.

[0015] In S2, since the resistance sensor is set on the pipe section, in order to prevent water and dust and ensure the durability of the sensor, it is necessary to install a one-way valve on the hole before installing the resistance sensor, and then install the resistance sensor; the sensor is connected to the lifting column, which is controlled by a cable to push the resistance sensor outward so that the resistance sensor can contact the soil to measure the resistance and retract it after the measurement is completed; the jacking force sensor is directly installed on the thrust plate of the jack.

[0016] In S5, it specifically includes: S5-1, when the jacking resistance increases, the structural performance of the pipe joint and the back wall of the working pit cannot be increased without limit, and the equipment's own capacity also has certain limits; therefore, when determining the maximum allowable construction resistance and jacking force, the mechanical properties of the pipe, the maximum allowable load of the back wall structure of the working pit, the capacity of the jacking equipment, and the construction technical measures should be comprehensively considered. When the system is initialized, the resistance value and the jacking force value are determined according to the construction design parameters; the jacking resistance should be calculated according to the local empirical formula. If there is no empirical value, refer to the following formula for calculation: ; In the formula is the jacking resistance (kN); is the outer diameter of the pipe (m); Design the jacking length of the pipeline (m); is the average friction resistance per unit area between the outer wall of the pipe and the soil (kN / m 2 ); is the head-on resistance of the pipe jacking machine (kN); S5-2, multiply the calculated resistance value by the safety factor to obtain the maximum and minimum resistance values, where the safety factor is selected by referring to the method of combining the theoretical calculation value with the current construction experience; then, the maximum and minimum top force values ​​are calculated by combining the resistance value and the design parameters, and the calculated maximum resistance value and top force value are set as the resistance warning and top force warning reference values ​​of the system; during the construction process, the warning values ​​need to be continuously improved and modified according to the actual engineering data; S5-3, early warning control is to compare the resistance and top force values ​​obtained by the system with the system early warning values ​​to determine whether the current real-time resistance and top force exceed the early warning value range. Once exceeded, the system alarm is triggered.

[0017] The main beneficial effects of the present invention are: A resistance and jacking force identification and early warning system for pipe jacking construction has been set up, which can dynamically identify the jacking resistance and jacking force during the jacking process, solving the problem that the calculation of resistance and jacking force in current construction does not conform to the actual situation. Through resistance and jacking force early warning during the construction process, it can promptly remind the adjustment of the construction plan, greatly improve construction efficiency and quality, and enhance the level of construction safety.

[0018] During the jacking process, when measuring the jacking resistance, the one-way valve on the pipe section opens, and the lifting column pushes out the pressure sensor. After extending out of the jacking pipe section through the opened one-way valve, the sensor contacts the soil. The sensor measures the pressure value, which is transmitted to the signal converter through a cable. The analog signal is then converted into an electrical signal. The electrical signal is transmitted to the control console through a communication cable at the data acquisition device. The resistance value is displayed on the control console to complete the identification of the resistance.

[0019] The jacking force sensor measures the jacking force value during the jacking process. The jacking force value is transmitted to the signal converter through the cable. At the data collector, the electrical signal is transmitted to the console through the communication cable. The jacking force value is displayed at the console to complete the identification of the jacking force.

[0020] The resistance and force warning values ​​are set in the console. When the resistance or force is greater than the threshold, the force value is significantly less than the resistance value, or the force value is significantly greater than the resistance value, the console will give an alarm. After the measurement is completed, the one-way valve is closed and the pressure sensor is retracted into the pipe section.

[0021] Through dynamic identification of jacking resistance and jacking force during pipe jacking construction, jacking force warning can be given to adjust the construction plan in time, improve the quality of construction process control, and ensure project progress and construction safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0023] Figure 1 This is a diagram for dividing the soil disturbance zone around the jacking pipe of the present invention.

[0024] Figure 2 It is a schematic diagram of the installation of the top force sensor of the present invention.

[0025] Figure 3 It is a schematic diagram of the marking position of the resistance sensor of the present invention.

[0026] Figure 4 This is a diagram of the installation positions of the resistance sensor and the one-way valve of the present invention.

[0027] Figure 5 This is the architecture diagram of the resistance dynamic measurement system of the present invention.

[0028] Figure 6 This is a hardware connection diagram of the pipe jacking construction resistance and jacking force identification and early warning system of the present invention.

[0029] Figure 7 This is a schematic diagram of the installation position structure of the resistance sensor pipe segment of the present invention.

[0030] In the figure: 1. jack, 2. supporting wall, 3. jacking iron, 4. supporting frame, 5. pipe jacking machine, 6. machine head, 7. pipe section, 8. first marking position, 9. second marking position, 10. third marking position, 11. jacking force sensor, 12. pressure sensor, 13. one-way valve, 14. signal converter, 15. data logger, 16. base bracket, 17. cable, 18. communication cable, 19. control console, 20. lifting column cable, 21. lifting column. DETAILED DESCRIPTION

[0031] like Figure 1 to Figure 7 In the invention, a pipe jacking construction resistance identification and jacking force warning system includes: a jack 1 arranged on a supporting wall 2, a jacking force sensor 11 arranged on the jack 1, a jacking iron 3 connecting the jack 1 and the pipe jacking machine 5, a support frame 4 arranged at the lower end of the jacking iron 3, a pipe jacking machine head 6 located at the front end of the pipe jacking machine 5, a one-way valve 13 arranged on the inner wall hole of the pipe section 7 of the pipe jacking machine, and three sensor installation marking positions 8, 9, and 10 arranged on the pipe section 7 of the pipe jacking machine, wherein the first marking position 8 is located one meter away from the pipe jacking machine head 6, the second marking position 9 is located at one-third of the pipe section 7 of the pipe jacking machine, and the third marking position 10 is located at two-thirds of the pipe section 7 of the pipe jacking machine. A pressure sensor 12 installed in the one-way valve 13, a signal converter 14 connected to the pressure sensor 12, a data collector 15 connected to the signal converter 14, a base bracket 16 arranged below the data collector 15, a cable 17 connected to the pressure sensor 12, and a communication cable 18 connecting the data collector 15 and the console 19. Among them, there are two jacking force sensors 11, six pressure sensors 12 are arranged on each pipe section circle where each marking position is located, the pressure sensor 12 is fixed on the lifting column 20 and connected to the lifting column cable 21, there are two signal converters 14, two data collectors 15, and two communication cables 17.

[0032] Embodiment 1, The data converter is associated with the data acquisition device 15. The data acquisition device 15 is used to condition the electrical signals output by the resistance sensor 12 and the top force sensor 11 to improve the quality and accuracy of the signals. The sampling frequency should be at least twice the highest frequency of the signal. Then the data acquisition device 15 converts the amplitude value of the sampled signal into a finite discrete value and introduces a quantization error to complete the quantization processing of the sampled signal; and converts the quantized discrete value into a binary code, and removes noise or interference in the signal through a filtering method, so that the monitoring host of the control console 19 can process and store the data.

[0033] The resistance and force data processed by the data collector 15 are transmitted to the console 19 through the communication cable 17. The console 19 mainly includes a display and a monitoring host, wherein the monitoring host includes a data acquisition gateway, a resistance and force data processing and visualization system. The data acquisition gateway is responsible for connecting the sensor and the data processing system, and has the functions of preliminary data processing and protocol conversion. The resistance and force data are stored in the database after being parsed by the MQTT data protocol of the monitoring host, and the data communication protocol is completed after data parsing.

[0034] Visualize the resistance and top force data and set up a data visualization system. The data visualization system consists of data visualization software and a well-supported human-computer interaction UI interface. By creating data tables, custom charts, etc. to interact with the visualization software, the resistance and top force data can be processed and visualized, thereby realizing the automatic identification of resistance and top force.

[0035] Set up a resistance and top force warning system. First, the initial resistance value and top force value of the system are determined according to the construction design. Generally, the top resistance should be calculated according to the local empirical formula. The calculated resistance value is multiplied by a certain safety factor to obtain the maximum and minimum resistance values. Then, the maximum and minimum top force values ​​are calculated by combining the resistance value with the design parameters. The calculated resistance value and top force value are set as the resistance warning and top force warning reference values ​​of the system. During the construction process, the warning value is continuously improved and modified according to the actual engineering data. Secondly, the warning value needs to be controlled by the system alarm. The resistance and top force values ​​obtained by the system are compared with the system warning value respectively to determine whether the current real-time resistance and top force exceed the warning value range. Once exceeded, the system alarm is triggered. The warning control is mainly implemented by the Arduino microcontroller, buzzer and LED light. First, the data acquisition module is connected to the analog input port of the Arduino microcontroller. Secondly, the buzzer and LED light are connected to the digital output port of the Arduino microcontroller. Thirdly, the Arduino microcontroller Python code is written to complete the warning control of resistance and top force.

[0036] Embodiment 2, The method for building a pipe jacking construction resistance identification and jacking force warning system includes the following steps: Step 1: Determine the installation area of ​​the pipe jacking resistance sensor. Through theoretical mechanical force analysis, the soil disturbance during pipe jacking construction is divided into zones to ensure the effectiveness of the resistance sensor installation location. The soil disturbed by pipe jacking construction can be divided into seven disturbance zones, such as Figure 1As shown, they are: extrusion disturbance zone, shear disturbance zone (front / back), unloading disturbance zone (upper / lower), grouting shear disturbance zone, and consolidation zone. During the jacking process, friction resistance is generated between the outer shell and the surrounding soil. The result of this force is the generation of a shear disturbance zone in the soil around the outer shell of the tunnel boring machine. The range of this zone is relatively smaller than other zones. When grouting is not performed, the soil in the grouting shear disturbance zone is subject to the shear friction resistance between the pipe and the surrounding soil. During the construction process, it will repeatedly move forward and backward along the axis of the pipe. After grouting, the mud converts the dry friction between the pipe and the soil into wet friction, reducing friction resistance, while supporting the surrounding soil and reducing soil deformation caused by the jacking construction.

[0037] Then, determine the installation position of the jacking force sensor. Through finite element analysis, the jacking force sensor should be installed on the thrust transmission path of the jack, and can be installed on the piston rod or thrust plate of the jack to achieve the effect of accurately measuring the jacking force. Figure 2 As shown, the jacking force sensor is installed on the jack push plate. During the installation of the resistance and jacking force sensors, the installation position of the sensor should ensure its stability to avoid being affected by vibration or other external forces during the jacking process. The resistance and jacking force sensors should be firmly fixed to avoid looseness.

[0038] Step 2: Install the resistance and jacking force sensors. Install the resistance sensor and jacking force sensor to the determined positions respectively. Before installing the resistance sensor, it is necessary to mark the installation position of the resistance sensor on the pipe section of the pipe jacking machine, such as Figure 3 As shown in the figure, there are three marked positions, and 6 resistance sensor installation holes are set at each marked position on the pipe section. The size of the hole must match the size of the resistance sensor. Since the resistance sensor is set on the pipe section, in order to prevent water and dust and ensure the durability of the sensor, it is necessary to install a one-way valve on the hole before installing the resistance sensor, and then install the resistance sensor. The installation position of the one-way valve and the resistance sensor is as follows: Figure 4 As shown. The sensor is connected to the lifting column, which is controlled by a cable to push the resistance sensor outward so that the resistance sensor can contact the soil to measure the resistance and return to its original position after the measurement is completed. The jacking force sensor is directly installed on the thrust plate of the jack.

[0039] The working principle of the resistance sensor and the top force sensor: the elastic element produces elastic deformation under the action of external force, causing the resistance / top force transformer and other conversion elements attached to its surface to deform, causing the resistance value / top force value to change, and then the corresponding measurement circuit converts this resistance change into an electrical signal, thus completing the process of converting external force into an electrical signal. The architecture of the resistance dynamic measurement system built by the resistance sensor is as follows Figure 5 shown.

[0040] Step 3: Install the resistance and force data converter and data collector. The data converter is associated with the data collector. The data collector conditions the electrical signals output by the resistance and force sensors in the signal conditioning circuit to improve the quality and accuracy of the signal. The sampling frequency must satisfy the Nyquist sampling theorem, that is, the sampling frequency should be at least twice the highest frequency of the signal. The data collector converts the amplitude value of the sampled signal into a finite discrete value and introduces a quantization error to complete the quantization processing of the sampled signal; and converts the quantized discrete value into a binary code for computer processing and storage; and removes noise or interference in the signal through filtering methods.

[0041] Step 4: Build the resistance and force control console. The data collector transmits the processed resistance and force data to the control console through the communication cable. The control console mainly includes a display and a monitoring host, where the monitoring host includes a data acquisition gateway, resistance and force data processing and visualization system. The data acquisition gateway is responsible for connecting the sensor and the data processing system to ensure the smooth transmission of data from the acquisition end to the processing end.

[0042] The data acquisition gateway has the function of data relay, preliminary data processing and protocol conversion, and can be applied to a variety of sensors and network environments. The resistance and top force data are stored in the database after being parsed by the MQTT data protocol of the monitoring host. The data parsing includes: installing Mosquitto, modifying the configuration, starting Mosquitto with code, creating an MQTT client with Python code, running Python code, the client will connect to the MQTT Broker, using the Mosquitto command line tool to test the communication, and completing the data communication protocol.

[0043] The data visualization system can support a good human-computer interaction UI interface. By creating data tables, custom charts, etc., it interacts with the visualization software to complete the processing and visualization of resistance and top force data, thereby realizing the automatic identification of resistance and top force resistance.

[0044] Step 5: Set up the resistance and top force warning system. First, you need to determine the warning values ​​of resistance and top force. Second, you need to control the warning values ​​with system alarms. This includes: (1) Generally speaking, as long as the jacking force is greater than the jacking resistance, the pipeline can be jacked normally. When the jacking resistance increases, the structural performance of the pipe joint and the back wall of the working pit cannot be increased indefinitely, and the equipment's own capacity also has certain limitations. Therefore, when determining the maximum allowable construction resistance and jacking force, factors such as the mechanical properties of the pipe, the maximum allowable load of the back wall structure of the working pit, the capacity of the jacking equipment, and construction technical measures should be considered comprehensively. When the system is initialized, the resistance value and the jacking force value can be determined according to the construction design parameters. Generally, the jacking resistance should be calculated according to the local empirical formula. If there is no empirical value, refer to the following formula for calculation:

[0045] In the formula is the jacking resistance (kN); is the outer diameter of the pipe (m); Design the jacking length of the pipeline (m); is the average friction resistance per unit area between the outer wall of the pipe and the soil (kN / m 2 ); is the headway resistance of the pipe jacking machine (kN).

[0046] The calculated resistance value is multiplied by a certain safety factor to obtain the maximum and minimum resistance values, where the safety factor is selected based on the combination of theoretical calculation values ​​and current construction experience. Then, the maximum and minimum top force values ​​are calculated by combining the resistance value and design parameters, and the calculated maximum resistance value and top force value are set as the system's resistance warning and top force warning reference values. Note that during the construction process, the warning value needs to be continuously improved and modified based on actual engineering data.

[0047] (2) Early warning control is to compare the resistance and force values ​​obtained by the system with the system early warning values ​​to determine whether the current real-time resistance and force exceed the early warning value range. Once exceeded, the system alarm is triggered. Early warning control is mainly implemented by Arduino microcontroller, buzzer and LED light. The user interface displays the real-time resistance and force values ​​and alarm status. The details are as follows: ① Connect the data acquisition module to the analog input port of the Arduino microcontroller.

[0048] ②Connect the buzzer and LED light to the digital output ports of the Arduino microcontroller.

[0049] ③Write Python code for Arduino microcontroller: const int sensorPin = A0; / / The sensor is connected to port A0 const int buzzerPin = 9; / / The buzzer is connected to digital port 9 const int ledPin = 13; / / LED light is connected to digital port 13 const int maxResistance = 100; / / Set the maximum resistance value void setup() { pinMode(buzzerPin, OUTPUT); pinMode(ledPin, OUTPUT); Serial.begin(9600); } void loop() { int sensorValue = analogRead(sensorPin); float resistance = sensorValue * (5.0 / 1023.0) * 100; / / Convert sensor value to resistance value Serial.println(resistance); if (resistance>maxResistance) { digitalWrite(buzzerPin, HIGH); / / Trigger the buzzer digitalWrite(ledPin, HIGH); / / Turn on the LED } else { digitalWrite(buzzerPin, LOW); digitalWrite(ledPin, LOW); } delay(1000); / / read once per second } ④ Check the real-time resistance value, top force value and warning status through the serial port monitor display connected to the console and monitoring host.

[0050] In the above implementation scheme, a jacking construction resistance and jacking force identification and early warning system is set up to dynamically identify the jacking resistance and jacking force during the jacking process, set resistance and jacking force early warning values ​​respectively, and compare the identified resistance value with the jacking force. Once the early warning value is exceeded, an alarm is sounded to remind on-site staff to adjust the jacking force or inject grouting to reduce resistance in time, thereby greatly improving construction efficiency and quality and enhancing the level of construction safety.

[0051] A one-way valve 13 is provided on the pipe section 7 . During measurement, the one-way valve 13 is opened and the pressure sensor 12 extends from the pipe section 7 . After the measurement is completed, the one-way valve 13 is closed and the pressure sensor 12 retracts into the inner wall of the pipe section 7 .

[0052] The pressure value or the push force value is transmitted to the signal converter 14 through the cable 17 , and then transmitted to the console 19 through the communication cable 18 by the data collector 15 , and the resistance value or the push force value is displayed at the console 19 .

[0053] Resistance and push force warning values ​​are set in the console 19. When the resistance or push force is greater than the threshold, the push force value is significantly smaller than the resistance value, or the push force value is significantly greater than the resistance value, the console 19 gives an alarm prompt.

[0054] In addition to setting six pressure sensors 12 at each marking position on the pipe section 7, the present application can also set different marking positions and different numbers of pressure sensors on the pipe section 7 according to the construction measurement conditions. Figure 2 As shown, six one-way valves 13 are arranged at each marking position on the pipe section 7, and a pressure sensor 12 is arranged in each one-way valve. The pressure sensors are spaced at an angle of 60°, or directly replaced by a resistance sensor.

[0055] The above-mentioned embodiments are only preferred technical solutions of the present invention and should not be regarded as limitations of the present invention. The embodiments and features in the embodiments of the present application can be arbitrarily combined with each other without conflict. The protection scope of the present invention shall be the technical solutions recorded in the claims, including the equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A pipe jacking construction resistance identification and jacking force early warning system, characterized by: The invention comprises a jack (1) arranged on a supporting wall (2), a jacking force sensor (11) arranged on the jack (1), a jacking iron (3) connecting the jack (1) and a pipe jacking machine (5), a support frame (4) arranged at the lower end of the jacking iron (3), a pipe jacking machine head (6) located at the front end of the pipe jacking machine (5), a one-way valve (13) arranged on an inner wall hole of a pipe section (7) of the pipe jacking machine, and a plurality of sensor installation marking positions arranged on the pipe section (7) of the pipe jacking machine.

2. The pipe jacking construction resistance identification and jacking force early warning system and method according to claim 1 is characterized by: A pressure sensor (12) is installed in the one-way valve (13), a signal converter (14) is connected to the pressure sensor (12), and a data acquisition device (15) is connected to the signal converter (14).

3. The pipe jacking construction resistance identification and jacking force early warning system and method according to claim 2 is characterized by: A base support (16) is provided below the data acquisition device (15), a cable (17) is connected to the pressure sensor (12), and a communication cable (18) is connected to the data acquisition device (15) and the control console (19).

4. The pipe jacking construction resistance identification and jacking force early warning system and method according to claim 1 is characterized by: There are two jacking force sensors (11), and six pressure sensors (12) are provided on the pipe segment circle where each marking position is located. The pressure sensors (12) are fixed on the lifting column (20) and connected to the lifting column cable (21).

5. The pipe jacking construction resistance identification and jacking force warning system and method according to claim 3 is characterized by: The data collector (15) is associated with a data converter, and the data collector (15) conditions the electrical signals output by the pressure sensor (12) and the top force sensor (11), thereby improving the quality and accuracy of the signals.

6. The pipe jacking construction resistance identification and jacking force warning system and method according to claim 5 is characterized by: The resistance and top force data processed by the data collector (15) are transmitted to the control console (19) via the communication cable (17).

7. The method for constructing a pipe jacking construction resistance identification and jacking force warning system according to any one of claims 1 to 6, characterized in that: The steps include: S1, determine the installation area of ​​the pipe jacking resistance sensor, and divide the soil disturbance during the pipe jacking construction into zones through theoretical mechanical force analysis to ensure the effectiveness of the resistance sensor installation position; S2, installing the resistance sensor and the jacking force sensor, respectively installing the resistance sensor and the jacking force sensor to the determined positions; before installing the resistance sensor, mark the installation position of the resistance sensor on the pipe section of the pipe jacking machine, set three marking positions, and set 6 resistance sensor installation holes at each marking position on the pipe section, and the size of the hole position must match the size of the resistance sensor; S3, install the resistance and top force data converter and data acquisition device. The data converter is associated with the data acquisition device. The data acquisition device conditions the electrical signals output by the resistance and top force sensors in the signal conditioning circuit to improve the quality and accuracy of the signals. The sampling frequency must satisfy the Nyquist sampling theorem, that is, the sampling frequency should be at least twice the highest frequency of the signal. The data acquisition device converts the amplitude value of the sampled signal into a finite discrete value and introduces a quantization error to complete the quantization processing of the sampled signal. The quantized discrete value is converted into a binary code for computer processing and storage. Noise or interference in the signal is removed by filtering. S4, build a resistance and top force console, and the data collector transmits the processed resistance and top force data to the console through a communication cable; support human-computer interaction UI interface, interact with visualization software by creating data tables and custom charts, complete resistance and top force data processing and visualization, and realize automatic identification of resistance and top force; S5, set up a resistance and top force warning system, determine the warning values ​​of resistance and top force, and perform system alarm control on the warning values.

8. The method for constructing a pipe jacking construction resistance identification and jacking force warning system according to claim 7 is characterized in that: S1 specifically includes: S1-1, the soil disturbed by pipe jacking construction is divided into several disturbance zones, namely: extrusion disturbance zone, shear disturbance zone, unloading disturbance zone, grouting shear disturbance zone and consolidation zone; S1-2, during the jacking process, friction resistance is generated between the casing and the surrounding soil. As a result of this force, a shear disturbance zone is generated in the soil around the casing of the tunnel boring machine. The range of this zone is smaller than that of other zones. S1-3, when no grouting is done, the soil in the grouting shear disturbance zone is subject to the shear friction resistance between the pipeline and the surrounding soil, and will repeatedly move forward and backward along the pipeline axis during the construction process. After grouting, the mud converts the dry friction between the pipeline and the soil into wet friction, reducing the friction resistance, while supporting the surrounding soil and reducing the soil deformation caused by the pipe jacking construction; S1-4, determine the installation position of the jacking force sensor; through finite element analysis, install the jacking force sensor on the thrust transmission path of the jack, that is, on the piston rod or thrust plate of the jack, so as to achieve the effect of accurately measuring the jacking force; S1-5. During the installation of the resistance and jacking force sensors, the installation position of the sensors should ensure their stability to avoid being affected by vibration or other external forces during the jacking process. The resistance and jacking force sensors should be firmly fixed to avoid loosening.

9. The method for constructing a pipe jacking construction resistance identification and jacking force warning system according to claim 7, characterized in that: In S2, since the resistance sensor is set on the pipe section, in order to prevent water and dust and ensure the durability of the sensor, it is necessary to install a one-way valve on the hole before installing the resistance sensor, and then install the resistance sensor; the sensor is connected to the lifting column, which is controlled by a cable to push the resistance sensor outward so that the resistance sensor can contact the soil to measure the resistance and retract it after the measurement is completed; the jacking force sensor is directly installed on the thrust plate of the jack.

10. The method for constructing a pipe jacking construction resistance identification and jacking force warning system according to claim 7, characterized in that: In S5, it specifically includes: S5-1, when the jacking resistance increases, the structural performance of the pipe joint and the back wall of the working pit cannot be increased without limit, and the equipment's own capacity also has certain limits; therefore, when determining the maximum allowable construction resistance and jacking force, the mechanical properties of the pipe, the maximum allowable load of the back wall structure of the working pit, the capacity of the jacking equipment, and the construction technical measures should be comprehensively considered. When the system is initialized, the resistance value and the jacking force value are determined according to the construction design parameters; the jacking resistance should be calculated according to the local empirical formula. If there is no empirical value, refer to the following formula for calculation: ； In the formula is the jacking resistance (kN); is the outer diameter of the pipe (m); Design the jacking length of the pipeline (m); is the average friction resistance per unit area between the outer wall of the pipe and the soil (kN / m 2 ); is the head-on resistance of the pipe jacking machine (kN); S5-2, multiply the calculated resistance value by the safety factor to obtain the maximum and minimum resistance values, where the safety factor is selected by referring to the method of combining the theoretical calculation value with the current construction experience; then, the maximum and minimum top force values ​​are calculated by combining the resistance value and the design parameters, and the calculated maximum resistance value and top force value are set as the resistance warning and top force warning reference values ​​of the system; during the construction process, the warning values ​​need to be continuously improved and modified according to the actual engineering data; S5-3, early warning control is to compare the resistance and top force values ​​obtained by the system with the system early warning values ​​to determine whether the current real-time resistance and top force exceed the early warning value range. Once exceeded, the system alarm is triggered.

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