A method and device for synchronous grouting of a tunnel boring machine (TBM) mounted on a trolley.

Abstract

This application discloses a TBM synchronous grouting method and grouting device mounted on a tunnel boring machine (TBM) trolley, applicable to the field of underground engineering construction technology. The method includes: determining the starting number of grouting rings and controlling the grouting device to move to the corresponding ring position to generate a grouting sequence; constructing a backwall void evolution model based on the grouting position to predict the optimal control trajectory; real-time monitoring of grouting pressure and shield tail grease pressure and setting a safe pressure difference threshold; determining a grout leakage state when the difference between the measured grouting pressure and the shield tail grease pressure exceeds the safe pressure difference threshold; and filling the grouting hole according to the current grouting pressure and measured grout flow rate, when the pressure reaches a preset upper limit and the flow rate drops below a threshold value set for the flow rate, and automatically switching to the next grouting hole according to the grouting sequence. This application combines dual-threshold filling judgment and automatic hole position switching to achieve intelligent closed-loop construction, shortening the construction period and reducing the risks of bias pressure and leakage.

Description

Technical Field

[0001] This application relates to the field of underground engineering construction technology, and more specifically, to a TBM synchronous grouting method and grouting device mounted on a tunnel boring machine trolley. Background Technology

[0002] TBM grouting (also known as synchronous grouting) refers to injecting cement mortar and other filling materials into the annular gap between the newly assembled tunnel segments and the surrounding rock through a grouting pump while the tunnel boring machine is excavating. Its purpose is to fill the gap in time, control ground settlement, prevent the tunnel segments from loosening, and ensure the tunnel is waterproof.

[0003] Traditional grouting methods involve mixing grout on the ground, mixing cement, bentonite, sand, and water according to a certain ratio, loading the mixture into a transport tank, and then transporting it a long distance along the tunnel track by an electric locomotive to the tail of the TBM. Finally, the grout is injected into the tunnel segment wall by a grouting pump.

[0004] Traditional methods have the following prominent drawbacks: ground mixing and long-distance transportation (40-60 minutes) lead to grout segregation and delayed grouting, forcing a reduction in speed and a shutdown; at the same time, there are also defects such as segment bias caused by fixed starting ring and unilateral grouting, incomplete backfilling and arch voids caused by experience-based open-loop setting, grout leakage risk caused by lack of linkage between grouting and grease pressure, frequent pipe blockage caused by grout rheological deterioration, and easy misjudgment of full pressure by a single pressure.

[0005] No effective solutions have yet been proposed to address the problems in the relevant technologies. Summary of the Invention

[0006] To overcome the above problems, this application aims to propose a TBM synchronous grouting method and grouting device mounted on a tunnel boring machine trolley. The purpose is to solve the problems of segment bias caused by fixed starting ring and unilateral grouting, incomplete backfilling and crown voids caused by empirical open-loop setting, grout leakage risk caused by lack of linkage between grouting and grease pressure, frequent pipe blockage caused by grout rheological deterioration, and easy misjudgment of full pressure by a single pressure.

[0007] Therefore, the specific technical solution adopted in this application is as follows: A first aspect of the present invention provides a method for synchronous grouting of a tunnel boring machine (TBM) mounted on a shield tunneling trolley, the method comprising: The starting number of grouting rings is determined based on the tunneling working parameters and geological conditions, and the grouting device is controlled to move to the corresponding ring position to generate a grouting sequence for balancing the stress on the tunnel segments, including the order and combination of grouting holes. Based on the grouting location, a back wall void evolution model is constructed to identify grout leakage and suppress it in conjunction with grouting grease. The optimal control trajectory, including grout flow rate and grouting pressure, is predicted at each future moment to obtain the undivided flow rate setpoint. The system monitors the grouting pressure and the shield tail grease pressure in real time and sets a safe pressure difference threshold. When the difference between the measured grouting pressure and the shield tail grease pressure exceeds the safe pressure difference threshold, it is determined to be a grout leakage state. The system automatically reduces the current grouting flow rate and increases the grease injection pressure. At the same time, after each batch of grouting is completed, the system collects the grouting and pumping response characteristics, predicts the grout rheological state, and automatically corrects the material ratio for the next batch. Based on the current grouting pressure and the measured grout flow rate, when the pressure reaches the preset upper limit and the flow rate drops below the threshold of the flow rate setting value, the grouting hole is filled and automatically switches to the next grouting hole according to the grouting sequence.

[0008] Optionally, a grouting sequence is generated to balance the stress on the tunnel lining segments, including: Collect tunneling condition parameters including tunneling speed, thrust, and torque, as well as geological condition parameters including stratum type and soil and rock strength; The number of initial grouting rings is determined based on tunneling working parameters and geological condition parameters; Based on the principle of segment stress balance, a grouting sequence with left-right symmetry and alternating skip holes is generated; Compare the current segment ring number with the grouting start ring number to determine whether the current segment ring number meets the grouting trigger condition. If so, a control command is issued to move the grouting device to the preset grouting hole of the target ring position and perform alignment operation, and determine the grouting sequence of each grouting hole according to the grouting sequence. If not, continue tunneling and return to collect tunneling condition parameters including tunneling speed, thrust, and torque, as well as geological condition parameters including stratum type and soil strength.

[0009] Optionally, the expression for the backwall void evolution model is: In the formula, This represents the void volume at the next sampling time. Indicates the first k The unfilled void volume behind the tube wall at each sampling time; Indicates the formation compressibility coefficient; Indicates the TBM tunneling speed; This represents the theoretical void area of ​​a single ring; Indicates the sampling period; Indicates the actual grouting flow rate; Indicates the leakage characteristic coefficient; Indicates real-time grouting pressure; Indicates the real-time shield tail grease pressure; Indicates the safe differential pressure threshold; This indicates reference pressure.

[0010] Optionally, the unpartitioned traffic settings are obtained, including: Obtain the tunneling speed, segment ring geometry parameters, and shield tail sealing status corresponding to the current grouting location, and construct a backwall void evolution model for identifying grout leakage and inhibiting it in conjunction with grouting grease. Taking the current void volume as the initial state, the prediction time domain for multiple future sampling periods is set, and the optimal grouting flow rate and grouting pressure at each future moment are solved in a rolling manner based on the void evolution model behind the wall to obtain the optimal control quantity trajectory. The grouting flow rate and grouting pressure at the current sampling moment are extracted from the optimal control trajectory as initial setpoints; Based on the filling difficulty and sealing capacity of different parts of the segment ring, the initial pressure setting value is differentiated by region to obtain the flow setting value without region.

[0011] Alternatively, the method for obtaining the optimal control trajectory is as follows: Obtain the current back-wall void volume and use it as the initial state value for model predictive control. The time length of multiple future sampling periods is set as the prediction time domain, and the range of change of grouting flow rate and pressure within each sampling period is determined; Starting from the initial state value, the optimal grouting flow rate and grouting pressure at each future time point are determined using the back wall void evolution model in each sampling period, forming a candidate control sequence; The flow rate and pressure values ​​of the first sampling period in the candidate control sequence are used as the execution values ​​at the current moment, and the entire sequence is defined as the optimal control trajectory.

[0012] Alternatively, the method for forming candidate control sequences is as follows: The current backwall void volume is obtained as the initial state value. The formation compressibility coefficient and grout leakage characteristic coefficient updated online in the previous cycle are read, and the parameters of the backwall void evolution model are updated. By defining the prediction time domain and the control time domain, a multi-objective cost function is constructed with the objectives of minimizing the gap tracking error, the grouting flow rate change rate, and the risk of grout leakage pressure difference, and the constraint range of grouting flow rate and pressure is determined. Taking the current void volume as the initial state, the control sequence in the prediction time domain is set as the decision variable, the cost function value corresponding to the current decision variable is determined, the gradient of the cost function with respect to the decision variable is calculated, the decision variable is updated along the negative gradient direction, and the decision variable that exceeds the constraint is projected back into the constraint boundary. Repeat the iterations until the change in the cost function value calculated between two adjacent iterations is less than a preset threshold, and obtain a set of optimal control sequences; Take the flow rate and pressure value of the first sampling period in the optimal control sequence as the execution command at the current moment, and store the entire sequence as a candidate control sequence.

[0013] Optionally, the rheological state of the slurry can be predicted and the material ratio for the next batch can be automatically adjusted, including: Real-time acquisition of grouting pressure and shield tail grease pressure, recording of current grouting flow rate, and continuous recording of pumping pressure change characteristics; The difference between the measured grouting pressure and the shield tail grease pressure is used to determine whether there is a grout leakage. If there is a grout leakage, the current grouting flow rate is automatically reduced and the grease injection pressure is increased. After each batch of grouting is completed, the grouting pressure change characteristics recorded in the current batch are extracted as operational response characteristics. The extracted operational response characteristics are compared with a preset rheological state comparison table to estimate the rheological state of the slurry. Based on the estimation results, the correction amount for the next batch of material proportions is obtained, and then the proportion adjustment is performed.

[0014] Optionally, the rheological state of the slurry is estimated, including: The extracted grouting pressure change features are matched with a preset rheological state feature template library, and the similarity between the current feature and each template in the preset rheological state feature template library is calculated. Select the rheological state category corresponding to the template with the highest similarity. Based on the rheological state category, call the pre-calibrated slump range and pressure fluctuation characteristic parameters. Combine the measured torque and pressure fluctuation amplitude of the current batch to calculate the deviation between the actual rheological parameters and the target rheological parameters. Calculate the correction amount for the water-cement ratio and the adjustment amount for the admixture based on the deviation value, and limit the correction amount for the water-cement ratio and the adjustment amount for the admixture within the preset safety boundary to obtain the proportion correction amount. The calculation formula is as follows: In the formula, Indicates the first s Correction amount for the proportion of each batch of slurry mixing; This represents a function that maps the identified rheological state category to the corresponding slump range and pressure fluctuation characteristic parameters. Represents the set of rheological state categories A Select the category that maximizes the value within the parentheses; Indicates the first s Feature vector of grouting pressure variation in each batch of grouting With rheological state category a Corresponding feature template Similarity function between them; Indicates the first s The characteristic vector of grouting pressure variation for each batch of grouting; Indicates the rheological state category a Corresponding preset feature template; This indicates the proportional coefficient of the proportional controller relative to the integral controller. Indicates the integral coefficient of the proportional and integral controller; This represents the deviation between the actual rheological parameters and the target rheological parameters; This indicates the time interval between two adjacent mixing batches; Indicates the first j Deviation values ​​for each batch; Indicates the batch number; Indicates from batch 0 to batch 1 s batch.

[0015] In a second aspect, the present invention provides a TBM synchronous grouting device mounted on a tunnel boring machine trolley. The TBM synchronous grouting device includes: a mixing tank, a grout storage tank, a conveying pump, a screw conveyor, and a dry powder silo. The outlet of the dry powder silo is connected to the inlet of the screw conveyor. The outlet of the screw conveyor is connected to the inlet of the mixing tank, the outlet of the mixing tank is connected to the inlet of the grout storage tank, and the outlet of the grout storage tank is connected to the inlet of the conveying pump. Optionally, the mixing tank is equipped with a biaxial stirring device for mixing grouting materials to prepare a uniform slurry; a weighing sensor is installed at the bottom of the mixing tank. The dual-shaft stirring device includes a second motor installed on one side of the stirring tank. One end of the output shaft of the second motor is equipped with a dual-shaft drive assembly, and both sides of one end of the dual-shaft drive assembly are respectively equipped with stirring shafts that cooperate with the inner wall of the stirring tank. Several stirring blades are evenly arranged on the outer side of the stirring shafts. The screw feeding device includes a feeding pipe, the inlet of which is connected to the outlet of the dry powder silo, and the feeding pipe is inclined; a third motor is installed on one side of the top of the feeding pipe, and a screw conveyor shaft is installed at the output end of the third motor.

[0016] Compared with the prior art, this application has the following beneficial effects: 1. This application eliminates grout segregation and transportation delays by using a trolley to load grout and mix it in real time; dynamically determines the starting number of grouting loops and generates a symmetrical alternating sequence to ensure balanced stress on the segments; integrates a void model with online parameter identification and model prediction control to optimize grouting flow and pressure in real time, actively identify grout leakage and link it with grease suppression; and achieves intelligent closed-loop construction based on pump response adaptive correction ratio, combined with dual threshold fullness judgment and automatic hole position switching, shortening the construction period and reducing the risk of bias pressure and leakage.

[0017] 2. This application uses real-time acquisition of tunneling and geological parameters to dynamically determine the number of initial rings, and generates a symmetrical alternating grouting sequence based on force balance; it constructs a void evolution model with online updated parameters, combines model predictive control and multi-objective cost function rolling optimization of flow and pressure, solves the optimal control sequence through gradient projection iteration, and sets differentiated pressure zones to achieve rapid void convergence and precise pressure matching, thereby improving filling density and safety.

[0018] 3. This application monitors the grouting pressure and shield tail grease pressure in real time. When signs of grout leakage appear, it automatically reduces the flow rate and increases the grease pressure. After each batch is completed, the pumping pressure characteristics are extracted and matched with the preset template library to identify the rheological category. The deviation is calculated by combining the measured torque and pressure fluctuation. The water-cement ratio and admixture dosage are dynamically adjusted using a proportional and integral controller. The ratio is corrected online to ensure the rheological stability of the grout and avoid segregation or pipe blockage. Attached Figure Description

[0019] The above-mentioned features, characteristics, and advantages of this application, as well as their implementation methods, will become clearer and more understandable in conjunction with the following description of the embodiments, which are illustrated in detail with reference to the accompanying drawings. Schematic diagrams are shown here: Figure 1 This is a flowchart of the TBM synchronous grouting method in this application; Figure 2 This is a schematic diagram of the TBM synchronous grouting device in this application; Figure 3 This is a top view of the TBM synchronous grouting device in this application; Figure 4 This is a schematic diagram of the dual grouting pump structure of the TBM synchronous grouting device in this application; Figure 5 This is a schematic diagram of the mixing effect of the TBM synchronous grouting method in this application; Figure 6 This is a schematic diagram of grout collapse in the TBM synchronous grouting method of this application; Figure 7 This is a schematic diagram of the synchronous backfilling and forming tunnel using the TBM synchronous grouting method in this application.

[0020] In the picture: 1. Mixing tank; 2. Slurry storage tank; 3. Conveying pump; 4. Screw feeder; 401. Feeding pipe; 402. Third motor; 403. Screw conveyor shaft; 5. Dry powder silo; 6. Dual-shaft mixing device; 601. Second motor; 602. Dual-shaft drive assembly; 603. Mixing shaft; 604. Mixing blades; 7. Weighing sensor. Detailed Implementation

[0021] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0022] This embodiment provides a TBM-mounted synchronous grouting method that utilizes a trolley-mounted grouting platform. By loading grout onto the trolley and mixing it instantly, grout segregation and transportation delays are eliminated. The method dynamically determines the initial grouting ring number and generates a symmetrical alternating sequence to ensure balanced stress on the tunnel segments. It integrates a void model with online parameter identification and model predictive control to optimize grouting flow and pressure in real time, actively identifying grout leakage and triggering grease suppression. Based on pump response, it adaptively corrects the mix ratio, combining dual-threshold fullness detection and automatic hole position switching to achieve intelligent closed-loop construction, shortening the construction period and reducing the risks of bias pressure and leakage. Figure 1 , Figures 5-7 As shown, the method includes: The starting number of grouting rings is determined based on the tunneling working parameters and geological conditions, and the grouting device is moved to the corresponding ring position to generate a grouting sequence that balances the stress on the tunnel segments by determining the order and combination of grouting holes.

[0023] Preferably, generating a grouting sequence for balancing the stress on the tunnel lining segments includes: Collect tunneling condition parameters including tunneling speed, thrust, and torque, as well as geological condition parameters including stratum type and soil and rock strength; The number of initial grouting rings is determined based on tunneling working parameters and geological condition parameters; Based on the principle of segment stress balance, a grouting sequence with left-right symmetry and alternating skip holes is generated; Compare the current segment ring number with the grouting start ring number to determine whether the current segment ring number meets the grouting trigger condition. If so, a control command is issued to move the grouting device to the preset grouting hole of the target ring position and perform alignment operation, and determine the grouting sequence of each grouting hole according to the grouting sequence. If not, continue tunneling and return to collect tunneling condition parameters including tunneling speed, thrust, and torque, as well as geological condition parameters including stratum type and soil strength.

[0024] It should be explained that tunneling operating parameters typically include tunneling speed, thrust, and torque, which are used to determine the current tunneling load and the formation response. Geological condition parameters include stratigraphic type (such as clay, sand, rock) and soil and rock strength (uniaxial compressive strength, etc.), which are generally obtained from geological survey reports or drilling parameter inversion. The principle of stress balance of tunnel segments refers to the use of symmetrical and alternating grouting sequences to ensure that the radial force generated by the grouting pressure on the tunnel segments is evenly distributed, so as to avoid excessive pressure on one side, which may lead to uneven pressure, elliptical deformation or misalignment of the joints. The positioning operation refers to precisely aligning the grouting head of the grouting device on the platform with the grouting hole on the segment wall and maintaining a seal to prevent grout leakage during grouting; this is usually achieved by driving the grouting head to extend or retract via a hydraulic or electric push rod, in conjunction with a sealing ring. Determining the grouting sequence of each grouting hole according to the grouting sequence means that after grouting is triggered, the valves of the corresponding grouting holes are automatically opened in sequence according to the pre-generated sequence (such as grouting at 0° and 180° simultaneously first, and then grouting at 90° and 270° simultaneously), and the grouting pump is controlled to inject in sequence.

[0025] Based on the grouting location, a back-wall void evolution model is constructed to identify grout leakage and suppress it in conjunction with grouting grease. The model also predicts the optimal control trajectory for grout flow rate and grouting pressure at future moments, thus obtaining the undivided flow rate setpoint.

[0026] Preferably, the expression for the evolution model of the back-wall void is: In the formula, This represents the void volume at the next sampling time. Indicates the first k The unfilled void volume behind the tube wall at each sampling time; Indicates the formation compressibility coefficient; Indicates the TBM tunneling speed; This represents the theoretical void area of ​​a single ring; Indicates the sampling period; Indicates the actual grouting flow rate; Indicates the leakage characteristic coefficient; Indicates real-time grouting pressure; Indicates the real-time shield tail grease pressure; Indicates the safe differential pressure threshold; This indicates reference pressure.

[0027] Preferably, obtaining the unpartitioned traffic setting includes: Obtain the tunneling speed, segment ring geometry parameters, and shield tail sealing status corresponding to the current grouting location, and construct a backwall void evolution model for identifying grout leakage and inhibiting it in conjunction with grouting grease. Taking the current void volume as the initial state, the prediction time domain for multiple future sampling periods is set, and the optimal grouting flow rate and grouting pressure at each future moment are solved in a rolling manner based on the void evolution model behind the wall to obtain the optimal control quantity trajectory. The grouting flow rate and grouting pressure at the current sampling moment are extracted from the optimal control trajectory as initial setpoints; Based on the filling difficulty and sealing capacity of different parts of the segment ring, the initial pressure setting value is differentiated by region to obtain the flow setting value without region.

[0028] Preferably, the method for obtaining the optimal control quantity trajectory is as follows: Obtain the current back-wall void volume and use it as the initial state value for model predictive control. The time length of multiple future sampling periods is set as the prediction time domain, and the range of change of grouting flow rate and pressure within each sampling period is determined; Starting from the initial state value, the optimal grouting flow rate and grouting pressure at each future time point are determined using the back wall void evolution model in each sampling period, forming a candidate control sequence; The flow rate and pressure values ​​of the first sampling period in the candidate control sequence are used as the execution values ​​at the current moment, and the entire sequence is defined as the optimal control trajectory.

[0029] Preferably, the method for forming candidate control sequences is as follows: The current backwall void volume is obtained as the initial state value. The formation compressibility coefficient and grout leakage characteristic coefficient updated online in the previous cycle are read, and the parameters of the backwall void evolution model are updated. By defining the prediction time domain and the control time domain, a multi-objective cost function is constructed with the objectives of minimizing the gap tracking error, the grouting flow rate change rate, and the risk of grout leakage pressure difference, and the constraint range of grouting flow rate and pressure is determined. Taking the current void volume as the initial state, the control sequence in the prediction time domain is set as the decision variable, the cost function value corresponding to the current decision variable is determined, the gradient of the cost function with respect to the decision variable is calculated, the decision variable is updated along the negative gradient direction, and the decision variable that exceeds the constraint is projected back into the constraint boundary. Repeat the iterations until the change in the cost function value calculated between two adjacent iterations is less than a preset threshold, and obtain a set of optimal control sequences; Take the flow rate and pressure value of the first sampling period in the optimal control sequence as the execution command at the current moment, and store the entire sequence as a candidate control sequence.

[0030] It should be explained that online identification refers to the process of continuously updating model parameters during grouting by using real-time collected data such as pressure, flow rate, and void volume, and through adaptive algorithms such as recursive least squares method or Kalman filtering, so that the model matches the actual formation response. The formation compressibility coefficient reflects the compressibility of the formation under grouting pressure. For example, soft soil > 1, hard rock ≈ 1. The leakage characteristic coefficient reflects the shield tail sealing performance and grout leakage sensitivity. The larger the value, the more serious the leakage under the same pressure difference. The multi-objective cost function includes void tracking error, grouting flow rate change rate, and grout leakage pressure risk; The decision variables are the grouting flow rate sequence and pressure sequence in the prediction time domain; gradient calculation requires the partial derivatives of the cost function with respect to each decision variable to be obtained based on the back wall void evolution model and through the chain rule. Projection operation refers to forcibly pulling the updated decision variable (such as the grouting flow rate at a certain moment) back to the nearest boundary value when it exceeds the preset upper and lower limits. The prediction time domain is the number of future sampling periods used to predict gap changes, while the control time domain is the period during which the decision variables can change freely.

[0031] Take a TBM tunnel project for urban rail transit as an example; This project adopted a new method of synchronous grouting using a shield tunneling machine trolley-mounted TBM. The grouting device is mounted on the trolley attached to the rear of the TBM, and the grout is stored and transported directly on the trolley, eliminating the need for ground mixing and long-distance transportation. In the tunneling working parameters, the TBM tunneling speed v=0.03m / min, which is forced to be reduced to 0.015m / min due to the lag in grouting under the traditional process; the thrust is 12000kN and the torque is 3500kN·m. Geological parameters: medium sand layer, uniaxial compressive strength 15MPa, soil with moderate compressibility; Slurry status: The trolley is equipped with a slurry mixing tank, and the slurry is prepared and used immediately. The time from preparation to injection is ≤5 minutes, which completely avoids the slurry segregation problem caused by 40-60 minutes of transportation mentioned in the briefing. In traditional processes, due to the delay in transportation by electric locomotives, the grouting start ring needs to lag behind the tunneling ring number + 5 rings. For example, if the tunneling reaches the 100th ring, the grout needs to be delivered 5 rings later. In this application, the grout is prepared and stored on-site, and the grouting starting ring can be adjusted to the tunneling ring number + 1 ring, reducing the grouting delay time from the traditional 45 minutes to less than 5 minutes. When the tunnel segment is advanced to the 100th ring, the grouting start ring is determined to be the 101st ring. The grouting action is triggered immediately when the tunnel reaches the 101st ring. The trolley carrying the grouting mechanism directly connects to the grouting hole of the ring without waiting for the grout to be transported to the site. Four grouting holes are evenly distributed around the circumference of the tunnel segment, with angles of 0°, 90°, 180°, and 270° respectively, generating a symmetrical alternating sequence based on the principle of segment stress balance. Phase 1: Grouting is performed simultaneously through the 0° top grouting hole and the 180° bottom grouting hole; Second stage: Grouting is carried out simultaneously through the 90° right-side grouting hole and the 270° left-side grouting hole; In contrast to traditional processes, the key parameter settings are shown in Table 1: Table 1 Key Parameter Settings Based on the design parameters in Table 1 and relying on the back wall void evolution formula, the grouting flow rate and pressure are optimized through model predictive control. The prediction time domain is set to N=5, and the control time domain is set to M=3. The objectives are to minimize void tracking error and achieve a flow rate change rate ≤0.02m. 3 To minimize the risk of grout leakage pressure difference, the optimal control quantity for the current moment is obtained: Grouting flow rate It can be dynamically adjusted in real time according to the on-site void condition; Grouting pressure This indicates that the differential pressure safety requirements are met and there is no risk of grout leakage. Calculate the void volume at the first sampling time. ; Changes in void volume at subsequent sampling times: ; ; The calculation results show that after adopting the trolley-mounted synchronous grouting process, the volume of voids behind the tunnel wall is steadily and rapidly reduced, and the grout is filled evenly and densely. This effectively solves two construction problems caused by the lag in grouting in the traditional process: void expansion and loss, and uneven filling caused by long-distance segregation of grout.

[0032] The system monitors the grouting pressure and the shield tail grease pressure in real time and sets a safe pressure difference threshold. When the difference between the measured grouting pressure and the shield tail grease pressure exceeds the safe pressure difference threshold, it is determined to be a grout leakage state. The system automatically reduces the current grouting flow rate and increases the grease injection pressure. At the same time, after each batch of grouting is completed, the system collects the grouting and pumping response characteristics, predicts the rheological state of the grout, and automatically corrects the material ratio for the next batch.

[0033] Preferably, predicting the rheological state of the slurry and automatically correcting the material ratio for the next batch includes: Real-time acquisition of grouting pressure and shield tail grease pressure, recording of current grouting flow rate, and continuous recording of pumping pressure change characteristics; The difference between the measured grouting pressure and the shield tail grease pressure is used to determine whether there is a grout leakage. If there is a grout leakage, the current grouting flow rate is automatically reduced and the grease injection pressure is increased. After each batch of grouting is completed, the grouting pressure change characteristics recorded in the current batch are extracted as operational response characteristics. The extracted operational response characteristics are compared with a preset rheological state comparison table to estimate the rheological state of the slurry. Based on the estimation results, the correction amount for the next batch of material proportions is obtained, and then the proportion adjustment is performed.

[0034] Preferably, estimating the rheological state of the slurry includes: The extracted grouting pressure change features are matched with a preset rheological state feature template library, and the similarity between the current feature and each template in the preset rheological state feature template library is calculated. Select the rheological state category corresponding to the template with the highest similarity. Based on the rheological state category, call the pre-calibrated slump range and pressure fluctuation characteristic parameters. Combine the measured torque and pressure fluctuation amplitude of the current batch to calculate the deviation between the actual rheological parameters and the target rheological parameters. Calculate the correction amount for the water-cement ratio and the adjustment amount for the admixture based on the deviation value, and limit the correction amount for the water-cement ratio and the adjustment amount for the admixture within the preset safety boundary to obtain the proportion correction amount. The calculation formula is as follows: In the formula, Indicates the first s Correction amount for the proportion of each batch of slurry mixing; This represents a function that maps the identified rheological state category to the corresponding slump range and pressure fluctuation characteristic parameters. Represents the set of rheological state categories A Select the category that maximizes the value within the parentheses; Indicates the first s Feature vector of grouting pressure variation in each batch of grouting With rheological state category a Corresponding feature template Similarity function between them; Indicates the first s The characteristic vector of grouting pressure variation for each batch of grouting; Indicates the rheological state category a Corresponding preset feature template; This indicates the proportional coefficient of the proportional controller relative to the integral controller. Indicates the integral coefficient of the proportional and integral controller; This represents the deviation between the actual rheological parameters and the target rheological parameters; This indicates the time interval between two adjacent mixing batches; Indicates the first j Deviation values ​​for each batch; Indicates the batch number; Indicates from batch 0 to batch 1 s batch.

[0035] It should be explained that pumping response characteristics refer to the dynamic signals generated by the grouting pump during operation due to changes in grout viscosity, pump pressure, and flow rate, such as the fluctuation amplitude, fluctuation frequency, and rise / fall rate of pump outlet pressure. Operational response characteristics are a broader concept, mainly referring to data collected from the mixing and pumping processes that can be used to determine the state of the slurry, including mixing torque, which reflects the consistency of the slurry; pumping pressure fluctuations, which reflect the fluidity; and pumping current, which reflects the load. The preset rheological state comparison table maps different operational response characteristics (such as pressure fluctuation amplitude and stirring torque range) to different slurry rheological state categories, such as too thin, normal, and too thick. Each row in the table records a set of characteristic threshold intervals and their corresponding rheological state, slump range, and suggested ratio correction direction. Similarity is used to measure the degree of matching between the feature vector of grouting pressure change in the current batch and the preset rheological state template; For each rheological state category, such as normal, the corresponding ideal slump range (e.g., 120±10mm) and standard pressure fluctuation characteristics (e.g., standard deviation of pressure fluctuation ≤0.02MPa) are determined in advance through experiments; the actual rheological parameters refer to the values ​​of slump, viscosity and other characteristics of fluidity of the slurry, which are calculated by looking up tables based on the measured torque, pressure fluctuation amplitude and other characteristics of the current batch. The water-cement ratio correction mainly affects the slump and setting time of the slurry; the amount of admixtures (such as thickeners and water-reducing agents) is used to fine-tune the fluidity or water retention.

[0036] Based on the current grouting pressure and the measured grout flow rate, when the pressure reaches the preset upper limit and the flow rate drops below the threshold of the flow rate setting value, the grouting hole is filled and automatically switches to the next grouting hole according to the grouting sequence.

[0037] It should be explained that by monitoring the difference between the grouting pressure and the shield tail grease pressure in real time, the early identification of grout leakage signs and the linkage control of flow rate and grease pressure can be achieved to avoid grout leakage from expanding the voids behind the wall. The shield tail grease pressure setting value is 0.25MPa, and the safe pressure difference threshold is 0.03MPa. Under normal working conditions, the difference between the grouting pressure and the grease pressure must be ≤0.03MPa to prevent the grout from penetrating the shield tail seal. During the grouting process, the current grouting pressure was monitored in real time to be 0.31 MPa, and the pressure difference was 0.06, which was greater than the safe pressure difference threshold, indicating a sign of grout leakage. Grouting flow rate adjustment: Reduce the current grouting flow rate from the optimal value to 0.07m. 3 / min decreased to 0.05m 3 / min, slowing down the slurry injection rate; Adjustment of shield tail grease pressure: Increase the shield tail grease pressure from 0.25MPa to 0.27MPa, reducing the pressure difference to 0.04MPa; subsequently, fine-tune the grouting pressure to 0.29MPa, and finally stabilize the pressure difference at 0.02MPa, eliminating the risk of grout leakage; In addition, after each batch of slurry mixing is completed, the rheological state of the slurry is predicted by collecting the slurry mixing and pumping response characteristics and the material ratio of the next batch is automatically corrected, which solves the problem of slurry rheological deterioration caused by long-distance transportation in traditional processes. The slurry of this method is used as soon as it is prepared, and there is no transportation deterioration, but the stability between batches can be ensured through adaptive correction. Taking the first batch of grout mixing (101-ring grouting batch) as an example: Data collection and operation response characteristics: Stirring torque: 25 N·m (target normal range: 20 ± 3 N·m); Pump pressure fluctuation standard deviation: 0.04MPa (target normal range: ≤0.02MPa); Calculated actual rheological parameters: slump 90mm (target normal range: 120±10mm), viscosity is too high, slurry is too thick; The current grouting pressure change feature vector is matched with a preset rheological state template library, and the similarity calculation results are as follows: Similarity to the overly dense template: 0.92; Similarity to the normal template: 0.65; Similarity to the template in the overly thin state: 0.30; therefore, the current rheological state of the slurry is identified as overly thick, and the ratio of the next batch needs to be adjusted to improve fluidity; Design the following specific parameters: A value of 1 indicates the first batch of grout mixing, corresponding to 101 rings of grouting; The rheological state mapping function has a correction coefficient of 1 for the overly viscous state, indicating that the water-cement ratio / water-reducing agent dosage needs to be adjusted in the positive direction to improve fluidity; The deviation between the actual rheological parameters and the target for the first batch is 30 mm. The target slump is 120 mm, the actual slump is 90 mm. A value of 0 indicates that batch 0 is the initial baseline and the deviation is 0. 30 minutes represents the time interval between adjacent mixing batches; It is 0.0005; Given a value of 0.00002, and based on the specific parameters mentioned above, calculate the ratio correction amount. Calculations yielded =1×(0.015+0.018)=0.033; Based on the calculation results, the mix proportions for the next batch (102-ring grouting batch) will be adjusted: Water-cement ratio: Originally 0.8, corrected to 0.80 + 0.033 = 0.833; Water-reducing agent dosage: originally 1.0% (by cement mass), revised to 1.2%; after the revision, the slump of the slurry is expected to increase to 115±5mm, meeting the target rheological requirements and solving the problem of slurry consistency between batches; Grouting holes: 0° (top) grouting holes, which are the grouting holes in the first stage of the symmetrical sequence; Preset parameters: Grouting pressure upper limit is 0.3MPa, flow rate threshold is 0.02m³ / min. 3 / min, when the flow rate is lower than this value, it is determined that the filling is close to saturation; During the grouting process, real-time monitoring showed that the grouting pressure reached 0.3 MPa, while the flow rate dropped to 0.018 m³ / s. 3 If the flow rate is less than the flow threshold, the grouting hole is determined to be fully filled. According to the preset symmetrical alternating grouting sequence, the valve of the 0° grouting hole is automatically closed, and the grouting operation is switched to the 180° (bottom) grouting hole to continue the grouting operation, so as to realize the orderly switching of the dual-hole synchronous grouting and ensure that the segment is subjected to uniform stress.

[0038] This embodiment also provides a TBM synchronous grouting device mounted on a tunnel boring machine trolley, such as... Figures 2-4 As shown, the TBM synchronous grouting device includes: a mixing tank 1, a slurry storage tank 2, a conveying pump 3, a screw conveyor 4, and a dry powder silo 5; the outlet of the dry powder silo 5 is connected to the inlet of the screw conveyor 4; the outlet of the screw conveyor 4 is connected to the inlet of the mixing tank 1, the outlet of the mixing tank 1 is connected to the inlet of the slurry storage tank 2, and the outlet of the slurry storage tank 2 is connected to the inlet of the conveying pump 3. Preferably, the mixing tank 1 is equipped with a biaxial stirring device 6 for stirring and mixing grouting materials to prepare a uniform slurry; a weighing sensor 7 is provided at the bottom of the mixing tank 1. The dual-shaft stirring device 6 includes a second motor 601 disposed on one side of the stirring tank 1. A dual-shaft drive assembly 602 is disposed at one end of the output shaft of the second motor 601. A stirring shaft 603 that cooperates with the inner wall of the stirring tank 1 is disposed on both sides of one end of the dual-shaft drive assembly 602. A plurality of stirring blades 604 are evenly disposed on the outer side of the stirring shaft 603. The spiral feeding device 4 includes a feeding pipe 401, the inlet of which is connected to the outlet of the dry powder silo 5, and the feeding pipe 401 is inclined; a third motor 402 is provided on one side of the top end of the feeding pipe 401, and a spiral conveying shaft 403 is provided at the output end of the third motor 402.

[0039] It should be explained that the dry powder silo 5 is used to store dry powder materials such as cement and bentonite. The sealed design prevents moisture or dust from spilling out. The bottom discharge port is connected to a screw feeding device. The remaining material is monitored in real time by the weighing sensor 7, which provides a basis for continuous material supply. The screw feeding device 4 is usually an inclined screw conveyor. It uses rotating screw blades to quantitatively and continuously push the powder in the dry powder bin to the feed inlet of the mixing tank 1. The conveying speed can be adjusted by a frequency converter motor and accurately dispensing the materials with the help of a weighing sensor. Mixing tank 1 receives dry powder, water, and additives. It is equipped with a dual-shaft forced mixing blade, which is driven by a motor to fully mix the materials in the tank to form a uniform grout. The mixing time and speed can be preset according to the grout ratio and rheological requirements. A weighing sensor is usually installed at the bottom of the tank to measure the total mass and control the discharge rate. The slurry storage tank 2 temporarily stores the mixed finished slurry to buffer the flow difference between mixing and grouting; the tank is usually equipped with a low-speed stirring device to prevent the slurry from settling or segregating; the outlet of the slurry storage tank is connected to the conveying pump 3; Pump 3 is a dual grouting pump, such as Figure 4 As shown, the slurry in the storage tank is pressurized by reciprocating motion and then transported to the grouting hole of the segment through pipeline; the flow rate and pressure of the pump can be adjusted by a variable frequency motor or hydraulic system, and accept the set value of the model predictive control (MPC) output; the pump outlet is usually connected in series with an electromagnetic flow meter and a pneumatic ball valve for accurate metering and on / off control.

[0040] It should be noted that the calculation formulas and all parameters involved in the calculations in this application have been dimensionless beforehand. The process of dimensionless processing is well known in the industry and will not be described here.

[0041] Although the present application has disclosed the preferred embodiments above, the embodiments are merely examples for the purpose of illustration and are not intended to limit the present application. Those skilled in the art can make some modifications and refinements without departing from the spirit and scope of the present application. The scope of protection claimed by the present application should be determined by the claims.

Claims

1. A method for synchronous grouting of a TBM mounted on a tunnel boring machine trolley, characterized in that, The method includes: The starting number of grouting rings is determined based on the tunneling working parameters and geological conditions, and the grouting device is controlled to move to the corresponding ring position to generate a grouting sequence for balancing the stress on the tunnel segments, including the order and combination of grouting holes. Based on the grouting location, a back wall void evolution model is constructed to identify grout leakage and suppress it in conjunction with grouting grease. The optimal control trajectory, including grout flow rate and grouting pressure, is predicted at each future moment to obtain the undivided flow rate setpoint. The system monitors the grouting pressure and the shield tail grease pressure in real time and sets a safe pressure difference threshold. When the difference between the measured grouting pressure and the shield tail grease pressure exceeds the safe pressure difference threshold, it is determined to be a grout leakage state. The system automatically reduces the current grouting flow rate and increases the grease injection pressure. At the same time, after each batch of grouting is completed, the system collects the grouting and pumping response characteristics, predicts the grout rheological state, and automatically corrects the material ratio for the next batch. Based on the current grouting pressure and the measured grout flow rate, when the pressure reaches the preset upper limit and the flow rate drops below the threshold of the set flow rate value, the grouting hole is filled and automatically switches to the next grouting hole according to the grouting sequence.

2. The TBM synchronous grouting method according to claim 1, characterized in that, The generation of the grouting sequence for balancing the stress on the tunnel lining segments includes: Collect tunneling condition parameters including tunneling speed, thrust, and torque, as well as geological condition parameters including stratum type and soil and rock strength; The number of initial grouting rings is determined based on tunneling working parameters and geological condition parameters; Based on the principle of segment stress balance, a grouting sequence with left-right symmetry and alternating skip holes is generated; Compare the current segment ring number with the grouting start ring number to determine whether the current segment ring number meets the grouting trigger condition. If so, a control command is issued to move the grouting device to the preset grouting hole of the target ring position and perform alignment operation, and determine the grouting sequence of each grouting hole according to the grouting sequence. If not, continue tunneling and return to collect tunneling condition parameters including tunneling speed, thrust, and torque, as well as geological condition parameters including stratum type and soil strength.

3. The TBM synchronous grouting method according to claim 1, characterized in that, The expression for the evolution model of the back-wall void is: In the formula, This represents the void volume at the next sampling time. Indicates the first k The unfilled void volume behind the tube wall at each sampling time; Indicates the formation compressibility coefficient; Indicates the TBM tunneling speed; This represents the theoretical void area of ​​a single ring; Indicates the sampling period; Indicates the actual grouting flow rate; Indicates the leakage characteristic coefficient; Indicates real-time grouting pressure; Indicates the real-time shield tail grease pressure; Indicates the safe differential pressure threshold; This indicates reference pressure.

4. The TBM synchronous grouting method according to claim 3, characterized in that, The process of obtaining the unpartitioned traffic setting includes: Obtain the tunneling speed, segment ring geometry parameters, and shield tail sealing status corresponding to the current grouting location, and construct a backwall void evolution model for identifying grout leakage and inhibiting it in conjunction with grouting grease. Taking the current void volume as the initial state, the prediction time domain for multiple future sampling periods is set, and the optimal grouting flow rate and grouting pressure at each future moment are solved in a rolling manner based on the void evolution model behind the wall to obtain the optimal control quantity trajectory. The grouting flow rate and grouting pressure at the current sampling moment are extracted from the optimal control trajectory as initial setpoints; Based on the filling difficulty and sealing capacity of different parts of the segment ring, the initial pressure setting value is differentiated by region to obtain the flow setting value without region.

5. The TBM synchronous grouting method according to claim 4, characterized in that, The method for obtaining the optimal control quantity trajectory is as follows: Obtain the current back-wall void volume and use it as the initial state value for model predictive control. The time length of multiple future sampling periods is set as the prediction time domain, and the range of change of grouting flow rate and pressure within each sampling period is determined; Starting from the initial state value, the optimal grouting flow rate and grouting pressure at each future time point are determined using the back wall void evolution model in each sampling period, forming a candidate control sequence; The flow rate and pressure values ​​of the first sampling period in the candidate control sequence are used as the execution values ​​at the current moment, and the entire sequence is defined as the optimal control trajectory.

6. The TBM synchronous grouting method according to claim 5, characterized in that, The method for forming the candidate control sequence is as follows: The current backwall void volume is obtained as the initial state value. The formation compressibility coefficient and grout leakage characteristic coefficient updated online in the previous cycle are read, and the parameters of the backwall void evolution model are updated. By defining the prediction time domain and the control time domain, a multi-objective cost function is constructed with the objectives of minimizing the gap tracking error, the grouting flow rate change rate, and the risk of grout leakage pressure difference, and the constraint range of grouting flow rate and pressure is determined. Taking the current void volume as the initial state, the control sequence in the prediction time domain is set as the decision variable, the cost function value corresponding to the current decision variable is determined, the gradient of the cost function with respect to the decision variable is calculated, the decision variable is updated along the negative gradient direction, and the decision variable that exceeds the constraint is projected back into the constraint boundary. Repeat the iterations until the change in the cost function value calculated between two adjacent iterations is less than a preset threshold, and obtain a set of optimal control sequences; Take the flow rate and pressure value of the first sampling period in the optimal control sequence as the execution command at the current moment, and store the entire sequence as a candidate control sequence.

7. The TBM synchronous grouting method according to claim 1, characterized in that, The method of predicting the rheological state of the slurry and automatically correcting the material ratio for the next batch includes: Real-time acquisition of grouting pressure and shield tail grease pressure, recording of current grouting flow rate, and continuous recording of pumping pressure change characteristics; The difference between the measured grouting pressure and the shield tail grease pressure is used to determine whether there is a grout leakage. If there is a grout leakage, the current grouting flow rate is automatically reduced and the grease injection pressure is increased. After each batch of grouting is completed, the grouting pressure change characteristics recorded in the current batch are extracted as operational response characteristics. The extracted operational response characteristics are compared with a preset rheological state comparison table to estimate the rheological state of the slurry. Based on the estimation results, the correction amount for the next batch of material proportions is obtained, and then the proportion adjustment is performed.

8. The TBM synchronous grouting method according to claim 7, characterized in that, The estimation of the rheological state of the slurry includes: The extracted grouting pressure change features are matched with a preset rheological state feature template library, and the similarity between the current feature and each template in the preset rheological state feature template library is calculated. Select the rheological state category corresponding to the template with the highest similarity. Based on the rheological state category, call the pre-calibrated slump range and pressure fluctuation characteristic parameters. Combine the measured torque and pressure fluctuation amplitude of the current batch to calculate the deviation between the actual rheological parameters and the target rheological parameters. The correction amount for the water-cement ratio and the adjustment amount for the admixture are calculated based on the deviation value. The correction amount for the water-cement ratio and the adjustment amount for the admixture are then limited within a preset safety boundary to obtain the proportion correction amount. The calculation formula is as follows: In the formula, Indicates the first s Correction amount for the proportion of each batch of slurry mixing; This represents a function that maps the identified rheological state category to the corresponding slump range and pressure fluctuation characteristic parameters. Represents the set of rheological state categories A Select the category that maximizes the value within the parentheses; Indicates the first s Feature vector of grouting pressure variation in each batch of grouting With rheological state category a Corresponding feature template Similarity function between them; Indicates the first s The characteristic vector of grouting pressure variation for each batch of grouting; Indicates the rheological state category a Corresponding preset feature template; This indicates the proportional coefficient of the proportional controller relative to the integral controller. Indicates the integral coefficient of the proportional and integral controller; This represents the deviation between the actual rheological parameters and the target rheological parameters; This indicates the time interval between two adjacent mixing batches; Indicates the first j Deviation values ​​for each batch; Indicates the batch number; Indicates from batch 0 to batch 1 s batch.

9. A TBM synchronous grouting device mounted on a tunnel boring machine trolley, applied to the TBM synchronous grouting method according to any one of claims 1-8, characterized in that, The TBM synchronous grouting device includes: a mixing tank (1), a slurry storage tank (2), a conveying pump (3), a screw feeder (4), and a dry powder silo (5). The outlet of the dry powder silo (5) is connected to the inlet of the screw feeder (4); the outlet of the screw feeder (4) is connected to the inlet of the mixing tank (1); the outlet of the mixing tank (1) is connected to the inlet of the slurry storage tank (2); and the outlet of the slurry storage tank (2) is connected to the inlet of the conveying pump (3).

10. The TBM synchronous grouting device according to claim 9, characterized in that, The mixing tank (1) is equipped with a biaxial mixing device (6) for mixing and mixing grouting materials to prepare a uniform slurry; a weighing sensor (7) is installed at the bottom of the mixing tank (1). The dual-shaft stirring device (6) includes a second motor (601) disposed on one side of the stirring tank (1). A dual-shaft drive assembly (602) is disposed at one end of the output shaft of the second motor (601). A stirring shaft (603) that cooperates with the inner wall of the stirring tank (1) is disposed on both sides of one end of the dual-shaft drive assembly (602). A plurality of stirring blades (604) are evenly disposed on the outer side of the stirring shaft (603). The spiral feeding device (4) includes a feeding pipe (401), the inlet of which is connected to the outlet of the dry powder silo (5), and the feeding pipe (401) is inclined; a third motor (402) is provided on one side of the top end of the feeding pipe (401), and a spiral conveying shaft (403) is provided at the output end of the third motor (402).

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