Hydraulic Engineering
- Flow Analysis Manning's equation: V = (1.49/n)R^(2/3)S^(1/2). Froude number: Fr = V/(gy)^(1/2). Reynolds number: Re = VD/ν. Energy grade line: Sf = hf/L.
- Design Parameters Minimum velocity: 2.0 ft/s. Maximum velocity: 10 ft/s. Flow depth ratio: 0.2-0.8 d/D. Hydraulic radius: R = A/P. Wetted perimeter: P = πD/2.
- Capacity Factors Full flow efficiency: 0.85-0.95. Roughness coefficient: 0.009-0.015. Form factor: 0.75-0.85. Head loss coefficient: 0.2-0.5.
Slope Requirements
- Grade Standards Minimum slope: 1/4" per foot (2%). Recommended range: 1-2%. Maximum slope: 8-10%. Critical slope: Sc = (n²q²/g)^(1/3).
- Performance Criteria Self-cleaning velocity: >2.5 ft/s. Tractive force: 0.1-0.4 lb/ft². Shear stress: τ = γRS. Critical shear: τc = 0.033(γs-γ)d.
- Safety Factors Design flow: 1.5× average. Structural safety: FS = 2.0. Uplift protection: 1.2× buoyant force. Scour prevention: 1.5× critical.
Installation Standards
- 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 Schedule 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 Criteria Grade loss: >0.1%. Capacity reduction: >15%. Structural rating: PACP >3. Joint offset: >1/4". Settlement: >1/2".