Pre-embedding of Mobile Toilet Pipelines

The pre-embedding of mobile toilet pipelines should follow the general specifications for pre-embedding sewer pipes in bathrooms, focusing on steps such as pipeline laying, fixation, and initial backfilling. The specific operations are as follows:

I. Pipeline Laying and Fixation

1. Trench Bottom Treatment Before pre-embedding, the trench bottom should be leveled, and sharp stones, roots, and other debris should be removed. Subsequently, a 10-centimeter-thick fine sand cushion should be laid. The sand cushion can buffer the direct contact between the pipeline and the hard base layer, preventing pipeline rupture due to ground settlement or external pressure.

2. Pipeline Fixation

   • Fixation Method: Use brick piers or plastic clamps to fix the pipeline, with fixation points spaced no more than 1 meter apart, ensuring the pipeline is level and does not sag. If the pipeline is long or at bends, increase the number of fixation points to enhance stability.
   • Joint Treatment: All pipeline joints should undergo a water flow test to check for tightness. If leakage is detected, reconnect and apply waterproof glue or use a dedicated sealing ring to ensure the joints are firm and leak-free.

II. Initial Backfilling Operations

1. Backfill Material Selection

   • Fine Sand Backfilling: Initial backfilling should use fine sand, filled simultaneously from both sides of the pipeline. After every 20-centimeter-thick layer is filled, water should be sprinkled, and the layer should be compacted with a hand tamper to avoid local voids. The fluidity of fine sand can reduce direct pressure on the pipeline while filling gaps to prevent settlement.
   • Layered Backfilling: When the sand layer is 15 centimeters above the top of the pipeline, switch to using original soil for backfilling to the design elevation. The original soil should be sieved to remove large debris, preventing sharp edges from cutting the pipeline.

2. Precautions

   • Prohibition of Construction Waste: Construction waste such as broken bricks and concrete blocks should not be mixed into the backfill material, as their sharp edges may puncture the pipeline or cause local stress concentration.
   • Avoid Direct Mechanical Backfilling: It is strictly prohibited to use heavy machinery such as excavators to directly dump sand and soil, preventing pipeline cracks or deformation due to impact. If mechanical assistance is required, manual backfilling should be carried out to a height of 50 centimeters above the pipeline before using machinery for layered compaction.

III. Key Details Supplement

• Slope Control: The pipeline should be laid with a slope of 0.5%-1% to ensure smooth drainage, preventing water accumulation from corroding the pipeline or breeding bacteria.
• Protective Layer Setting: Lay warning tapes or marker plates above the pipeline to prevent damage from subsequent construction excavation.
• Acceptance Criteria: After backfilling, a pressure test (if applicable) or visual inspection should be conducted to confirm no settlement, cracking, or leakage before proceeding with the next construction step.

By following standardized operations, the service life of mobile toilet pipelines can be effectively extended, reducing later maintenance costs.