PCCP (prestressed concrete cylinder pipe) reelable steel plate reinforcing equipment

Abstract

The invention relates to the field of pipe reinforcement, in particular to PCCP reelable steel plate reinforcement equipment. The PCCP reelable steel plate reinforcing equipment comprises a concrete pipe body. A plurality of stiffening rings and a plurality of reelable steel plates are mounted in the concrete pipe body at positions corresponding to broken wires or cracks, and the mounted reelable steel plates are cylindrical; the reelable steel plate is wound and unfolded through an intelligent steel cylinder transport vehicle and transported to the position where wire breakage or cracks exist along the end opening of the concrete pipe body, and the maximum diameter length of the reelable steel plate obtained after winding is smaller than the inner diameter of the concrete pipe body. The unfolded reelable steel plate is attached to the inner wall of the stiffening ring, and a grouting layer is formed between the reelable steel plate and the stiffening ring. According to the PCCP reelable steel plate reinforcing equipment provided by the invention, a pipeline is more convenient to repair and reinforce, meanwhile, the repairing and reinforcing quality is higher, the maintenance and replacement cost is reduced, the water delivery efficiency is improved, the water supply safety is guaranteed, and the environmental influence is reduced.

Description

Technical Field

[0001] The present invention relates to the field of pipe reinforcement, and in particular to PCCP rollable steel plate reinforcement equipment. Background Art

[0002] According to the structural characteristics of PCCP pipelines, the current repair and reinforcement methods for PCCP with broken wires mainly include prestressed steel ring reinforcement, carbon fiber reinforcement inside the pipe, and pipeline excavation and replacement.

[0003] The prestressed external reinforcement process requires the entire line to be shut down and drained, and the construction excavation area is large, which may involve land occupation; the implementation of carbon fiber reinforcement inside the pipe does not require excavation, and has less impact on the surrounding environment. Although this technology can be used to implement repair and reinforcement without interrupting water supply (single-line water shutdown); however, for pipe sections with large-scale broken wires (when the broken wire rate of pipe sections exceeds 50%) and cracked pipe sections, the reinforcement effect needs to be demonstrated and tested; the implementation effect of pipe section excavation and replacement is the most direct, but the construction project requires the entire line to be shut down and drained, and the excavation of pipe sections has a greater impact on the surrounding environment; there is a land occupation problem.

[0004] The three broken wire pipe repair and reinforcement technologies, namely prestressed steel ring reinforcement, carbon fiber reinforcement inside the pipe, and pipeline excavation and replacement, have limitations and cannot simultaneously meet the requirements of broken wire pipe repair and reinforcement without interrupting water supply (single-line water outage), without excavation, and without large-scale broken wire pipe sections and cracked pipe sections.

[0005] To address this issue, PCCP rollable steel plate reinforcement technology can ensure uninterrupted water supply (single-line water outages) and maintain normal water supply during project maintenance. This technology requires no excavation and has minimal impact on the surrounding environment. Lining with rollable steel pipe significantly improves the overall structural strength of the PCCP pipeline, making it more resistant to external loads and internal pressures. It can also repair and reinforce large-scale broken and cracked pipe sections, completely resolving structural safety issues.

[0006] Traditional PCCP rollable steel plate reinforcement technologies include PCCP rollable steel plate lining bonded steel reinforcement technology, PCCP rollable steel plate bolt reinforcement technology, and PCCP rollable steel plate L-shaped equal-angle steel reinforcement technology. However, bonded steel reinforcement technology has certain requirements for the temperature and humidity of the construction environment. It is necessary to ensure that the construction environment temperature and humidity are appropriate to ensure the curing effect and bonding quality of the structural adhesive. If the construction environment does not meet the requirements, it is necessary to ensure the flatness and density of the steel plate bonding, as well as the uniformity of the structural adhesive application. The reinforcement effect of bonded steel reinforcement technology is affected by many factors, such as the steel plate material, thickness, structural adhesive properties, construction process, etc. If these factors are not properly controlled, the reinforcement effect may be affected. While bonded steel reinforcement technology offers numerous advantages, it also has limitations. The gaps between the bonded steel and the PCCP pipe cannot be filled, preventing the bonded steel and PCCP pipe from forming a single unit and bearing joint forces. The stability of this technology needs further optimization. PCCP rollable steel plate bolt reinforcement technology carries the risk of damaging the PCCP pipe. The drilling and bolt installation process may cause damage to the pipe steel plate, compromising the structural stability of the entire PCCP pipe segment. Furthermore, the bolts need to be punched and welded to the inner lining steel plate, leaving gaps in the weld seam, making it impossible to ensure airtightness. This can easily lead to instability in the bolted and welded steel plate during water delivery, posing certain safety concerns. PCCP rollable steel plate L-shaped equal-angle steel reinforcement technology can adapt to the internal spaces of PCCP pipes of varying specifications and shapes, providing customized reinforcement solutions. Compared to other reinforcement methods, steel plate reinforcement has a relatively simple construction process and does not require complex machinery and equipment, reducing the difficulty, complexity, and time costs of on-site construction. While the initial investment may be higher, the high strength and durability of steel plates, as well as reduced maintenance and replacement costs, may offer better long-term economic benefits. This reinforcement solution also has disadvantages such as heavy weight, difficult installation, high corrosion protection requirements, low technical maturity, and high cost.

[0007] Therefore, it is necessary to provide a new PCCP rollable steel plate reinforcement equipment to solve the above technical problems. Summary of the Invention

[0008] In order to solve the above technical problems, the present invention provides a PCCP rollable steel plate reinforcement equipment.

[0009] The PCCP rollable steel plate reinforcement equipment provided by the present invention includes a concrete pipe body;

[0010] A plurality of stiffening rings and a plurality of rollable steel plates are installed at locations corresponding to broken wires or cracks inside the concrete pipe body, and the rollable steel plates are cylindrical after installation;

[0011] The rollable steel plate is wound and unfolded by a steel drum intelligent transport vehicle and transported along the port of the concrete pipe body to the location where the wire breakage or cracks are present. The maximum diameter of the rolled steel plate is smaller than the inner diameter of the concrete pipe body, so that the rollable steel plate does not contact or scratch the inner wall of the concrete pipe body during transportation. The unfolded rollable steel plate is attached to the inner wall of the stiffening ring, forming a grouting layer between the two, and the grouting is filled to eliminate the gap between the concrete pipe body and the rollable steel plate.

[0012] After the rollable steel plates are laid, a welding device is inserted along the end of the concrete pipe body to weld the longitudinal seams on the cylindrical rollable steel plates and the circumferential seams between adjacent rollable steel plates.

[0013] Preferably, the concrete pipe body includes a steel cylinder located in the middle layer, and the inner and outer layers of the steel cylinder respectively have an inner core concrete layer and an outer core concrete layer. Prestressed steel wire and mortar protective layer are arranged outside the outer core concrete layer, and the surface of the prestressed steel wire and mortar protective layer is coated with an epoxy asphalt coating.

[0014] Preferably, local cutting is performed at the broken wire or crack of the concrete pipe body, and a spigot steel ring and a socket steel ring are installed at the cut-off portion. The spigot steel ring and the socket steel ring are in close contact with each other, and a rubber ring is provided between the two for sealing.

[0015] Preferably, the steel tube intelligent transport vehicle includes a vehicle body, which is a pipeline walking trolley. At least three groups of annularly distributed hydraulic rods are installed at the feed end of the vehicle body, and the telescopic ends of the hydraulic rods are fixed with automatic clamps for clamping rollable steel plates.

[0016] Preferably, the plurality of hydraulic rods are mounted on a rotatable shaft, and the rotation of the shaft can drive the plurality of hydraulic rods to rotate in a circular motion, thereby realizing the winding and releasing of the rollable steel plate.

[0017] Preferably, three groups of annularly distributed grouting ports are provided on the rollable steel plate, and the grouting ports are connected to the grouting layer.

[0018] Preferably, an automatic track can be laid inside the concrete pipe body along the port of the concrete pipe body;

[0019] When performing longitudinal seam welding of the rollable steel plate, longitudinal seam submerged arc automatic welding equipment is used, and when performing circumferential seam welding of the rollable steel plate, circumferential seam CO2 shielded automatic welding equipment is used.

[0020] Preferably, the longitudinal seams between adjacent rollable steel plates are staggered.

[0021] A PCCP rollable steel plate reinforcement method, comprising:

[0022] S1: Evaluate the PCCP pipeline's wire breakage rate, cracks, and other damage conditions, determine the pipe sections that require reinforcement, and then prepare reinforcement materials, namely prefabricated rollable steel plates (Q355 material, inner diameter 3900mm, wall thickness 15mm) and stiffening rings (height 119mm, thickness 20mm);

[0023] S2: Mark the locations of the stiffening rings on the inner wall of the PCCP (at intervals of 1600 mm), excavate the concrete core (depth ≤ 50 mm), and expose the original steel cylinder. The stiffening rings are then welded to the inner wall of the PCCP steel cylinder and the weld quality is inspected (no cracks or pores).

[0024] S3: Use the steel drum intelligent transport vehicle to transport the rolled steel plate in sections to the repair location, extend the hydraulic rod and release the automatic clamp to display the rollable steel plate, so that the steel plate unfolds and forms a cylindrical steel drum along the inner wall of the pipeline;

[0025] S4: Use longitudinal seam submerged arc automatic welding equipment to weld the longitudinal seam formed by coiling the coiled steel plate, and use circumferential seam CO2 shielded automatic welding equipment to weld the circumferential seam between adjacent coiled steel plates;

[0026] S5: Install closed-cell foam board between the PCCP original pipe and the inner lining steel cylinder to form a grouting layer. Then, pour slightly expansive cement mortar (pressure 0.3-0.5MPa) from the bottom grouting port. The top grouting port serves as an air outlet and is sealed after the slurry overflows to ensure dense filling (density ≥ 95%).

[0027] S6: Use ultrasonic testing (UT) or radiographic testing (RT) to inspect welds, and use ultrasonic testing to inspect grouting density.

[0028] Compared with related technologies, the PCCP rollable steel plate reinforcement equipment provided by the present invention has the following beneficial effects:

[0029] It is more convenient to repair and reinforce pipelines, and the quality of repair and reinforcement is higher, which reduces maintenance and replacement costs, improves water transmission efficiency, ensures water supply safety, and reduces environmental impact. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a structural schematic diagram of the cross section of the steel cylinder after the rollable steel plate provided by the present invention is unfolded and welded;

[0031] Figure 2 This is a schematic diagram of the structure of the rollable steel plate installation shown in the present invention;

[0032] Figure 3 This is a schematic diagram of the structure of the distributed installation of the reinforcement rings shown in the present invention;

[0033] Figure 4This is a schematic structural diagram of the reinforcement ring and the rollable steel plate shown in the present invention;

[0034] Figure 5 This is a schematic structural diagram of the rollable steel plate longitudinal seam welding shown in the present invention;

[0035] Figure 6 This is a structural schematic diagram of the rollable steel plate girth welding shown in the present invention.

[0036] Numbers in the figure: 1. Concrete pipe body; 11. Epoxy asphalt coating; 12. Prestressed steel wire and mortar protective layer; 13. Outer concrete layer of pipe core; 14. Steel cylinder; 15. Inner concrete layer of pipe core; 16. Socket steel ring; 17. Socket steel ring; 2. Rollable steel plate; 3. Steel cylinder intelligent transport vehicle; 31. Vehicle body; 32. Hydraulic rod; 33. Automatic clamp; 4. Stiffening ring; 5. Grouting layer; 6. Grouting port; 7. Longitudinal seam submerged arc automatic welding equipment; 71. Automatic track; 8. Circumferential seam CO2 protection automatic welding equipment. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0038] The specific implementation of the present invention is described in detail below with reference to specific embodiments.

[0039] See also Figures 1 to 6 The embodiment of the present invention provides a PCCP rollable steel plate reinforcement device, which includes a concrete pipe body 1, the concrete pipe body 1 including a steel cylinder 14 located in the middle layer, an inner core concrete layer 15 and an outer core concrete layer 13 respectively arranged in the inner and outer layers of the steel cylinder 14, and a prestressed steel wire and mortar protective layer 12 arranged outside the outer core concrete 13, and the surface of the prestressed steel wire and mortar protective layer 12 is coated with an epoxy asphalt coating 11;

[0040] A plurality of reinforcing rings 4 and a plurality of rollable steel plates 2 are installed at locations corresponding to broken wires or cracks inside the concrete pipe body 1. The rollable steel plates 2 are cylindrical after installation. Three groups of annular grouting ports 6 are opened on the rollable steel plates 2. The grouting ports 6 are connected to the grouting layer 5.

[0041] The rollable steel plate 2 is wound and unwound by the steel drum intelligent transport vehicle 3 and transported along the end of the concrete pipe body 1 to the location where the wire is broken or cracked. The maximum diameter of the rolled steel plate 2 is smaller than the inner diameter of the concrete pipe body 1, so that the rollable steel plate 2 does not contact or scratch the inner wall of the concrete pipe body 1 during transportation. The unwound rollable steel plate 2 is attached to the inner wall of the stiffening ring 4, and a grouting layer 5 is formed between the two. The grouting layer is then filled to eliminate the gap between the concrete pipe body 1 and the rollable steel plate 2.

[0042] After the rollable steel plate 2 is laid, the welding device is inserted along the end of the concrete pipe body 1 to weld the longitudinal seams on the cylindrical rollable steel plate 2 and the circumferential seams between adjacent rollable steel plates 2;

[0043] An automatic track 71 can be laid inside the concrete pipe body along the end of the concrete pipe body 1;

[0044] When welding the longitudinal seam of the rollable steel plate 2, a longitudinal seam submerged arc automatic welding device 7 is used. When welding the circumferential seam of the rollable steel plate 2, a circumferential seam CO2 shielded automatic welding device 8 is used.

[0045] The longitudinal seams between adjacent rollable steel plates 2 are staggered.

[0046] It should be noted that, based on the premise that the PCCP can withstand external pressure but not internal pressure, a low-alloy, high-strength steel plate (Q355) rolled steel pipe is designed to strengthen the pipe's internal water pressure. The steel pipe surface is sandblasted to remove rust and then sprayed with epoxy white ceramic paint for good corrosion resistance and low surface roughness to ensure the pipe's durability and flow rate. At the same time, considering minimizing the flow area within the PCCP pipe and improving the rigidity and stability of the composite structure, a PCCP + lining + PCCP rollable steel plate steel cylinder structure was determined for this study.

[0047] The length of the rollable steel tube depends on the curvature radius and angle of the horizontal and vertical elbows in the PCCP pipeline. It is also related to the transport capacity, climbing ability, turning radius of the transport vehicle, and the transport vehicle's ability to control the opening of the rollable steel tube.

[0048] Analysis of PCCPDE4000 rollable steel plate and steel tube structure

[0049] 1. Basic design parameters

[0050] (1) Steel grade Q355C, elastic modulus E = 206000N / mm 2 , yield strength σ s =355MPa.

[0051] (2) Poisson’s ratio of steel μ = 0.3.

[0052] (3) Bulk density of steel γ s =0.0000785N / mm 2 .

[0053] (4) Bulk density of water γ s =0.0000098N / mm 2 .

[0054] (5) DN4000PCCP rollable steel plate steel cylinder inner diameter D i =3900mm.

[0055] (6) The inclination angle of the steel pipe axis is α = 90°.

[0056] (7) For the fixed spacing of steel pipes, take the length of two PCCP sections, L = 10000mm.

[0057] (8) The spacing between stiffening rings is L = 1600 mm.

[0058] (9) Height of stiffening ring h = 119 mm.

[0059] (10) Thickness of stiffening ring a = 20 mm.

[0060] (11) Weld coefficient Ψ = 0.95.

[0061] (12) The internal water pressure at the center of the designed cross-section pipe is H = 102040 mm, and the internal water pressure is P = 1.0 MPa.

[0062] 2. Determination of the inner diameter of the PCCP rollable steel plate cylinder

[0063] (1) Calculate the inner diameter of the PCCP rollable steel plate cylinder using the Hazen-Williams formula

[0064] Q=0.432C h D o 2.63 (h L / L) 0.54

[0065] Where: Q-pipeline flow, assumed to be constant here.

[0066] C h =139.3+2.028d

[0067] D o - The inner diameter of the pipe is 4m for PCCP.

[0068] h L -Head loss. h L =3.021(L / D o1.167 )(V / C k ) 1.852 , V velocity is a constant, assuming 3.021×L 1.167 ×V 1.582 =m,h L =m(1 / D o 1.167 )(1 / C k 1.852 )

[0069] L - pipeline length, which is assumed to be constant.

[0070] C k -Roughness coefficient: PCCP takes 0.0115, and steel pipe takes 0.01.

[0071] 0.432×(139.3+2.028×4) 2.63 (m×(1 / 4 1.167 )×(1 / 0.0115 1.852 ) / L) 0.54

[0072] =0.432×(139.3+2.028×D i ) 2.63 (m×(1 / D i 1.167 )×(1 / 0.0115 1.852 ) / L) 0.54

[0073] Simplify: D i 1.99982 =13.90942

[0074] Calculate the inner diameter D of the steel pipe i =3.73(m)

[0075] Assuming the inner diameter of the steel pipe D i =3.9(m), which can better meet the flow rate requirements.

[0076] (2) After the PCCP is reinforced with rollable steel plates and steel tubes, the pipe diameter is reduced, resulting in the maximum thrust generated by water pressure.

[0077] F=SP

[0078] Where: S-the area of pipe diameter reduction after rollable steel plate steel tube reinforcement, S=0.25π(D o -D i ) 2 , m 2 .

[0079] P-design pressure, calculated according to the maximum pressure of the entire pipeline, = working pressure + instantaneous pressure, P = 1.0 + 0.4 = 1.4 MPa.

[0080] F=SP=1.4×0.25×π×(4-3.9) 2 =868.65(kN)

[0081] (3) The maximum thrust that a single section of DN4000PCCP direct buried pipe can withstand is calculated based on the shallowest soil cover of 2m.

[0082] f=L1H s γ s ν+(H s γ s +G 管 +G 水 )ν

[0083] Where: H s - The soil cover on the top of DN4000PCCP pipe is 2m.

[0084] γ s - The soil density of DN4000PCCP pipe top is 18kN / m 2 .

[0085] G 管 -The weight of a single section of DN4000PCCP pipe is 700kN.

[0086] G 水 - Water weight in single DN4000PCCP pipe, G 水 =0.25×π×3.9 2 ×5×10=597.3kN.

[0087] ν - friction coefficient, take 0.3.

[0088] L1 - Double 0PCCP length, take 10

[0089] f=10×18×0.3+(10×18+700+597.3)×0.3

[0090] =994.38≥868.85(kN)

[0091] Therefore, DN4000PCCP will not produce axial and radial offset

[0092] 3. Calculation of pipe wall thickness

[0093] (1) Preliminary estimate of tube wall thickness according to GB150 boiler formula,

[0094]

[0095] [σ]=0.55σ s

[0096] Table 5-1 Preliminary Estimation Calculation Table for Steel Pipe Wall Thickness t

[0097]

[0098] Take the calculated pipe wall thickness t = 13mm.

[0099] Taking into account the 2mm corrosion allowance, the pipe wall structure thickness is initially determined to be t=15mm.

[0100] (2) Whether the thickness of the pipe wall structure meets the minimum requirements of process, installation and transportation to ensure the rigidity:

[0101] t≥D i / 800+4=3900 / 800+4=8.875mm

[0102] (3) The actual selected pipe wall thickness is t = 15mm, which meets the process, installation and transportation requirements and ensures the minimum stiffness requirement.

[0103] 4. Calculation of stiffening ring parameters

[0104] (1) The inverse k of the equivalent flange of the pipe wall (on one side)

[0105]

[0106] Table 5-2 Calculation table of equivalent flange of pipe wall

[0107] r(mm) t(mm) K(1 / m) 1950 13 0.008

[0108] (3) Net area of stiffening ring ARo

[0109] A Ro =a(h+t)

[0110] Table 5-3 Calculation table of net area of stiffening ring ARo

[0111] a(mm) h(mm) t(mm) ARo(mm2) 20 119 13 2640

[0112] (4) Effective area of stiffening ring AR

[0113]

[0114] Table 5-4 Calculation table of effective area AR of stiffening ring

[0115] a(mm) h(mm) K(1 / m) t(mm) AR(mm2) 20 119 0.008 13 5890

[0116] (5) The effective area of the stiffening ring is measured from the centroid axis to the center of the pipe. k

[0117]

[0118] Table 5-5 Calculation table of the distance rk from the effective section centroid axis of the stiffening ring to the pipe center

[0119] a(mm) h(mm) K(1 / m) t(mm) r(mm) <![CDATA[rk(mm 2 )]]> 20 119 0.008 13 1950 1983.169

[0120] (6) Distance parameters y1, y2

[0121]

[0122] y2=r k -(r+t)

[0123] Table 5-6 Distance parameter y1, y2 calculation table

[0124] h(mm) t(mm) r(mm) rk(mm) y1(mm) y2(mm2) 119 13 1950 1983.19 39.331 20.169

[0125] (7) Effective section moment of inertia of stiffening ring J k

[0126]

[0127] Table 5-7 Calculation table of effective section inertia moment Jk of stiffening ring

[0128] h(mm) a(mm) k t(mm) y1(mm) <![CDATA[y2(mm 2 )]]> <![CDATA[Jk(mm 4 )]]> 119 20 0.08 13 39.331 20.169 9036155

[0129] (8) Ratio of the net cross-section of the stiffening ring to the effective cross-sectional area (relative stiffness coefficient) β

[0130]

[0131] Table 5-8 Calculation table of effective section inertia moment Jk of stiffening ring

[0132] a(mm) t(mm) ARO AR β 20 13 2640 5890 0.404

[0133] (9) Calculation of axial force ∑A

[0134] (a) Force perpendicular to the tube axis (normal force)

[0135] The weight of two DN4000PCCP steel pipes is Q S =q s Lcosα.

[0136] The weight of the steel pipe per unit length, taking into account the accessories such as stiffening rings, the additional weight is 25% of the weight of the steel pipe, q s =1.25πD i tγ s

[0137] Table 5-9 Calculation table of steel pipe self-weight component force Qs

[0138] <![CDATA[D i (mm)]]> t(mm) γs α L <![CDATA[qs(N / mm 2 )]]> Qs(N) 3900 15 0.0000785 45° 10000 18.034 127520

[0139] (PCCP rollable steel plate reinforcement equipment), water weight component Qw in steel pipe

[0140] Two sections of DN4000PCCP long steel pipe with water weight Q w =q w Lcosα.

[0141] The weight of water per unit length of steel pipe,

[0142] Table 5-10 Calculation table of steel pipe self-weight component force Qs

[0143] Di (mm) γw α L qw(N / mm2) Qw(N) 3900 0.0000098 45° 10000 117.07 827810

[0144] (c) Axial force ∑A

[0145] (i) Axial force A1 due to the deadweight of the steel pipe.

[0146] A1=q s L3sinα

[0147] Where: L3 is the length of the steel pipe at the reduced section, which is 10000mm.

[0148] Table 5-11 Calculation table of axial force component A1 of steel pipe deadweight

[0149] α L3 qs(N / mm2) A1(N) 45° 10000 18.034 127520

[0150] (ii) After the rollable steel plate steel tube is reinforced, the axial force A2 is generated by the reduction of the tube diameter.

[0151] After the rollable steel plate and steel tube are reinforced, the axial force A2 generated by the reduction of the tube diameter has been calculated in Section 1.1, A2 = F = 868650 (N).

[0152] (d) Axial force ΣA = A1 + A2 = 127520 + 868650 = 996170 (N).

[0153] (10) Calculation of cross-sectional stress of the stiffening ring and its side pipe wall.

[0154] (a) Circumferential stress σ generated by radial water pressure P in the pipe wall θ2 ;

[0155]

[0156] Table 5-12 Effective section moment of inertia J of stiffening ring k Calculation table

[0157]

[0158] (PCCP rollable steel plate reinforcement equipment), the axial stress σx1 (tensile stress is positive) generated by the axial force ∑A on the cross section.

[0159]

[0160] Table 5-13 Calculation table of axial stress σx1 of stiffening ring and its side pipe

[0161] ∑A t(mm) r(mm) σX1(N / mm2) 996170 13 1 -6.254

[0162] (c) Axial stress σx2 generated by the normal force on the cross section.

[0163]

[0164] Table 1-13 Calculation table of axial stress σx2 of stiffening ring and its side pipe

[0165]

[0166] (d) Axial stress σx3 generated by local constraint of the stiffening ring.

[0167]

[0168] Table 5-14 Calculation table of axial stress σx3 of stiffening ring and its side pipe

[0169] β t(mm) r(mm) P (MPa) <![CDATA[σX1(N / mm 2 )]]> 0.404 13 1950 1 110.049

[0170] (e) Radial stress σr generated by internal water pressure P on the inner edge of the pipe wall

[0171] σ r =-P=-γ w (Hr cosθcosα)

[0172] Table 5-15 Calculation table of axial stress σr of stiffening ring and its side pipe

[0173]

[0174] (11) Review of stress conditions at each calculation point of the stiffening ring and its adjacent pipe wall section

[0175]

[0176] σ θ =σ θ2

[0177] σ X =σ X1 +σ X2 +σ X3

[0178] Where: The allowable stress of the corresponding calculation condition is: [σ] = 0.67σs = 231.15N / mm 2

[0179] Table 5-16 Calculation results of stress condition review of stiffening ring and its side pipe sections

[0180]

[0181] 5. Analysis of the stability of steel pipe wall against external pressure

[0182] (1) The safety factor of the steel pipe wall and stiffening ring against external pressure shall not be less than 2.

[0183]

[0184] (2) For steel pipes with stiffening rings, the critical external pressure Pcr of the pipe wall between the stiffening rings can be calculated using the Mises formula, that is:

[0185]

[0186] Table 5-17 Calculation table of critical external pressure Pcr of pipe wall

[0187]

[0188] Table 5-18 Calculation table of safety factor K of pipe wall stability against external pressure

[0189] One standard atmosphere (MPa) Critical external pressure value (MPa) K 0.1 0.573 5.73

[0190] Conclusion: The safety factor of the pipe wall's resistance to external pressure is K=5.73>2, so the steel pipe wall's resistance to external pressure is safe.

[0191] 6. Stability analysis of stiffening ring against external pressure

[0192] (1) The safety factor of the steel pipe wall and stiffening ring against external pressure shall not be less than 2.

[0193]

[0194] (2) For steel pipes with stiffening rings, the critical external pressure Pcr of the pipe wall between the stiffening rings can be calculated using the following formula:

[0195]

[0196] Table 5-19 Calculation table of critical external pressure Pcr of steel pipe stiffening ring

[0197]

[0198] Table 5-20 Calculation table of safety factor K of stiffening ring against external pressure

[0199] One standard atmosphere (MPa) Critical external pressure value (MPa) K 0.1 0.286 2.86

[0200] Conclusion: The safety factor of the stiffening ring against external pressure K=2.86>2, so the stiffening ring is safe against external pressure.

[0201] For the arrangement of stiffening rings in PCCP:

[0202] (1) Partial excavation of concrete pipe core

[0203] Partial excavation of the concrete pipe core is usually carried out for fixing the pipeline reinforcement ring 4.

[0204] First, determine the specific location and scope to be excavated and mark them accurately. Prepare the necessary excavation tools and equipment, such as electric hammers and cutters, and ensure a safe work area. Excavate according to the marked location and scope, paying attention to controlling the excavation depth and width to avoid unnecessary damage to other parts of the pipeline. After excavation is completed, clean up the debris and debris generated by the excavation, and inspect the concrete quality and pipeline structure of the excavated area for damage.

[0205] (2) Arrangement of stiffening rings

[0206] The stiffening ring 4 is used to enhance the rigidity and pressure bearing capacity of the pipeline, especially when the pipeline is subjected to a large internal pressure or external load.

[0207] Measure and determine the installation location and quantity of stiffening rings 4 based on the design requirements and actual conditions of the pipeline; prepare stiffening rings 4 according to the design requirements, including checking the size, material, and welding quality of the steel rings; place stiffening rings 4 in the location of the excavated concrete pipe core and securely install them on the pipeline using welding or other fixing methods; after installation, check and adjust the position, fixing condition, and overall effect of stiffening rings 4 to ensure that they meet the design requirements;

[0208] (3) Artificial potting process

[0209] Grouting is to fill the gaps in pipe joints or excavated areas to ensure the sealing and corrosion prevention of pipes. Use brushes, high-pressure water guns and other tools to clean the dirt, debris, etc. on the joints or excavated areas to ensure that the surface is clean and pollution-free; install a wrapping tape formed by closed-cell foam boards or other flexible materials around the joints or excavated areas to form a grouting cavity and prevent leakage; prepare cement mortar or other grouting materials according to design requirements to ensure that the material has sufficient fluidity and strength; use manual methods (such as hand-held grouting guns) to slowly pour the grouting material into the cavity of the joint or excavated area to ensure that the grouting is full and free of bubbles. Pay attention to controlling the grouting speed and pressure to avoid impact or damage to the pipe; after grouting is completed, maintain the grouting area to ensure that the grouting material is fully hardened and reaches the design strength. During the maintenance period, the grouting area should be kept moist and avoid external interference.

[0210] For the deployment of rollable steel plates and steel cylinders in PCCP

[0211] (1) The rollable steel plate steel cylinder is the main load-bearing structure of the pipeline and is arranged in the center of the pipeline. When installing the steel cylinder, it is necessary to ensure that it is accurately positioned and firmly fixed to facilitate subsequent processes such as concrete pouring and prestressed steel wire winding. The reinforced steel ring is arranged on the outside of the steel cylinder and fits tightly with the steel cylinder. The gap grouting is to fill the gap between the pipeline interface or the steel cylinder and the concrete to ensure the sealing of the pipeline and prevent corrosion.

[0212] For manufacturing and construction technology

[0213] (1) Selection of rollable steel plate, steel cylinder and diameter

[0214] To ensure adequate flow area, the outer diameter of the rollable steel pipe is typically selected to be similar to the inner diameter of the PCCP. Furthermore, the space required for transportation, installation, welding, and grouting within the pipeline must be considered, so determining the outer diameter of the rollable steel pipe is crucial. When using a rollable steel liner, the rigidity of the steel pipe wall must be kept to a minimum, as this will affect the rollable steel pipe's rollout and even the opening of the cutout, directly impacting welding quality and weld inspection.

[0215] In most applications, the rollable steel tube will be constructed with minimum wall thickness material based on operating pressure calculations to meet the required pressure, negative pressure, and external grouting pressure. Alternatively, through force and strain analysis, and considering quality, safety, and economic considerations, reinforcing rings can be added to the PCCP. These rings are welded to the unrolled rollable steel tube to offset the stiffness effects of negative pressure and external grouting pressure.

[0216] Steel pipes and steel cylinders can be made into rollable, fixed cylinders with a diameter less than 150mm of the inner diameter of PCCP. The cylinders are hybrid and the longitudinal seams are not welded, so as to roll the cylinder and reduce the diameter by 400mm, which is convenient for long-distance transportation and passing through horizontal and vertical elbows.

[0217] (2) Selection of the length of the rollable steel plate and steel tube

[0218] The length of the rollable steel tube depends on the curvature radius and angle of the horizontal and vertical elbows in the PCCP pipeline. It is also related to the transport capacity, climbing ability, turning radius of the transport vehicle, and the transport vehicle's ability to control the opening of the rollable steel tube.

[0219] The length of the rollable steel tube is closely related to its fixing method. Generally, the length of the PCCP pipe or half the length of the pipe is selected. The width of the rollable steel tube is set according to the clearance between the four stiffening rings, approximately 1500mm. To account for weld shrinkage and PCCP pipe length deviations, tracking measurements are required. The rollable steel tube length can be adjusted multiple times within a PCCP repair length.

[0220] Space and connection design

[0221] The gap between the PCCP and the lined steel pipe is a key area for research. If the gap is too small, the profile of the rollable steel plate and steel cylinder will increase, making it difficult to pass through large-angle elbows. This will affect the welding of the fixings between the PCCP and the lined steel pipe. Grouting channel design and exhaust will be difficult, which will have a significant impact on the aesthetics of the PCCP lined steel pipe reinforcement and repair. The rollable steel plate and steel cylinder reinforcement and repair are designed to be connected to the PCCP. While ensuring sealing, connection strength, and durability, it is also necessary to minimize the time and intensity of operations in confined spaces, achieving low carbon and high efficiency. Grouting filling material selection should be based on the use environment and performance requirements of the composite structure, selecting appropriate micro-expansive cement-based filling materials to improve the overall performance and durability of the structure.

[0222] After the welding of the rollable steel plate and steel tube for PCCP repair is completed and passed inspection, grouting will be carried out immediately. There is no grouting port 6 at the bottom of the cover plate connected to the grouting pipe. Open the upper grouting port 6 and pour cement mortar from the bottom. When cement flows out from the top, stop grouting and close the upper grouting port.

[0223] Longitudinal seam welding of lined steel pipe and steel cylinder

[0224] The PCCP repair rollable steel plate and steel tube are transported to the designated location by an intelligent transport vehicle. The operator controls the unrolling of the rollable steel plate and steel tube, which is then unrolled along a fixed equilateral angle steel arc to form a complete ring. Once the steel tube and steel tube pass inspection, they are welded using automatic submerged arc welding.

[0225] Butt welding of lined steel pipe and steel cylinder

[0226] The rollable steel plate and steel cylinder for PCCP repair is transported to the designated location by an intelligent transport vehicle. After unfolding, it is welded to the base layer with the circumferential seams, reinforcement rings, and longitudinal seams of the previous section of steel pipe and cylinder. After passing inspection, it is then automatically welded using CO2 shielded welding. Cross welds must be avoided during the butt joint, and the spacing between the longitudinal seams of adjacent lining steel pipes and cylinders must be ≥ 500mm. Welding and inspection must be carried out according to the approved construction plan. Grouting is then performed after welding is completed.

[0227] In the embodiments of the present invention, see Figure 5 and Figure 6, perform local repair on the broken wire or crack of the concrete pipe body 1, install the socket steel ring 16 and the socket steel ring 17 at the cut-off point, the socket steel ring 16 and the socket steel ring 17 are in close contact with each other, and a rubber ring is set between the two for sealing.

[0228] In the embodiments of the present invention, see Figures 1 to 3 The steel tube intelligent transport vehicle 3 includes a vehicle body 31, which is a pipeline walking vehicle. At least three groups of annularly distributed hydraulic rods 32 are installed at the feed end of the vehicle body 31. The telescopic ends of the hydraulic rods 32 are fixed with automatic clamps 33 for clamping the rollable steel plate 2.

[0229] A plurality of hydraulic rods 32 are mounted on a rotatable shaft. The rotation of the shaft drives the plurality of hydraulic rods 32 to rotate in a circular manner, thereby achieving the winding and releasing of the rollable steel plate 2.

[0230] An automatic track 71 can be laid inside the concrete pipe body along the end of the concrete pipe body 1;

[0231] When welding the longitudinal seam of the rollable steel plate 2, a longitudinal seam submerged arc automatic welding device 7 is used. When welding the circumferential seam of the rollable steel plate 2, a circumferential seam CO2 shielded automatic welding device 8 is used.

[0232] The longitudinal seams between adjacent rollable steel plates 2 are staggered.

[0233] It should be noted that the intelligent steel tube transport vehicle 3 utilizes a hydraulic drive design, with individual or combined wheel drive and individual or combined steering, making it suitable for transporting rollable steel plates 2 to designated locations within 60° elbows. The intelligent steel tube and steel tube transport vehicle 3 enters the operating space of the PCCP pipeline repair line and lifts, lowers, and clamps the rollable steel plates 2. It transports and loads and unloads rollable steel tubes and steel tubes within the PCCP. It also functions as an operating platform, deploying steel tubes and steel tubes, assisting with circumferential seam docking, and other functions.

[0234] A PCCP rollable steel plate reinforcement method, comprising:

[0235] S1: Evaluate the PCCP pipeline's wire breakage rate, cracks, and other damage conditions to determine the pipe sections requiring reinforcement. Prepare reinforcement materials, including prefabricated rollable steel plates (Q355 material, inner diameter 3900mm, wall thickness 15mm) and stiffening rings (height 119mm, thickness 20mm).

[0236] S2: Mark the locations of the stiffening rings 4 on the inner wall of the PCCP (with spacing of 1600 mm), excavate the concrete core (depth ≤ 50 mm), and expose the original steel cylinder 14. The stiffening rings 4 are then welded to the inner wall of the PCCP steel cylinder 14 and the weld quality is inspected (no cracks or pores).

[0237] S3: Use the steel drum intelligent transport vehicle 3 to transport the rolled steel plate into sections (lengths adapted to the length of a single section of the PCCP pipe) to the repair location, extend the hydraulic rod 32, and release the automatic clamp 33 from the rollable steel plate 2, allowing the steel plate to unfold and form a cylindrical steel drum along the inner wall of the pipe;

[0238] S4: welding the longitudinal seam formed by the coiled steel plate 2 using the longitudinal seam submerged arc automatic welding equipment 7, and welding the circumferential seam between adjacent coiled steel plates 2 using the circumferential seam CO2 shielded automatic welding equipment 8;

[0239] S5: Install closed-cell foam board between the PCCP original pipe and the inner lining steel cylinder to form a grouting layer 5. Then, pour slightly expansive cement mortar (pressure 0.3-0.5MPa) from the bottom grouting port 6. The top grouting port 6 serves as an air outlet and is sealed after the slurry overflows to ensure dense filling (density ≥ 95%).

[0240] S6: Use ultrasonic testing (UT) or radiographic testing (RT) to inspect welds, and use ultrasonic testing to inspect grouting density.

[0241] The above are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A PCCP rollable steel plate reinforcement device, comprising a concrete pipe body (1), characterized in that: A plurality of stiffening rings (4) and a plurality of rollable steel plates (2) are installed inside the concrete pipe body (1) at positions corresponding to broken wires or cracks, and the rollable steel plates (2) are cylindrical after installation; The rollable steel plate (2) is rolled and unfolded by a steel drum intelligent transport vehicle (3) and transported along the end of the concrete pipe body (1) to a position where a broken wire or crack exists. The maximum diameter of the rolled steel plate (2) is smaller than the inner diameter of the concrete pipe body (1), so that the rollable steel plate (2) does not contact or scratch the inner wall of the concrete pipe body (1) during transportation. The rolled steel plate (2) is attached to the inner wall of the stiffening ring (4) after unfolding, and a grouting layer (5) is formed between the two, and the grouting layer is filled to eliminate the gap between the concrete pipe body (1) and the rollable steel plate (2). After the rollable steel plate (2) is laid, a welding device is inserted along the end of the concrete pipe body (1) to weld the longitudinal seams on the cylindrical rollable steel plate (2) and the circumferential seams between adjacent rollable steel plates (2).

2. The PCCP rollable steel plate reinforcement equipment according to claim 1 is characterized in that: The concrete pipe body (1) comprises a steel cylinder (14) located in the middle layer, wherein the inner and outer layers of the steel cylinder (14) respectively comprise an inner core concrete layer (15) and an outer core concrete layer (13), and a prestressed steel wire and a mortar protective layer (12) are arranged outside the outer core concrete layer (13), and the outer surface of the prestressed steel wire and the mortar protective layer (12) is coated with an epoxy asphalt coating (11).

3. The PCCP rollable steel plate reinforcement equipment according to claim 2, characterized in that: A local cut is made at the broken wire or crack of the concrete pipe body (1), and a spigot steel ring (16) and a socket steel ring (17) are installed at the cut-off portion. The spigot steel ring (16) and the socket steel ring (17) are in close contact with each other, and a rubber ring is arranged between the two for sealing.

4. The PCCP rollable steel plate reinforcement equipment according to claim 1, characterized in that: The steel tube intelligent transport vehicle (3) includes a vehicle body (31), which is a pipeline walking vehicle. At least three groups of annularly distributed hydraulic rods (32) are installed at the feed end of the vehicle body (31), and automatic clamps (33) for clamping the rollable steel plate (2) are fixed at the telescopic ends of the hydraulic rods (32).

5. The PCCP rollable steel plate reinforcement equipment according to claim 4, characterized in that: The plurality of hydraulic rods (32) are mounted on a rotatable shaft, and the rotation of the shaft can drive the plurality of hydraulic rods (32) to rotate in a circular motion, thereby realizing the winding and releasing of the rollable steel plate (2).

6. The PCCP rollable steel plate reinforcement equipment according to claim 1, characterized in that: Three groups of annularly distributed grouting ports (6) are provided on the rollable steel plate (2), and the grouting ports (6) are connected to the grouting layer (5).

7. The PCCP rollable steel plate reinforcement equipment according to claim 3, characterized in that: An automatic track (71) can be laid along the end of the concrete pipe body (1) and inside the pipe body; When performing longitudinal seam welding of the rollable steel plate (2), a longitudinal seam submerged arc automatic welding device (7) is used, and when performing circumferential seam welding of the rollable steel plate (2), a circumferential seam CO2 shielded automatic welding device (8) is used.

8. The PCCP rollable steel plate reinforcement equipment according to claim 7, characterized in that: The longitudinal seams between adjacent rollable steel plates (2) are staggered.

9. A PCCP rollable steel plate reinforcement method according to claims 1-7, characterized in that: include: S1: Evaluate the damage of PCCP pipelines such as broken wire rate and cracks, determine the pipe sections that need to be reinforced, and then prepare reinforcement materials, namely prefabricated rollable steel plates (2) (Q355 material, inner diameter 3900mm, wall thickness 15mm) and stiffening rings (4) (height 119mm, thickness 20mm); S2: Mark the position of the stiffening ring (4) on the inner wall of the PCCP (spacing 1600mm), excavate the concrete core (depth ≤ 50mm), and expose the original steel cylinder (14); then weld the stiffening ring (4) to the inner wall steel cylinder (14) of the PCCP and check the welding quality (no cracks or pores); S3: Using the steel drum intelligent transport vehicle (3), the rolled steel plate is transported to the repair location in sections (the length of which is adapted to the length of a single section of the PCCP pipe), the hydraulic rod (32) is extended, and the automatic clamp (33) is released from the display of the rollable steel plate (2), so that the steel plate is unfolded and forms a cylindrical steel drum along the inner wall of the pipe; S4: using a longitudinal seam submerged arc automatic welding device (7) to weld the longitudinal seam formed by the coiled rollable steel plate (2), and using a circumferential seam CO2 shielded automatic welding device (8) to weld the circumferential seam between adjacent coilable steel plates (2); S5: Install a closed-cell foam board between the PCCP original pipe and the inner lining steel cylinder to form a grouting layer (5), and then pour micro-expansive cement mortar (pressure 0.3-0.5MPa) from the bottom grouting port (6). The top grouting port (6) serves as an air outlet and is sealed after the slurry overflows to ensure dense filling (density ≥ 95%). S6: Use ultrasonic testing (UT) or radiographic testing (RT) to inspect welds, and use ultrasonic testing to inspect grouting density.

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