Subway tunnel shield construction safety early warning system and use method thereof

Abstract

The invention discloses a subway tunnel shield construction safety early warning system and a use method thereof. The system comprises a shield tunneling machine data acquisition terminal, a settlement acquisition terminal, an underground water level acquisition terminal, a gas concentration acquisition terminal, a gateway, a system server and a remote mobile terminal. The shield tunneling machine data acquisition terminal acquires shield tunneling machine state data in real time, the settlement acquisition terminal acquires settlement data of the earth surface, pipelines and buildings in real time, the underground water level acquisition terminal acquires underground water level data in real time, and the gas concentration acquisition terminal acquires underground gas and oxygen concentration data in real time. And the system server adopts measures of shield tunneling machine cutter adjustment, tunnel reinforcement, drainage, grouting and ventilation according to the risk judgment rule, and transmits the measures to a site construction manager through the gateway and the remote mobile terminal. The method has the advantages that safety monitoring is performed on the shield construction process from multiple dimensions, and lean management of the shield machine state, geological structure judgment and construction environment in shield construction is realized.

Description

Technical Field

[0001] The invention relates to the technical field of shield construction, and in particular to a subway tunnel shield construction safety early warning system and a use method thereof. Background Art

[0002] In recent years, my country's urban rail transit projects have developed rapidly, especially in large central cities, where the scale of operation and construction has grown rapidly. By the end of 2023, the mileage of urban rail transit lines under construction in China will reach 6,350.55 kilometers, and the total length of 308 operating lines will reach 11,232.65 kilometers, ranking first in the world in terms of overall scale. However, due to the large scale of construction and operation, there are more and more cases of crossing and approaching existing lines, and the situation is becoming more and more complicated. Different types of new and old building complexes, complex geological environments, numerous underground pipelines, high construction risks, and difficulty in deformation control are becoming increasingly prominent. How to implement a real-time intelligent safety monitoring system in subway tunnel construction has become a key issue in the safety of subway shield construction.

[0003] With the development of science and technology, shield construction has also seen the emergence of automated monitoring methods based on artificial intelligence technology. For example, Chinese patent CN117935507A discloses a real-time early warning system for shield construction and an early warning method that uses Ethernet connection equipment to monitor the data status of the internal sensors of the shield machine to prevent overload, uses geological radar detectors and rock detectors to detect geological structures to prevent geological disasters, monitors soil deformation, and prevents environmental risks. However, how to effectively utilize the working status data of the shield machine, predict geological changes during excavation, adjust the shield cutter, reduce mechanical damage, monitor risk factors such as shield machine excavation, geological subsidence, groundwater level, and gas concentration, introduce risk assessment levels, and present risk control measures to shield construction site managers in real time are technical issues that urgently need to be addressed. Summary of the invention

[0004] In view of this, the present invention proposes a subway tunnel shield construction safety early warning system and its use method to solve the problems of real-time monitoring of shield machine excavation, settlement, groundwater level, gas and oxygen concentration, risk assessment, and real-time introduction of corresponding control measures in shield safety lean management in existing shield construction.

[0005] The technical solution of the present invention is implemented as follows: On the one hand, the present invention provides a subway tunnel shield construction safety early warning system, which includes a shield machine data acquisition terminal, a settlement acquisition terminal, a groundwater level acquisition terminal, a gas concentration acquisition terminal, a gateway, a system server and a remote mobile terminal;

[0006] The shield machine data acquisition terminal is installed in the shield machine PLC control system, connected to the gateway LoRa network, and reads the real-time total thrust, cutter head torque, excavation speed, penetration and soil pressure average value of the shield machine during construction as a Modbus master station and sends them to the gateway;

[0007] The settlement collection terminal is installed on the ground surface, pipelines and buildings, and is connected to the gateway LoRa network, and is used to collect settlement data of the ground surface, pipelines and buildings in real time and send it to the gateway;

[0008] The groundwater level collection terminal is installed on the top of the water level hole buried in the soil layer above the shield tunnel, and is connected to the gateway LoRa network to collect the height data of the groundwater level in real time and send it to the gateway;

[0009] The gas concentration collection terminal is installed in the shield tunnel and connected to the gateway LoRa network to collect gas concentration and oxygen data in the tunnel in real time and send them to the gateway;

[0010] The gateway is installed at the entrance of the tunnel and is used for mutual conversion between the LoRa protocol and the 5G protocol;

[0011] The system server is connected to the gateway 5G network, and is used to receive data from the shield machine data acquisition terminal, the settlement acquisition terminal, the groundwater level acquisition terminal, and the gas concentration acquisition terminal sent by the gateway, determine the risk level according to the risk determination rules, and launch risk control measures to send to the remote mobile terminal via the gateway;

[0012] The remote mobile terminal displays the risk level and risk control measures to the on-site construction manager to guide the on-site construction.

[0013] Preferably, the shield machine data acquisition terminal includes a TTL to 485 module, an MCU controller and a LoRa module;

[0014] The TTL to 485 module is connected to the TTL serial port of the MCU controller, and is used to convert the Modbus master station command sent by the MCU controller from the TTL serial port signal to the 485 signal and send it to the PLC slave station, and convert the PLC data received from the PLC slave station from the 485 signal to the TTL serial port signal and send it to the MCU controller;

[0015] The MCU controller is connected to the TTL serial port of the LoRa module, and is used to send the data read by the MCU controller as a Modbus master station through the LoRa module.

[0016] The 4G / 5G module is electrically connected to the MCU controller, and is used to receive 4G / 5G signals and send the signals to the MCU controller;

[0017] The MCU controller is electrically connected to the LoRa module, so that the MCU controller sends a signal through the LoRa module.

[0018] Preferably, the settlement collection terminal includes a static level, an MCU controller and a LoRa module;

[0019] The static level is connected to the AD port of the MCU controller, and is used to receive the static level signal and send the signal to the MCU controller via the AD port at 0-10V or 4-20mA;

[0020] The MCU controller is connected to the TTL serial port of the LoRa module, and is used to send the settlement data read by the MCU controller through the LoRa module.

[0021] Preferably, the groundwater level acquisition terminal includes a water level depth probe, an MCU controller and a LoRa module;

[0022] The water level depth probe is connected to the AD port of the MCU controller, and is used to receive the water level depth probe signal and send the signal to the MCU controller via the AD port at 0-10V or 4-20mA;

[0023] The MCU controller is connected to the TTL serial port of the LoRa module, and is used to send the groundwater depth data read by the MCU controller through the LoRa module.

[0024] Preferably, the gas concentration collection terminal includes a gas concentration probe, an oxygen concentration probe, an MCU controller and a LoRa module;

[0025] The gas concentration probe is connected to the AD port of the MCU controller, and is used to receive the gas concentration probe signal and send the signal to the MCU controller via the AD port at 0-10V or 4-20mA;

[0026] The oxygen concentration probe is connected to the AD port of the MCU controller, and is used to receive the oxygen concentration probe signal and send the signal to the MCU controller via the AD port at 0-10V or 4-20mA;

[0027] The MCU controller is connected to the TTL serial port of the LoRa module, and is used to send the gas concentration and oxygen concentration data read by the MCU controller through the LoRa module.

[0028] Preferably, the gateway includes a 4G / 5G module, an MCU controller and a LoRa module;

[0029] The 4G / 5G module is connected to the USB port of the MCU controller, and is used for information exchange between the 4G / 5G data signal and the MCU controller data signal;

[0030] The MCU controller is connected to the LoRa module TTL serial port for information exchange between the MCU controller data signal and the LoRa data signal.

[0031] Preferably, the remote mobile terminal includes a tablet computer and a LoRa module;

[0032] The tablet computer is connected to the TTL serial port of the LoRa module for receiving LoRa module signals and displaying them on the tablet computer.

[0033] On the other hand, the present invention provides a method for using a subway tunnel shield construction safety early warning system; the method comprises the following steps:

[0034] S1. The shield machine data acquisition terminal collects the real-time total thrust, cutter head torque, cutter head speed, excavation speed, penetration and average soil pressure of the shield machine during construction and sends them to the system server via the gateway;

[0035] S2. The system server calculates the tunneling specific energy in real time according to the tunneling specific energy formula, inputs the geological identification model to identify the geological structure in front of the shield machine, determines the tunneling risk level according to different geological structures, and uses the empirical formula for the number of cutters to adjust the corresponding cutters to prevent mechanical damage to the shield machine;

[0036] S3. The settlement collection terminal collects the real-time settlement data of the ground surface, pipelines and buildings during the construction of the shield machine and sends it to the system server via the gateway;

[0037] S4. The system server determines the settlement risk level and sends tunnel reinforcement measures based on the risk level to prevent ground collapse or damage to underground facilities;

[0038] S5. The groundwater level collection terminal collects the real-time groundwater level data during the shield machine construction and sends it to the system server via the gateway;

[0039] S6. The system server determines the risk level of the groundwater level and sends drainage or grouting measures based on the risk level to prevent groundwater leakage or water inrush accidents;

[0040] S7. The gas concentration collection terminal collects the real-time gas concentration data in the tunnel during the construction of the shield machine and sends it to the system server via the gateway;

[0041] S8. The system server determines the gas concentration risk level and sends ventilation measures according to the risk level to prevent explosion accidents;

[0042] S9. The system server determines the oxygen concentration risk level and sends ventilation measures according to the risk level to prevent suffocation accidents;

[0043] S10. The remote mobile terminal receiving system server displays the risk status to the on-site construction manager through the gateway to guide the on-site safe construction.

[0044] The subway tunnel shield construction safety early warning system and its use method of the present invention have the following beneficial effects compared with the prior art:

[0045] (1) A shield machine data acquisition terminal was designed to realize real-time acquisition of shield machine status data. The geological identification model was used to analyze the geological structure in front of the shield machine in real time and determine the excavation risk level;

[0046] (2) An empirical formula for the number of cutterheads was constructed to adjust the number of different cutters according to the tunneling risk level to prevent mechanical damage to the shield machine;

[0047] (3) The settlement collection terminal, groundwater level collection terminal, and gas concentration collection terminal were designed to define the risk levels of settlement, groundwater level, gas concentration, and oxygen concentration. Corresponding control measures were introduced based on the risk levels, thus achieving lean management of shield construction safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0049] Figure 1 This is a structural diagram of the subway tunnel shield construction safety early warning system of the present invention;

[0050] Figure 2 This is a structural diagram of the shield machine data acquisition terminal of the present invention;

[0051] Figure 3 This is a structural diagram of the settlement collection terminal of the present invention;

[0052] Figure 4 This is a structural diagram of the groundwater level acquisition terminal of the present invention;

[0053] Figure 5 This is a structural diagram of the gas concentration acquisition terminal of the present invention;

[0054] Figure 6 is a structural diagram of a gateway of the present invention;

[0055] Figure 7 It is a structural diagram of a remote mobile terminal of the present invention;

[0056] Figure 8The present invention is a flowchart of the method for using the subway tunnel shield construction safety early warning system. DETAILED DESCRIPTION

[0057] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] Embodiment 1

[0059] like Figure 1-7 As shown, the subway tunnel shield construction safety early warning system of the present invention includes a shield machine data acquisition terminal, a settlement acquisition terminal, a groundwater level acquisition terminal, a gas concentration acquisition terminal, a gateway, a system server and a remote mobile terminal;

[0060] The shield machine data acquisition terminal is installed in the shield machine PLC control system, connected to the gateway LoRa network, and reads the real-time total thrust, cutter head torque, excavation speed, penetration and soil pressure average value of the shield machine during construction as a Modbus master station and sends them to the gateway;

[0061] The settlement collection terminal is installed on the ground surface, pipelines and buildings, and is connected to the gateway LoRa network, and is used to collect settlement data of the ground surface, pipelines and buildings in real time and send it to the gateway;

[0062] The groundwater level collection terminal is installed on the top of the water level hole buried in the soil layer above the shield tunnel, and is connected to the gateway LoRa network to collect the height data of the groundwater level in real time and send it to the gateway;

[0063] The gas concentration collection terminal is installed in the shield tunnel and connected to the gateway LoRa network to collect gas concentration and oxygen concentration data in the tunnel in real time and send them to the gateway;

[0064] The gateway is installed at the entrance of the tunnel and is used for mutual conversion between the LoRa protocol and the 5G protocol;

[0065] The system server is connected to the gateway 5G network, and is used to receive data from the shield machine data acquisition terminal, the settlement acquisition terminal, the groundwater level acquisition terminal, and the gas concentration acquisition terminal sent by the gateway, determine the risk level according to the risk determination rules, and launch risk control measures to send to the remote mobile terminal via the gateway;

[0066] The remote mobile terminal displays the risk level and risk control measures to the on-site construction manager to guide the on-site construction.

[0067] This system uses shield machine data acquisition terminals, settlement acquisition terminals, groundwater level acquisition terminals, gas concentration acquisition terminals, gateways, system servers and remote mobile terminals to realize the subway tunnel shield construction safety early warning system. The system monitors the shield construction process from multiple dimensions such as shield machine excavation, settlement, groundwater level, gas concentration and oxygen concentration, determines the risk level and launches corresponding control measures to the construction site, realizing the lean management of shield machine status, geological structure determination and construction environment during shield construction; through design, simulation and verification, modular products are formed, which can realize rapid transplantation between different platforms and accelerate the product development process.

[0068] The shield machine data acquisition terminal includes a TTL to 485 module, an MCU controller and a LoRa module;

[0069] The TTL to 485 module is connected to the TTL serial port of the MCU controller, and is used to convert the Modbus master station command sent by the MCU controller from the TTL serial port signal to the 485 signal and send it to the PLC slave station, and convert the PLC data received from the PLC slave station from the 485 signal to the TTL serial port signal and send it to the MCU controller;

[0070] The MCU controller is connected to the TTL serial port of the LoRa module, and is used to send the data read by the MCU controller as a Modbus master station through the LoRa module.

[0071] The settlement collection terminal includes a static level, an MCU controller and a LoRa module;

[0072] The static level is connected to the AD port of the MCU controller, and is used to receive the static level signal and send the signal to the MCU controller via the AD port at 0-10V or 4-20mA;

[0073] The MCU controller is connected to the TTL serial port of the LoRa module, and is used to send the settlement data read by the MCU controller through the LoRa module.

[0074] The underground water level acquisition terminal includes a water level depth probe, an MCU controller and a LoRa module;

[0075] The water level depth probe is connected to the AD port of the MCU controller, and is used to receive the water level depth probe signal and send the signal to the MCU controller via the AD port at 0-10V or 4-20mA;

[0076] The MCU controller is connected to the TTL serial port of the LoRa module, and is used to send the groundwater depth data read by the MCU controller through the LoRa module.

[0077] The gas concentration collection terminal includes a gas concentration probe, an oxygen concentration probe, an MCU controller and a LoRa module;

[0078] The gas concentration probe is connected to the AD port of the MCU controller, and is used to receive the gas concentration probe signal and send the signal to the MCU controller via the AD port at 0-10V or 4-20mA;

[0079] The oxygen concentration probe is connected to the AD port of the MCU controller, and is used to receive the oxygen concentration probe signal and send the signal to the MCU controller via the AD port at 0-10V or 4-20mA;

[0080] The MCU controller is connected to the TTL serial port of the LoRa module, and is used to send the gas concentration data read by the MCU controller through the LoRa module.

[0081] The gateway includes a 4G / 5G module, an MCU controller and a LoRa module;

[0082] The 4G / 5G module is connected to the USB port of the MCU controller, and is used for information exchange between the 4G / 5G data signal and the MCU controller data signal;

[0083] The MCU controller is connected to the LoRa module TTL serial port for information exchange between the MCU controller data signal and the LoRa data signal.

[0084] The remote mobile terminal includes a tablet computer and a LoRa module;

[0085] The tablet computer is connected to the TTL serial port of the LoRa module for receiving LoRa module signals and displaying them on the tablet computer.

[0086] Among them, the 4G / 5G module is implemented by Fibocom FG132, the LoRa module is implemented by Chengdu Yibite's E22-230T33S, the MCU controller is ST's STM32F407, and is compiled in Keil uVision 5 software using C language.

[0087] The subway tunnel shield construction safety warning system in this embodiment adopts the shield machine data acquisition terminal, settlement acquisition terminal, groundwater level acquisition terminal, gas concentration acquisition terminal, gateway, system server and remote mobile terminal to realize the subway tunnel shield construction safety warning system. The system monitors the shield construction process from multiple dimensions such as shield machine excavation, settlement, groundwater level and gas concentration, determines the risk level and launches corresponding control measures to the construction site, realizing the lean management of shield machine status, geological structure determination and construction environment during shield construction; through design, simulation and verification, a modular product is formed, which can realize rapid transplantation between different platforms and accelerate the product development process.

[0088] Embodiment 2

[0089] A method for using a subway tunnel shield construction safety early warning system is provided, which uses the subway tunnel shield construction safety early warning system as described in Example 1, and includes the following steps:

[0090] S1. The shield machine data acquisition terminal collects the real-time total thrust, cutter head torque, cutter head speed, excavation speed, penetration and average soil pressure of the shield machine during construction and sends them to the system server via the gateway;

[0091] S2. The system server calculates the tunneling specific energy in real time according to the tunneling specific energy formula, inputs the geological identification model to identify the geological structure in front of the shield machine, determines the tunneling risk level according to different geological structures, and uses the empirical formula for the number of cutters to adjust the corresponding cutters to prevent mechanical damage to the shield machine;

[0092] S3. The settlement collection terminal collects the real-time settlement data of the ground surface, pipelines and buildings during the construction of the shield machine and sends it to the system server via the gateway;

[0093] S4. The system server determines the settlement risk level and sends tunnel reinforcement measures based on the risk level to prevent ground collapse or damage to underground facilities;

[0094] S5. The groundwater level collection terminal collects the real-time groundwater level data during the shield machine construction and sends it to the system server via the gateway;

[0095] S6. The system server determines the risk level of the groundwater level and sends drainage or grouting measures based on the risk level to prevent groundwater leakage or water inrush accidents;

[0096] S7. The gas concentration collection terminal collects the real-time gas concentration data in the tunnel during the construction of the shield machine and sends it to the system server via the gateway;

[0097] S8. The system server determines the gas concentration risk level and sends ventilation measures according to the risk level to prevent explosion accidents;

[0098] S9. The system server determines the oxygen concentration risk level and sends ventilation measures according to the risk level to prevent suffocation accidents;

[0099] S10. The remote mobile terminal receiving system server displays the risk status to the on-site construction manager through the gateway to guide the on-site safe construction.

[0100] Among them, the excavation specific energy formula is: SE stands for excavation specific energy, unit: KJ / m 3 , F represents the total thrust, in N, v represents the excavation speed, in mm / min, T represents the cutter head torque, in kN·m, w represents the cutter head speed, in r / min, and R0 represents the cutter head excavation radius, in m;

[0101] The geological identification model includes one of a KNN algorithm model or an EWM-KNN algorithm model;

[0102] The geological structure includes one of hard rock, relatively hard rock, soft rock and isolated rock;

[0103] The excavation risk level is determined according to the geological structure type. Hard rock is judged as high risk, and relatively hard rock is judged as high risk. Integer operation, N0 represents the number of cutters, in pieces, N1 represents the number of hobs, in pieces, N represents the total number of tools, in pieces, SE represents the current excavation specific energy, in KJ / m 3 , SE′ represents the average specific energy of excavation corresponding to the geological structures of hard rock, relatively hard rock, soft rock and isolated rock, in KJ / m 3 β is an empirical coefficient, a dimensionless quantity, and its value range is between [0,30]. Generally, β for hard rock is 0, β for relatively hard rock is between (0,10], β for soft rock is between (10,20], and β for isolated rock is between (20,30].

[0105] The settlement risk level is determined by the ratio of the actual settlement height to the standard settlement height. When the ratio is less than 30%, it is determined to be low risk, 30% to 60% is determined to be medium risk, and the rest is determined to be high risk.

[0106] The groundwater level risk level is determined by the ratio of the actual water level drop to the theoretical water level drop. When the ratio is less than 20%, it is determined to be low risk, 20% to 60% is determined to be medium risk, and the rest is determined to be high risk.

[0107] The gas concentration risk level is determined by the actual gas concentration. When the gas concentration is less than 0.1%, it is determined as low risk, 0.1% to 0.2% is determined as medium risk, and the rest is determined as high risk.

[0108] The oxygen concentration risk level is determined by the actual oxygen concentration. When the oxygen concentration is between 20% and 23.5%, it is determined to be low risk, and the rest is determined to be high risk.

[0109] Among them, the KNN algorithm model and EWM-KNN algorithm were compiled using Python3.9 software.

[0110] like Figure 8 As shown, the shield machine data acquisition terminal collects the shield machine status data in real time, the settlement acquisition terminal collects the settlement data of the surface, pipelines and buildings in real time, the groundwater level acquisition terminal collects the groundwater level data in real time, and the gas concentration acquisition terminal collects the underground gas concentration data in real time and sends it to the system server through the gateway. The system server takes measures such as adjusting the shield machine cutter, tunnel reinforcement, drainage, grouting, and ventilation according to the risk judgment rules, and transmits it to the on-site construction manager through the gateway and the remote mobile terminal to guide the on-site construction.

[0111] The method for using the subway tunnel shield construction safety early warning system in this embodiment adopts a modular design method, and uses a shield machine data acquisition terminal, a settlement acquisition terminal, a groundwater level acquisition terminal, a gas concentration acquisition terminal, a gateway, a system server and a remote mobile terminal to realize the subway tunnel shield construction safety early warning system. The system monitors the shield construction process from multiple dimensions such as shield machine excavation, settlement, groundwater level, gas concentration and oxygen concentration, determines the risk level and launches corresponding control measures to the construction site, realizing lean management of shield machine status, geological structure determination and construction environment during shield construction.

[0112] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. The subway tunnel shield construction safety early warning system mainly includes shield machine data acquisition terminal, settlement acquisition terminal, groundwater level acquisition terminal, gas concentration acquisition terminal, gateway, system server and remote mobile terminal; The shield machine data acquisition terminal is installed in the shield machine PLC control system, connected to the gateway LoRa network, and reads the real-time total thrust, cutter head torque, excavation speed, penetration and soil pressure average value of the shield machine during construction as a Modbus master station and sends them to the gateway; The settlement collection terminal is installed on the ground surface, pipelines and buildings, and is connected to the gateway LoRa network, and is used to collect settlement data of the ground surface, pipelines and buildings in real time and send it to the gateway; The groundwater level collection terminal is installed on the top of the water level hole buried in the soil layer above the shield tunnel, and is connected to the gateway LoRa network to collect the height data of the groundwater level in real time and send it to the gateway; The gas concentration collection terminal is installed in the shield tunnel and connected to the gateway LoRa network to collect gas concentration and oxygen concentration data in the tunnel in real time and send them to the gateway; The gateway is installed at the entrance of the tunnel and is used for mutual conversion between the LoRa protocol and the 5G protocol; The system server is connected to the gateway 5G network, and is used to receive data from the shield machine data acquisition terminal, the settlement acquisition terminal, the groundwater level acquisition terminal, and the gas concentration acquisition terminal sent by the gateway, determine the risk level according to the risk determination rules, and launch risk control measures to send to the remote mobile terminal via the gateway; The remote mobile terminal displays the risk level and risk control measures to the on-site construction manager to guide the on-site construction.

2. The subway tunnel shield construction safety early warning system as claimed in claim 1, characterized in that: The shield machine data acquisition terminal includes a TTL to 485 module, an MCU controller and a LoRa module; The TTL to 485 module is connected to the TTL serial port of the MCU controller, and is used to convert the Modbus master station command sent by the MCU controller from the TTL serial port signal to the 485 signal and send it to the PLC slave station, and convert the PLC data received from the PLC slave station from the 485 signal to the TTL serial port signal and send it to the MCU controller; The MCU controller is connected to the TTL serial port of the LoRa module, and is used to send the data read by the MCU controller as a Modbus master station through the LoRa module.

3. The subway tunnel shield construction safety early warning system as claimed in claim 1, characterized in that: The settlement collection terminal includes a static level, an MCU controller and a LoRa module; The static level is connected to the AD port of the MCU controller, and is used to receive the static level signal and send the signal to the MCU controller via the AD port at 0-10V or 4-20mA; The MCU controller is connected to the TTL serial port of the LoRa module, and is used to send the settlement data read by the MCU controller through the LoRa module.

4. The subway tunnel shield construction safety early warning system as claimed in claim 1, characterized in that: The groundwater level acquisition terminal includes a water level depth probe, an MCU controller and a LoRa module; The water level depth probe is connected to the AD port of the MCU controller, and is used to receive the water level depth probe signal and send the signal to the MCU controller via the AD port at 0-10V or 4-20mA; The MCU controller is connected to the TTL serial port of the LoRa module, and is used to send the groundwater depth data read by the MCU controller through the LoRa module.

5. The subway tunnel shield construction safety early warning system as claimed in claim 1, characterized in that: The gas concentration collection terminal includes a gas concentration probe, an oxygen concentration probe, an MCU controller and a LoRa module; The gas concentration probe is connected to the AD port of the MCU controller, and is used to receive the gas concentration probe signal and send the signal to the MCU controller via the AD port at 0-10V or 4-20mA; The oxygen concentration probe is connected to the AD port of the MCU controller, and is used to receive the oxygen concentration probe signal and send the signal to the MCU controller via the AD port at 0-10V or 4-20mA; The MCU controller is connected to the TTL serial port of the LoRa module, and is used to send the gas concentration and oxygen concentration data read by the MCU controller through the LoRa module.

6. The subway tunnel shield construction safety early warning system as claimed in claim 1, characterized in that: The gateway includes a 4G / 5G module, an MCU controller and a LoRa module; The 4G / 5G module is connected to the USB port of the MCU controller, and is used for information exchange between the 4G / 5G data signal and the MCU controller data signal; The MCU controller is connected to the LoRa module TTL serial port for information exchange between the MCU controller data signal and the LoRa data signal.

7. The subway tunnel shield construction safety early warning system as claimed in claim 1, characterized in that: The remote mobile terminal includes a tablet computer and a LoRa module; The tablet computer is connected to the TTL serial port of the LoRa module for receiving LoRa module signals and displaying them on the tablet computer.

8. The method for using the subway tunnel shield construction safety early warning system according to any one of claims 1 to 7, characterized in that: The steps include: S1. The shield machine data acquisition terminal collects the real-time total thrust, cutter head torque, cutter head speed, excavation speed, penetration and average soil pressure of the shield machine during construction and sends them to the system server via the gateway; S2. The system server calculates the tunneling specific energy in real time according to the tunneling specific energy formula, inputs the geological identification model to identify the geological structure in front of the shield machine, determines the tunneling risk level according to different geological structures, and uses the empirical formula for the number of cutters to adjust the corresponding cutters to prevent mechanical damage to the shield machine; S3. The settlement collection terminal collects the real-time settlement data of the ground surface, pipelines and buildings during the construction of the shield machine and sends it to the system server via the gateway; S4. The system server determines the settlement risk level and sends tunnel reinforcement measures based on the risk level to prevent ground collapse or damage to underground facilities; S5. The groundwater level collection terminal collects the real-time groundwater level data during the shield machine construction and sends it to the system server via the gateway; S6. The system server determines the risk level of the groundwater level and sends drainage or grouting measures based on the risk level to prevent groundwater leakage or water inrush accidents; S7. The gas concentration collection terminal collects the real-time gas concentration and oxygen concentration data in the tunnel during the construction of the shield machine and sends them to the system server via the gateway; S8. The system server determines the gas concentration risk level and sends ventilation measures according to the risk level to prevent explosion accidents; S9. The system server determines the oxygen concentration risk level and sends ventilation measures according to the risk level to prevent suffocation accidents; S10. The remote mobile terminal receiving system server displays the risk status to the on-site construction manager through the gateway to guide the on-site safe construction.

9. The method for using the subway tunnel shield construction safety early warning system as claimed in claim 8, characterized in that: The excavation specific energy formula is: SE stands for excavation specific energy, unit is KJ / m 3 , F represents the total thrust, in N, v represents the excavation speed, in mm / min, T represents the cutter head torque, in kN·m, w represents the cutter head speed, in r / min, and R0 represents the cutter head excavation radius, in m; The geological identification model includes one of a KNN algorithm model or an EWM-KNN algorithm model; The geological structure includes one of hard rock, relatively hard rock, soft rock and isolated rock; The excavation risk level is determined according to the geological structure type. Hard rock is judged as high risk, and relatively hard rock is judged as high risk. Integer operation, N0 represents the number of cutters, in pieces, N1 represents the number of hobs, in pieces, N represents the total number of tools, in pieces, SE represents the current excavation specific energy, in KJ / m 3 , SE′ represents the average specific energy of excavation corresponding to the geological structures of hard rock, relatively hard rock, soft rock and isolated rock, in KJ / m 3 β is an empirical coefficient, a dimensionless quantity, and its value range is between [0,30]. Generally, β for hard rock is 0, β for relatively hard rock is between (0,10], β for soft rock is between (10,20], and β for isolated rock is between (20,30].

10. The method for using the subway tunnel shield construction safety early warning system as claimed in claim 8, characterized in that: The settlement risk level is determined by the ratio of the actual settlement height to the standard settlement height. When the ratio is less than 30%, it is determined to be low risk, 30% to 60% is determined to be medium risk, and the rest is determined to be high risk; The groundwater level risk level is determined by the ratio of the actual water level drop to the theoretical water level drop. When the ratio is less than 20%, it is determined to be low risk, 20% to 60% is determined to be medium risk, and the rest is determined to be high risk. The gas concentration risk level is determined by the actual gas concentration. When the gas concentration is less than 0.1%, it is determined as low risk, 0.1% to 0.2% is determined as medium risk, and the rest is determined as high risk. The oxygen concentration risk level is determined by the actual oxygen concentration. When the oxygen concentration is between 20% and 23.5%, it is determined to be low risk, and the rest is determined to be high risk.

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