I. Product Introduction:
Fiberglass Reinforced Pipe (FRP) is a newly developed pipeline product in the water supply and drainage field. It can complete underground pipeline construction and installation without excavating the ground. It can directly cross roads, railways, rivers, and ground buildings. Due to its excellent corrosion resistance, lightweight, smooth inner wall, high flow rate, and good geological condition adaptability, it has become a pipeline material for large and medium-sized urban pipeline projects.
Section II: Product Features:
1. Lightweight (one-tenth the weight of concrete pipes), low foundation requirements, minimal requirements for lifting and pipe-laying equipment, easy to construct.
2. Due to low settlement and low uplift, pipeline alignment correction is easy.
3. Smooth inner wall, high flow rate; under a fixed flow rate, a smaller pipe diameter can be used, which can reduce the overall engineering cost.
4. Smooth surface, low thrust, the soil's cohesion has less effect on the glass fiber reinforced pipe, no pipe holding or dead pipe phenomenon, long single push-in length, low requirements for push-in equipment.
Section 3: Process Route:
Utilizing a 12-meter long fixed-length winding glass fiber reinforced plastic (GFRP) sand-filled pipe production process, four 3-meter-long GFRP culverts are produced per mold, with intermittent sand filling according to the design layers. The 300~800mm pure GFRP sections at both ends of each culvert are reinforced locally with glass fiber fabrics. The culverts are milled and cut between segments using special equipment, and once the required shape and size are achieved, they can be removed from the mold in one go. The production efficiency fully meets the specified project progress requirements. A design and production process that integrates pure GFRP with GFRP sand-filled composite reinforcement is adopted.
Section 4: Design Technology
Based on the specific application conditions of glass-fiber reinforced plastic (GRP) sand-cored pipe in pipe jacking projects, determine design parameters such as pipe diameter, pipe material stiffness level, soil parameters, design loads (including internal pressure, vacuum, vertical static soil pressure on the pipe crown, live load of ground vehicles, and soil stacking load), etc. These parameters provide a theoretical basis for the structural calculations of the GRP sand-cored pipe.
V. Structural Calculation:
Based on the selected design conditions and parameters, the structural calculations for glass fiber reinforced plastic manholes are conducted in accordance with China's national standard "Glass Fiber Reinforced Plastic Manholes" (GB/T21492-2008), "Manhole Construction Technology," and computer nonlinear finite element numerical calculations. The structural calculations of the pipe material include calculations, analyses, and verifications for uplift strength, stiffness, deflection deformation, bending strength, stability analysis, seismic strength analysis, etc.
Section 6: Production Process
1. Confirm and approve the design and production plan.
2. Lining Production
3. Glass fiber hoop-wound and cross-wound internal structure layers.
4. Special sand-blasting with intermittent sand-blasting cloth (the sand-blasting cloth is continuous at the pure glass fiber but stops at the sand-blasting point).
5. Promptly fabricate the pure fiberglass sections after each layer of sand sandwiching.
6. Glass fiber hoop and cross-woven external structural layer.
7. Trim and cut to uniform shape and specified dimensions.
8. After demolding, the products are inspected and then fitted with steel sleeve rings before being shipped out.
Section 7: Connection Method:
The pipe sections are connected and positioned using embedded steel sleeve rings. During jacking, glass fiber reinforced plastic resin is used for sealing. After the two pipes are joined, they serve as a water seal. A platform is machined at both ends of the jacking pipe to ensure that the outer diameter of the steel sleeve ring matches the jacking pipe's outer diameter after it is fitted onto the pipe end. The steel sleeve ring serves as a positioning device and enhances the ability to resist uneven settlement. The resin mouth provides sealing, and after the two pipes are joined, it acts as a water seal. A platform is machined at both ends of the jacking pipe to ensure that the outer diameter of the steel sleeve ring matches the jacking pipe's outer diameter after it is fitted onto the pipe end. The steel sleeve ring serves as a positioning device and enhances the ability to resist uneven settlement.
Section 8: Applicable Locations:
● Water supply and domestic water engineering. ● Petroleum and chemical engineering. ● Civil engineering. ● Sewage engineering. ● Power, metallurgy, and environmental protection engineering. In summary, FRP manholes can complete the construction and installation of underground pipelines without excavation of the ground. FRP manholes can directly cross highways, railways, rivers, and ground buildings, due to their inherent properties such as excellent corrosion resistance, light weight, smooth inner walls, high flow rate, and good adaptability to geological conditions.
