PVCM Double Wall Corrugated Pipe Rural Sewage Pipe Network Construction Scheme: Anti-aging and Low-cost Installation

rural sewage treatment is an important livelihood project to improve the living environment, and pipe network construction, as the core link, faces the pain points of insufficient material weather resistance and high construction cost. PVCM double-wall corrugated pipe has become an ideal choice for rural sewage pipe network due to its advantages of excellent anti-aging performance and low installation cost. Combining engineering practice, this paper constructs a set of sewage pipe network construction plans suitable for rural scenes from the aspects of material characteristics, construction process, anti-aging measures and cost control.

First, material selection: anti-aging performance as the core

PVCM double-wall corrugated pipe is based on polyvinyl chloride (PVC), and the weather resistance of materials is improved by adding modified ingredients such as antioxidants, ultraviolet absorbers and carbon black masterbatch. The inner wall is smooth to reduce the water flow resistance, and the corrugated structure on the outer wall enhances the ring stiffness, which can withstand soil pressure and ground load. Before construction, the factory report of the material needs to be checked, focusing on the hydrostatic strength (20 ℃ 100h16MPa), drop weight impact performance (9/10 does not break at 0 ℃) and weather resistance index (80% tensile strength retention rate after artificial accelerated aging) to ensure that the material is suitable for the rural open-air laying environment.

Second, low-cost construction process design

#1. Optimize trench excavation to reduce the amount of earthwork

Rural areas are mostly clay or sandy soil. Shallow laying design (pipe top covering depth 0.6-1 m) is adopted, which reduces the amount of earthwork excavation by 30% compared with the traditional deep burying scheme. The width of the trench is controlled according to the "outer diameter of the pipeline + 0.6m", the slope of the slope is adjusted according to the soil type (clay 1:0.5, sand 1:1.25), and the combination of mechanical excavation and manual dressing is used to avoid over-excavation and disturbing the original soil.

#2. Socket connection improves installation efficiency

Pipeline connection adopts the composite process of "rubber ring socket + electric fusion reinforcement": first insert the rubber ring into the socket groove, apply lubricant and then slowly push the socket in with a wire tightener to ensure uniform clearance; for key nodes (such as turns and variable diameters), the electric fusion sleeve is used to connect, and the pipe and sleeve are fused into one through special welding machine heating, and the interface strength reaches more than 90% of the pipe body. This process saves 50% man-hours compared with flange connection, and a single shift can lay the pipeline 200-300m.

#3. Graded backfill control cost and protection Pipeline

Backfill is implemented in three steps: ① The bottom cushion of the pipe adopts graded sand and gravel (particle diameter 5-10mm), thickness 100mm, artificial tamping avoids pipeline settlement; ② The backfill around the pipe is made of plain soil or fine sand, with a layered thickness of 200mm, and the light road roller is rolled to a compaction degree of 90%; ③ The surface backfill uses excavated earth and is mixed with 30% broken bricks or construction waste (particle diameter 50mm) to reduce the cost of purchased materials.

III. Anti-aging construction safeguards

#1. Material storage and laying protection

pipe storage needs to be covered with sunshade cloth to avoid aging caused by direct sunlight; in case of high temperature weather during laying, lay straw curtains at the bottom of the trench to moisturize to prevent the pipe from being deformed due to temperature difference. Wrap anti-ultraviolet tape at the interface, the width is not less than 200mm, forming double protection.

#2. Soil corrosion prevention and control

For acidic soil (pH0.3%) that may exist in rural areas, double-layer pipe laying is used, the inner layer is PVCM pipe, and the outer layer is wrapped with glass fiber cloth and coated with epoxy resin to isolate corrosive media.

IV. Key points of cost control

1. Local resource utilization: local sand, gravel and clay are preferred as backfill materials, and transportation costs are reduced by 40%; in cooperation with the surrounding building materials market, bulk purchase pipes enjoy 10% -15% discount.

2. Lightweight construction machinery: small excavators (1.5t class) and electric tamping machines are used to replace large equipment, fuel consumption is reduced by 60%, and it is suitable for narrow roadway operations in rural areas.

3. Construction period compression: "segmented parallel construction" is adopted, trench excavation, pipeline laying and backfilling are advanced simultaneously, and the construction period of a single kilometer pipe network is controlled in 7-10 days, and labor costs are reduced by 25%.

Fifth, Engineering effect verification

A southern rural sewage treatment project applies this scheme, laying PVCM double-wall corrugated pipes 3.2km, and the pipes are DN300-DN600 specifications. The construction cost is reduced to 85 yuan/m (traditional HDPE pipes are about 120 yuan/m), saving investment 112,000 yuan. After 3 years of operation, the pipeline inspection showed that there was no scaling on the inner wall, no cracks on the outer wall, the anti-aging performance met the design requirements (life expectancy of 50 years), and the sewage collection rate increased from 65% to 92%.

PVCM double-wall corrugated pipe rural sewage pipe network construction plan, through anti-aging material selection, optimization of construction process and localized resource integration, a balance of "durability" and "economy" was achieved. In the future, pressure sensors can be installed at key nodes of the pipeline in combination with smart monitoring technology to warn of blockage or damage in real time, and further improve the long-term effectiveness of rural sewage treatment.