Slope Engineering
- Grade Requirements Minimum slope: 1/4" per foot (2%). Maximum slope: 1" per foot (8%). Critical slope: (n²q²/g)^(1/3). Energy gradient: S = hf/L.
- Flow Characteristics Shear stress: τ = γRS. Critical velocity: Vc = (8gRSf)^(1/2). Depth ratio: y/D = 0.2-0.8. Flow area ratio: A/Af = 0.3-0.95.
- Design Parameters Manning's n: 0.009-0.015. Roughness height: k = 0.0002-0.006 ft. Form factor: 0.75-0.85. Hydraulic radius: R = A/P.
Performance Standards
- Hydraulic Efficiency Full flow capacity: 0.85-0.95. Velocity maintenance: >2 ft/s. Head loss coefficient: 0.2-0.5. Energy dissipation: 0.1-0.3 ft/ft.
- System Requirements Self-cleaning velocity: 2.5 ft/s min. Maximum velocity: 10 ft/s. Depth control: d/D < 0.75. Freeboard: 20% of diameter.
- Safety Factors Design flow: 1.5× average. Structural safety: FS = 2.0. Uplift protection: 1.2× buoyant force. Scour prevention: 1.5× critical.
Installation Guidelines
- Layout Controls Grade stakes: 25' intervals. Laser level accuracy: ±1/16". Benchmark reference: 200' max. Alignment tolerance: ±1" horizontal.
- Bedding Requirements Material: Class I-III. Compaction: 90-95% SPD. Thickness: 4-6". Side support: 60-120° arc. Haunching: 0.7× diameter.
- Quality Assurance Slope verification: ±0.02%. Level survey: 50' intervals. Deflection test: <5%. Infiltration test: 50 gal/in-mile/day.
Maintenance Protocol
- Inspection Requirements CCTV survey: 5-year cycle. Slope measurement: annual. Joint inspection: 2-year interval. Flow monitoring: quarterly.
- Performance Metrics Flow capacity: ±10% design. Sediment accumulation: <10% area. Structural integrity: PACP 1-5. Joint alignment: ±1°.
- Remediation Triggers Grade loss: >0.1%. Capacity reduction: >15%. Structural rating: PACP >3. Joint offset: >1/4". Settlement: >1/2".