Mobile trolley for secondary grouting of double-shield TBM

Abstract

This invention discloses a mobile trolley for secondary grouting in double-shield TBMs, belonging to the technical field of tunnel construction equipment. Addressing the problems of uneven grout mixing, inaccurate grouting pressure control, and low automation in existing double-shield TBM secondary grouting equipment, this invention uses a mobile support platform to carry the grout storage system and the grouting execution system. The grout storage system utilizes dual storage tanks, a spiral agitator, and a liquid level monitoring module to achieve grout storage and agitation control. The grouting execution system uses a dual-outlet grouting pump, a pressure sensor, and a frequency converter to achieve precise pressure control. A central controller receives liquid level and pressure signals and intelligently adjusts the agitator speed, grouting pump speed, and grout tank switching. This mobile trolley is mainly used for secondary grouting operations during double-shield TBM construction, improving grouting efficiency and quality, and ensuring the safety and stability of tunnel construction.

Description

Technical Field

[0001] This invention relates to the technical field of double-shield TBM construction equipment. More specifically, this invention relates to a mobile trolley for secondary grouting in a double-shield TBM. Background Technology

[0002] In the construction of dual-shield TBMs (tunnel boring machines), secondary grouting is a crucial step in ensuring the stability of the tunnel lining structure, controlling ground deformation, and waterproofing. Traditional mobile trolleys used for secondary grouting in dual-shield TBMs present technical challenges in grout management and grouting pressure control during practical applications. In terms of grouting pressure control, traditional grouting execution systems using grouting trolleys mostly adopt a fixed parameter operation mode. During the grouting process, due to the complex and variable geological conditions of the tunnel, factors such as pipeline length and grout viscosity can cause fluctuations in grouting resistance, but existing systems cannot respond to pressure changes in real time. When the grouting pressure is too high, it may damage the tunnel lining structure, causing cracks or deformation; when the pressure is too low, it cannot ensure that the grout fully fills the voids, resulting in incomplete grouting and affecting the tunnel's waterproof performance and long-term stability. Moreover, the speed adjustment of traditional grouting pumps relies on manual intervention, resulting in a slow response speed, which is difficult to meet the requirements for precise pressure control under complex working conditions.

[0003] However, there are many difficulties in solving the above problems. The mechanism of slurry sedimentation and segregation is complex and is affected by a variety of factors such as slurry ratio, settling time, and storage environment. Summary of the Invention

[0004] One objective of this invention is to provide a mobile trolley for secondary grouting of a double-shield TBM.

[0005] To achieve these objectives and other advantages of the present invention, a mobile trolley for secondary grouting of a double-shield TBM is provided, comprising: a mobile support platform, a grout storage system, a grouting execution system, and a central controller; The slurry storage system includes a first slurry storage tank, a second slurry storage tank, an agitator assembly, and a liquid level monitoring module. The first and second slurry storage tanks are fixed on a movable support platform. The agitator assembly includes spiral agitators that are vertically inserted into the first and second slurry storage tanks, respectively. The liquid level monitoring module uses an ultrasonic sensor installed on the top of the first and second slurry storage tanks. The grouting execution system includes a dual-outlet grouting pump, a pressure sensor, a frequency converter, a grouting hose, and a grouting nozzle. The inlet of the dual-outlet grouting pump is connected to the bottom outlet of the first grout storage tank and the second grout storage tank respectively through pipelines. The pressure sensor is embedded in the middle section of the grouting hose, and the end of the grouting hose is connected to the grouting nozzle. The frequency converter is electrically connected to the drive motor of the dual-outlet grouting pump. The central controller receives the liquid level signal from the liquid level monitoring module. When the liquid level in the first slurry storage tank drops to the first preset threshold, the central controller sends a first speed adjustment command to the agitator group, increasing the speed of the spiral agitator in the first slurry storage tank from the base speed of 20 revolutions per minute to 40 revolutions per minute. When the liquid level in the first slurry storage tank drops to the second preset threshold, the central controller sends a second speed adjustment command, increasing the speed of the spiral agitator to 50 revolutions per minute. The pressure sensor is used to collect the grout pressure value in the grouting hose in real time. The central controller is connected to the pressure sensor and can obtain the pressure value collected by the pressure sensor. When the pressure data exceeds the set pressure range for 3 seconds, the central controller sends an adjustment command to the frequency converter, and the frequency converter adjusts the speed of the dual-outlet grouting pump drive motor. The central controller synchronously controls the switching of the slurry storage system. When the liquid level in the first slurry storage tank drops to the emptying threshold, the central controller starts the spiral agitator of the second slurry storage tank to the basic speed of 20 revolutions per minute and switches the dual-outlet grouting pump to the second inlet connection state.

[0006] Preferably, the grouting execution system is equipped with a pressure stabilizing buffer unit, which includes: A buffer tank is connected in parallel to the outlet end of the dual-outlet grouting pump. The volume of the buffer tank is 5%-8% of the volume of the first grout storage tank. An electric regulating valve is installed at the inlet end of the buffer tank. The closed-loop control module is connected to both the pressure sensor and the central controller. When the central controller issues a command to switch the slurry storage tank, the closed-loop control module is activated simultaneously. The slurry supply to the buffer tank is dynamically adjusted through the electric regulating valve, so that the pressure fluctuation in the grouting hose is controlled within ±10% of the set pressure range.

[0007] Preferably, the inner wall of the buffer tank is coated with a hydrophobic nano-ceramic coating, and a porous flow-guiding grid is provided inside it; When the central controller detects that the electric regulating valve has been continuously open at less than 40% for more than 3 minutes, it starts the pulse cleaning program: the electric regulating valve switches back and forth between 20% and 60% opening at a frequency of 0.5Hz; at the same time, the output flow of the dual-outlet grouting pump increases by 10% and is maintained for 10 seconds.

[0008] Preferably, the pulse cleaning program is executed synchronously after it starts: Adaptive filtering: When the pressure sensor switches to pulse follower mode, its low-pass filter cutoff frequency automatically matches twice the current cleaning pulse frequency. Intelligent sleep mode: The central controller pauses the pressure over-limit judgment function, and the sleep duration is the same as the pulse cleaning program, with a minimum of 3 complete pulse cycles.

[0009] Preferably, the slurry storage system further includes a tank temperature control module, the tank temperature control module comprising: The heat tracing material is wrapped around the outer walls of the first and second slurry storage tanks; Temperature sensors are inserted into the bottom of the first slurry storage tank and the second slurry storage tank; Both the temperature sensor and the heating tape are connected to the central controller. When the spiral agitator of the second slurry storage tank is started to the basic speed, the central controller starts the heating tape according to the temperature sensor data. If the temperature at the bottom of the tank is less than 10°C, the heating tape heats up to 15°C at a rate of 5°C per minute. During the heating, the agitator group alternates between 10 seconds of forward rotation and 5 seconds of reverse rotation.

[0010] Preferably, when the central controller executes the command to switch to the second slurry storage tank, it simultaneously triggers a temperature control pre-check program, which includes the following steps: Read real-time data from the temperature sensor at the bottom of the second slurry storage tank; If the real-time temperature is below 8°C, the heat tracing cable wrapped around the outer wall of the second slurry storage tank will be activated and heated at a rate of 5°C / minute. At the same time, the slurry storage tank switching operation will be delayed until the temperature sensor data reaches above 12°C. During the delay, the grouting operation of the first slurry storage tank and the operation of the agitator group will be maintained. If the liquid level in the first grout storage tank drops to the emptying threshold and the heating time of the second grout storage tank exceeds 5 minutes and the temperature still does not reach 12°C, the central controller immediately executes an emergency switching command, switching the dual-outlet grouting pump to be connected to the second grout storage tank and reducing the speed of the grouting pump drive motor to 60% of the base speed, while the heating cable continues to heat at a rate of 10°C / minute; when the temperature of the second grout storage tank reaches 12°C, the central controller gradually increases the speed of the grouting pump to normal operating conditions.

[0011] Preferably, after an emergency switch, when the grouting pump operates at 60% of its base speed, the central controller executes a dynamic overload protection protocol: The load rate of the drive motor is calculated in real time, with a sampling frequency of once every 0.1 seconds; When the load rate is greater than 85% for 2 consecutive seconds, the forward and reverse pulse sequence is started. Forward phase: maintained for 10 seconds, the output torque is 120% of the rated value. Reverse phase: maintained for 1 second, the output torque is 1.2 times the real-time motor load rate. The pulse sequence is executed cyclically at a frequency of 0.2Hz until the load rate drops below 75% or the grouting pump speed returns to normal operation.

[0012] Preferably, the stirrer assembly further includes a defoaming mechanism, which includes: Ultrasonic vibrating plates are attached to the inner walls of the first and second slurry storage tanks; Bubble sensor installed on top of the tank; When the speed of the agitator assembly increases to more than 40 revolutions per minute, the central controller starts the ultrasonic vibrator, and the bubble sensor monitors the air content of the slurry in real time. If the air content exceeds 3% by volume, the speed of the spiral agitator is reduced to 35 rpm and the ultrasonic vibrator is kept working until the air content meets the standard.

[0013] Preferably, the movable support platform includes: The support frame includes multiple vertical columns, with a top operating platform and side operating platforms located on both sides of the top operating platform at the top of the multiple vertical columns. The lower ends of the vertical columns are provided with wheels. Two pairs of trapezoidal top supports are respectively installed on both sides of the locomotive track, and each pair of trapezoidal top supports is equipped with a walkway plate, and the traveling wheels are located on the walkway plate; Multiple guardrails are installed on both sides of the top operating platform and the side operating platform; A ladder is installed at the edge of the side operating platform; Multiple triangular braces are installed in the upper part of the vertical column and connected to the side operating platform or the top operating platform. Multiple horizontal braces are installed between two vertical columns.

[0014] The present invention has at least the following beneficial effects: First, this invention, through the linkage control of liquid level and stirring speed, effectively avoids sedimentation and segregation of the grout due to prolonged standing, ensuring that the grout injected into the tunnel always maintains uniform and stable performance. The coordinated operation of the pressure sensor and frequency converter allows for real-time adjustment of the grouting pressure according to actual working conditions, preventing excessive pressure from damaging the tunnel structure or insufficient pressure from causing incomplete grouting. This significantly improves the construction quality and reliability of secondary grouting, ensuring the long-term stable operation of the tunnel project. The pressure stabilizing buffer unit can dynamically adjust the grout supply to control the pressure within a reasonable range during stages prone to pressure fluctuations, such as grout tank switching. This not only avoids problems such as grouting pipeline rupture and grout leakage caused by sudden pressure changes but also ensures a stable grout flow rate at the grouting nozzle, allowing the grout to better fill tunnel voids, improving the density and uniformity of the grouting, and thus enhancing the waterproofness and structural strength of the tunnel lining.

[0015] Secondly, the hydrophobic nano-ceramic coating and porous flow-guiding grid design on the inner wall of the buffer tank, combined with the pulse cleaning program, effectively reduce the adhesion and accumulation of grout on the tank wall and in the pipes, lowering the risk of equipment blockage. This eliminates the need for frequent shutdowns for cleaning, significantly improving the continuous operation time and efficiency of the equipment, while reducing maintenance costs and workload, ensuring the smooth progress of tunnel construction. The adaptive filtering and intelligent sleep functions in the pulse cleaning program effectively solve the problem of pressure monitoring being easily interfered with during the cleaning process. The pressure sensor accurately collects data in pulse-following mode, and the central controller avoids misjudgments, ensuring that the cleaning operation can thoroughly remove residual grout from the equipment without interrupting normal operation due to erroneous triggering of the protection mechanism, further improving the stability and reliability of the grouting system. Third, the coordinated operation of the tank temperature control module and the agitator group ensures that the grout maintains good fluidity and coagulation characteristics even at low temperatures. Precise heating with a heat tracing cable and alternating stirring by the agitator ensure uniform heating of the grout, preventing grout from solidifying and clogging pipelines due to excessively low temperatures, or affecting grouting results due to uneven temperature distribution. This provides reliable technical support for tunnel grouting construction in cold regions. The dynamic overload protection protocol monitors the drive motor load in real time. When an overload trend is detected, the torque output is adjusted promptly through a forward and reverse pulse sequence, effectively solving motor overload problems caused by grout blockage and increased resistance. This not only protects key equipment such as the motor and grouting pump, extending their service life, but also reduces downtime due to equipment failure, improving the overall efficiency of tunnel grouting construction.

[0016] Fourth, this invention consists of components such as a trolley walkway, trapezoidal top support, traveling wheels, vertical columns, horizontal supports, two side operating platforms, triangular diagonal braces, a top operating platform, guardrails, and ladders. Each component can be manually installed inside the tunnel, simplifying the installation process, improving construction efficiency, and solving the problem of requiring a mobile, reliable, and easily accessible vehicle during secondary grouting in a double-shield TBM. The main material of this invention is square steel, with an adjustable length to adapt to different tunnel sizes. Square steel has good weldability, mechanical properties, and lightweight properties, ensuring the strength, durability, and practicality of the device. The trolley of this invention ensures simultaneous implementation of secondary grouting and TBM excavation, enhancing the mobility of secondary grouting. Through optimized design, this invention reduces material usage and simplifies installation and disassembly processes, helping to lower construction costs.

[0017] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0018] Figure 1This is a schematic diagram of the structure of the mobile support platform according to one of the technical solutions of the present invention; Figure 2 This is a schematic diagram of the structure of the mobile support platform according to one of the technical solutions of the present invention. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0020] This invention provides a mobile trolley for secondary grouting of a double-shield TBM, comprising: a mobile support platform, a grout storage system, a grouting execution system, and a central controller; The slurry storage system includes a first slurry storage tank, a second slurry storage tank, an agitator assembly, and a liquid level monitoring module. The first and second slurry storage tanks are fixed on a movable support platform. The agitator assembly includes spiral agitators that are vertically inserted into the first and second slurry storage tanks, respectively. The liquid level monitoring module uses an ultrasonic sensor installed on the top of the first and second slurry storage tanks. The grouting execution system includes a dual-outlet grouting pump, a pressure sensor, a frequency converter, a grouting hose, and a grouting nozzle. The inlet of the dual-outlet grouting pump is connected to the bottom outlet of the first grout storage tank and the second grout storage tank respectively through pipelines. The pressure sensor is embedded in the middle section of the grouting hose, and the end of the grouting hose is connected to the grouting nozzle. The frequency converter is electrically connected to the drive motor of the dual-outlet grouting pump. The central controller receives the liquid level signal from the liquid level monitoring module. When the liquid level in the first slurry storage tank drops to the first preset threshold, the central controller sends a first speed adjustment command to the agitator group, increasing the speed of the spiral agitator in the first slurry storage tank from the base speed of 20 revolutions per minute to 40 revolutions per minute. When the liquid level in the first slurry storage tank drops to the second preset threshold, the central controller sends a second speed adjustment command, increasing the speed of the spiral agitator to 50 revolutions per minute. The pressure sensor is used to collect the grout pressure value in the grouting hose in real time. The central controller is connected to the pressure sensor and can obtain the pressure value collected by the pressure sensor. When the pressure data exceeds the set pressure range for 3 seconds, the central controller sends an adjustment command to the frequency converter, and the frequency converter adjusts the speed of the dual-outlet grouting pump drive motor. The central controller synchronously controls the switching of the slurry storage system. When the liquid level in the first slurry storage tank drops to the emptying threshold, the central controller starts the spiral agitator of the second slurry storage tank at a base speed of 20 rpm and switches the dual-outlet grouting pump to the second inlet connection state. The first preset threshold can be set to 30% of the total tank volume, the second preset threshold to 20%, and the emptying threshold to 5%. The base speed of the spiral agitator is 20 rpm, and the boost speeds are 40 rpm and 50 rpm respectively. The pressure range can be set to 0.3-0.8 MPa according to specific grouting requirements, such as under common geological conditions. The first and second slurry storage tanks can be stainless steel cylindrical containers with a volume of 2-5 cubic meters. The spiral agitator of the agitator assembly can be a corrosion-resistant spiral blade with a diameter of 10-15 cm and a length adapted to the tank depth. The ultrasonic sensor of the liquid level monitoring module can be a general-purpose sensor with a range of 5-10 meters. The dual-outlet grouting pump can be a diaphragm pump with a flow rate of 50-100 L / min. The pressure sensor can be a strain gauge pressure sensor with a range of 1 MPa. The frequency converter can be a universal frequency converter adapted to the power of the grouting pump motor. The grout hose can be made of high-pressure resistant and corrosion-resistant rubber. In terms of assembly, the first and second grout storage tanks are fixedly installed on the top operating platform of the mobile support. The agitator assembly is vertically installed at the center of the top of the storage tank, and the liquid level monitoring module is installed at the top edge of the storage tank. The dual-outlet grouting pump is installed on the mobile support platform near the outlet of the storage tank. The pressure sensor is embedded in the middle section of the grouting hose, 1-2 meters from the pump outlet. The end of the grouting hose is connected to the grouting nozzle.

[0021] Working Process: The liquid level monitoring module monitors the liquid level in the storage tank in real time. When the liquid level in the first slurry storage tank drops to 30% of the total volume, the central controller sends a command to increase the speed of the corresponding spiral agitator to 40 revolutions per minute to enhance agitation and prevent slurry sedimentation. When it drops to 20%, the speed is further increased to 50 revolutions per minute. The pressure sensor continuously collects the pressure inside the grouting hose. When the pressure data exceeds the range of 0.3-0.8 MPa for 3 consecutive seconds, the central controller adjusts the speed of the dual-outlet grouting pump drive motor through the frequency converter to control the grouting pressure. When the liquid level in the first slurry storage tank drops to 5%, the central controller starts the spiral agitator of the second slurry storage tank to 20 revolutions per minute, and simultaneously switches the dual-outlet grouting pump to connect with the inlet of the second slurry storage tank to continue the grouting operation.

[0022] By employing this technical solution, the present invention effectively avoids sedimentation and segregation of the grout due to prolonged standing through the linkage control of liquid level and stirring speed, ensuring that the grout injected into the tunnel maintains uniform and stable performance. The coordinated operation of the pressure sensor and frequency converter allows for real-time adjustment of the grouting pressure according to actual working conditions, preventing excessive pressure from damaging the tunnel structure or insufficient pressure from causing incomplete grouting. This significantly improves the construction quality and reliability of secondary grouting, ensuring the long-term stable operation of the tunnel project.

[0023] In another technical solution, the grouting execution system is further equipped with a pressure stabilizing buffer unit, which includes: A buffer tank is connected in parallel to the outlet end of the dual-outlet grouting pump. The volume of the buffer tank is 5%-8% of the volume of the first grout storage tank. An electric regulating valve is installed at the inlet end of the buffer tank. The closed-loop control module is connected to both the pressure sensor and the central controller. When the central controller issues a command to switch the slurry storage tank, the closed-loop control module is simultaneously activated. This module dynamically adjusts the slurry supply to the buffer tank via an electric regulating valve, ensuring that pressure fluctuations within the grouting hose are controlled within ±10% of the set pressure range. A buffer tank volume of 6% of the first slurry storage tank volume is suitable, with ±10% of the set pressure range serving as the pressure fluctuation control target. The electric regulating valve's opening range is 0-100%. The buffer tank can be a cylindrical pressure vessel with a volume between 0.1 and 0.4 cubic meters, depending on the storage tank size. A pneumatic diaphragm regulating valve can be selected for its fast response and high adjustment accuracy. The closed-loop control module can employ a PLC-based control unit, capable of stably processing pressure sensor data and communicating with the central controller.

[0024] The working process is as follows: When the central controller issues a command to switch the grout storage tank, the closed-loop control module is simultaneously activated. The pressure sensor transmits the pressure data inside the grouting hose to the closed-loop control module in real time. The module adjusts the opening of the electric regulating valve according to the pressure fluctuations, dynamically controlling the amount of grout supplied from the buffer tank to the main pipeline. If the pressure is too high, the grout supply to the buffer tank is increased; if the pressure is too low, the grout supply is reduced, thereby controlling the pressure fluctuations inside the grouting hose within ±10% of the set pressure range, avoiding sudden pressure changes caused by switching grout storage tanks that could affect the grouting effect.

[0025] By adopting this technical solution and incorporating a pressure-stabilizing buffer unit, the pressure can be controlled within a reasonable range during stages prone to pressure fluctuations, such as grout tank switching, by dynamically adjusting the grout supply. This not only avoids problems such as grouting pipeline rupture and grout leakage caused by sudden pressure changes, but also ensures a stable grout flow rate at the grouting nozzle, allowing the grout to better fill tunnel voids, improving the density and uniformity of the grouting, and thus enhancing the waterproofness and structural strength of the tunnel lining.

[0026] In another technical solution, the inner wall of the buffer tank is coated with a hydrophobic nano-ceramic coating, and a porous flow-guiding grid is provided inside it. When the central controller detects that the electric regulating valve has been continuously open at less than 40% for more than 3 minutes, it initiates a pulse cleaning program: the electric regulating valve switches back and forth between 20% and 60% opening at a frequency of 0.5Hz; simultaneously, the output flow of the dual-outlet grouting pump increases by 10% and is maintained for 10 seconds. The hydrophobic nano-ceramic coating on the inner wall of the buffer tank can be made of silica-based nano-ceramic material, which has good hydrophobicity and wear resistance. The porous flow guide grid can be made of stainless steel with a pore size of 5-10 mm and a porosity of 40-60%. In terms of assembly, the hydrophobic nano-ceramic coating is evenly applied to the inner wall of the buffer tank, and the porous flow guide grid is horizontally installed inside the buffer tank 10-20 cm from the inlet. The electric regulating valve is installed on the inlet pipe of the buffer tank.

[0027] Working Process: The central controller monitors the opening of the electric regulating valve in real time. When it detects that the electric regulating valve has been continuously open less than 40% for more than 3 minutes, the pulse cleaning program is initiated. The electric regulating valve switches back and forth between 20% and 60% opening at a frequency of 0.5Hz, while the output flow of the dual-outlet grouting pump increases by 10% and is maintained for 10 seconds. During this process, the high-speed flowing grout, under the change of the electric regulating valve opening, flushes the inner wall of the buffer tank and the pipes. Combined with the hydrophobicity of the hydrophobic nano-ceramic coating, residual grout on the inner wall is effectively removed. The porous guide grid helps to evenly disperse the grout, enhancing the cleaning effect, preventing blockage inside the buffer tank, and ensuring the continuous and stable operation of the grouting system.

[0028] This technical solution, employing a hydrophobic nano-ceramic coating and a porous flow-guiding grid design on the inner wall of the buffer tank, combined with a pulse cleaning program, effectively reduces the adhesion and accumulation of grout on the tank wall and in the pipes, lowering the risk of equipment blockage. This eliminates the need for frequent shutdowns for cleaning of the grouting system, significantly improving the continuous operating time and efficiency of the equipment, while reducing maintenance costs and workload, ensuring the smooth progress of tunnel construction.

[0029] In another technical solution, the pulse cleaning program is executed synchronously after it is started: Adaptive filtering: When the pressure sensor switches to pulse follower mode, its low-pass filter cutoff frequency automatically matches twice the current cleaning pulse frequency. The intelligent sleep mode suspends the pressure over-limit judgment function of the central controller. The sleep duration is the same as the pulse cleaning program cycle, and is no less than 3 complete pulse cycles. In the pulse cleaning program, the frequency of the electric regulating valve is fixed at 0.5Hz, the opening range is 20%-60%, and the output flow of the dual-outlet grouting pump increases by 10% for 10 seconds. The low-pass filter cutoff frequency of the pressure sensor automatically matches twice the current cleaning pulse frequency, i.e., 1Hz. The pressure sensor can be an intelligent pressure sensor with multiple working mode switching functions, which can be switched to pulse following mode through software settings.

[0030] The operating process is as follows: After the pulse cleaning program starts, the pressure sensor automatically switches to pulse follower mode, and its low-pass filter cutoff frequency is adjusted to 1Hz, ensuring that the sensor only filters signals higher than 1Hz, thus preventing the cleaning pulse signal from interfering with pressure data acquisition. Simultaneously, the central controller suspends its pressure over-limit judgment function and enters sleep mode. The sleep duration is the same as the pulse cleaning program cycle and is no less than three complete 0.5Hz pulse cycles (i.e., 6 seconds). During the cleaning process, the pressure sensor accurately acquires the real pressure signal, and the central controller avoids misjudgments due to pressure fluctuations caused by cleaning, ensuring stable system operation. After cleaning, the pressure sensor and central controller return to normal operating mode.

[0031] This technical solution, with its adaptive filtering and intelligent sleep functions in the pulse cleaning program, effectively solves the problem of pressure monitoring being easily interfered with during the cleaning process. The pressure sensor accurately collects data in pulse-following mode, and the central controller avoids misjudgments, ensuring that the cleaning operation thoroughly removes residual slurry from the equipment without interrupting normal operation due to erroneous triggering of the protection mechanism. This further improves the stability and reliability of the grouting system.

[0032] In another technical solution, the slurry storage system further includes a tank temperature control module, which includes: The heat tracing material is wrapped around the outer walls of the first and second slurry storage tanks; Temperature sensors are inserted into the bottom of the first slurry storage tank and the second slurry storage tank; Both the temperature sensor and the heating cable are connected to the central controller. When the agitator of the second slurry storage tank reaches its base speed, the central controller activates the heating cable based on the temperature sensor data. If the tank bottom temperature is less than 10°C, the heating cable heats the tank to 15°C at a rate of 5°C per minute. During heating, the agitator group alternates between 10 seconds of forward rotation and 5 seconds of reverse rotation. The heating rate of the heating cable is normally 5°C per minute, and the tank bottom temperature setting thresholds are 10°C and 15°C. The agitator group rotates forward for 10 seconds and reverse for 5 seconds. A self-regulating electric heating cable can be selected, with power selected according to the tank size, and it can automatically adjust the temperature. A Pt100 resistance temperature sensor can be selected, offering high measurement accuracy and stability. The outer sheath of the heating cable is made of flame-retardant and corrosion-resistant polyolefin material. In terms of assembly, the heating cable is evenly wrapped around the outer walls of the first and second slurry storage tanks, and the temperature sensor is vertically inserted into the center of the tank bottom, 5-10 cm away from the bottom.

[0033] The working process is as follows: When the spiral agitator in the second slurry storage tank starts at a base speed of 20 revolutions per minute, the central controller reads the temperature sensor data. If the tank bottom temperature is less than 10°C, the heating cable is activated at a rate of 5°C per minute, while the agitator group is controlled to alternate between 10 seconds of forward rotation and 5 seconds of reverse rotation. Forward rotation agitates the slurry to flow, while reverse rotation helps break up slurry vortices, enhances heat transfer efficiency, and ensures that the slurry is heated evenly until the tank bottom temperature reaches 15°C. This ensures that the slurry is injected at a suitable temperature, avoiding poor slurry fluidity or solidification due to excessively low temperatures.

[0034] This technical solution, through the coordinated operation of the tank temperature control module and the agitator assembly, ensures that the grout maintains good fluidity and coagulation characteristics even at low temperatures. Precise heating with a heat tracing cable and alternating agitation by the agitator ensure uniform heating of the grout, preventing grout from solidifying and clogging pipelines due to excessively low temperatures, or affecting the grouting effect due to uneven temperature distribution. This provides a reliable technical guarantee for tunnel grouting construction in cold regions.

[0035] In another technical solution, when the central controller executes the instruction to switch to the second slurry storage tank, it simultaneously triggers a temperature control pre-check program, which includes the following steps: Read real-time data from the temperature sensor at the bottom of the second slurry storage tank; If the real-time temperature is below 8°C, the heat tracing cable wrapped around the outer wall of the second slurry storage tank will be activated and heated at a rate of 5°C / minute. At the same time, the slurry storage tank switching operation will be delayed until the temperature sensor data reaches above 12°C. During the delay, the grouting operation of the first slurry storage tank and the operation of the agitator group will be maintained. If the liquid level in the first grout storage tank drops to the emptying threshold, and the heating time in the second grout storage tank exceeds 5 minutes without reaching 12°C, the central controller immediately executes an emergency switching command. This switches the dual-outlet grouting pump to be connected to the second grout storage tank and reduces the grouting pump drive motor speed to 60% of its base speed. Simultaneously, the heating cable continues heating at a rate of 10°C / minute. Once the temperature in the second grout storage tank reaches 12°C, the central controller gradually increases the grouting pump speed back to normal operating conditions. The temperature thresholds in the temperature control pre-check procedure are set to 8°C and 12°C. The heating rate of the heating cable is 5°C / minute under normal conditions and 10°C / minute in emergency situations. 60% of the grouting pump's base speed is used as the operating speed after the emergency switch.

[0036] The working process is as follows: Before executing the command to switch to the second slurry storage tank, the central controller first reads the real-time data from the temperature sensor at the bottom of the second slurry storage tank. If the real-time temperature is below 8℃, the heating cable wrapped around the outer wall of the second slurry storage tank is immediately activated, heating at a rate of 5℃ / minute. Simultaneously, the slurry tank switching operation is delayed, while the grouting operation of the first slurry storage tank and the agitator group are maintained. If the liquid level in the first slurry storage tank drops to the emptying threshold, and the heating time of the second slurry storage tank exceeds 5 minutes and the temperature still does not reach 12℃, the central controller immediately executes an emergency switching command, switching the dual-outlet grouting pump to the connected state with the second slurry storage tank and reducing the speed of the grouting pump drive motor to 60% of the base speed to reduce grouting pressure and prevent the low-temperature slurry from affecting the grouting quality. Simultaneously, the heating cable continues to heat at a rate of 10℃ / minute. When the temperature of the second slurry storage tank reaches 12℃, the central controller gradually increases the speed of the grouting pump to normal operating conditions, restoring normal grouting efficiency.

[0037] This technical solution, with its temperature control pre-inspection procedure and emergency switching mechanism, fully considers the complexities of switching grout tanks in low-temperature environments. Through measures such as delayed switching and emergency speed reduction, it ensures the continuity of grouting operations during switching, avoids the impact of low-temperature grout injection on tunnel quality, and allows for rapid adjustment of equipment operating parameters in extreme situations to prevent equipment damage due to overload operation, thus guaranteeing the safe and stable operation of the entire grouting system under low-temperature conditions.

[0038] In another technical solution, after the emergency switch, when the grouting pump operates at 60% of its base speed, the central controller executes a dynamic overload protection protocol: The drive motor load rate (power load rate) is calculated in real time, with a sampling frequency of once every 0.1 seconds; When the load rate is greater than 85% for 2 consecutive seconds, the forward and reverse pulse sequence is started. Forward phase: maintained for 10 seconds, the output torque is 120% of the rated value. Reverse phase: maintained for 1 second, the output torque is 1.2 times the real-time motor load rate. The pulse sequence is executed cyclically at a frequency of 0.2Hz until the load rate drops below 75% or the grouting pump speed returns to normal operation. The drive motor load rate is sampled every 0.1 seconds. A load rate > 85% for 2 consecutive seconds is used as the condition to start the forward and reverse pulse sequence. The forward phase lasts for 10 seconds, with the output torque at 120% of the rated value. The reverse phase lasts for 1 second, with the output torque at 1.2 times the real-time motor load rate. The pulse sequence frequency is 0.2Hz. A load rate below 75% is used as the condition to stop the pulse sequence.

[0039] The working process is as follows: After emergency switching, the grouting pump runs at 60% of its base speed. The central controller calculates the drive motor load rate in real time every 0.1 seconds. When the load rate is detected to be greater than 85% for two consecutive seconds, a forward and reverse pulse sequence is initiated. During the forward rotation phase, the motor is maintained for 10 seconds, and the output torque is increased to 120% of the rated value, enhancing the driving force. During the reverse rotation phase, it is maintained for 1 second, and the output torque is 1.2 times the real-time motor load rate. This torque change helps to break up any potential grout blockages or jams. The pulse sequence is executed cyclically at a frequency of 0.2Hz until the load rate drops below 75% or the grouting pump speed returns to normal operating conditions, effectively preventing motor overload damage and ensuring the continuous and stable operation of the grouting pump.

[0040] This technical solution enables the dynamic overload protection protocol to monitor the drive motor load in real time. When an overload trend is detected, the torque output is adjusted promptly through a forward and reverse pulse sequence, effectively resolving motor overload issues caused by grout blockage and increased resistance. This not only protects critical equipment such as the motor and grouting pump, extending their service life, but also reduces downtime due to equipment failure, improving the overall efficiency of tunnel grouting construction.

[0041] In another technical solution, the stirrer assembly further includes a defoaming mechanism, which comprises: Ultrasonic vibrating plates are attached to the inner walls of the first and second slurry storage tanks; Bubble sensor installed on top of the tank; When the agitator speed reaches 40 rpm or higher, the central controller activates the ultrasonic vibrator, and the bubble sensor monitors the gas content of the slurry in real time. If the gas content exceeds 3% by volume, the speed of the helical agitator is reduced to 35 rpm, and the ultrasonic vibrator continues to operate until the gas content reaches the target. When the agitator speed reaches 40 rpm or higher, the ultrasonic vibrator is activated, the bubble content by volume threshold is set to 3%, and the helical agitator speed is reduced to 35 rpm as an adjustment speed. A waterproof vibrator with a power of 100-200W can be selected, and the bubble sensor can be a gas content sensor based on infrared detection principles, capable of accurately measuring the gas content of the slurry. The outer shell of the ultrasonic vibrator is made of waterproof and corrosion-resistant plastic. In terms of assembly, the ultrasonic vibrator is attached to the middle of the inner wall of the first and second slurry storage tanks, and the bubble sensor is installed at the center of the top of the storage tanks.

[0042] The working process is as follows: When the speed of the agitator group increases to over 40 revolutions per minute, the central controller activates the ultrasonic vibrator to break up air bubbles in the grout through high-frequency vibration. A bubble sensor monitors the air content of the grout in real time. If the air content exceeds 3% by volume, it indicates that too many bubbles may affect the grouting quality. The central controller then reduces the speed of the spiral agitator to 35 rpm to reduce new bubbles generated by agitation, while simultaneously maintaining the operation of the ultrasonic vibrator to continuously defoam until the air content meets the standard, ensuring the compactness and stability of the grout.

[0043] This technical solution allows for precise control of the air content in the grout by the defoaming mechanism, effectively preventing problems such as voids and insufficient strength caused by excessive air bubbles. The coordinated adjustment of the ultrasonic vibrator and stirring speed efficiently breaks down existing air bubbles and reduces the generation of new ones, ensuring the grout injected into the tunnel meets the required density, improving the waterproofing performance and structural integrity of the tunnel lining, and guaranteeing project quality.

[0044] In another technical solution, such as Figure 1 and Figure 2 As shown, the movable support platform includes: The support frame includes multiple vertical columns 4, with a top operating platform 8 and lateral operating platforms 6 located on both sides of the top operating platform 8 at the top of the multiple vertical columns 4. The lower ends of the vertical columns 4 are provided with wheels 3. Two pairs of trapezoidal top supports 2 are respectively provided on both sides of the locomotive track. Each pair of trapezoidal top supports 2 is provided with a walkway plate, and the traveling wheel 3 is located on the walkway plate. Multiple guardrails 9 are installed on both sides of the top operating platform 8 and the side operating platform 6; Ladder 10 is located at the side of the lateral operating platform 6; Multiple triangular braces 7 are installed in the upper part of the vertical column 4 and connected to the lateral operating platform 6 or the top operating platform 8; Multiple horizontal braces 4 are installed between two vertical columns 4. The trolley walkway 1, made of high-strength channel steel, is installed along the axis on both sides of the lower middle section of the tunnel, straddling the locomotive rails. Trapezoidal top supports 2, welded from high-strength square steel and steel pipes, support the locomotive rails at the bottom and top of the trolley walkway 1. There are four traveling wheels 3, featuring internal steel wheels and external solid rubber wheels, with inverted triangular concave brackets at the top, installed at the bottom of the trolley. There are four vertical columns 4, made of high-strength square steel, connected at the bottom to the traveling wheels 3, in the middle and upper parts to the triangular diagonal braces 7, and at the top to the operating platform. Four horizontal braces 4, also made of high-strength square steel, are installed between two vertical columns 4. The operating platforms on both sides are located on the outside of the vertical columns 4 and secured using the triangular diagonal braces 7. Six triangular braces 7 are installed on each side of the upper part of the vertical column 4. Two of them connect to the vertical column 4 and the side operating platform 6, and the other two connect to the vertical column 4 and the top operating platform 8. They are made of high-strength square steel connected into a ring frame and then fully covered with roughened steel plates. The top operating platform 8 is located at the top of the vertical column 4, and is also made of high-strength square steel connected into a ring frame and then fully covered with roughened steel plates. Guardrails 9 are installed on both sides of the operating platform, made of small high-strength square steel, and their height is adjusted according to actual conditions. Ladders 10 are installed at the edge of the side operating platform 6 and are made of high-strength square steel.

[0045] The installation method for the mobile support platform includes the following steps: S1: Welding is carried out outside the hole to form various components. Enlarged pads are added and holes are drilled at the connection points of each component to facilitate bolt connection. S2: Secure the bottom of the trapezoidal top support 2 onto the locomotive track; S3: Place the trolley walkway 1 on the trapezoidal top support 2; S4: Install the walking wheel 3 on the vertical column 4 and fix it with iron shoes; S5: Connect the vertical column 4 to the horizontal brace 4; S6: Connect the vertical column 4 to the top operating platform 8 and the triangular brace 7; S7: Connect the two operating platforms to the vertical column 4 and the triangular brace 7; S8: Install the ladder 10 and connect it to the vertical column 4 and the side operating platform; S9: Install guardrails 9.

[0046] This invention, employing this technical solution, comprises components such as a trolley walkway 1, trapezoidal top support 2, traveling wheels 3, vertical columns 4, horizontal supports 4, two side operating platforms, triangular diagonal supports 7, top operating platform 8, guardrails 9, and ladders 10. The components can be manually installed inside the tunnel, simplifying the installation process, improving construction efficiency, and solving the problem of requiring a mobile, reliable, and safe vehicle for double-shield TBMs during secondary grouting. The main material of this invention is square steel, with adjustable length to adapt to different tunnel sizes. Square steel possesses excellent weldability, mechanical properties, and lightweight characteristics, ensuring the strength, durability, and practicality of the device. The trolley of this invention ensures simultaneous implementation of secondary grouting and TBM excavation, enhancing the mobility of secondary grouting. Through optimized design, this invention reduces material usage and simplifies installation and disassembly processes, contributing to lower construction costs.

[0047] The number of devices and processing scale described herein are for the purpose of simplifying the description of the invention. Applications, modifications, and variations of the mobile trolley for secondary grouting of the double-shield TBM of this invention will be readily apparent to those skilled in the art.

[0048] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A mobile trolley for secondary grouting of a double-shield TBM, characterized in that, include: Mobile support platform, grout storage system, grouting execution system, and central controller; The slurry storage system includes a first slurry storage tank, a second slurry storage tank, an agitator assembly, and a liquid level monitoring module. The first and second slurry storage tanks are fixed on a movable support platform. The agitator assembly includes spiral agitators that are vertically inserted into the first and second slurry storage tanks, respectively. The liquid level monitoring module uses an ultrasonic sensor installed on the top of the first and second slurry storage tanks. The grouting execution system includes a dual-outlet grouting pump, a pressure sensor, a frequency converter, a grouting hose, and a grouting nozzle. The inlet of the dual-outlet grouting pump is connected to the bottom outlet of the first grout storage tank and the second grout storage tank respectively through pipelines. The pressure sensor is embedded in the middle section of the grouting hose, and the end of the grouting hose is connected to the grouting nozzle. The frequency converter is electrically connected to the drive motor of the dual-outlet grouting pump. The central controller receives the liquid level signal from the liquid level monitoring module. When the liquid level in the first slurry storage tank drops to the first preset threshold, the central controller sends a first speed adjustment command to the agitator group, increasing the speed of the spiral agitator in the first slurry storage tank from the base speed of 20 revolutions per minute to 40 revolutions per minute. When the liquid level in the first slurry storage tank drops to the second preset threshold, the central controller sends a second speed adjustment command, increasing the speed of the spiral agitator to 50 revolutions per minute. The pressure sensor is used to collect the grout pressure value in the grouting hose in real time. The central controller is connected to the pressure sensor and can obtain the pressure value collected by the pressure sensor. When the pressure data exceeds the set pressure range for 3 seconds, the central controller sends an adjustment command to the frequency converter, and the frequency converter adjusts the speed of the dual-outlet grouting pump drive motor. The central controller synchronously controls the switching of the slurry storage system. When the liquid level of the first slurry storage tank drops to the emptying threshold, the central controller starts the spiral agitator of the second slurry storage tank to the basic speed of 20 revolutions per minute and switches the dual-outlet grouting pump to the second inlet connection state. The slurry storage system also includes a tank temperature control module, which comprises: The heat tracing material is wrapped around the outer walls of the first and second slurry storage tanks; Temperature sensors are inserted into the bottom of the first slurry storage tank and the second slurry storage tank; Both the temperature sensor and the heating tape are connected to the central controller. When the spiral agitator of the second slurry storage tank is started to the basic speed, the central controller starts the heating tape according to the temperature sensor data. If the temperature at the bottom of the tank is less than 10°C, the heating tape heats up to 15°C at a rate of 5°C per minute. During the heating period, the agitator group alternates between 10 seconds of forward rotation and 5 seconds of reverse rotation. When the central controller executes the command to switch to the second slurry storage tank, it simultaneously triggers a temperature control pre-check program, which includes the following steps: Read real-time data from the temperature sensor at the bottom of the second slurry storage tank; If the real-time temperature is below 8°C, the heat tracing cable wrapped around the outer wall of the second slurry storage tank will be activated and heated at a rate of 5°C / minute. At the same time, the slurry storage tank switching operation will be delayed until the temperature sensor data reaches above 12°C. During the delay, the grouting operation of the first slurry storage tank and the operation of the agitator group will be maintained. If the liquid level in the first grout storage tank drops to the emptying threshold and the heating time of the second grout storage tank exceeds 5 minutes and the temperature still does not reach 12°C, the central controller immediately executes an emergency switching command, switching the dual-outlet grouting pump to be connected to the second grout storage tank and reducing the speed of the grouting pump drive motor to 60% of the base speed, while the heating cable continues to heat at a rate of 10°C / minute; when the temperature of the second grout storage tank reaches 12°C, the central controller gradually increases the speed of the grouting pump to normal operating conditions.

2. The mobile trolley for secondary grouting of a double-shield TBM as described in claim 1, characterized in that, The grouting execution system is equipped with a pressure stabilizing buffer unit, which includes: A buffer tank is connected in parallel to the outlet end of the dual-outlet grouting pump. The volume of the buffer tank is 5%-8% of the volume of the first grout storage tank. An electric regulating valve is installed at the inlet end of the buffer tank. The closed-loop control module is connected to both the pressure sensor and the central controller. When the central controller issues a command to switch the slurry storage tank, the closed-loop control module is activated simultaneously. The slurry supply to the buffer tank is dynamically adjusted through the electric regulating valve, so that the pressure fluctuation in the grouting hose is controlled within ±10% of the set pressure range.

3. The mobile trolley for secondary grouting of a double-shield TBM as described in claim 2, characterized in that, The inner wall of the buffer tank is coated with a hydrophobic nano-ceramic coating, and a porous flow-guiding grid is set inside it. When the central controller detects that the electric regulating valve has been continuously open at less than 40% for more than 3 minutes, it starts the pulse cleaning program: the electric regulating valve switches back and forth between 20% and 60% opening at a frequency of 0.5Hz; at the same time, the output flow of the dual-outlet grouting pump increases by 10% and is maintained for 10 seconds.

4. The mobile trolley for secondary grouting of a double-shield TBM as described in claim 3, characterized in that, The pulse cleaning program executes synchronously after it starts: Adaptive filtering: When the pressure sensor switches to pulse follower mode, its low-pass filter cutoff frequency automatically matches twice the current cleaning pulse frequency. Intelligent sleep mode: The central controller pauses the pressure over-limit judgment function, and the sleep duration is the same as the pulse cleaning program, with a minimum of 3 complete pulse cycles.

5. The mobile trolley for secondary grouting of a double-shield TBM as described in claim 1, characterized in that, After the emergency switch, when the grouting pump runs at 60% of its base speed, the central controller executes the dynamic overload protection protocol: The load rate of the drive motor is calculated in real time, with a sampling frequency of once every 0.1 seconds; When the load rate is greater than 85% for 2 consecutive seconds, the forward and reverse pulse sequence is started. Forward phase: maintained for 10 seconds, the output torque is 120% of the rated value. Reverse phase: maintained for 1 second, the output torque is 1.2 times the real-time motor load rate. The pulse sequence is executed cyclically at a frequency of 0.2Hz until the load rate drops below 75% or the grouting pump speed returns to normal operation.

6. The mobile trolley for secondary grouting of a double-shield TBM as described in claim 1, characterized in that, The stirrer assembly also includes a defoaming mechanism, which includes: Ultrasonic vibrating plates are attached to the inner walls of the first and second slurry storage tanks; A bubble sensor installed on the top of the tank; When the speed of the agitator assembly increases to more than 40 revolutions per minute, the central controller starts the ultrasonic vibrator, and the bubble sensor monitors the air content of the slurry in real time. If the air content exceeds 3% by volume, the speed of the spiral agitator is reduced to 35 rpm and the ultrasonic vibrator is kept working until the air content meets the standard.

7. The mobile trolley for secondary grouting of a double-shield TBM as described in claim 1, characterized in that, The mobile support platform includes: The support frame includes multiple vertical columns, with a top operating platform and side operating platforms located on both sides of the top operating platform at the top of the multiple vertical columns. The lower ends of the vertical columns are provided with wheels. Two pairs of trapezoidal top supports are respectively installed on both sides of the locomotive track, and each pair of trapezoidal top supports is equipped with a walkway plate, and the traveling wheels are located on the walkway plate; Multiple guardrails are installed on both sides of the top operating platform and the side operating platform; A ladder is installed at the edge of the side operating platform; Multiple triangular braces are installed in the upper part of the vertical column and connected to the side operating platform or the top operating platform. Multiple horizontal braces are installed between two vertical columns.

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