Settlement monitoring system in shield construction and use method thereof

Abstract

The invention discloses a settlement monitoring system in shield construction and a use method thereof. The settlement monitoring system comprises an unmanned aerial vehicle surveying instrument, a laser scanning terminal, a system server, a gateway and a mobile terminal, the unmanned aerial vehicle surveying instrument is used for measuring terrain and ground building elevation, the laser scanning terminal is used for measuring the size of a three-dimensional structure in a tunnel, the system server analyzes data changes before and during shield construction, settlement data are obtained, the settlement risk level is judged according to a settlement risk index formula, and a settlement control plan is pushed out. And the revised construction process is sent to the mobile terminal to guide on-site construction. Shield process simulation is established through the unmanned aerial vehicle photography technology, the three-dimensional laser scanning technology and the finite element method, a three-dimensional settlement distribution diagram is formed, grouting measures are simulated to determine the grouting amount and the optimal settlement control range, the settlement risk level is judged according to actual settlement data in construction, and a corresponding control plan is pushed out and sent to a construction site. And lean management of settlement control in shield construction is realized.

Description

Technical Field

[0001] The invention relates to the technical field of shield construction, and in particular to a surface settlement monitoring system and a use method thereof in shield construction. Background Art

[0002] With the acceleration of China's urbanization process, urban rail transit construction has developed rapidly. Urban subway lines are becoming increasingly dense, and the geological conditions of the strata that new tunnels pass through are becoming more and more complex. It is inevitable to encounter special working conditions such as passing under existing pipelines and buildings. The shield method is often the first choice in urban underground tunnel construction due to its advantages such as good construction conditions, high safety, and less disturbance to the surrounding environment. However, when the shield tunnel passes through a building at a close distance, it is easy to cause deformation of the surrounding strata due to factors such as the loss of the shield excavation stratum, resulting in uneven settlement of the building, thereby affecting the safety of adjacent buildings. How to reduce disturbance and control settlement during tunnel construction has become a key issue in the safety of urban rail 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 CN118714478A discloses a remote automated monitoring method for shield tunnels that uses wireless communication technology to accurately analyze the path of the shield machine and monitor the tunneling process of the shield machine in real time, thereby achieving safe monitoring and adjustment of the tunneling route and the shield machine. However, the settlement monitoring of tunneling work is still carried out manually at regular intervals using a level. Therefore, how to effectively use artificial intelligence, monitor settlement data in real time, introduce a settlement risk index formula, evaluate the settlement risk level, and launch a settlement control plan and revise the closed-loop lean management of the construction work plan in real time is a technical problem that urgently needs to be solved. Summary of the invention

[0004] In view of this, the present invention proposes a settlement monitoring system for shield construction and a method of using the same to solve the closed-loop lean management problems of real-time settlement monitoring, risk assessment, real-time introduction of settlement control plans and revision of construction work plans in existing shield construction.

[0005] To achieve the above object, the technical solution of the present invention is implemented as follows:

[0006] On the one hand, the present invention provides a settlement monitoring system during shield construction, including an unmanned aerial vehicle surveying instrument, a laser scanning terminal, a system server, a gateway and a mobile terminal;

[0007] The drone surveying instrument is used to measure the elevation of terrain and ground buildings, and transmit the information to the system server through 4G or 5G signals; the drone surveying instrument is equipped with one or more components of InSAR radar, GNSS receiver, tilt camera, attitude positioning system, laser altimeter, and barometer to measure the elevation;

[0008] The laser scanning terminal is used to measure the three-dimensional structure size in the tunnel, and transmits the information to the system server via the gateway through the LoRa signal;

[0009] The system server is connected to the gateway via a 4G or 5G network, and is used to establish a ground digital elevation map and a three-dimensional point cloud map of the tunnel after receiving data from the drone surveying instrument and the laser scanning terminal, analyze the changes in data before and during shield construction, obtain settlement data, determine the settlement risk level of the construction site according to the settlement risk index formula, and launch a settlement control plan, revise the construction process, and finally transmit the result information to the gateway;

[0010] The gateway is connected to the mobile terminal via a LoRa network, and is used to convert information from a 5G protocol into a LoRa protocol and send it to the mobile terminal;

[0011] The mobile terminal is used to display the settlement risk level, settlement control plan and revised construction procedures to the on-site construction manager to guide the on-site construction.

[0012] Preferably, the laser scanning terminal includes a three-dimensional laser scanner, a tablet computer, a USB to serial port module and a LoRa module;

[0013] The three-dimensional laser scanner is connected to the LAN interface of the tablet computer, and uses the target sphere as a reference for point cloud registration to scan the structural data in the tunnel and send it to the tablet computer;

[0014] The tablet computer is connected to the USB interface of the USB-to-serial port module, and is used to receive data from the three-dimensional laser scanner and form a three-dimensional point cloud map of the tunnel and send it to the USB-to-serial port module;

[0015] The USB to serial port module converts the tunnel three-dimensional point cloud data from the USB port to the serial port and sends it to the LoRa module;

[0016] The LoRa module is used to send the tunnel three-dimensional point cloud map data to the system service through the LoRa protocol.

[0017] Preferably, the LoRa gateway includes a 4G / 5G module, an MCU controller and a LoRa module;

[0018] The 4G / 5G module is electrically connected to the MCU controller for information exchange between the 4G / 5G module and the MCU controller;

[0019] The MCU controller is electrically connected to the LoRa module for information exchange between the MCU controller and the LoRa module.

[0020] Preferably, the mobile terminal includes a tablet computer and a LoRa module;

[0021] The tablet computer is electrically connected to the LoRa module and is used to receive LoRa module signals and display them on the tablet computer.

[0022] On the other hand, the present invention provides a method for using settlement monitoring in shield construction; the method comprises the following steps:

[0023] S1. The system server obtains the data of the drone surveying instrument and laser scanning terminal before construction, and establishes the ground digital elevation map and the three-dimensional point cloud map of the tunnel before construction;

[0024] S2. Use manual exploration method to complete the collection of geological exploration data of shield tunnel and establish a three-dimensional geological structure map;

[0025] S3. The system server uses finite element software simulation method to input geological structure, elastic modulus, cohesion, internal friction angle, Poisson's ratio and gravity data to establish shield process simulation, form a three-dimensional settlement distribution map, and mark the maximum settlement position and settlement amount of the shield;

[0026] S4. The system server simulates the thick slurry method to carry out grouting measures on the pipe roof, and re-establishes the shield process simulation by changing the properties of the shield shell and the grouting layer to form an improved three-dimensional settlement distribution map to determine the grouting amount and the optimal settlement control range;

[0027] S5. The system server formulates the construction process according to the improved three-dimensional settlement distribution map and sends it to the mobile terminal through the gateway to guide the on-site construction of the shield machine;

[0028] S6. The system server obtains data from the drone surveying instrument and laser scanning terminal during construction, establishes a ground digital elevation map and a three-dimensional point cloud map of the tunnel during construction, generates an actual three-dimensional settlement distribution map, and obtains the settlement area and settlement amount data;

[0029] S7. The system server substitutes the settlement area range and settlement amount data into the settlement risk index formula, calculates the settlement risk index, and defines the settlement risk level;

[0030] S8. The system server revises the settlement control operation process based on the original construction process according to the settlement risk level, and forwards it to the mobile terminal through the gateway;

[0031] S9. The mobile terminal displays the settlement risk level to the on-site construction manager, updates the construction procedures, and guides the on-site construction.

[0032] The shield construction settlement monitoring system and its use method proposed by the present invention have the following beneficial effects compared with the prior art:

[0033] (1) The use of drone photogrammetry and 3D laser scanning technology to complete the digital elevation map of the surface and the 3D point cloud map of the tunnel has changed the traditional way of manually measuring settlement with a level instrument, and achieved real-time, visual and accurate data collection;

[0034] (2) Before construction, the shield construction process was simulated using finite element software to form a three-dimensional settlement distribution map. The grouting measures were simulated to form an improved three-dimensional settlement distribution map to determine the grouting amount and the optimal settlement control range to guide the actual construction;

[0035] (3) During construction, the actual three-dimensional settlement distribution map is generated based on the actual data, the settlement area and settlement amount are obtained, the settlement risk index is calculated according to the settlement risk index formula, and the settlement risk level is defined. This creatively provides a theoretical basis for risk assessment, inserts the settlement control plan in real time according to the risk level, revises the construction process and guides the on-site construction of the shield tunnel, thus completing the closed-loop lean management of settlement monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] 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.

[0037] Figure 1 It is a structural diagram of the settlement monitoring system in shield construction of the present invention;

[0038] Figure 2 This is a structural diagram of the laser scanning terminal of the present invention;

[0039] Figure 3 is a structural diagram of a gateway of the present invention;

[0040] Figure 4 is a structural diagram of a mobile terminal of the present invention;

[0041] Figure 5 The present invention is a flowchart of the settlement monitoring system in shield construction and the method of using the same;

[0042] Figure 6 The present invention is a settlement control plan diagram of the settlement monitoring system and the use method thereof in shield construction. DETAILED DESCRIPTION

[0043] 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.

[0044] Embodiment 1: Figure 1-Figure 4 As shown, the settlement monitoring system in shield construction provided by the present invention includes an unmanned aerial vehicle surveying instrument, a laser scanning terminal, a system server, a gateway and a mobile terminal;

[0045] The drone surveying instrument is used to measure the elevation of terrain and ground buildings, and transmit the information to the system server through 4G or 5G signals; the drone surveying instrument is equipped with one or more components of InSAR radar, GNSS receiver, tilt camera, attitude positioning system, laser altimeter, and barometer to measure the elevation;

[0046] The laser scanning terminal is used to measure the three-dimensional structure size in the tunnel, and transmits the information to the system server via the gateway through the LoRa signal;

[0047] The system server is connected to the gateway via a 4G or 5G network, and is used to establish a ground digital elevation map and a three-dimensional point cloud map of the tunnel after receiving data from the drone surveying instrument and the laser scanning terminal, analyze the changes in data before and during shield construction, obtain settlement data, determine the settlement risk level of the construction site according to the settlement risk index formula, and launch a settlement control plan, revise the construction process, and finally transmit the result information to the gateway;

[0048] The gateway is connected to the mobile terminal via a LoRa network, and is used to convert information from a 5G protocol into a LoRa protocol and send it to the mobile terminal;

[0049] The mobile terminal is used to display the settlement risk level, settlement control plan and revised construction procedures to the on-site construction manager to guide the on-site construction.

[0050] This system uses drone surveying instruments, laser scanning terminals, system servers, gateways and mobile terminals to realize the settlement monitoring system during shield construction. It uses drone photography technology, 3D laser scanning technology and finite element method to establish shield process simulation, form a 3D settlement distribution map and simulate grouting measures to determine the grouting amount and the optimal settlement control range. During construction, the settlement risk level is determined based on the actual settlement data and the corresponding control plan is launched and sent to the construction site, realizing the lean management of settlement control during shield construction; through design, simulation and verification, modular products are formed, which can achieve rapid transplantation between different platforms and accelerate the product development process.

[0051] Wherein, the laser scanning terminal includes a three-dimensional laser scanner, a tablet computer, a USB to serial port module and a LoRa module;

[0052] The three-dimensional laser scanner is connected to the LAN interface of the tablet computer, and uses the target sphere as a reference for point cloud registration to scan the structural data in the tunnel and send it to the tablet computer;

[0053] The tablet computer is connected to the USB interface of the USB-to-serial port module, and is used to receive data from the three-dimensional laser scanner and form a three-dimensional point cloud map of the tunnel and send it to the USB-to-serial port module;

[0054] The USB to serial port module converts the tunnel three-dimensional point cloud data from the USB port to the serial port and sends it to the LoRa module;

[0055] The LoRa module is used to send the tunnel three-dimensional point cloud map data to the system service through the LoRa protocol.

[0056] Wherein, the LoRa gateway includes a 4G / 5G module, an MCU controller and a LoRa module;

[0057] The 4G / 5G module is electrically connected to the MCU controller for information exchange between the 4G / 5G module and the MCU controller;

[0058] The MCU controller is electrically connected to the LoRa module for information exchange between the MCU controller and the LoRa module.

[0059] Wherein, the mobile terminal includes a tablet computer and a LoRa module;

[0060] The tablet computer is electrically connected to the LoRa module and is used to receive LoRa module signals and display them on the tablet computer.

[0061] Among them, the three-dimensional laser scanner is implemented by RIEGL VZ-1000, the USB to serial port module is implemented by PL2303HX of Litte Company, the 4G / 5G module is implemented by Fibocom FG132, the LoRa module is implemented by E22-230T33S of Chengdu Yibite, and the MCU controller is STM32F407 of ST Company, which is compiled by KeiluVision 5 software using C language.

[0062] The settlement monitoring system during shield construction in this embodiment adopts an unmanned aerial vehicle surveying instrument, a laser scanning terminal, a system server, a gateway and a mobile terminal to realize the settlement monitoring system during shield construction. The system uses unmanned aerial vehicle photography technology, three-dimensional laser scanning technology and the finite element method to establish a shield process simulation, form a three-dimensional settlement distribution map and simulate grouting measures to determine the grouting amount and the optimal settlement control range. During construction, the settlement risk level is determined according to the actual settlement data and the corresponding control plan is launched and sent to the construction site, realizing the lean management of settlement control 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.

[0063] Embodiment 2: Figure 5 and Figure 6 The method for using the settlement monitoring system during shield construction provided by the present invention adopts the settlement monitoring system during shield construction as described in Example 1, and comprises the following steps:

[0064] S1. The system server obtains the data of the drone surveying instrument and laser scanning terminal before construction, and establishes the ground digital elevation map and the three-dimensional point cloud map of the tunnel before construction;

[0065] S2. Use manual exploration method to complete the collection of geological exploration data of shield tunnel and establish a three-dimensional geological structure map;

[0066] S3. The system server uses finite element software simulation method to input geological structure, elastic modulus, cohesion, internal friction angle, Poisson's ratio and gravity data to establish shield process simulation, form a three-dimensional settlement distribution map, and mark the maximum settlement position and settlement amount of the shield;

[0067] S4. The system server simulates the thick slurry method to carry out grouting measures on the pipe roof, and re-establishes the shield process simulation by changing the properties of the shield shell and the grouting layer to form an improved three-dimensional settlement distribution map to determine the grouting amount and the optimal settlement control range;

[0068] S5. The system server formulates the construction process according to the improved three-dimensional settlement distribution map and sends it to the mobile terminal through the gateway to guide the on-site construction of the shield machine;

[0069] S6. The system server obtains data from the drone surveying instrument and laser scanning terminal during construction, establishes a ground digital elevation map and a three-dimensional point cloud map of the tunnel during construction, generates an actual three-dimensional settlement distribution map, and obtains the settlement area and settlement amount data;

[0070] S7. The system server substitutes the settlement area range and settlement amount data into the settlement risk index formula, calculates the settlement risk index, and defines the settlement risk level;

[0071] S8. The system server revises the settlement control operation process based on the original construction process according to the settlement risk level, and forwards it to the mobile terminal through the gateway;

[0072] S9. The mobile terminal displays the settlement risk level to the on-site construction manager, updates the construction procedures, and guides the on-site construction.

[0073] The artificial exploration method includes one method or a combination of multiple methods including geological survey method, advance drilling method, geophysical prospecting method and advance pilot pit prediction method.

[0074] The finite element software simulation method uses one or more combinations of MIDAS GTS, PLAXIS 3D, FLAC 3D, and ABAQUS.

[0075] The subsidence risk index formula is Among them, S i Represents the surface settlement area of ​​the i-th block, in m 2 , L i represents the cumulative settlement corresponding to the surface settlement area of ​​the ith area, in mm, δ represents the weight coefficient of the cumulative value of surface settlement to the settlement risk index and δ∈(0,1), S j ′ represents the settlement area of ​​the jth tunnel, in m 2 , L j ′ represents the cumulative settlement corresponding to the settlement area of ​​the jth tunnel, in mm, and S represents the total surface settlement area, in m 2 , L represents the maximum allowable surface settlement, in mm, S′ represents the total tunnel settlement area, in m 2 , L′ represents the maximum allowable settlement of the tunnel, in mm.

[0076] The settlement risk level is that the risk index is [0.3, +∞) as high risk, the risk index is [0.1, 0.2) as medium risk, and the rest are low risk.

[0077] The settlement control operation process comprises the following steps:

[0078] L1. Obtain the settlement risk level;

[0079] L2. If the settlement risk level is high, secondary grouting will be used to fill the building gaps behind the segments in the shield construction tunnel according to the actual three-dimensional settlement distribution map until settlement stops. The slurry for the secondary grouting is a double slurry of cement and water glass, with the principle of small amounts and multiple times;

[0080] L3. If the settlement risk level is medium, follow-up grouting is carried out for specific ring numbers according to the actual three-dimensional settlement distribution map until settlement stops. The slurry for follow-up grouting is the same as that for secondary grouting;

[0081] L4. If the settlement risk level is low, the segment joints shall be grouted using the segment joint plugging method according to the actual three-dimensional settlement distribution map until the settlement stops. The grouting slurry is the same as the secondary grouting slurry.

[0082] like Figure 5-6 As shown, the system server obtains data from the drone surveyor and laser scanning terminal, establishes a ground digital elevation map and a three-dimensional point cloud map of the tunnel before construction, completes the three-dimensional geological structure map of the shield tunnel through manual exploration, uses the finite element software simulation method to establish a shield process simulation, and forms a three-dimensional settlement distribution map. The system server simulates the thick slurry method to carry out pipe-roof grouting measures to form an improved three-dimensional settlement distribution map to determine the grouting amount and the optimal settlement control range. The data of the drone surveyor and laser scanning terminal during construction are used to establish a new ground digital elevation map and a three-dimensional point cloud map of the tunnel, generate an actual three-dimensional settlement distribution map, obtain the settlement area range and settlement data, calculate the settlement risk index according to the settlement risk index formula, define the settlement risk level, revise the settlement control operation process based on the original construction process, and send it to the mobile terminal to guide on-site construction.

[0083] The settlement monitoring system and its use method in shield construction in this embodiment adopts a modular design method, uses an unmanned aerial vehicle surveying instrument, a laser scanning terminal, a system server, a gateway and a mobile terminal to realize the settlement monitoring system in shield construction, and uses unmanned aerial vehicle photography technology, three-dimensional laser scanning technology and finite element method to establish a shield process simulation, form a three-dimensional settlement distribution map and simulate grouting measures to determine the grouting amount and the optimal settlement control range. During construction, the settlement risk level is determined according to the actual settlement data and the corresponding control plan is launched and sent to the construction site, realizing the lean management of settlement control in shield construction.

[0084] 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 settlement monitoring system during shield construction is characterized by: Including drone surveying instruments, laser scanning terminals, system servers, gateways and mobile terminals; The drone surveying instrument is used to measure the elevation of terrain and ground buildings, and transmit the information to the system server through 4G or 5G signals; the drone surveying instrument is equipped with one or more components of InSAR radar, GNSS receiver, tilt camera, attitude positioning system, laser altimeter, and barometer to measure the elevation; The laser scanning terminal is used to measure the three-dimensional structure size in the tunnel, and transmits the information to the system server via the gateway through the LoRa signal; The system server is connected to the gateway via a 4G or 5G network, and is used to establish a ground digital elevation map and a three-dimensional point cloud map of the tunnel after receiving data from the drone surveying instrument and the laser scanning terminal, analyze the changes in data before and during shield construction, obtain settlement data, determine the settlement risk level of the construction site according to the settlement risk index formula, and launch a settlement control plan, revise the construction process, and finally transmit the result information to the gateway; The gateway is connected to the mobile terminal via a LoRa network, and is used to convert information from a 5G protocol into a LoRa protocol and send it to the mobile terminal; The mobile terminal is used to display the settlement risk level, settlement control plan and revised construction procedures to the on-site construction manager to guide the on-site construction.

2. The shield construction settlement monitoring system according to claim 1, characterized in that: The laser scanning terminal includes a three-dimensional laser scanner, a tablet computer, a USB to serial port module and a LoRa module; The three-dimensional laser scanner is connected to the LAN interface of the tablet computer, and uses the target sphere as a reference for point cloud registration to scan the structural data in the tunnel and send it to the tablet computer; The tablet computer is connected to the USB interface of the USB-to-serial port module, and is used to receive data from the three-dimensional laser scanner and form a three-dimensional point cloud map of the tunnel and send it to the USB-to-serial port module; The USB to serial port module converts the tunnel three-dimensional point cloud data from the USB port to the serial port and sends it to the LoRa module; The LoRa module is used to send the tunnel three-dimensional point cloud map data to the system service through the LoRa protocol.

3. The shield construction settlement monitoring system according to claim 1, characterized in that: The LoRa gateway includes a 4G / 5G module, an MCU controller and a LoRa module; The 4G / 5G module is electrically connected to the MCU controller for information exchange between the 4G / 5G module and the MCU controller; The MCU controller is electrically connected to the LoRa module for information exchange between the MCU controller and the LoRa module.

4. The shield construction settlement monitoring system according to claim 1, characterized in that: The mobile terminal includes a tablet computer and a LoRa module; The tablet computer is electrically connected to the LoRa module and is used to receive LoRa module signals and display them on the tablet computer.

5. A method for using settlement monitoring during shield construction, which uses the settlement monitoring system during shield construction as described in any one of claims 1 to 4; characterized in that: The steps include: S1. The system server obtains the data of the drone surveying instrument and laser scanning terminal before construction, and establishes the ground digital elevation map and the three-dimensional point cloud map of the tunnel before construction; S2. Use manual exploration method to complete the collection of geological exploration data of shield tunnel and establish a three-dimensional geological structure map; S3. The system server uses finite element software simulation method to input geological structure, elastic modulus, cohesion, internal friction angle, Poisson's ratio and gravity data to establish shield process simulation, form a three-dimensional settlement distribution map, and mark the maximum settlement position and settlement amount of the shield; S4. The system server simulates the thick slurry method to carry out grouting measures on the pipe roof, and re-establishes the shield process simulation by changing the properties of the shield shell and the grouting layer to form an improved three-dimensional settlement distribution map to determine the grouting amount and the optimal settlement control range; S5. The system server formulates the construction process according to the improved three-dimensional settlement distribution map and sends it to the mobile terminal through the gateway to guide the on-site construction of the shield machine; S6. The system server obtains data from the drone surveying instrument and laser scanning terminal during construction, establishes a ground digital elevation map and a three-dimensional point cloud map of the tunnel during construction, generates an actual three-dimensional settlement distribution map, and obtains the settlement area and settlement amount data; S7. The system server substitutes the settlement area range and settlement amount data into the settlement risk index formula, calculates the settlement risk index, and defines the settlement risk level; S8. The system server revises the settlement control operation process based on the original construction process according to the settlement risk level, and forwards it to the mobile terminal through the gateway; S9. The mobile terminal displays the settlement risk level to the on-site construction manager, updates the construction procedures, and guides the on-site construction.

6. The method for using settlement monitoring in shield construction as claimed in claim 5, characterized in that: In step S2, the artificial exploration method includes one method or a combination of multiple methods selected from the group consisting of geological survey method, advance drilling method, geophysical prospecting method, and advance pilot pit prediction method.

7. The method for using settlement monitoring in shield construction as claimed in claim 5, characterized in that: In step S3, the finite element software simulation method includes one method or a combination of multiple methods selected from the group consisting of MIDAS GTS, PLAXIS 3D, FLAC 3D, and ABAQUS.

8. The method for using settlement monitoring in shield construction as claimed in claim 5, characterized in that: In step S7, the subsidence risk index formula is as follows: Among them, S i Represents the surface settlement area of ​​the i-th block, in m 2 ; L i represents the cumulative settlement corresponding to the surface settlement area of ​​the ith area, in mm; δ represents the weight coefficient of the cumulative value of surface settlement in the settlement risk index and δ∈(0,1); S j ′ represents the settlement area of ​​the jth tunnel, in m 2 ; L j ′ represents the cumulative settlement corresponding to the settlement area of ​​the jth tunnel, in mm; S represents the total surface settlement area, in m 2 ; L represents the maximum allowable surface settlement, in mm; S′ represents the total tunnel settlement area, in m 2 ; L′ represents the maximum allowable settlement of the tunnel, in mm; The subsidence risk level is divided into three levels: high risk, medium risk and low risk. Among them, the risk index in [0.3, +∞) is defined as high risk, the risk index in [0.1, 0.2) is defined as medium risk, and the rest are defined as low risk.

9. The method for using settlement monitoring in shield construction as claimed in claim 5, characterized in that: In step S8, the settlement control operation process specifically includes the following steps: L1. Obtain the settlement risk level; L2. If the settlement risk level is high, secondary grouting will be used to fill the building gaps behind the segments in the shield construction tunnel according to the actual three-dimensional settlement distribution map until settlement stops. The slurry for the secondary grouting is a double slurry of cement and water glass, with the principle of small amounts and multiple times; L3. If the settlement risk level is medium, follow-up grouting is carried out for specific ring numbers according to the actual three-dimensional settlement distribution map until settlement stops. The slurry for follow-up grouting is the same as that for secondary grouting; L4. If the settlement risk level is low, the segment joints shall be grouted using the segment joint plugging method according to the actual three-dimensional settlement distribution map until the settlement stops. The grouting slurry is the same as the secondary grouting slurry.

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