Chief Rebar's site office
Chief Rebar · Structural & Civil · 17 calculators
Truss AnalysisMoment DistributionStormwater RunoffCulvert FlowColumn BucklingSteel ConnectionStress ConcentrationConcrete StrengthRebar SizingAsphalt ThicknessBeam DeflectionFooting DesignConcrete VolumeConcrete Mix DesignExcavation VolumeSoil Compaction CheckMasonry Block Count
The Structural & Civil department works out of a site office: a desk under the window, drawings pinned to the corkboard, samples on the shelves and plant on the floor. Everything in the room is one of the department's calculators. Click it to open it.
Structural work follows the load down. A floor load bends the joists and beams, the beams hand it to columns, the columns to footings and the footings to the soil, and each calculator here checks one link in that chain. Where a real project needs several links in a row, the project guides below run them in order, carrying the values from one step to the next.
Civil work is the ground around the building: how much concrete and block to order, how far to compact the fill under a slab, how thick to lay a drive, how much rain a site sheds in a storm and whether the culvert under the road can carry it.
“Double a beam's span and, under the same uniform load, it sags sixteen times as much.” — Chief Rebar
In this office
- Beam Deflection: Calculate deflection of beams under uniform loads
- Column Buckling: Axial capacity of a steel column, from Euler buckling with the AISC inelastic reduction for stocky columns
- Footing Design: Size a square spread footing from the column load and the allowable soil pressure
- Concrete Strength: Estimate concrete strength development
- Steel Connection: Design bolted steel connections
- Truss Analysis: Screening check of one steel truss member: tension and compression capacity against an applied axial load
- Moment Distribution: Support and span bending moments of a two-span continuous beam under uniform loads (three-moment equation)
- Stress Concentration: Calculate stress concentration factors
- Concrete Mix Design: Estimate cement, sand, gravel, and water for a volume-ratio concrete mix
- Concrete Volume: Work out how much concrete a slab or footing needs, in the units ready-mix is sold by
- Rebar Sizing: Estimate rebar count and weight for a two-way slab grid
- Masonry Block Count: Estimate concrete block and mortar quantities for a wall
- Asphalt Thickness: Simplified planning estimate for driveway/parking-lot asphalt + base thickness
- Excavation Volume: Cut volume and truck loads for hauling excavated soil off site
- Stormwater Runoff: Peak runoff rate from a drainage area using the Rational Method
- Culvert Flow: Full-flow capacity of a circular culvert using Manning's equation
- Soil Compaction Check: Compare a field density test against the lab Proctor maximum
Project guides
- Build a Deck: Check the joists and beam for stiffness and size the footings for a backyard deck, following the load from the deck boards down to the soil.
- Pour a Concrete Patio or Slab: Work out how much concrete and gravel to order, how to batch the concrete if you mix it yourself, and how much rebar to place, in the order you'd actually plan the pour.