AWWA D103 Structural Members & Anchor Bolts Calculator

AWWA D103 Structural Members & Anchor Bolts

Bolt shear/tension, roof support spacing, steel thickness limits, and foundation anchor bolt design (ANSI/AWWA D103-09, §5.5.5–5.9)

◉ ANSI/AWWA D103-09 §5.5.5–5.9 STYLE CHECK · NOT A REGULATORY SUBMISSION TOOL

⚠ Indicative tool only, and a companion to the existing AWWA D103 Shell & Joint Design calculator. That tool covers plate net-section stresses (§5.4–5.5.4); this one covers bolt-specific allowable stresses, roof structural members, and foundation anchorage. Verified directly against this edition's page images.

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Research entries stay private to you for practice/testing. Switch to Official once this is a real design your company should see.

Bolt Shear & Tension, Non-Anchor Bolts (§5.5.5–.6, Eq 5-6/5-7/5-8)

F_y — Bolt Minimum Yield Strength psi

F_u — Bolt Minimum Tensile Strength psi

f_v = F_u(0.6)(0.9)/2.2 ≤ 0.25F_u. f_t = lesser of 0.6F_y or F_u/2.2. Applies to the tensile stress area or gross area as applicable — does not apply to anchor bolts (see below).

Result

Allowable shear stress f_v—

Allowable tensile stress f_t—

Weld Design (§5.6.1, reference)

Welded structural joint stresses, as a percentage of the allowable tensile stress of the material joined: groove welds — tension 85%, compression 100%, shear 75%; fillet welds — transverse shear 65%, longitudinal shear 50%, varying shear on circular weldments 60%. Fillet weld throat = 0.707 × the shorter leg length (flat or slightly convex profile).

Maximum Roof Support Spacing (§5.7.6, Eq 5-9)

F_y — Roof Sheet Yield Strength psi

t — Roof Sheet Thickness in

W — Roof Dead + Live Load lb/ft²

L = √(300F_yt²/W) ≤ 60in. Column slenderness ratio KL/r shall not exceed 175 (§5.7.3), where L is laterally unsupported column length and r is least radius of gyration.

Result

Maximum centerline spacing L—

Steel Thickness Limits (§5.8, reference)

Roof sheets: slope ≥1:2.75 — minimum 0.070in (D≤35ft) or 0.094in (D>35ft); slope <1:2.75, any diameter — minimum 0.094in. Bottom sheets: minimum 0.094in. Formed flange shell plates: 0.094–0.3125in. Flat panel shell plates: 0.094–0.50in. ASTM A1011 components: <0.230in. Plates/sheets shall not be stacked or laminated to achieve a design thickness.

Anchor Bolt Design Tension Force (§5.9.8.1, Eq 5-10/5-11)

Load Type

M — Overturning Moment ft-lb

N — Number of Anchor Bolts

d — Anchor Bolt Circle Diameter ft

W — Resisting Weight (shell + roof dead-load reaction + permanent accessories) lb

P = 4(M/Nd) − (W/N). This is the net uplift force after dead-weight reduction, not the gross overturning tension. A negative result means no uplift anchorage is required for this load case (per the standard's own text) — check both wind and seismic and design for the greater positive demand.

Result Not evaluated

Design tension force per anchor bolt—

Foundation Anchor Bolt Allowable Tension (§5.9.3.2)

Material Listed in §4.2?

F_y — Anchor Bolt Yield Strength psi

F_u — Anchor Bolt Tensile Strength psi

Listed material: allowable tension = lesser of 0.6F_y or 0.33F_u (based on root area). Other material: allowable tension = 0.70F_u. These two paths are for different material-listing scenarios, not alternative/equivalent formulas for the same case.

Result

Path used—

Allowable anchor bolt tensile stress—

Reference (§5.9.1–.4, §5.9.7): anchor bolts required when wind/seismic loads exceed self-anchored limits. Maximum spacing 10ft (3m); minimum 5 anchor bolts if anchored. Minimum anchor bolt diameter ¾in (19mm). 2in (51mm) nominal thread projection above nuts. Cast-in-place recommended; epoxy/wedge-type anchors permitted per manufacturer's specifications. Anchor bolt attachments shall be designed so the bolt yields before the anchor chair or attachment fails, checked in both as-built and corroded conditions. Embedment design per IBC/ACI 318/ACI 349, minimum 3in (76mm) clear cover to bottom of foundation, bond stress not considered in embedment capacity.

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