A high-quality production process for shield segments

Abstract

The present invention discloses a production process for high-quality shield segments, and the process is as follows: Step 1: Welding of steel reinforcement cages: Workers set programs on steel reinforcement processing equipment according to the steel reinforcement cutting list, and process the raw steel reinforcement into semi-finished products through processes such as straightening, shearing, hoop bending, arc bending, bending, and spring coiling. Welders use carbon dioxide gas shielded welding to combine the semi-finished steel reinforcement at the designated die stations to weld into steel reinforcement cages; The beneficial effects of the present invention are: The finishing station is fixed, with high operation efficiency, improving the production efficiency of segments; During the production process of the production equipment, the production monitoring system monitors and records real-time production data, and compares it with the production data in the production database of the production monitoring system. When abnormalities are found, reminders are given, and the production process can be monitored, facilitating the timely discovery of problems and thus making corrections.

Description

Technical Field

[0001] The present invention belongs to the technical field of segment production, and particularly relates to a production process for high-quality shield segments. Background Art

[0002] Segment types are mainly classified from aspects such as production materials, connection methods, and combination forms; in terms of materials, there are mainly cast iron segments, steel pipe segments, reinforced (steel fiber) concrete segments, composite segments, etc.; the following is a brief introduction to segments made of different materials: Cast iron segments: Cast iron segments have high strength, good ductility, are easy to cast into thin-walled structures, have a light segment weight, and are convenient for handling and installation; cast iron segments have high requirements for accuracy and waterproofing, so they have high requirements for processing equipment and high costs. They were used more in early shield applications and are now rarely seen in China; Steel pipe segments: They are mainly welded and processed from section steel or steel plates. They have high strength, good ductility, are convenient for transportation and installation, and have slightly lower accuracy than cast iron segments. However, they are prone to deformation under construction stress during construction and are also prone to corrosion in the bottom layer. They are commonly used in connection channels between tunnels; Reinforced concrete segments: Segments made of this material have a certain strength, are relatively easy to process and manufacture, are corrosion-resistant, and have low costs. They are the most commonly used segment type in subway tunnels, but they are relatively heavy and are prone to damage during transportation, installation, and construction. Most shields in China currently use such segments; Composite segments: The outer shell is made of 5-sided steel plates, and steel bars and steel materials are arranged inside the steel shell. The steel materials and concrete are integrally combined into composite segments, which can be made thinner and wider under conditions of high water and soil pressure or special load positions; Composite segments can use various types of joints and are suitable for construction not only in large-section tunnels but also in positions such as curve sections and open intervals; Combination of straight lining rings and wedge-shaped lining rings: Shield tunnels are designed as smooth curves by fitting several broken lines on curves; in design and construction, the wedge-shaped lining rings and straight lining rings are preferably combined for line fitting; according to the turning direction of the line and the need for construction deviation correction, left, right, and straight lining rings are designed; during design, the lining rings are arranged throughout the line according to the line conditions to control the tunnel design fitting error within the allowable range; during shield propulsion, the type of the next ring of lining is determined based on the arrangement diagram and the current construction error; since the type of lining ring used is not completely determined, it brings certain difficulties to the production and supply of segments; Universal segments: Only one type of wedge-shaped lining ring is used. During shield tunneling, the rotation angle of the next ring is determined through the information of the inner circumferential jack sensors of the shield machine to place the maximum wedge amount at the position with the longest jack stroke. Generally speaking, the segment lining ring can rotate 360°. Since it only requires one type of segment, the cost of the segment mold can be reduced, but the assembly difficulty of universal segments is relatively high.

[0003] The segment production process often uses the fixed pedestal method, the unit flow method, and the flow conveyor method. The fixed pedestal method is a production flow system centered around a fixed mold with a crane as the main transportation tool. The dispersed layout occupies a large area, and manual vibration affects the quality stability of the products. The unit flow method is a production flow system centered around a fixed vibrating table with a crane as the main transportation tool. Lifting the mold increases the load on the crane, and the frequent movement of the mold is prone to deformation. The flow conveyor method is a production flow system centered around a fixed vibrating table, using an automated conveyor line as the main transportation method. The product quality and production efficiency are greatly affected by the conveyor line. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-quality shield segment production process, improve the production efficiency of segments, enable the production process to be monitored, and facilitate timely problem discovery and correction.

[0005] To achieve the above object, the present invention provides the following technical solution: A high-quality shield segment production process, and the process is as follows:

[0006] Step 1: Welding of steel reinforcement cage: The operator sets the program on the steel reinforcement processing equipment according to the steel reinforcement cutting list, and processes the steel reinforcement raw material into semi-finished products through processes such as straightening, shearing, hoop bending, arc bending, bending, and spring coiling. The welder uses carbon dioxide gas shielded welding to combine the steel reinforcement semi-finished products at the designated formwork station to weld into a steel reinforcement cage.

[0007] Step 2: Mold cleaning: The operator uses compressed air and special tools to thoroughly clean the residual concrete blocks and mud on each surface and each joint of the inner side of the mold.

[0008] Step 3: Coating of release agent: At the release agent coating station, the operator first checks and confirms that the mold has been completely cleaned, and then uses tools such as dry rags to coat the inner surface of the mold with release agent.

[0009] Step 4: Hoisting of steel reinforcement cage: After the oil film is completely formed in the mold, a special lifting tool is used to hoist the finished steel reinforcement cage at the top of the steam curing kiln into the mold.

[0010] Step 5: Installation of embedded parts: Assemble various embedded parts inside the segment according to the design requirements.

[0011] Step 6: Quality inspection: Check and confirm the installation quality of the embedded parts and the steel reinforcement cage, the tightening degree of the bolts, and the thickness of the protective layer. After passing the inspection, close the mold covers on both sides, and the tightening bolts of the covers must be tightened to the specified torque.

[0012] Step 7: Concrete pouring: The railcar enters the concrete pouring chamber with the mold. ① The operator connects the air pipe of the vibrating pump. ② The mold trolley is lifted by the wheel support vibration isolation table and separated from the ground. ③ The access door of the pouring chamber is closed. ④ The concrete is fed, and the middle vibrator of the mold is turned on while feeding. When the concrete fills the bottom plate of the mold, all vibrators are turned on for stratified vibration. Stop feeding when the concrete reaches the top plate of the mold and a little overflows. Stop vibrating when there are no more bubbles on the concrete surface. ⑤ Disconnect the air pipe of the vibrating pump. ⑥ Open the access door of the pouring chamber. After the operator completes the above work, lower the mold trolley and press the work completion button. The control system receives the vibration completion signal and waits for the next mold to enter the warehouse to enter the next cycle.

[0013] Step 8: Primary surface finishing: After pouring, open the cover plate for water collecting and surface finishing operations. First, use a screed to level the excess concrete, and then use a trowel to finish the surface to make the concrete surface smooth and free of impurities.

[0014] Step 9: Secondary surface finishing: Use a trowel for secondary surface finishing after the concrete surface has dried to make the surface of the segment keep an arc shape and be flat without unevenness.

[0015] Step 10: Tertiary surface finishing: Conduct the third surface finishing when there is a slight indentation when gently pressing the concrete surface with a finger and the hand is not sticky to the surface concrete. Use a trowel to press and make the outer arc surface of the segment smooth and flat.

[0016] Step 11: Steam curing: After completing the above work, the segments will be sent to the steam curing kiln for steam curing. The steam curing process mainly includes four stages: static curing, heating up, constant temperature, and cooling down. The heating up speed is set at 10°C / h, the cooling down speed does not exceed 20°C / h, the constant temperature is set at 40 - 50°C, and the steam curing time is adjusted according to the same-curing strength reached by the segments at demolding.

[0017] Step 12: Demolding and marking: After the segments meet the demolding conditions, they are transported to the demolding station through the traction device. The operator opens the side mold and end mold of the mold in the specified order, and uses a vacuum suction cup to lift the segments from the mold, moves them to the turning machine for a 90-degree flip. The operator marks the production date and type information of the segments as required, and they are lifted by the overhead crane to the storage and cooling area. After all the above processes are completed, the production of the next segment is carried out.

[0018] Step 13: Cooling and finishing: After demolding and marking, use special tools to remove the steel sleeve caps and gaskets of the segments, cover the protective caps, and repair the appearance defects of the segments. When the temperature difference between the segments and the outside is no more than 20°C, use an infrared thermometer to measure the temperature of the segments.

[0019] Step 14: Final inspection: The quality inspection content includes: the appearance quality and dimensional deviation of the segment products.

[0020] Step 15: Curing of segment in water: The segment is lifted by the overhead crane using a professional lifting tool onto the flatbed truck, and then transported by the flatbed truck to the water curing tank for 7 - 14 days of water curing. The pH value of the curing water is controlled within the range of 7 - 10;

[0021] Step 16: Storage of segment in warehouse: After the segment is cured in water, the operator uses the gantry crane to lift the segment in the water curing tank, move it to the turning machine for a 90 - degree turn, and then the forklift places the segment flat on the truck and finally transports it to the designated location in the yard for storage according to requirements;

[0022] Step 17: Natural curing: After the segment is stored in the warehouse, natural curing is carried out, and the total time of natural curing and water curing is not less than 28 days.

[0023] As a preferred technical solution of the present invention, in the above - mentioned Step 5, the embedded parts include elbow pipes, rubber gaskets, embedded steel sleeves, grouting pipes, large and small spring steel bars.

[0024] As a preferred technical solution of the present invention, in the above - mentioned Step 6, the specified torque is 300 N·M.

[0025] As a preferred technical solution of the present invention, the appearance quality of the segment finished product includes through - cracks, cracks on the splicing surface, non - through - cracks, exposed steel bars on the inner and outer surfaces, holes, pitted surfaces, sticking skins, honeycombing, looseness, slag inclusions, ring and longitudinal bolt holes, chipping and corner breakage.

[0026] As a preferred technical solution of the present invention, the dimensional deviations include width and thickness of the steel bar protection layer.

[0027] As a preferred technical solution of the present invention, the preparation method of the mold release agent is as follows: Add carboxymethyl cellulose to the reaction kettle, heat and stir, then add aluminum - magnesium refractory mud, pulverized coal, and sodium - based bentonite, add water and continue to stir, and cool to room temperature.

[0028] As a preferred technical solution of the present invention, it also includes the monitoring of the shield segment production process, specifically as follows: Input the shield segment production data into the production monitoring system and match it with the production data in the production database of the production monitoring system; the production monitoring system then transmits the production data to the manufacturing management system; the manufacturing management system controls the production equipment according to the production data for production; when the production equipment is in the production process, the production monitoring system monitors and records the real - time production data and compares it with the production data in the production database of the production monitoring system.

[0029] As a preferred technical solution of the present invention, the production monitoring system monitors and records the real - time production data, compares it with the production data in the production database of the production monitoring system, and when an abnormality is found, gives a reminder and makes corrections according to the reminder.

[0030] Compared with the prior art, the beneficial effects of the present invention are:

[0031] The finishing station is fixed, with high operation efficiency, improving the efficiency of segment production.

[0032] Input the production data of shield segments into the production monitoring system and match it with the production data in the production database of the production monitoring system; the production monitoring system then transmits the production data to the manufacturing management system; the manufacturing management system controls the production equipment according to the production data; during the production process of the production equipment, the production monitoring system monitors and records the real-time production data and compares it with the production data in the production database of the production monitoring system. When abnormalities are found, reminders are given. The production process can be monitored, facilitating the timely discovery of problems for correction. Description of the Drawings

[0033] Figure 1 It is the process flow chart of the segment production process of the present invention. Detailed Embodiments

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0035] Embodiment 1

[0036] Please refer to Figure 1 , which is the first embodiment of the present invention. This embodiment provides a high-quality shield segment production process, and the process is as follows:

[0037] Step 1: Welding of the steel cage: The operator sets the program on the steel bar processing equipment according to the steel bar cutting list, and processes the steel bar raw materials into semi-finished products through the processes of straightening, shearing, bending the hoop, bending the arc, bending, and coiling the spring. The welder combines the steel bar semi-finished products using carbon dioxide gas shielded welding at the designated formwork station to weld into a steel cage;

[0038] Step 2: Cleaning of the mold: The operator uses compressed air and special tools to thoroughly clean the residual concrete blocks and mud on each surface and each joint of the inner side of the mold;

[0039] Step 3: Coating the release agent: At the release agent coating station, the operator first checks and confirms that the mold has been completely cleaned, and then uses tools such as dry rags to coat the inner surface of the mold with the release agent;

[0040] Step 4: Lifting of the steel cage: After the oil film is completely formed in the mold, use a special lifting tool to lift the finished steel cage at the top of the steam curing kiln into the mold;

[0041] Step 5: Embedded part installation: Assemble various embedded parts inside the segment according to the design requirements. The embedded parts include elbow pipes, rubber gaskets, embedded steel sleeves, grouting pipes, large and small spring bars;

[0042] Step 6: Quality inspection: Check and confirm the installation quality of the embedded parts and the steel reinforcement cage, the tightening degree of the bolts, and the cover thickness. After passing the inspection, close the mold covers on both sides. The tightening bolts of the covers must be tightened to the specified torque, and the specified torque is 300 N·M;

[0043] Step 7: Concrete pouring: The railcar takes the mold into the concrete pouring chamber: ① The operator connects the air pipe of the vibrating pump; ② The mold trolley is lifted by the wheeled vibration isolation table and separated from the ground; ③ The inlet and outlet doors of the pouring chamber are closed; ④ Concrete is fed. While feeding, turn on the vibrator in the middle of the mold. When the mold bottom plate is filled with concrete, turn on all vibrators for layered vibration. Stop feeding when the concrete reaches the mold top plate and there is a little overflow. Stop vibrating when there are no more bubbles on the concrete surface; ⑤ Remove the air pipe of the vibrating pump; ⑥ Open the inlet and outlet doors of the pouring chamber. After the operator completes the above work, lower the mold trolley and press the work completion button. The control system receives the vibration completion signal and waits for the next mold to enter the warehouse to enter the next cycle;

[0044] Step 8: Primary surface finishing: After the pouring is completed, open the cover for water collecting and surface finishing operations. First, use a screed to level the excess concrete, and then use a trowel to finish the surface to make the concrete surface smooth and free of impurities;

[0045] Step 9: Secondary surface finishing: Use a trowel for secondary surface finishing after the concrete surface has dried to make the segment surface maintain a smooth arc and have no concave or convex feeling;

[0046] Step 10: Tertiary surface finishing: Conduct the third surface finishing when the concrete surface has a slight indentation when gently pressed with a finger and the hand is not sticky to the surface concrete. Use a trowel to smear and press to make the outer arc surface of the segment smooth and flat; To increase the water retention of the concrete and avoid cracks in the later stage, cover it with a plastic film;

[0047] Step 11: Steam curing: After completing the above work, the segment will be sent to the steam curing kiln for steam curing. The steam curing process mainly includes four stages: static curing, heating up, constant temperature, and cooling down. The heating rate is set at 10℃ / h, the cooling rate does not exceed 20℃ / h, the constant temperature is set at 40℃, and the steam curing time is adjusted according to the same-curing strength of the segment when demolding;

[0048] Step Twelve: Demoulding Identification: After the segment meets the demoulding conditions, it is transported to the demoulding station through the traction device. The operators open the side mould and end mould of the mould in the specified order, and lift the segment from the mould with a vacuum suction cup, then move it to the turning machine for a 90-degree flip. The operators identify the production date and type information of the segment as required, and then it is lifted by the overhead crane to the storage and cooling area. After all the above processes are completed, the production of the next segment begins;

[0049] Step Thirteen: Cooling and Finishing: After demoulding identification, the steel sleeve cap plugs and rubber gaskets of the segment are removed using special tools, a protective cap is put on, and the appearance defects of the segment are repaired. When the temperature difference between the segment and the outdoor environment is no more than 20°C, an infrared thermometer gun is used to measure the temperature of the segment;

[0050] Step Fourteen: Finished Product Inspection: The quality inspection content includes: the appearance quality and dimensional deviation of the segment finished product. The appearance quality of the segment finished product includes through cracks, joint surface cracks, non-through cracks, exposed reinforcement on the inner and outer surfaces, holes, pitted surfaces, sticking skins, honeycombing, looseness, slag inclusions, circumferential and longitudinal bolt holes, and chipped corners. The dimensional deviation includes width and thickness of the steel bar protection layer.

[0051] Step Fifteen: Water Curing of Segments: The segment is lifted by the overhead crane using a special lifting tool and placed on a flatbed truck, and then transported by the flatbed truck to the water curing tank for 7 days of water curing. The pH value of the curing water is controlled at 7;

[0052] Step Sixteen: Segment Storage: After the segment is cured in water, the operator uses a gantry crane to lift the segment in the water curing tank, move it to the turning machine for a 90-degree flip, and then the forklift places the segment flat on the truck and finally transports it to the designated location in the storage yard for storage as required;

[0053] Step Seventeen: Natural Curing: After the segment is stored, natural curing is carried out, and the total time of natural curing and water curing is not less than 28 days;

[0054] Step Eighteen: Factory Acceptance: After the segment is stored, the defective segments are repaired. After repair, the on-site supervisor is requested for acceptance and a repair record is formed. After the segment meets the 28-day age requirement and a qualified report is issued, the on-site supervisor is requested for acceptance. After passing the acceptance, fill in the "Segment Factory Inspection Form";

[0055] Step Nineteen: Segment Shipment: The segments that pass the acceptance are loaded onto the truck according to the demand plan of the user unit, fixed with fastening belts, and safely transported to the designated location; Note: ① The segment certificate shall be attached to the vehicle. ② Rubber pads must be provided on the forklift forks.

[0056] In this embodiment, preferably, the release agent is prepared as follows: Add carboxymethyl cellulose to the reaction kettle, heat and stir, then add aluminum-magnesium refractory mud, pulverized coal, and sodium-based bentonite, add water and continue to stir, and cool to room temperature.

[0057] In this embodiment, preferably, it also includes monitoring of the shield segment production process, which is specifically as follows: input shield segment production data into the production monitoring system, and match it with the production data in the production database of the production monitoring system; the production monitoring system then transmits the production data to the manufacturing management system; the manufacturing management system controls the production of the production equipment according to the production data; when the production equipment is in production, the production monitoring system monitors and records the real-time production data, and compares it with the production data in the production database of the production monitoring system, and when an abnormality is found, a reminder is issued, and corrections are made based on the reminder.

[0058] The length of the steel bar cutting is too long or too short, resulting in uneven steel bar lap. The main reasons are: workers make mistakes in operation and fail to perform construction according to the material order; the cutting equipment is not self-calibrated before use; the machine cutter head is worn, resulting in shearing errors. To solve the above problems, you can adopt the following methods: ① Self-calibrate the equipment before cutting each shift, and check the length of the first batch of steel bars cut. During the process, the quality inspector will conduct spot checks every day; ② The machine repair team will regularly check the equipment and do daily maintenance. Once a problem is found, it will be dealt with in time;

[0059] The main reasons for the de-welding of the main reinforcement of the steel cage or other steel bars are: insufficient penetration depth of the welding point, resulting in a cold weld; the main reinforcement is not welded at two points, resulting in insufficient connection strength; external forces such as transportation and lifting process lead to de-welding. To solve the above problems, the following can be adopted: ① Regular education and training for the reinforcement class, and irregular on-site guidance; ② The quality inspector conducts daily inspections during the process, and timely educates and supervises rectification when problems are found, and at the same time increases the assessment intensity; ③ Violent lifting is strictly prohibited during the reverse transportation process, and the lifting should be stable;

[0060] Outdoor steel cages are stored without covers or pads, which can easily lead to rust. The main reasons are: welders rush to finish the work and seek convenience; discontinuous production of pipe segments leads to a serious backlog of steel cages and no storage space. To solve the above problems, the following can be adopted: ① Regular education and training for the steel bar team, and irregular on-site guidance; ② Quality inspectors conduct daily inspections during the process, and timely educate and urge rectification when problems are found, and at the same time increase the assessment efforts;

[0061] The spacing of the mold assembly positioning holes does not meet the requirements of the drawings, resulting in the inability to assemble the pipe segments. The main reasons are: ① The manufacturer did not strictly follow the drawings during the mold processing stage; ② The manufacturer did not conduct factory acceptance or the acceptance was not in place before leaving the factory; To solve the above problems, you can adopt: ① The mold processing is strictly constructed according to the drawings; ② The mold is fully inspected before leaving the factory without omission; ③ The mold needs to be inspected by three parties after it arrives at the factory; ④ When it is found that there is a problem with the spacing of the mold assembly positioning holes, stop using the mold immediately and contact the manufacturer for repair immediately;

[0062] The inner arc surface of the mold is marked incorrectly, forming the opposite direction to the propulsion direction, which affects the segment assembly. The main reasons are as follows: ① The manufacturer did not strictly construct according to the drawings during the mold processing stage; ② The manufacturer did not conduct factory acceptance or the acceptance was not in place before leaving the factory. To solve the above problems, the following measures can be taken: ① The mold processing should be strictly carried out according to the drawings; ② The mold should be comprehensively inspected before leaving the factory without omission; ③ The mold needs to be jointly inspected by three parties after arriving at the factory; ④ When the mold marking problem is found, the use of the mold should be stopped immediately and the manufacturer should be contacted immediately for repair.

[0063] During the use of the mold, the edges of the track wheels are worn, resulting in the derailment of the mold. The main reasons are as follows: ① The mold wheel shaft was not lubricated and maintained in time during use; ② The wheels are in a welded form and wear quickly; ③ When the segment is demolded, the mold drops and the wheel edges are impacted, causing damage; ④ The track of the production line settles and deforms, accelerating the wear of the wheels. To solve the above problems, the following measures can be taken: ① The mold wheel shaft should be lubricated and maintained in time during use; ② The manufacturer is required to replace the integral wheels; ③ The track should be finely adjusted regularly to reduce wheel wear; ④ When it is found that the edges of the track wheels are worn during the use of the mold, the maintenance personnel should be arranged in time for repair and replacement.

[0064] The mold corners are not cleaned thoroughly, the rubber strips are aged and deformed, and there are knocks and bumps, resulting in the end and side plates not closing tightly and the mold measurement being out of width. The main reasons are as follows: ① The workers did not clean the mold thoroughly and rushed for work; ② The mold rubber strips are aged and deformed, affecting the mold clamping; ③ The workers hit the mold edge when installing the steel reinforcement cage, resulting in deformation and the mold not closing tightly. To solve the above problems, the following measures can be taken: ① The workers are required to open the mold and clean it thoroughly; ② Replace the aged rubber strips in time; ③ Strengthen the training of workers, install the steel reinforcement cage according to the requirements, and focus on the process inspection; ④ When it is found that the mold corners are cleaned thoroughly during the use of the mold, the rubber strips are not aged or impacted and deformed, and the mold size deviation exceeds the error, the manufacturer should be arranged in time for repair and rectification.

[0065] Example 2

[0066] Please refer to Figure 1 , which is the second embodiment of the present invention. This embodiment is based on the previous embodiment, and the differences are as follows:

[0067] The segments will be sent to the steam curing kiln for steam curing. The steam curing process mainly includes four stages: static curing, heating up, constant temperature, and cooling down. The heating up speed is set at 10 °C / h, the cooling down speed does not exceed 20 °C / h, the constant temperature is set at 45 °C, and the steam curing time is adjusted according to the same-curing strength reached by the segments at demolding.

[0068] The segments are lifted to the flatbed truck by the gantry crane using professional lifting tools, and then transported to the water curing pond by the flatbed truck for 10 days of water curing. The pH value of the curing water is controlled at 9.

[0069] Example 3

[0070] Please refer to Figure 1 , which is the third embodiment of the present invention. This embodiment is based on the previous embodiment, and the differences are as follows:

[0071] The segment will be sent into a steam curing kiln for steam curing. The steam curing process mainly includes four stages: static curing, heating up, constant temperature, and cooling down. The heating rate is set at 10°C / h, the cooling rate does not exceed 20°C / h, the constant temperature is set at 50°C, and the steam curing time is adjusted according to the same-curing strength of the segment when demoulding;

[0072] The segment is lifted by a truss crane using a professional lifting tool onto a flatbed truck, and then transported by the flatbed truck to a water curing pond for 14 days of water curing. The pH value of the curing water is controlled at 10.

[0073] Although the embodiments of the present invention have been shown and described, see the above detailed description. For those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-quality production process for shield segments, characterized in that: The process is as follows: Step 1: Welding of steel reinforcement cage: Workers set programs on steel bar processing equipment according to the steel bar cutting list, and process the raw steel bars into semi-finished products through straightening, shearing, hoop bending, arc bending, bending, and spring coiling processes. Welders use carbon dioxide gas shielded welding to combine the semi-finished steel bars at the designated die station and weld them into a steel reinforcement cage; Step 2: Mold cleaning: Workers use compressed air and special tools to thoroughly clean the residual concrete blocks and mud on each surface and each joint of the inner side of the mold; Step 3: Coating of release agent: At the release agent coating station, workers first check and confirm that the mold has been completely cleaned, and then use tools such as dry rags to coat the inner surface of the mold with release agent; Step 4: Hoisting of steel reinforcement cage: After a complete oil film is formed inside the mold, use a special lifting tool to hoist the finished steel reinforcement cage at the top of the steam curing kiln into the mold; Step 5: Installation of embedded parts: Assemble various embedded parts inside the segment according to the design requirements; Step 6: Quality inspection: Check and confirm the installation quality of the embedded parts and the steel reinforcement cage, the tightening degree of the bolts, and the thickness of the protective layer. After passing the inspection, close the mold covers on both sides, and the tightening bolts of the covers must be tightened to the specified torque; Step 7: Concrete pouring: The rail car takes the mold into the concrete pouring room: ① Workers connect the air pipe of the vibrating pump; ② The mold trolley is lifted by the wheel-mounted vibration isolation platform and separated from the ground; ③ The inlet and outlet doors of the pouring room are closed; ④ Concrete is fed. While feeding, turn on the vibrator in the middle of the mold. When the concrete fills the bottom plate of the mold, turn on all vibrators for layered vibration. Stop feeding when the concrete reaches the top plate of the mold and there is a little overflow. Stop vibration when there are no more bubbles on the concrete surface; ⑤ Remove the air pipe of the vibrating pump; ⑥ Open the inlet and outlet doors of the pouring room. After workers complete the above work, lower the mold trolley and press the work completion button. The control system receives the vibration completion signal and waits for the next mold to enter the warehouse to enter the next cycle; Step 8: Primary surface finishing: After pouring is completed, open the cover for water collecting and surface finishing operations. First, use a screed to level the excess concrete, and then use a trowel to finish the surface to make the concrete surface smooth and free of impurities; Step 9: Secondary surface finishing: Use a trowel for secondary surface finishing after the concrete surface has dried to make the segment surface maintain a smooth arc and no uneven feeling; Step 10: Tertiary surface finishing: Conduct the third surface finishing when the concrete surface has a slight indentation when gently pressed with a finger and the hand does not stick to the surface concrete. Use a trowel to smear and press to make the outer arc surface of the segment smooth and flat; Step 11: Steam curing: After completing the above work content, the segment will be sent to the steam curing kiln for steam curing. The steam curing process mainly includes four stages: static curing, heating up, constant temperature, and cooling down. The heating rate is set at 10°C / h, the cooling rate does not exceed 20°C / h, the constant temperature is set at 40 - 50°C, and the steam curing time is adjusted according to the same-curing strength reached by the segment at demolding; Step Twelve: Demoulding Identification: After the segment meets the demoulding conditions, it is transported to the demoulding station through the traction device. The operators open the side formwork and end formwork of the mold in the specified order, lift the segment from the mold with a vacuum suction cup, move it to the turning machine for a 90-degree flip. The operators identify the production date and type information of the segment as required, and then it is lifted by the overhead crane to the storage and cooling area. After all the above processes are completed, the production of the next segment begins; Step Thirteen: Cooling and Finishing: After demoulding identification, the steel sleeve caps and rubber gaskets of the segment are removed using special tools, a protective cap is covered, and the appearance defects of the segment are repaired; When the temperature difference between the segment and the outdoor environment is no more than 20°C, an infrared temperature gun is used to measure the temperature of the segment; Step Fourteen: Final Product Inspection: The quality inspection content includes: the appearance quality and dimensional deviation of the segment final product; Step Fifteen: Segment Water Curing: The segment is lifted by the overhead crane using a professional lifting tool to a flatbed truck, and then transported by the flatbed truck to the water curing pond for 7 - 14 days of water curing. The pH value of the curing water is controlled within the range of 7 - 10; Step Sixteen: Segment Storage: After the segment is cured in water, the operator uses a gantry crane to lift the segment in the water curing pond, move it to the turning machine for a 90-degree flip, and then the forklift places the segment flat on the truck and finally transports it to the designated location in the yard for storage as required; Step Seventeen: Natural Curing: After the segment is stored, natural curing is carried out. The total time of natural curing and water curing is not less than 28 days.

2. A high-quality production process for shield segments according to claim 1, characterized in that: In the above Step Five, the embedded parts include elbow pipes, rubber rings, embedded steel sleeves, grouting pipes, large and small spring bars.

3. A high-quality production process for shield segments according to claim 1, characterized in that: In the above Step Six, the specified torque is 300 N·M.

4. A high-quality production process for shield segments according to claim 1, characterized in that: The appearance quality of the segment final product includes through cracks, splicing surface cracks, non-through cracks, exposed reinforcement on the inner and outer surfaces, holes, pitted surfaces, sticking skins, honeycombing, looseness, slag inclusions, circumferential and longitudinal bolt holes, edge chipping and corner breaking.

5. A high-quality production process for shield segments according to claim 1, characterized in that: The dimensional deviation includes width and steel bar cover thickness.

6. A high-quality production process for shield segments according to claim 1, characterized in that: The preparation method of the demoulding agent is as follows: Add carboxymethyl cellulose to the reaction kettle, heat and stir, then add aluminum-magnesium refractory mud, pulverized coal, and sodium-based bentonite, add water and continue to stir, and cool to room temperature.

7. A high-quality production process for shield segments according to claim 1, characterized in that: It also includes the monitoring of the shield segment production process, specifically as follows: Input the shield segment production data into the production monitoring system and match it with the production data in the production database of the production monitoring system; The production monitoring system then transmits the production data to the manufacturing management system; The manufacturing management system controls the production equipment according to the production data; During the production process of the production equipment, the production monitoring system monitors and records the real-time production data and compares it with the production data in the production database of the production monitoring system.

8. A high-quality production process for shield segments according to claim 7, characterized in that: The production monitoring system monitors and records the real-time production data and compares it with the production data in the production database of the production monitoring system. When abnormalities are found, reminders are given and corrections are made for the reminders.

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