I. Product Introduction:
Glass-reinforced plastic (GRP) pipe is a newly developed pipeline product for the drainage and water supply field. It can complete underground pipeline construction and installation without excavating the ground. It can directly cross highways, railways, rivers, and ground buildings. Due to its excellent properties such as good corrosion resistance, light weight, smooth inner wall, high flow rate, 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), low foundation requirements, minimal demands on hoisting 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 construction cost.
4. Smooth surface, low thrust, soil cohesion has minimal effect on the glass fiber pipe, no tube gripping or clogging, long single push-in length, low requirements for thrusting 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 processed and cut using specialized equipment, and once shaped and sized to specification, they can be demolded in one go. The production efficiency fully meets the required project progress. An integrated design and production process featuring pure GFRP and GFRP sand-filled composite reinforcement is adopted.
Four: Design Technology
Based on the specific application conditions of the glass fiber reinforced plastic (FRP) sand-filled pipe used in jacking projects, determine design parameters such as pipe diameter, material stiffness grade, soil parameters, design loads (including internal pressure, vacuum, vertical static soil pressure on the pipe crown, live load from ground vehicles, and soil heap load), etc. These parameters 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 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 thrust strength, stiffness, deflection deformation, bending strength, stability analysis, seismic strength analysis, and more.
VI. Production Process:
1. Confirm and approve the design and production plan.
2. Lining manufacturing
3. Glass fiber hoop and cross-wound internal structure layer
4. Special sandblasting with intermittent sandblasting paper (the sandblasting paper is continuous at the pure glass fiber but stops at the sandblasting point).
5. Timely fabricate the pure fiberglass section after each layer of sand sandwiching.
6. Glass fiber hoop and cross-wound outer structural layer
7. Trim and cut to a uniform shape and specified dimensions.
8. After demolding, the products are inspected and, upon passing, are fitted with steel sleeve rings before being shipped out.
Section 7: Connection Method:
The pipeline sections are connected by embedded steel sleeve rings for positioning. During jacking, glass fiber reinforced plastic resin flanges are used for sealing. After the two pipes are joined, they provide water-sealing. 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 when it is fitted onto the pipe end. The steel sleeve ring serves as a positioning device and enhances resistance to uneven settlement. The resin flange provides sealing, and the two pipes offer water-sealing upon connection. 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 when it is fitted onto the pipe end. The steel sleeve ring serves as a positioning device and enhances resistance to uneven settlement.
Section 8: Applicable Locations:
● Water supply and public utility projects. ● Petroleum and chemical engineering. ● Construction projects. ● Sewage engineering. ● Power, metallurgy, and environmental protection engineering. In summary, FRP pipe can complete the construction and installation of underground pipelines without excavation of the ground surface. It can directly cross highways, railways, rivers, and ground buildings. This is due to the FRP pipe's inherent characteristics of excellent corrosion resistance, light weight, smooth inner wall, high flow rate, and good adaptability to geological conditions.
