Structural Calculator

Anchor Bolt Design Calculator

Design and verify cast-in anchor bolts with automated compliance checks for all failure modes defined in ACI 318-19 Chapter 17. Interactive graphics, step-by-step calculations, and one-click PDF export.

ACI 318-19 Chapter 17 · LRFD · SI Units
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What This Calculator Covers

All critical ACI 318-19 anchor-bolt failure modes and design checks in one integrated tool.

Cast-in Anchor Bolts (M12 – M48)

Full range of metric headed bolt sizes with automatic property lookup for grade 4.6, 5.8, and 8.8 steel.

Steel Tension Check

Verify steel tensile capacity of anchor bolts against factored tensile demand per ACI 318-19 Sec. 17.6.1.

Concrete Breakout (Tension & Shear)

CCD method for concrete breakout cones including edge effects, group factors, and eccentricity modifications.

Pullout Capacity

Bearing-based pullout check for headed anchors per Sec. 17.6.3, including cracking factor adjustments.

Side-Face Blowout

Lateral blowout check for anchors near a free edge per Sec. 17.6.4, with group and edge-distance corrections.

Steel Shear Check

Steel shear strength of anchor bolts with lever-arm considerations per Sec. 17.7.1.

Pryout Shear

Concrete pryout capacity for short, stiff anchors per Sec. 17.7.3 with automatic kcp factor selection.

Tension-Shear Interaction

Tri-linear and elliptical interaction checks per Sec. 17.8 for combined loading conditions.

Weld Check

Base-plate-to-anchor fillet weld capacity including effective throat and directional strength increase.

Bearing Check

Concrete bearing pressure under anchor head and base plate verified against allowable limits.

Elastic Method for Bolt Force Distribution

Distributes combined axial, shear, and moment loads to individual bolts using elastic analysis.

Interactive Plan & Elevation Graphics

Real-time SVG drawings of your anchor layout in plan and elevation that update as you change inputs.

Step-by-Step Calculation Sheet

Transparent output showing every formula, variable, and intermediate result for full traceability.

PDF Export

One-click export of the complete calculation package for submittal, review, or archival.


How It Works

Four straightforward steps from inputs to a print-ready calculation sheet.

1

Define Layout & Properties

Select bolt size, grade, embedment depth, edge distances, and anchor group geometry from the input panel.

2

Enter Forces

Input factored axial loads, shear forces, and moments. The elastic method distributes them to each bolt automatically.

3

Auto-Check All 10 ACI Criteria

The calculator evaluates every failure mode -- tension, shear, breakout, pullout, pryout, blowout, interaction, weld, and bearing -- in real time.

4

Export PDF

Generate a professional calculation sheet with all inputs, diagrams, formulas, and pass/fail results ready for submittal.

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