Pallet Rack Base Plate Anchorage and Overturning

Resolves lateral force on a rack frame into overturning and resisting moments, net anchor uplift.

Run the calculator

Example

You enter

Frame weight including product (lb) 15000
Frame depth (in) 42
Top beam elevation (ft) 20
Lateral force coefficient 0.2
Effective height as a fraction of the frame 0.666667
Allowable tension per anchor (lb) 1800
Anchor holes in the base plate 2
Allowable tension in a better slab (lb) 2800

You get

Lateral force 3000
Overturning moment 40000 ft-lb
Resisting moment from weight 26250 ft-lb (66% of the overturning)
Net uplift per column 3929 lb of anchor tension
Anchors required 3 against the holes available -- SHORT by 1
Anchors in the better slab 2 -- the standard plate carries it
Arm ratio 7.61905

Details, formula, and sources

Resolves lateral force on a rack frame into overturning and resisting moments, net anchor uplift, and the anchor count against the base plate's holes. The worked frame needs 3 anchors into 2 holes, and 2 in a better slab. The anchorage question is really a question about the floor.

Overturning M_o = lateral force x effective height; resisting M_r = frame weight x half the frame depth; net uplift = (M_o - M_r) / frame depth; anchors = net uplift / allowable tension per anchor, rounded up.

ANSI MH16.1, the applicable building code and its seismic provisions, and the post-installed anchor's evaluation report at the slab thickness, concrete strength, and edge distance actually present.

The statics are public; ANSI MH16.1 and anchor evaluation reports are published by their own bodies.

Estimate. AHJ and licensed professional govern.

Field names used by the API: frame_weight_lb, frame_depth_in, top_beam_height_ft, lateral_force_coefficient, effective_height_fraction, allowable_anchor_tension_lb, base_plate_holes, improved_anchor_tension_lb, lateral_force_lb, overturning_moment_ftlb, resisting_moment_ftlb, net_uplift_lb, anchors_required, anchors_required_improved, arm_ratio

Lateral force entered as a coefficient on the frame weight acting at a fraction of the frame heightspec-v1811 screening idealisation
Remedies a larger plate, a thicker or reinforced slab, a shallower frame, or bracing to the structure -- none is a field decisionrack design engineer