Tunnel Waterproofing Calculator

Membrane area and injection quantities for tunnel systems.

Tunnel length (ft)

Tunnel diameter/width (ft)

Shape (1=circular, 2=horseshoe, 3=rect)

System (1=PVC, 2=spray, 3=injection)

Groundwater head (ft)

Construction joints

Tab to move between fields

Membrane area (sq ft)

36,128

Hydrostatic pressure (PSI)13

Material quantity (rolls/gal)85

Waterstop (linear ft)1,257

Estimated inflow (GPM)7.65

Material cost ($)$67,858.00

Cross-section area (sq ft)314.2

How to Use This Calculator

Enter Tunnel Length (ft) and Tunnel Diameter/Width (ft) — the interior dimensions of the tunnel.
Select Cross-Section Shape (1=circular, 2=horseshoe, 3=rectangular) to apply the correct perimeter calculation.
Choose Waterproofing System (1=PVC sheet membrane, 2=spray-applied, 3=injection grouting for repairs).
Enter Groundwater Head (ft) — the height of water above the tunnel crown driving hydrostatic pressure.
Input Number of Construction Joints requiring waterstop treatment.
Review Membrane Area (sq ft), Hydrostatic Pressure (PSI), Waterstop (linear ft), and Estimated Material Cost for design and procurement.

How the result changes with Tunnel length (ft)

Tunnel length (ft): Total length of tunnel requiring waterproofing.
Tunnel diameter/width (ft): Interior diameter for circular tunnels or width for rectangular.
Shape (1=circular, 2=horseshoe, 3=rect): 1 = Circular (TBM bored). 2 = Horseshoe (drill-and-blast). 3 = Rectangular (cut-and-cover).
System (1=PVC, 2=spray, 3=injection): 1 = PVC sheet membrane. 2 = Spray-applied membrane. 3 = Injection grouting (repair).
Groundwater head (ft): Height of groundwater above tunnel crown in feet.
Construction joints: Number of construction joints requiring waterstop treatment.

Membrane area (sq ft): Total waterproofing area including 15% waste for tunnel geometry.
Hydrostatic pressure (PSI): Water pressure at tunnel based on groundwater head.
Material quantity (rolls/gal): Membrane rolls, spray gallons, or injection grout gallons.
Waterstop (linear ft): PVC waterstop needed at construction joints.
Estimated inflow (GPM): Estimated groundwater inflow rate without waterproofing.
Material cost ($): Estimated material cost for membrane/grout and waterstop.
Cross-section area (sq ft): Interior cross-sectional area of the tunnel.

Identify Input Parameters
4 parameters
Tunnel length (ft) = 500, Tunnel diameter/width (ft) = 20, Shape (1=circular, 2=horseshoe, 3=rect) = 1, System (1=PVC, 2=spray, 3=injection) = 1 = 6 input(s) provided
Calculate Membrane area
Membrane area = totalMembraneArea * 1.15
36128 = 36128
Calculate Hydrostatic pressure
Hydrostatic pressure = groundwaterHeadFt * 0.433
13 = 13
Calculate Material quantity
Material quantity
85 = 85