Live Demo — Anchor J-Bolt Layout Design Calculator
Enter the overturning moment, shear force and bolt layout to verify the anchor J-bolt tension, shear and embedment length instantly.
Anchor J-Bolt Layout Design Calculator
Free professional anchor J-bolt layout design calculator for solar street light foundations. Input the overturning moment at the base, horizontal shear force, and the bolt layout (count, circle diameter, size and property class) to verify the critical bolt tension, shear stress and anchorage length, ensuring the pole flange connection stays secure under high wind.
Key Features
Load Parameters
Input the overturning moment at the base (ft·lbf, obtainable from the b5 pole bending-moment calculator) and the horizontal shear force (lbf).
Bolt Layout
Choose the number of bolts (4 / 6 / 8), the bolt circle diameter, the bolt size (M16-M30) and the property class (4.8 / 6.8 / 8.8).
Tension Verification
Checks the critical bolt tension T_max = M / D_bolt against the allowable N_allow = A_s × f_t / γ for the selected layout.
Shear Verification
Divides the horizontal shear equally among the bolts V_each = V / n and verifies τ = V_each / A_s against the allowable shear stress.
Anchorage Length
Checks the embedment rule h_bolt ≥ 25 × d for J-type hook anchorage in Q235 / C30 concrete against the available foundation depth.
Reference Tables
Shows bolt effective cross-sectional areas A_e (M16-M30) and property class design values for tension and shear in ksi.
Technical Specifications
| Platform | HTML5 Web App | Android (via WebView) |
| Core Calculation | T_max = M / D_bolt ≤ N_allow = A_s × f_t / γ |
| Overturning Moment | ft·lbf (default 22,000 ft·lbf) |
| Shear Force | lbf (default 1,124 lbf) |
| Bolt Count | 4 / 6 / 8 |
| Bolt Size | M16 / M20 / M24 / M30 (A_e 157-561 mm²) |
| Property Class | 4.8 / 6.8 / 8.8 (f_t 24.7 / 34.8 / 58.0 ksi) |
| Anchorage | ≥ 25 × d embedment (Q235, C30 concrete) |
| Industry Standards | EN 1993-1-8, EN 1090-2, ASTM F1554 |
| Output | Pass/fail tension & shear verification + anchorage length check |
Frequently Asked Questions
Where does the overturning moment come from?
It is the base bending moment M_total produced by wind on the pole and mounted equipment, and can be taken directly from the b5 pole bending-moment calculator (or the concrete foundation calculator). The default example uses 22,000 ft·lbf; convert kN·m by 1 kN·m = 737.6 ft·lbf.
How is the critical bolt tension found?
For a 4-bolt square layout the maximum tension is T_max = M / D_bolt. The precise multi-bolt method is T_max = M × Y_max / ΣY_i², where Y_max is the lever arm of the bolt farthest from the overturning axis and ΣY_i² sums the squared distances of all bolts.
What does the property class number (e.g. 6.8) mean?
The first digit times 100 gives the nominal tensile strength in MPa, and the second digit is the yield ratio. Class 6.8 therefore has about 600 MPa tensile strength, and the calculator uses f_t = 34.8 ksi and f_v = 25.4 ksi design values from its property class table.
Why is the embedment at least 25 × d required?
The J-hook must be buried deep enough for the surrounding C30 concrete to transfer the bolt tension without pulling out. h_bolt ≥ 25 × d is the empirical value for Q235 bolts; for example, an M22 bolt needs about 550 mm (21.7 in) of embedment, which fits within a typical 1,200 mm foundation.
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