Rectangular corrugated steel cylinder concrete jacking pipe and preparation method thereof

Abstract

The invention discloses a rectangular corrugated steel cylinder concrete jacking pipe and a preparation method thereof, and relates to the technical field of concrete pipes, the preparation method comprises the following specific steps: S1, selecting a rectangular corrugated steel plate of a preset specification, adopting a steel and concrete composite beam algorithm to carry out rectangular corrugated steel rib calculation, and carrying out rust removal and anticorrosion primer treatment; s2, the pretreated rectangular corrugated steel plate is rolled into a circular cylinder through a plate rolling machine; s3, the butt joint position of the circular barrel is welded through double-face submerged arc welding; s4, reinforcing ribs are welded to the inner wall of the circular cylinder, and an integrated corrugated steel framework is formed; and S5, the corrugated steel framework is hoisted into the prefabricated mold, the coaxiality is adjusted, an inner mold plate and an outer mold plate are installed, and compact concrete is poured. The rectangular corrugated steel ribs are calculated by introducing a steel and concrete combined beam algorithm, the thicknesses of the steel plates and the steel ribs are accurately calculated and determined, the material consumption is reduced on the premise that the structural strength is guaranteed, and meanwhile the steel and concrete cooperative stress efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of concrete pipe technology, and in particular to a rectangular corrugated steel cylinder concrete jacking pipe and its preparation method. Background Technology

[0002] Pipe jacking, as a trenchless underground engineering technology, has significant advantages due to its minimal impact on surface traffic, surrounding buildings, and the ecological environment. Corrugated steel cylinder concrete jacking pipes, as an advanced prefabricated component for underground engineering, are widely used in urban integrated pipe corridors, municipal drainage, and tunnel engineering. Traditional pipe jacking fabrication technologies can no longer meet the multiple demands of modern engineering for efficiency, durability, and economy. Currently, the pipe jacking fabrication methods commonly used in the industry are mainly divided into two categories: reinforced concrete pipe jacking and steel cylinder concrete jacking, but both have obvious technical shortcomings.

[0003] Traditional reinforced concrete pipe jacking uses a process of binding steel bars into a cage and casting it into a formwork. Specifically, it involves processes such as binding the steel cage, erecting the formwork, pouring concrete, and steam curing. Although this method is technically mature, it has the following prominent problems: First, the processing precision of the steel cage is low, which can easily lead to uneven thickness of the concrete cover and affect the durability of the structure. Second, the formwork engineering is complex, especially the curved formwork, which has high production costs and low turnover rate, resulting in high production costs. Third, it is difficult to ensure the compaction of the concrete, which can easily lead to quality defects such as honeycomb and voids. In addition, the reinforced concrete pipe jacking is relatively heavy, which increases the overall cost of the project.

[0004] Existing technologies mostly use flat steel coils for forming or directly use finished steel pipes. Steel cylinders made from flat steel coils have low circumferential stiffness and are prone to deformation during concrete pouring, affecting the forming accuracy. On the other hand, using finished steel pipes is not flexible enough to meet the personalized requirements of different projects for pipe diameter and wall thickness. Furthermore, when used for cable jacking, it is difficult to achieve the shielding function for electromagnetic signals. Traditionally, a shielding pipe is installed inside the jacking pipe, which not only increases the amount of material used but also cannot guarantee the stability of the shielding pipe's position. Inadequate design of corrugated steel cylinder concrete jacking pipes can easily create safety hazards. Summary of the Invention

[0005] The purpose of this invention is to provide a rectangular corrugated steel cylinder concrete jacking pipe and its preparation method, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing a rectangular corrugated steel cylinder concrete jacking pipe, comprising the following specific steps:

[0007] S1. Select a rectangular corrugated steel plate of a preset specification, use the steel and concrete composite beam algorithm to calculate the rectangular corrugated steel frame, and perform rust removal and anti-corrosion primer treatment.

[0008] S2. The pre-treated rectangular corrugated steel plate is rolled into a cylindrical shape using a plate rolling machine, and the alignment deviation of the corrugated grooves at the joint and the roundness error of the cylindrical shape are controlled.

[0009] S3. Double-sided submerged arc welding is used to weld the butt joint of the cylindrical tubes to ensure the quality of the weld.

[0010] S4. Weld reinforcing ribs to the inner wall of the cylindrical tube to form an integrated corrugated steel skeleton, and perform penetrant testing on the weld.

[0011] S5. Hoist the corrugated steel frame into the precast mold and adjust its coaxiality. Install the inner and outer templates, pour dense concrete, vibrate in layers, and remove the templates after curing to obtain the finished product.

[0012] Preferably, in step S1, the calculation method for the rectangular corrugated steel frame in the positive bending moment segment is as follows:

[0013] S11, the plastic neutralization axis is within the concrete flange, i.e. hour:

[0014]

[0015]

[0016] Where M is the design value of the positive bending moment, and A is the cross-sectional area of ​​the steel beam. The height of the compression zone of the concrete flange. This is the distance between the resultant stress of the steel beam section and the resultant stress of the concrete compression zone section. This is the design value for the compressive strength of concrete;

[0017] S12, the plastic neutralization axis is within the steel beam section, i.e. hour:

[0018]

[0019]

[0020] in, The cross-sectional area of ​​the compression zone of the steel beam is given. This is the distance from the centroid of the tension zone section of the steel beam to the centroid of the compression zone section of the concrete flange. This is the distance from the centroid of the tension zone section to the centroid of the compression zone section of the steel beam.

[0021] Preferably, in step S1, the rectangular corrugated steel reinforcement uses 60×15mm corrugated steel to replace the outer circumferential reinforcement of the reinforced concrete pipe. The outer circumferential stirrups of the reinforced concrete pipe use HRB400 grade steel bars with a reinforcement ratio of Φ12@50, wherein:

[0022]

[0023]

[0024] The calculation method for rectangular corrugated steel reinforcement is as follows:

[0025]

[0026]

[0027] Thickness is

[0028] Where l is the unfolded length of the rectangular corrugated steel frame.

[0029] Preferably, in step S1, a shot blasting device is used to perform rust removal treatment of Sa2.5 level or above. The shot blasting device has a shot blasting rate of 200kg / min and a shot blasting speed of 70m / s. Then, two coats of epoxy zinc-rich anti-corrosion primer are applied by an automatic spraying device. The total dry film thickness of the epoxy zinc-rich primer is not less than 80μm.

[0030] Preferably, step S2 includes the following steps:

[0031] S21. A CNC three-roll plate rolling machine is used to roll rectangular corrugated steel plates. Before rolling, parameters are input through the CNC system according to the inner diameter of the jacking pipe design to adjust the roller spacing and curvature. The inner diameter error of the rolled cylinder does not exceed ±5mm.

[0032] S22. The pre-treated rectangular corrugated steel plate is smoothly fed into the plate rolling machine. During the rolling process, the deformation of the corrugated structure is monitored in real time by an infrared distance measuring sensor to control the uniform pressure of the rollers. After the rolling is completed, the two ends of the rectangular corrugated steel plate are fixed with the help of a manual hoist so that the two ends are joined to form a cylindrical shape. The alignment deviation of the corrugated grooves at the joint does not exceed 2mm. The roundness of the cylindrical shape is detected by a laser roundness meter to ensure that the roundness error is controlled within ±3mm / m. If it exceeds the error range, it is corrected by a second fine adjustment of the plate rolling machine.

[0033] Preferably, step S3 includes the following steps:

[0034] S31. The joint of the cylindrical cylinder is welded using a double-sided submerged arc welding machine. The welding material is H08MnA welding wire with HJ431 flux. Before welding, an arc-starting plate and an arc-ending plate are set at both ends of the joint. The material of the arc-starting plate and the arc-ending plate is the same as that of the rectangular corrugated steel plate. They are fixed at the joint by manual arc welding.

[0035] S32. When welding, weld the inner weld first, then weld the outer weld. When welding the inner weld, use an inner welding jig for support to prevent welding deformation. After welding, remove the arc-starting plate and the arc-ending plate.

[0036] S33. Ultrasonic testing of welds shall be performed using non-destructive testing equipment to ensure that the weld quality meets the specified weld standards and is free from defects such as porosity, slag inclusions, incomplete penetration, and cracks. Welds that fail the test shall be removed by carbon arc gouging and then re-welded.

[0037] Preferably, step S4 includes the following steps:

[0038] S41. Reinforcing ribs are evenly arranged along the circumferential and axial directions on the inner wall of the welded cylindrical tube. The reinforcing ribs are made of angle steel or channel steel. The spacing of the reinforcing ribs in the circumferential direction is 500-800mm. The number of axial reinforcing ribs is set according to the inner diameter of the cylindrical tube, with no less than 4 ribs per meter of inner diameter. The intersection of the axial reinforcing ribs and the circumferential reinforcing ribs is fixed by welding to form a grid-like reinforcing structure.

[0039] S42. The reinforcing ribs and the inner wall of the cylindrical tube are fixed by manual arc welding with fillet welds. The weld height is not less than 6mm and the welding length of each weld is not less than 90% of the length of the reinforcing rib. After welding, an integrated corrugated steel skeleton is formed.

[0040] S43. Use a penetrant tester to perform penetrant testing on all welds of the corrugated steel frame. After the test is qualified, apply a layer of epoxy zinc-rich primer to the weld for touch-up, with a dry film thickness of not less than 80μm.

[0041] Preferably, step S5 includes the following steps:

[0042] S51. A special balancing hoist is used in conjunction with a bridge crane to hoist the corrugated steel frame into the precast mold. During the hoisting process, a theodolite is used to monitor the verticality of the corrugated steel frame in real time. The corrugated steel frame is placed on the support rollers of the precast mold, and the position of the corrugated steel frame is adjusted by the spiral set screw to make it coaxial with the precast mold. The coaxiality is checked with an inside micrometer, and the coaxiality error does not exceed 2mm.

[0043] S52. Install templates on the inner and outer sides of the corrugated steel frame. The outer template is made of steel template, and the inner template is made of film-coated plywood. The thickness of the concrete pouring layer is reserved between the outer template and the corrugated steel frame. The thickness of the pouring layer is set to 80-150mm according to the design strength of the jacking pipe. The template is fixed by tie bolts and the template joints are sealed with polyurethane sealant.

[0044] S53. After the template is installed, use a level to check the flatness of the template. The flatness error shall not exceed 2mm / m.

[0045] Preferably, the strength grade of the concrete in step S5 is not lower than C50, and the mix proportion is:

[0046] Cement:Sand:Aggregate:Water:Admixture:Mineral admixture = 1:1.8:2.5:0.45:0.015:0.2, with a test slump of 240-260mm, a spread of not less than 600mm, a rated discharge of concrete pump ≥60m³ / h, a vibration frequency of immersion vibrator of 50Hz, and a curing temperature of 5-25℃ and humidity ≥90%.

[0047] A rectangular corrugated steel cylinder concrete jacking pipe is applied to the above-described method for preparing a rectangular corrugated steel cylinder concrete jacking pipe.

[0048] The technical effects and advantages of this invention are as follows:

[0049] (1) This invention introduces a steel and concrete composite beam algorithm to calculate rectangular corrugated steel skeleton, establishes a complete mechanical calculation model, including two working conditions: the plastic neutral axis is in the concrete flange and the steel beam section. It accurately calculates and determines the thickness of the steel plate and steel skeleton, avoids the blindness of traditional design, and makes the steel skeleton structure accurately match the design requirements of the jacking pipe. It saves material usage while ensuring structural strength, and improves the efficiency of steel and concrete co-force.

[0050] (2) This invention uses shot blasting equipment to remove rust at Sa2.5 level or above, with precise parameter control. It innovatively uses automatic spraying equipment to apply two coats of epoxy zinc-rich anti-corrosion primer, with a total dry film thickness of not less than 80μm. The spraying parameters are precisely controlled, and the anti-corrosion system is combined with the subsequent welding process, which extends the service life of the jacking pipe, far exceeding the service life of traditional jacking pipes.

[0051] (3) By using rectangular corrugated steel plates to roll into a circular cylinder, compared with the traditional arc-shaped corrugated steel plate splicing process, there is no need to customize arc-shaped processing molds, which simplifies the plate processing process, improves the utilization rate of raw materials, reduces production costs, and the straight corrugations of the rectangular corrugated steel plates form a ring-shaped strengthening effect after rolling, which improves the circumferential stiffness of the steel cylinder and effectively enhances the deformation resistance of the jacking pipe.

[0052] (4) The present invention uses an integrated corrugated steel skeleton design to weld the cylindrical tube and longitudinal and transverse reinforcing ribs to form an integral load-bearing structure. Compared with the traditional steel reinforcement binding skeleton, the overall structure is improved and the bonding area with concrete is increased, making the synergistic stress effect of steel and concrete better. This allows the jacking pipe to have both the high crack resistance of corrugated steel and the high compressive strength of concrete. Under the same strength requirements, the self-weight of the jacking pipe can be reduced, and the transportation and hoisting costs can be reduced.

[0053] (5) The present invention adopts double-sided submerged arc welding process for the butt joint of the circular cylinder with arc initiation plate and arc termination plate design, and the weld quality meets the standard. Compared with traditional manual electric arc welding, the tensile strength of the weld is improved and the risk of leakage is reduced. Combined with rust removal and anti-corrosion treatment, the corrosion resistance of the jacking pipe is improved and the service life can be extended. The entire preparation process adopts CNC plate rolling machine, automatic spraying equipment, special lifting tool automation and customization equipment, realizing industrial mass production. The production efficiency is improved compared with traditional concrete jacking pipe, and the finished jacking pipe has high dimensional accuracy, stable mechanical properties, and wide applicability. Attached Figure Description

[0054] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0055] Figure 1 This is a diagram illustrating the steps of the method of the present invention;

[0056] Figure 2 This is a cross-section and stress diagram of the composite beam when the plastic neutralization axis of the present invention is inside the concrete flange;

[0057] Figure 3 This is a cross-section and stress diagram of the composite beam when the plastic neutralization axis of the present invention is inside the steel beam;

[0058] Figure 4 This is a diagram of the sinusoidal corrugated plate of the present invention;

[0059] Figure 5 This is a side view of the rectangular corrugated plate structure of the present invention. Detailed Implementation

[0060] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0061] This invention provides, for example Figures 1-5 The present invention illustrates a method for preparing a rectangular corrugated steel cylinder concrete jacking pipe.

[0062] The specific steps include the following:

[0063] S1. Select a rectangular corrugated steel plate of a preset specification, use the steel and concrete composite beam algorithm to calculate the rectangular corrugated steel frame, and perform rust removal and anti-corrosion primer treatment.

[0064] In step S1, the calculation method for the rectangular corrugated steel frame in the section under positive bending moment is as follows:

[0065] S11, the plastic neutralization axis is within the concrete flange, i.e. hour:

[0066]

[0067]

[0068] Where M is the design value of the positive bending moment (N·mm), and A is the cross-sectional area of ​​the steel beam (mm²). 2 ), The height of the compression zone of the concrete flange (mm). It represents the distance (mm) between the resultant stress of the steel beam section and the resultant stress of the concrete compression zone section. Design value of concrete compressive strength (N / mm²) 2 ); and among them , The values ​​are shown in the attached diagram in the instruction manual. Figure 2 As shown;

[0069] S12, the plastic neutralization axis is within the steel beam section, i.e. hour:

[0070]

[0071]

[0072] in, The cross-sectional area of ​​the compression zone of the steel beam is given. This is the distance from the centroid of the tension zone section of the steel beam to the centroid of the compression zone section of the concrete flange. is the distance from the centroid of the tension zone section to the centroid of the compression zone section of the steel beam; and where , The values ​​are shown in the attached diagram in the instruction manual. Figure 3 As shown.

[0073] Calculation of sinusoidal corrugated steel frame: Select a 300×110×3mm waveform, as shown in the attached diagram in the instruction manual. Figure 4 As shown;

[0074]

[0075] The neutral axis is located within the concrete flange.

[0076]

[0077]

[0078]

[0079] Therefore, the thickness of the corrugated steel plate is taken as 3mm.

[0080] In step S1, the rectangular corrugated steel frame uses a 60×15mm waveform, as shown in the attached diagram in the instruction manual. Figure 5 As shown, the outer circumferential reinforcement of the reinforced concrete pipe is replaced. The outer circumferential stirrups of the reinforced concrete pipe are made of HRB400 grade steel bars, with a reinforcement of Φ12@50, wherein:

[0081]

[0082]

[0083] The calculation method for rectangular corrugated steel reinforcement is as follows:

[0084]

[0085]

[0086] The thickness of the steel frame is

[0087] Where l is the unfolded length of the rectangular corrugated steel frame;

[0088] Specifically:

[0089] = =109.5 kN.m

[0090] Calculation of rectangular corrugated steel frame:

[0091] =20.405mm

[0092]

[0093] The unfolded length of the rectangular corrugated steel frame is 1250 mm / m. Rounded down to 1.8mm.

[0094] In step S1, rust removal treatment of Sa2.5 grade or above is performed using a shot blasting equipment with a shot blasting rate of 200kg / min and a blasting speed of 70m / s. Then, two coats of epoxy zinc-rich anti-corrosion primer are applied using an automatic spraying equipment, with a total dry film thickness of not less than 80μm. By introducing the parameter calculation of rectangular corrugated steel frame, the calculation of rectangular corrugated steel frame is determined through targeted calculation, avoiding the blindness of traditional steel frame design, so that the steel frame structure is accurately matched with the design requirements of the jacking pipe. While ensuring structural strength, the material consumption is reduced by 15-20%, while improving the synergistic stress efficiency of steel and concrete by more than 30%. In addition, the setting of rectangular corrugated steel plate can achieve the shielding function of electromagnetic signals generated by cables, and can also replace some of the reinforcing steel bars in reinforced concrete pipes to reduce steel consumption and improve the functionality of rectangular corrugated steel cylinder concrete jacking pipes.

[0095] During the rust removal and anti-corrosion primer treatment, the rust removal is first carried out using shot blasting equipment to achieve a rust removal grade of Sa2.5 or higher, ensuring that the surface of the rectangular corrugated steel plate is free of visible grease, dirt, scale, rust, paint coatings, and other adhering substances, with only slight spotting or streaking marks remaining. Subsequently, two coats of epoxy zinc-rich anti-corrosion primer are applied to the surface using automatic spraying equipment, with a spraying pressure of 0.6-0.8MPa and a spraying speed of 1-2m / min. The dry film thickness of the first primer is not less than 40μm, and the total dry film thickness after the second primer is applied is not less than 80μm. The primer is allowed to cure naturally for more than 24 hours after application.

[0096] S2. The pre-treated rectangular corrugated steel plate is rolled into a cylindrical shape using a plate rolling machine, and the alignment deviation of the corrugated grooves at the joint and the roundness error of the cylindrical shape are controlled.

[0097] Step S2 includes the following steps:

[0098] S21. A CNC three-roll plate rolling machine is used to roll rectangular corrugated steel plates. Before rolling, according to the inner diameter of the jacking pipe (1000-4000mm), parameters are input through the CNC system to adjust the roller spacing and curvature. The inner diameter error of the rolled cylinder does not exceed ±5mm.

[0099] S22. The pre-treated rectangular corrugated steel plate is smoothly fed into the rolling machine. During the rolling process, the deformation of the corrugated structure is monitored in real time by an infrared distance sensor with a measurement accuracy of ±0.1mm. The roller pressure is controlled to be uniform, with a pressure range of 10-20MPa, to prevent the corrugations from being squeezed and deformed. After rolling, a manual hoist is used to help fix the two ends of the rectangular corrugated steel plate so that the two ends are joined to form a cylindrical shape. The alignment deviation of the corrugated grooves at the joint does not exceed 2mm. A laser roundness meter is used to detect the roundness of the cylindrical shape. The measurement range of the laser roundness meter is 500-5000mm, and the measurement accuracy is ±0.01mm, ensuring that the roundness error is controlled within ±3mm / m. If it exceeds the error range, it is corrected by secondary fine adjustment of the rolling machine. Using rectangular corrugated steel plates to roll cylindrical shapes eliminates the need for customized arc molds, increasing the raw material utilization rate from 70% in traditional processes to over 95%, reducing production costs by 20-30%, and the straight corrugations form a ring-shaped reinforcement effect after rolling, increasing the circumferential stiffness of the steel cylinder by more than 35% and enhancing its resistance to deformation.

[0100] S3. Double-sided submerged arc welding is used to weld the butt joint of the cylindrical tubes to ensure the quality of the weld.

[0101] Step S3 includes the following steps:

[0102] S31. The joint of the cylindrical cylinder is welded using a double-sided submerged arc welding machine. The welding material is H08MnA welding wire with HJ431 flux. Before welding, an arc-starting plate and an arc-ending plate are set at both ends of the joint. The material of the arc-starting plate and the arc-ending plate is the same as that of the rectangular corrugated steel plate. They are fixed at the joint by manual arc welding.

[0103] S32. When welding, weld the inner weld first, then weld the outer weld. When welding the inner weld, use an inner welding jig for support to prevent welding deformation. After welding, remove the arc-starting plate and the arc-ending plate.

[0104] S33. Ultrasonic testing of welds is performed using non-destructive testing equipment to ensure that the weld quality meets the specified weld standards, free from defects such as porosity, slag inclusions, incomplete penetration, and cracks. This ensures that the weld quality meets the Class II weld standard specified in GB / T12469-2012. Welds that fail the test must be removed by carbon arc gouging and then re-welded. The butt welds of the circular cylinder adopt double-sided submerged arc welding and arc initiation and termination plate design, achieving Class II weld quality, increasing tensile strength by 20%, and reducing leakage risk by 90%. Combined with Sa2.5 grade rust removal and epoxy zinc-rich primer for corrosion protection, the service life of the jacking pipe is extended to more than 50 years, far exceeding the 30-year service life of traditional jacking pipes.

[0105] S4. Weld reinforcing ribs to the inner wall of the cylindrical tube to form an integrated corrugated steel skeleton, and perform penetrant testing on the weld.

[0106] Step S4 includes the following steps:

[0107] S41. Reinforcing ribs are evenly arranged along the circumference and axial direction on the inner wall of the welded circular cylinder. The reinforcing ribs are made of angle steel or channel steel. The reinforcing ribs are made of angle steel of ∠50×50×5~∠100×100×10 or channel steel of 8~14. The spacing of the reinforcing ribs in the circumference direction is 500-800mm. The number of axial reinforcing ribs is set according to the inner diameter of the circular cylinder, with no less than 4 ribs per meter of inner diameter. The intersection of the axial reinforcing ribs and the circumference reinforcing ribs is fixed by welding to form a grid-like reinforcing structure.

[0108] S42. The reinforcing ribs and the inner wall of the cylindrical tube are fixed by manual arc welding with fillet welds. The weld height is not less than 6mm and the welding length of each weld is not less than 90% of the length of the reinforcing rib. After welding, an integrated corrugated steel skeleton is formed.

[0109] S43. Use a penetrant tester to perform penetrant testing on all welds of the corrugated steel frame. After the test is qualified, apply a layer of epoxy zinc-rich primer to the weld for touch-up, with a dry film thickness of not less than 80μm.

[0110] Through the integrated corrugated steel skeleton design, the circular cylinder is welded with longitudinal and transverse reinforcing ribs to form an integral load-bearing structure. Compared with the traditional steel reinforcement skeleton, the overall structural integrity is improved, and the bonding area with concrete is increased. The overall structural integrity is improved by more than 40%, and the bonding area with concrete is increased by more than 50%, resulting in better synergistic stress-bearing effect between steel and concrete. This allows the jacking pipe to combine the high crack resistance of corrugated steel and the high compressive strength of concrete. The crack width of the high crack resistance is controlled within 0.1mm. Under the same strength requirements, the self-weight of the jacking pipe can be reduced by 15-20%, and the transportation and hoisting costs can be reduced by more than 25%.

[0111] S5. Hoist the corrugated steel frame into the precast mold and adjust its coaxiality. Install the inner and outer templates, pour dense concrete, vibrate in layers, and remove the templates after curing to obtain the finished product.

[0112] Step S5 includes the following steps:

[0113] S51. A special balancing lifting device is used in conjunction with a bridge crane. The special balancing lifting device has 4 lifting points, and the spacing between the lifting points is set according to the length of the corrugated steel frame. The main body of the lifting device is made of Q355B. A 10mm thick rubber buffer pad is set at the lifting point. The corrugated steel frame is lifted into the precast mold. During the lifting process, a theodolite is used to monitor the verticality of the corrugated steel frame in real time. The corrugated steel frame is placed on the support rollers of the precast mold. There are no less than 4 support rollers, which are evenly distributed. The position of the corrugated steel frame is adjusted by the spiral set screw. The adjustment accuracy of the spiral set screw is ±0.5mm to make it coaxial with the precast mold. The coaxiality is checked with an inside micrometer. The coaxiality error does not exceed 2mm. The inside micrometer (measuring range 500-5000mm, accuracy ±0.01mm)

[0114] S52. Install templates on the inner and outer sides of the corrugated steel frame. The outer template is made of steel template, and the inner template is made of film-coated plywood with a thickness of 18mm and a surface film thickness of 0.2mm. A concrete pouring layer is reserved between the outer template and the corrugated steel frame. The pouring layer thickness is set to 80-150mm according to the design strength of the jacking pipe. The template is fixed with tie bolts, and the template joints are sealed with polyurethane sealant.

[0115] S53. After the template is installed, use a level to check the flatness of the template. The flatness error shall not exceed 2mm / m.

[0116] In step S5, the concrete strength grade shall not be lower than C50, and the mix proportion is as follows:

[0117] Cement:Sand:Aggregate:Water:Admixtures:Mineral admixtures = 1:1.8:2.5:0.45:0.015:0.2, wherein the concrete slump is 240-260mm, the spread is not less than 600mm, the rated discharge of the concrete pump is ≥60m³ / h, the vibration frequency of the immersion vibrator is 50Hz, and the curing temperature is 5-25℃ with humidity ≥90%.

[0118] The cement used is P.O42.5 grade ordinary Portland cement, the sand is medium sand with a fineness modulus of 2.3-3.0, the aggregate is 5-25mm continuously graded crushed stone, the admixture is a polycarboxylate-based high-efficiency water-reducing agent with a water reduction rate ≥25%, and the mineral admixture is Grade I fly ash. The inverted cone method for venting takes no more than 20 seconds. Concrete slump gauges and concrete spread gauges are used for on-site testing. The spread gauge has a range of 1000mm and an accuracy of 1mm. A concrete pump is used for layered pouring. The pump has a rated displacement of 60m³ / h and a working pressure of 16MPa. The pouring speed is controlled at 0.5-1m / h, and each layer thickness does not exceed 500mm. An immersion vibrator is used for compaction during pouring. The vibration frequency of the immersion vibrator is 50Hz, the amplitude is 1.8mm, and the spacing between vibration points does not exceed 300mm. The vibration of each vibration point... The compaction time is 20-30 seconds, until the concrete surface is covered with slurry and no air bubbles overflow. The vibrator should not be inserted more than 50mm into the previous layer of concrete and should not touch the corrugated steel frame and formwork. After pouring, cover the concrete surface with geotextile and water for curing. The geotextile has a unit area mass of 300g / ㎡. Use a constant temperature and humidity curing shed to control the curing environment. The temperature control range of the constant temperature and humidity curing shed is 5-25℃, and the humidity control range is ≥90%. The curing time is not less than 14 days. Water should be sprayed no less than 4 times a day for the first 7 days and no less than 2 times a day for the next 7 days. During the curing period, the concrete strength should be tested regularly with a concrete rebound hammer. The concrete rebound hammer has a measurement range of 10-60MPa. When the concrete strength reaches more than 75% of the design strength, the formwork can be removed. After removing the formwork, continue curing for 14 days to obtain the finished rectangular corrugated steel cylinder concrete jacking pipe.

[0119] After the finished pipe jacking is cured, its appearance quality, dimensional deviation, and mechanical properties are inspected. Appearance quality is assessed visually combined with weld gauge inspection, requiring the surface to be free of exposed reinforcement, honeycombing, holes, cracks, and other defects, and the welds to be smooth without obvious protrusions. Dimensional deviation is inspected using a laser rangefinder and a roundness meter. The laser rangefinder has a measuring range of 0.05-150m, an accuracy of ±1mm, an inner diameter error not exceeding ±5mm, a roundness error not exceeding ±3mm / m, and a length error not exceeding ±10mm. For mechanical property testing, 3% of the finished product is randomly selected for compressive strength and impermeability tests. The compressive strength test uses a pressure testing machine with a maximum test force of 2000kN and an accuracy of ±1%. The impermeability test uses a concrete impermeability meter with a maximum working pressure of 4MPa. The compressive strength must be no less than 115% of the design strength, and the impermeability grade must be no less than P8.

[0120] The entire manufacturing process utilizes automated and customized equipment such as CNC plate rolling machines, automatic spraying equipment, and specialized lifting tools, enabling industrialized mass production. This increases production efficiency by more than 30% compared to traditional concrete jacking pipes, reducing the production cycle of a single jacking pipe section from 48 hours in the traditional process to less than 32 hours. Furthermore, the finished jacking pipes exhibit high dimensional accuracy and stable mechanical properties, with an inner diameter error of ±5mm and a roundness error of ±3mm / m. The compressive strength variation coefficient is ≤5%, making the finished products suitable for large-span, high-pressure underground engineering scenarios, especially adaptable to complex geological conditions such as soft soil strata and high groundwater pressure.

[0121] The rectangular corrugated steel plates used are standardized industrial products with a wide range of procurement channels. Compared with customized arc-shaped corrugated steel plates, the raw material cost is reduced by 15-20%. At the same time, the integrated corrugated steel skeleton replaces the traditional steel skeleton, reducing the steel binding process and saving more than 30% of steel usage, further reducing the preparation cost of the jacking pipe and showing obvious economic advantages.

[0122] A rectangular corrugated steel cylinder concrete jacking pipe is applied to the above-described method for preparing a rectangular corrugated steel cylinder concrete jacking pipe.

[0123] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a rectangular corrugated steel cylinder concrete jacking pipe, characterized in that, The specific steps include the following: S1. Select a rectangular corrugated steel plate of a preset specification, use the steel and concrete composite beam algorithm to calculate the rectangular corrugated steel frame, and perform rust removal and anti-corrosion primer treatment. S2. The pre-treated rectangular corrugated steel plate is rolled into a cylindrical shape using a plate rolling machine, and the alignment deviation of the corrugated grooves at the joint and the roundness error of the cylindrical shape are controlled. S3. Double-sided submerged arc welding is used to weld the joint of the cylindrical tubes to ensure the quality of the weld. S4. Weld reinforcing ribs to the inner wall of the cylindrical tube to form an integrated corrugated steel skeleton, and perform penetrant testing on the weld. S5. Hoist the corrugated steel frame into the precast mold and adjust its coaxiality. Install the inner and outer templates, pour dense concrete, vibrate in layers, and remove the templates after curing to obtain the finished product.

2. The method for preparing a rectangular corrugated steel cylinder concrete jacking pipe according to claim 1, characterized in that, In step S1, the calculation method for the rectangular corrugated steel frame in the positive bending moment segment is as follows: S11, the plastic neutralization axis is within the concrete flange, i.e. hour: Where M is the design value of the positive bending moment, and A is the cross-sectional area of ​​the steel beam. The height of the compression zone of the concrete flange. This is the distance between the resultant stress of the steel beam section and the resultant stress of the concrete compression zone section. This is the design value for the compressive strength of concrete; S12, the plastic neutralization axis is within the steel beam section, i.e. hour: in, The cross-sectional area of ​​the compression zone of the steel beam is given. This is the distance from the centroid of the tension zone section of the steel beam to the centroid of the compression zone section of the concrete flange. This is the distance from the centroid of the tension zone section to the centroid of the compression zone section of the steel beam.

3. The method for preparing a rectangular corrugated steel cylinder concrete jacking pipe according to claim 1, characterized in that, In step S1, the rectangular corrugated steel reinforcement uses 60×15mm diameter steel bars to replace the outer circumferential reinforcement of the reinforced concrete pipe. The outer circumferential stirrups of the reinforced concrete pipe use HRB400 grade steel bars with a reinforcement ratio of Φ12@50, wherein: The calculation method for rectangular corrugated steel reinforcement is as follows: Thickness is Where l is the unfolded length of the rectangular corrugated steel frame.

4. The method for preparing a rectangular corrugated steel cylinder concrete jacking pipe according to claim 1, characterized in that, In step S1, a shot blasting device is used to perform rust removal treatment of Sa2.5 grade or above. The shot blasting device has a shot blasting rate of 200kg / min and a shot blasting speed of 70m / s. Then, two coats of epoxy zinc-rich anti-corrosion primer are applied by an automatic spraying device. The total dry film thickness of the epoxy zinc-rich primer is not less than 80μm.

5. The method for preparing a rectangular corrugated steel cylinder concrete jacking pipe according to claim 1, characterized in that, Step S2 includes the following steps: S21. A CNC three-roll plate rolling machine is used to roll rectangular corrugated steel plates. Before rolling, parameters are input through the CNC system according to the inner diameter of the jacking pipe design to adjust the roller spacing and curvature. The inner diameter error of the rolled cylinder does not exceed ±5mm. S22. The pre-treated rectangular corrugated steel plate is smoothly fed into the plate rolling machine. During the rolling process, the deformation of the corrugated structure is monitored in real time by an infrared distance measuring sensor to control the uniform pressure of the rollers. After the rolling is completed, the two ends of the rectangular corrugated steel plate are fixed with the help of a manual hoist so that the two ends are joined to form a cylindrical shape. The alignment deviation of the corrugated grooves at the joint does not exceed 2mm. The roundness of the cylindrical shape is detected by a laser roundness meter to ensure that the roundness error is controlled within ±3mm / m. If it exceeds the error range, it is corrected by a second fine adjustment of the plate rolling machine.

6. The method for preparing a rectangular corrugated steel cylinder concrete jacking pipe according to claim 1, characterized in that, Step S3 includes the following steps: S31. The joint of the cylindrical cylinder is welded using a double-sided submerged arc welding machine. The welding material is H08MnA welding wire with HJ431 flux. Before welding, an arc-starting plate and an arc-ending plate are set at both ends of the joint. The material of the arc-starting plate and the arc-ending plate is the same as that of the rectangular corrugated steel plate. They are fixed at the joint by manual arc welding. S32. When welding, weld the inner weld first, then weld the outer weld. Use an inner welding jig for support during inner weld welding to prevent welding deformation. After welding, remove the arc-starting plate and arc-ending plate. S33. Ultrasonic testing of welds shall be performed using non-destructive testing equipment to ensure that the weld quality meets the specified weld standards and is free from defects such as porosity, slag inclusions, incomplete penetration, and cracks. Welds that fail the test shall be removed by carbon arc gouging and then re-welded.

7. The method for preparing a rectangular corrugated steel cylinder concrete jacking pipe according to claim 1, characterized in that, Step S4 includes the following steps: S41. Reinforcing ribs are evenly arranged along the circumferential and axial directions on the inner wall of the welded cylindrical tube. The reinforcing ribs are made of angle steel or channel steel. The spacing of the reinforcing ribs in the circumferential direction is 500-800mm. The number of axial reinforcing ribs is set according to the inner diameter of the cylindrical tube, with no less than 4 ribs per meter of inner diameter. The intersection of the axial reinforcing ribs and the circumferential reinforcing ribs is fixed by welding to form a grid-like reinforcing structure. S42. The reinforcing ribs and the inner wall of the cylindrical tube are fixed by manual arc welding with fillet welds. The weld height is not less than 6mm and the welding length of each weld is not less than 90% of the length of the reinforcing rib. After welding, an integrated corrugated steel skeleton is formed. S43. Use a penetrant tester to perform penetrant testing on all welds of the corrugated steel frame. After the test is qualified, apply a layer of epoxy zinc-rich primer to the weld for touch-up, with a dry film thickness of not less than 80μm.

8. The method for preparing a rectangular corrugated steel cylinder concrete jacking pipe according to claim 1, characterized in that, Step S5 includes the following steps: S51. A special balancing hoist is used in conjunction with a bridge crane to hoist the corrugated steel frame into the precast mold. During the hoisting process, a theodolite is used to monitor the verticality of the corrugated steel frame in real time. The corrugated steel frame is placed on the support rollers of the precast mold, and the position of the corrugated steel frame is adjusted by the spiral set screw to make it coaxial with the precast mold. The coaxiality is checked with an inside micrometer, and the coaxiality error does not exceed 2mm. S52. Install templates on the inner and outer sides of the corrugated steel frame. The outer template is made of steel template, and the inner template is made of film-coated plywood. The thickness of the concrete pouring layer is reserved between the outer template and the corrugated steel frame. The thickness of the pouring layer is set to 80-150mm according to the design strength of the jacking pipe. The template is fixed by tie bolts and the template joints are sealed with polyurethane sealant. S53. After the template is installed, use a level to check the flatness of the template. The flatness error shall not exceed 2mm / m.

9. The method for preparing a rectangular corrugated steel cylinder concrete jacking pipe according to claim 1, characterized in that, The concrete strength grade in step S5 is not lower than C50, and the mix proportion is: Cement:Sand:Aggregate:Water:Admixture:Mineral admixture = 1:1.8:2.5:0.45:0.015:0.2, with a test slump of 240-260mm, a spread of not less than 600mm, a rated discharge of concrete pump ≥60m³ / h, a vibration frequency of immersion vibrator of 50Hz, and a curing temperature of 5-25℃ and humidity ≥90%.

10. A rectangular corrugated steel cylinder concrete jacking pipe, applied to the preparation method of a rectangular corrugated steel cylinder concrete jacking pipe as described in any one of claims 1-9.

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