Shield construction settlement control method

Abstract

The invention relates to the technical field of shield tunneling machine construction, in particular to a shield tunneling machine settlement control method which comprises the steps that the maximum pressure and the minimum pressure of a shield tunneling machine in an undercrossing subway tunnel section are calculated according to the burial depth and geological data, and when the shield tunneling machine conducts tunneling, the notch pressure of an excavation face is monitored according to the maximum pressure and the minimum pressure; in the tunneling process of the underpass subway tunnel section, the tunneling speed and the unearthing amount of a shield tunneling machine are monitored, meanwhile, grouting is conducted through radial holes in a shield shell by adopting a plastic material, and a gap, caused by excavation, between a soil body and the shield shell is filled; and when the shield tunneling machine tunnels to the granite layer, slurry injection parameters are controlled. According to the scheme, the safety and reliability of the construction process can be effectively controlled, the construction settlement condition is effectively controlled, it is guaranteed that the safety of the subway tunnel and the surrounding ground is effectively guaranteed, and related potential safety hazards are eliminated.

Description

Technical Field

[0001] This invention relates to the field of tunnel boring machine (TBM) construction technology, and in particular to a method for controlling settlement during TBM construction. Background Technology

[0002] With the development of intercity railway tunnel construction, large-diameter shield tunneling has been widely used due to constraints imposed by surrounding environmental factors and geological conditions. However, large-section shield tunneling can cause disturbance to existing subway tunnels and roads, thus affecting traffic safety. Large-section shield tunneling offers advantages such as economy, safety, and efficiency, and is currently widely used in the construction of intercity railway tunnels. However, the shield tunneling process disrupts the original soil conditions, causing deformation of the soil and surrounding structures.

[0003] Currently, traditional tunnel boring machine (TBM) construction control schemes cannot effectively control the construction process and settlement during the TBM's passage under subway tunnels, resulting in the inability to effectively guarantee the safety of the subway tunnel and the surrounding ground, and posing certain safety hazards. Summary of the Invention

[0004] The purpose of this invention is to solve at least one technical problem in the background art and to provide a method for controlling settlement during shield tunneling construction.

[0005] To achieve the above objectives, the present invention provides a method for controlling settlement during tunnel boring machine (TBM) construction, comprising: Based on the burial depth and geological data, the maximum and minimum pressures of the tunnel boring machine (TBM) in the section passing under the subway tunnel are calculated. During the TBM excavation, the cutting pressure at the excavation face is monitored based on the maximum and minimum pressures. During the excavation of the section passing under the subway tunnel, the tunneling speed and soil excavation volume of the tunnel boring machine are monitored. At the same time, plastic materials are used to inject grout through the radial holes on the shield shell to fill the gaps between the excavated soil and the shield shell. When the tunnel boring machine reaches the granite layer, the parameters of the injected mud are controlled.

[0006] According to one aspect of the present invention, the calculation of the maximum and minimum pressures of the tunnel boring machine (TBM) in the section passing under the subway tunnel based on burial depth and geological data, and the monitoring of the cutting pressure at the excavation face based on the maximum and minimum pressures during TBM excavation, includes: Based on the burial depth and geological data, the soil and water pressure in front of the shield machine cutterhead is calculated according to the cut ring calculation formula, and the maximum and minimum soil and water pressure of the shield machine in the section passing under the subway tunnel are obtained. During tunneling, the water and soil pressure at the excavation face is monitored. The water and soil pressure is controlled by the tunnel boring machine's automatic pressure-maintaining system, keeping it within the range of maximum and minimum water and soil pressure, with an accuracy of ±0.1 bar.

[0007] According to one aspect of the present invention, the tunneling speed of a tunnel boring machine is monitored as follows: During the excavation of the section passing under the subway tunnel, the tunneling speed of the tunnel boring machine was monitored and controlled between 15 and 20 mm / min.

[0008] According to one aspect of the present invention, the amount of excavated soil from a tunnel boring machine is monitored as follows: During the excavation of the section passing under the subway tunnel, the amount of soil excavated by the tunnel boring machine (TBM) was monitored, and the amount of soil excavated by the TBM was controlled to be 98% to 100% of the theoretical amount.

[0009] According to one aspect of the present invention, the plastic material is a clay-based material, which is composed of synthetic sodium-based clay minerals, cellulose derivatives, colloidal stabilizers and dispersants; During the excavation of the section passing under the subway tunnel, the injection rate of the mud-effect was 120% of the volume of the gap between the shield body and the surrounding soil after the shield machine cutterhead had been excavated.

[0010] According to one aspect of the invention, the method further includes: during the excavation of the section passing under the subway tunnel, monitoring the tracking grouting; when the tunnel boring machine (TBM) has excavated to a preset position, connecting to the segment that has detached from the tail of the TBM via a three-way pipe, and performing secondary tracking grouting, so that the grout behind the segment wall solidifies in time to form a ring, blocking the flow of groundwater into the excavation chamber behind the segment wall; and controlling the grouting pressure of the secondary grouting to be 0.3 to 0.5 MPa.

[0011] According to one aspect of the present invention, when the tunnel boring machine (TBM) tunnels into a granite layer, controlling the parameters of the injected mud includes: Control the feed pulp specific gravity to 1.1–1.15 g / cm³. 3 ; Control the mud viscosity to 26–28 seconds; Control the mud water loss rate to ≤15mL / 30min; Control the mud colloid content to above 96%; Control the pH value of the mud to 8-10.

[0012] To achieve the above objectives, the present invention also provides a settlement control system for tunnel boring machine (TBM) construction, comprising: The excavation face cutting pressure monitoring module calculates the maximum and minimum pressure of the tunnel boring machine (TBM) in the section passing under the subway tunnel based on the burial depth and geological data. When the TBM is excavating, it monitors the cutting pressure of the excavation face based on the maximum and minimum pressure. The tunneling monitoring and control module monitors the tunneling speed and excavation volume of the tunnel boring machine during the tunneling process of the section under the subway. At the same time, plastic materials are used to inject grout through the radial holes on the shield shell to fill the gap between the excavated soil and the shield shell. The mud parameter control module controls the parameters of the injected mud when the tunnel boring machine reaches the granite layer.

[0013] To achieve the above objectives, the present invention also provides an electronic device, including a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the computer program, when executed by the processor, implements the shield tunneling settlement control method as described above.

[0014] To achieve the above objectives, the present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the shield tunneling settlement control method as described above.

[0015] According to the present invention, simultaneous grouting of plastic materials during shield tunneling ensures the safety of existing tunnels. Furthermore, the control and adjustment of shield parameters are strengthened during shield tunneling, and the pressure and excavated soil volume of the shield's slurry chamber are adjusted in a timely manner. Sufficient injection of plastic materials near existing tunnels also ensures the shield machine passes smoothly and at a uniform speed, further reducing disturbance to the soil.

[0016] According to the above-described solution of the present invention, the present invention can effectively control the safety and reliability of the construction process, effectively control the construction settlement, ensure the safety of the subway tunnel and the surrounding ground, and eliminate related safety hazards. Attached Figure Description

[0017] Figure 1 The flowchart schematically illustrates a method for controlling settlement during tunnel boring machine (TBM) construction according to one embodiment of the present invention. Detailed Implementation

[0018] The invention will now be discussed with reference to exemplary embodiments. It should be understood that the described embodiments are merely intended to enable those skilled in the art to better understand and thus implement the invention, and are not intended to imply any limitation on the scope of the invention.

[0019] As used herein, the term "comprising" and its variations are to be interpreted as open-ended terms meaning "including but not limited to". The term "based on" is to be interpreted as "at least partially based on". The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment".

[0020] Figure 1 A flowchart illustrating a method for controlling settlement during tunnel boring machine (TBM) construction according to one embodiment of the present invention is shown. Figure 1 As shown, in this embodiment, the method for controlling settlement during tunnel boring machine (TBM) construction includes: Based on the burial depth and geological data, the maximum and minimum pressures of the tunnel boring machine (TBM) in the section passing under the subway tunnel are calculated. During the TBM excavation, the cutting pressure at the excavation face is monitored based on the maximum and minimum pressures. During the excavation of the section passing under the subway tunnel, the tunneling speed and soil excavation volume of the tunnel boring machine are monitored. At the same time, plastic materials are used to inject grout through the radial holes on the shield shell to fill the gaps between the excavated soil and the shield shell. When the tunnel boring machine reaches the granite layer, the parameters of the injected mud are controlled.

[0021] Furthermore, according to one embodiment of the present invention, based on the burial depth and geological data, the maximum and minimum pressures of the tunnel boring machine (TBM) in the section passing under the subway tunnel are calculated. During the TBM's excavation, the cutting pressure at the excavation face is monitored based on the maximum and minimum pressures, including: Based on the burial depth and geological data, the soil and water pressure in front of the shield machine cutterhead is calculated according to the cut ring calculation formula, and the maximum and minimum soil and water pressure of the shield machine in the section passing under the subway tunnel are obtained. During tunneling, the water and soil pressure at the excavation face is monitored. The water and soil pressure is controlled by the tunnel boring machine's automatic pressure-maintaining system, keeping it within the range of maximum and minimum water and soil pressure, with an accuracy of ±0.1 bar.

[0022] Furthermore, according to one embodiment of the present invention, the tunneling speed of the tunnel boring machine is monitored as follows: During the excavation of the section passing under the subway tunnel, the tunneling speed of the tunnel boring machine was monitored and controlled between 15 and 20 mm / min.

[0023] Furthermore, according to one embodiment of the present invention, the amount of excavated soil from the tunnel boring machine is monitored as follows: During the excavation of the section passing under the subway, the amount of soil excavated by the tunnel boring machine (TBM) was monitored, and the amount of soil excavated by the TBM was controlled to be 98% to 100% of the theoretical amount. Theoretical excavation volume = tunneling mileage * excavation face area.

[0024] Furthermore, according to one embodiment of the present invention, the plastic material is a clay-based material, which is composed of synthetic sodium-based clay minerals, cellulose derivatives, colloidal stabilizers, and dispersants; During the excavation of the section passing under the subway tunnel, the injection rate of the mud-effect was 120% of the volume of the gap between the shield body and the surrounding soil after the shield machine cutterhead had been excavated.

[0025] Furthermore, according to one embodiment of the present invention, the present invention further includes: during the excavation of the section passing under the subway tunnel, monitoring the tracking grouting; when the tunnel boring machine excavates to a preset position, connecting to the segment that has detached from the shield tail of the tunnel boring machine through a three-way pipe, performing tracking secondary grouting, so that the grout behind the segment wall solidifies in time, forming a ring, sealing the groundwater flowing into the excavation chamber behind the segment wall, while controlling the grouting pressure of the secondary grouting to be 0.3 to 0.5 MPa.

[0026] Furthermore, according to one embodiment of the present invention, when the tunnel boring machine excavates to the granite layer, the parameters of the injected mud are controlled, including: Control the feed pulp specific gravity to 1.1–1.15 g / cm³. 3 ; Control the mud viscosity to 26–28 seconds; Control the mud water loss rate to ≤15mL / 30min; Control the mud colloid content to above 96%; Control the pH value of the mud to 8-10.

[0027] According to the above-described scheme of the present invention, simultaneous grouting of plastic materials during shield tunneling ensures the safety of existing tunnels. Furthermore, the control and adjustment of shield parameters are strengthened during shield tunneling, and the pressure and excavated soil volume of the shield slurry chamber are adjusted in a timely manner. Sufficient injection of plastic materials when approaching existing tunnels ensures the smooth and uniform passage of the shield machine, further reducing disturbance to the soil.

[0028] According to the above-described solution of the present invention, the present invention can effectively control the safety and reliability of the construction process, effectively control the construction settlement, ensure the safety of the subway tunnel and the surrounding ground, and eliminate related safety hazards.

[0029] Furthermore, to achieve the above objectives, the present invention also provides a tunnel boring machine (TBM) settlement control system, comprising: The excavation face cutting pressure monitoring module calculates the maximum and minimum pressure of the tunnel boring machine (TBM) in the section passing under the subway tunnel based on the burial depth and geological data. When the TBM is excavating, it monitors the cutting pressure of the excavation face based on the maximum and minimum pressure. The tunneling monitoring and control module monitors the tunneling speed and excavation volume of the tunnel boring machine during the tunneling process of the section under the subway. At the same time, plastic materials are used to inject grout through the radial holes on the shield shell to fill the gap between the excavated soil and the shield shell. The mud parameter control module controls the parameters of the injected mud when the tunnel boring machine reaches the granite layer.

[0030] Furthermore, according to one embodiment of the present invention, based on the burial depth and geological data, the maximum and minimum pressures of the tunnel boring machine (TBM) in the section passing under the subway tunnel are calculated. During the TBM's excavation, the cutting pressure at the excavation face is monitored based on the maximum and minimum pressures, including: Based on the burial depth and geological data, the soil and water pressure in front of the shield machine cutterhead is calculated according to the cut ring calculation formula, and the maximum and minimum soil and water pressure of the shield machine in the section passing under the subway tunnel are obtained. During tunneling, the water and soil pressure at the excavation face is monitored. The water and soil pressure is controlled by the tunnel boring machine's automatic pressure-maintaining system, keeping it within the range of maximum and minimum water and soil pressure, with an accuracy of ±0.1 bar.

[0031] Furthermore, according to one embodiment of the present invention, the tunneling speed of the tunnel boring machine is monitored as follows: During the excavation of the section passing under the subway tunnel, the tunneling speed of the tunnel boring machine was monitored and controlled between 15 and 20 mm / min.

[0032] Furthermore, according to one embodiment of the present invention, the amount of excavated soil from the tunnel boring machine is monitored as follows: During the excavation of the section passing under the subway, the amount of soil excavated by the tunnel boring machine (TBM) was monitored, and the amount of soil excavated by the TBM was controlled to be 98% to 100% of the theoretical amount. The theoretical excavation volume refers to the theoretical excavation volume of the tunnel boring machine.

[0033] Furthermore, according to one embodiment of the present invention, the plastic material is a clay-based material, which is composed of synthetic sodium-based clay minerals, cellulose derivatives, colloidal stabilizers, and dispersants; During the excavation of the section passing under the subway tunnel, the injection rate of the mud-effect was 120% of the volume of the gap between the shield body and the surrounding soil after the shield machine cutterhead had been excavated.

[0034] Furthermore, according to one embodiment of the present invention, the present invention further includes: during the excavation of the section passing under the subway tunnel, monitoring the tracking grouting; when the tunnel boring machine excavates to a preset position, connecting to the segment that has detached from the shield tail of the tunnel boring machine through a three-way pipe, performing tracking secondary grouting, so that the grout behind the segment wall solidifies in time, forming a ring, sealing the groundwater flowing into the excavation chamber behind the segment wall, while controlling the grouting pressure of the secondary grouting to be 0.3 to 0.5 MPa.

[0035] Furthermore, according to one embodiment of the present invention, when the tunnel boring machine excavates to the granite layer, the parameters of the injected mud are controlled, including: Control the feed pulp specific gravity to 1.1–1.15 g / cm³. 3 ; Control the mud viscosity to 26–28 seconds; Control the mud water loss rate to ≤15mL / 30min; Control the mud colloid content to above 96%; Control the pH value of the mud to 8-10.

[0036] According to the above-described scheme of the present invention, simultaneous grouting of plastic materials during shield tunneling ensures the safety of existing tunnels. Furthermore, the control and adjustment of shield parameters are strengthened during shield tunneling, and the pressure and excavated soil volume of the shield slurry chamber are adjusted in a timely manner. Sufficient injection of plastic materials when approaching existing tunnels ensures the smooth and uniform passage of the shield machine, further reducing disturbance to the soil.

[0037] According to the above-described solution of the present invention, the present invention can effectively control the safety and reliability of the construction process, effectively control the construction settlement, ensure the safety of the subway tunnel and the surrounding ground, and eliminate related safety hazards.

[0038] Furthermore, to achieve the above objectives, the present invention also provides an electronic device, including a processor, a memory, and a computer program stored in the memory and executable on the processor. When the computer program is executed by the processor, it implements the shield tunneling settlement control method as described above.

[0039] Furthermore, to achieve the above objectives, the present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the shield tunneling settlement control method as described above.

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely one preferred embodiment of this invention and are only used to explain this invention. They do not limit the scope of protection of this invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0041] Example 1 To ensure that the subway's displacement remains within a controllable range during the tunnel boring machine's passage under the subway tunnel, surface grouting reinforcement treatment was carried out in the area before the tunnel boring machine passed under it.

[0042] For the subway tunnel and the area within a 3m projection range on both sides, oblique grouting is used. A two-component grout with good fluidity is selected, with a grout mix ratio (cement grout to water glass volume ratio) of C:S=1:(0.6~1.0), a cement grout water-cement ratio of 0.8:1~1:1, and a grouting pressure control value of 0.5~0.8MPa. For the area within a 3m~8.5m projection range on both sides of Line 3, vertical surface grouting is used, with a 1:1 cement grout. The spacing between the surface reinforcement grouting pipes is 1.5m×1.5m, and the grouting pressure control value is 0.5~1.0MPa. Grouting is stopped when the grouting pressure reaches the control value or the grouting volume reaches the design value. If the soil layer is prone to borehole collapse, forward grouting is adopted; otherwise, backward grouting is used.

[0043] Grouting parameters, grout mix ratio, grouting pressure, and grouting volume can be further refined and adjusted based on on-site grouting tests.

[0044] In this embodiment, a slurry-balanced shield tunneling process is used for shield tunneling under a subway tunnel. The slurry-balanced shield tunneling process mainly involves the cutterhead cutting the soil at the tunnel face. The cut soil first enters the slurry chamber, where it is mixed evenly with fresh pumped slurry using a mixing device. Then, it is transported to a surface spoil disposal center via a slurry circulation system for separation. After separating sand and gravel, the clean slurry is pumped back into the slurry chamber. During this process, propulsion cylinders (jacks) provide the tunneling power, and the cutterhead main drive provides the rotation power for the cutterhead. Pressurization of the slurry chamber maintains a balance between the soil pressure at the tunnel face and the pressure in the slurry chamber, thus maintaining tunnel face stability. After tunneling one ring segment length (e.g., 2m), the segments are assembled, and then the next ring is tunneled. The slurry delivery pipeline is extended every 6m of tunneling.

[0045] Furthermore, in this embodiment, to ensure the safety of passing under the operating subway tunnel, a test section is set up 50m before the underpass point to summarize the various tunneling parameters of the shield, the balance of excavated soil and soil, and the control of slurry pressure fluctuations. An advanced grouting operation is then carried out to prepare for passing under the subway tunnel.

[0046] Furthermore, in this embodiment, the method for controlling settlement during shield tunneling when passing under a subway tunnel includes the following steps: (1) Earth pressure control Based on the burial depth and geological data, the soil and water pressure in front of the cutterhead is calculated using the formula for the cutterhead ring. The maximum and minimum soil and water pressures for the tunnel boring machine (TBM) in the section passing under the subway tunnel are 150 kPa and 130 kPa, respectively. During tunneling, the cutterhead pressure must be strictly monitored and controlled by an automatic pressure-maintaining system to ensure its accuracy is within ±0.1 bar of the set values ​​(maximum and minimum soil and water pressures).

[0047] (2) Tunneling speed control To minimize soil disturbance, the tunneling speed should not be too fast during the underpass construction. In the underpass section, the principle is to ensure the stability of the excavation face, and the tunnel boring machine should be kept at a constant speed to maintain unobstructed circulation. The tunneling speed in the underpass section is controlled between 15 and 20 mm / min.

[0048] (3) Control of mud indexes Gravity control: According to the survey report, when the tunnel body under the subway is located in blocky strongly weathered granite or moderately strongly weathered granite, the grout specific gravity should be controlled between 1.1 and 1.15 g / cm³. 3 When the mud has a high specific gravity and viscosity, water is added to dilute it. When the mud has a low specific gravity and viscosity, bentonite is added appropriately to increase the mud-water ratio.

[0049] Viscosity control: The viscosity of the slurry is mainly used to suspend and carry the soil cut by the cutter head. In terms of the suspension of soil particles, the higher the viscosity of the slurry, the better. However, increasing the viscosity will increase the gel strength and plasticity of the slurry, increase the load on the slurry pump, and increase the difficulty of slurry separation. Taking all the above factors into consideration, the viscosity value is set at 26 to 28 seconds.

[0050] Water loss rate, colloid content, and pH control: The water loss rate of mud is the amount of water that seeps into the formation within a certain time under the influence of internal and external water head pressure differences. The water loss rate should be controlled to ≤15mL / 30min. The colloid content of mud is a simple and effective measure of the degree of clay hydration and dispersion and the stability of its suspension state. The colloid content is largely related to the viscosity of the mud-water mixture; good suspension means less water separation, and vice versa. Therefore, the colloid content of the mud-water mixture should be controlled above 96% to reduce soil particles and increase the viscosity of the mud. The pH value of the mud-water mixture must be alkaline, generally controlled between 8 and 10.

[0051] (4) Control of excavated soil volume Controlling the amount of excavated soil is the key to controlling the settlement of the subway above. The key points of control are: first, to ensure that the actual amount of excavated soil matches the theoretical amount of excavated soil; and second, to accurately measure the actual amount of excavated soil.

[0052] For example, if the tunnel boring machine has an excavation diameter of 13.27m and a segment ring width of 2m, the theoretical excavation volume per ring is 276.5m³. 3 .

[0053] The actual excavation volume of a slurry shield tunnel consists of two parts: dry slag and wet slag. Dry slag refers to the solid soil and debris separated by primary and dewatering screens after passing through the slurry return pipeline of the slurry circulation system and the slurry screening equipment; wet slag refers to the slurry separated after primary screening.

[0054] The volume of dry slag was measured using lidar modeling. The volume of wet slag was calculated according to equations (1) and (2). The sum of the volumes of dry and wet slag was compared with the theoretical excavation volume to confirm the over- or under-excavation situation of each ring. Under normal circumstances, the amount of excavated soil was controlled at 98% to 100% of the theoretical excavation volume, and the stratum loss rate was controlled within 3‰.

[0055] (1) (2) In the formula: This represents the increase in the volume of the wet slag. M represents the increase in weight of wet sludge in the mud pit. ; The density of the wet residue discharged from the initial screening. ; To increase the volume of mud in the post-mud pit, ; To increase the volume of mud in the front mud pit, ; To increase the density of the mud in the post-mud pit, ; To increase the mud density in the front mud pit, ; (5) Grouting of the outer plastic material of the shield shell The plastic material used in this embodiment is Kelp, which is composed of synthetic sodium-based clay minerals, cellulose derivatives, colloidal stabilizers and dispersants.

[0056] During tunneling, grouting with plastic material is performed through radial holes in the shield shell to promptly fill the voids between the soil and the shield shell caused by excavation. This measure can prevent soil settlement above the shield during tunneling and prevent the mud in the slurry chamber from spreading around the shield, causing a drop in slurry chamber pressure, resulting in elastic-plastic deformation of the soil at the excavation face and causing ground subsidence. It can also prevent soil displacement caused by friction and shear between the shield and the soil above.

[0057] Based on the shield parameters, hydrogeological risk sources, and past construction experience, the mud injection rate during the underpass is 120% of the volume of the gap between the shield and the surrounding soil after the cutterhead excavation.

[0058] Furthermore, in this embodiment, in addition to the control steps described above, the following controls are also performed: (6) Synchronous and secondary grouting control The grout used for synchronous grouting is selected with a cement mortar mix ratio that has a short initial setting time and low bleeding rate. During the tunneling process, the synchronous grouting volume and grouting pressure are strictly controlled. Based on the deformation of the tunnel lining segments and the deformation monitoring results of the ground and the existing subway tunnel, the grouting parameters and construction process parameters are adjusted in a timely manner.

[0059] During the tunnel boring machine (TBM) tunneling process, tracking grouting is a routine procedure for TBM advancement. When the TBM advances to the set ring number, it is connected to the segment that has detached from the shield tail through a T-junction pipe to perform timely tracking secondary grouting. This allows the grout behind the segment wall to solidify in time, forming a ring and sealing the groundwater behind the segment wall from flowing into the excavation chamber.

[0060] The secondary grouting uses a two-component grout (cement grout + water glass). The water-cement ratio of the cement grout is 1:1, the water to water glass (volume ratio) is 1:1, and the volume ratio of cement grout to water glass grout is 1:1. The grouting pressure for secondary grouting is controlled within the range of 0.3–0.5 MPa.

[0061] (7) Axis and attitude control During the tunnel boring machine (TBM) excavation process, the automatic guidance system and manual measurement are used to monitor the attitude of the TBM. Combined with the segment assembly, the spatial state of the TBM is controlled in real time through the hydraulic propulsion system to keep the deviation of the formed tunnel within the design allowable range.

[0062] (8) Management measures during the period of passing under the existing subway line Before the underpass was completed, a three-dimensional laser scan was conducted on the subway tunnel within a range of approximately 120 meters before and after the underpass section to ascertain the current clearance status of the tunnel in this section and to determine the deformation control value of the existing line.

[0063] Before the tunnel goes under, automated monitoring points are set up inside the tunnel and manual monitoring and measurement points are set up on the ground surface. During the tunneling process, the settlement of the ground surface and the subway is fully understood to guide the tunneling construction.

[0064] Those skilled in the art will recognize that the modules and algorithm steps described in conjunction with the embodiments disclosed herein can be implemented using electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0065] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the above-described apparatus and equipment can be referred to the corresponding process in the foregoing method implementation, and will not be repeated here.

[0066] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or modules may be electrical, mechanical, or other forms.

[0067] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the objectives of the embodiments of the present invention, depending on actual needs.

[0068] In addition, the functional modules in the embodiments of the present invention can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0069] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the sending / receiving methods of various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0070] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in this application.

[0071] It should be understood that the sequence number of each step in the invention and its embodiments does not absolutely imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

Claims

1. A method for controlling settlement during shield tunneling construction, characterized in that, include: Based on the burial depth and geological data, the maximum and minimum pressures of the tunnel boring machine (TBM) in the section passing under the subway tunnel are calculated. During the TBM excavation, the cutting pressure at the excavation face is monitored based on the maximum and minimum pressures. During the excavation of the section passing under the subway tunnel, the tunneling speed and soil excavation volume of the tunnel boring machine are monitored. At the same time, plastic materials are used to inject grout through the radial holes on the shield shell to fill the gaps between the excavated soil and the shield shell. When the tunnel boring machine reaches the granite layer, the parameters of the injected mud are controlled.

2. The method for controlling settlement during shield tunneling construction according to claim 1, characterized in that, Based on the burial depth and geological data, the maximum and minimum pressures of the tunnel boring machine (TBM) in the section passing under the subway tunnel are calculated. During TBM excavation, the cutting pressure at the excavation face is monitored based on the maximum and minimum pressures, including: Based on the burial depth and geological data, the soil and water pressure in front of the shield machine cutterhead is calculated according to the cut ring calculation formula, and the maximum and minimum soil and water pressure of the shield machine in the section passing under the subway tunnel are obtained. During tunneling, the water and soil pressure at the excavation face is monitored. The water and soil pressure is controlled by the tunnel boring machine's automatic pressure-maintaining system, keeping it within the range of maximum and minimum water and soil pressure, with an accuracy of ±0.1 bar.

3. The method for controlling settlement during shield tunneling construction according to claim 1, characterized in that, The tunneling speed of the tunnel boring machine is monitored as follows: During the excavation of the section passing under the subway tunnel, the tunneling speed of the tunnel boring machine was monitored and controlled between 15 and 20 mm / min.

4. The method for controlling settlement during shield tunneling construction according to claim 1, characterized in that, The amount of excavated soil from the tunnel boring machine is monitored as follows: During the excavation of the section passing under the subway tunnel, the amount of soil excavated by the tunnel boring machine (TBM) was monitored, and the amount of soil excavated by the TBM was controlled to be 98% to 100% of the theoretical amount.

5. The method for controlling settlement during shield tunneling construction according to claim 1, characterized in that, The plastic material is a clay-based material, which is composed of synthetic sodium-based clay minerals, cellulose derivatives, colloidal stabilizers, and dispersants. During the excavation of the section passing under the subway tunnel, the injection rate of the mud-effect was 120% of the volume of the gap between the shield body and the surrounding soil after the shield machine cutterhead had been excavated.

6. The method for controlling settlement during shield tunneling construction according to claim 1, characterized in that, Also includes: During the excavation of the section passing under the subway tunnel, the tracking grouting is monitored. When the tunnel boring machine (TBM) reaches the preset position, a secondary tracking grouting is performed by connecting the T-junction pipe to the segment that has detached from the TBM tail. This allows the grout behind the segment wall to solidify in time, forming a ring to block the flow of groundwater into the excavation chamber. At the same time, the grouting pressure of the secondary grouting is controlled at 0.3 to 0.5 MPa.

7. The method for controlling settlement during shield tunneling construction according to any one of claims 1-6, characterized in that, When the tunnel boring machine reaches the granite layer, the parameters of the injected mud are controlled, including: Control the feed pulp specific gravity to 1.1–1.15 g / cm³. 3 ; Control the mud viscosity to 26–28 seconds; Control the mud water loss rate to ≤15mL / 30min; Control the mud colloid content to above 96%; Control the pH value of the mud to 8-10.

8. A settlement control system for shield tunneling construction, characterized in that, include: The excavation face cutting pressure monitoring module calculates the maximum and minimum pressure of the tunnel boring machine (TBM) in the section passing under the subway tunnel based on the burial depth and geological data. When the TBM is excavating, it monitors the cutting pressure of the excavation face based on the maximum and minimum pressure. The tunneling monitoring and control module monitors the tunneling speed and excavation volume of the tunnel boring machine during the tunneling process of the section under the subway. At the same time, plastic materials are used to inject grout through the radial holes on the shield shell to fill the gap between the excavated soil and the shield shell. The mud parameter control module controls the parameters of the injected mud when the tunnel boring machine reaches the granite layer.

9. An electronic device, characterized in that, It includes a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the computer program, when executed by the processor, implements the shield tunneling settlement control method as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, A computer program is stored on the computer-readable storage medium, which, when executed by a processor, implements the shield tunneling settlement control method as described in any one of claims 1-7.

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