I. Product Introduction:
Glass fiber reinforced plastic pipe is a newly developed pipeline product in the field of water supply and drainage. It can complete underground pipeline construction and installation without excavation of the ground. It can directly cross roads, railways, rivers, and ground buildings. Due to its excellent corrosion resistance, lightweight, smooth inner wall, large flow capacity, and good adaptability to geological conditions, it has become a pipeline material for pipeline projects in large and medium-sized cities.
II. Product Features:
1. Lightweight (1/10th the weight of concrete pipes), with low foundation requirements, minimal lifting and pipeline machinery needs, and easy construction.
2. Due to reasons such as low settlement and low thrust, 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 construction cost.
4. Smooth surface, low thrust, soil cohesion has minimal effect on the glass fiber reinforced pipe, no occurrence of pipe gripping or dead pipe, long single push-in length, low requirements for push-in equipment.
Section 3: Process Route:
Utilizing a 12-meter long fixed-length winding process for glass fiber reinforced plastic (GFRP) sand-filled pipes, four 3-meter-long GFRP culverts are produced per mold, with intermittent sand filling according to the design layers. The pure GFRP sections at both ends of each culvert, ranging from 300 to 800mm, are locally reinforced with glass fiber fabrics. The culverts are milled and cut using specialized equipment, and once the specified shape and size are achieved, they can be demolded in one go. The production efficiency fully meets the required project progress. The design and production process integrate pure GFRP with GFRP sand-filled composite reinforcement.
Section 4: Design Technology
Based on the specific application conditions of glass fiber reinforced plastic (FRP) sand-filled pipe in pipe jacking projects, determine design parameters such as pipe diameter, material stiffness grade, soil parameters, and design loads (including internal pressure, vacuum, vertical static soil pressure at the pipe crown, live load from ground vehicles, and soil stacking load) to provide a theoretical basis for the structural calculations of the FRP sand-filled pipe.
V. Structural Calculation:
Based on the selected design conditions and parameters, the structural calculations for glass fiber reinforced plastic pipe are conducted in accordance with the Chinese National Standard "Glass Fiber Reinforced Plastic Pipe" (GB/T21492-2008), "Pipe Jacking Construction Technology," and computer nonlinear finite element numerical calculations. The pipe material structural calculations encompass force strength, stiffness, deflection deformation, bending strength, stability analysis, earthquake resistance analysis, and other calculations, analyses, and verifications.
VI. Production Process:
1. Confirm and approve the design and production plan.
2. Lining manufacturing
3. Glass fiber hoop and cross-woven inner structural layer
4. Special sandblasting with intermittent sandblasting cloth (sandblasting cloth continuous at pure fiberglass but stops at the sanding point).
5. After each layer of sand-lamination, promptly fabricate the pure fiberglass sections.
6. Glass fiber hoop and cross-woven outer structural layer.
7. Trim and cut to achieve uniform shape and specified dimensions.
8. Demold, inspect for quality, and then fit the steel sleeve before shipping out.
Section 7: Connection Method:
The pipe sections are connected by an embedded steel sleeve ring for positioning. During jacking, a glass fiber reinforced plastic resin mouth is sealed to prevent water leakage. 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 slipped onto the pipe end. The steel sleeve ring serves as a positioning device and enhances the pipe's resistance to uneven settlement. The resin mouth provides a seal, and the two pipes act as a water barrier upon connection.
Section 8: Applicable Locations:
● Water supply and tap water engineering. ● Petroleum and chemical engineering. ● Construction engineering. ● Sewage engineering. ● Power, metallurgy, and environmental protection engineering. In summary, glass fiber reinforced plastic (GRP) pipe can complete underground pipeline construction and installation without excavation of the ground. The GRP pipe can directly cross highways, railways, rivers, and ground buildings, thanks to its inherent properties such as excellent corrosion resistance, light weight, smooth inner wall, high flow rate, and good adaptability to geological conditions.
