The Impact of Rigid Inclusions on the Design of Footings and Slabs-Video

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Video Summary

The presentation examines when rigid inclusions can be treated as ground improvement and when their interaction with slabs and footings requires coordinated structural design. Rigid inclusions transfer loads through a load-transfer platform (LTP), with load sharing depending on soil conditions, element spacing and diameter. On competent near-surface soils, modest settlement improvement and a thick LTP generally support a ground-improvement approach; soft soils, high loads or concentrated stresses increase risk and require closer coordination.<br /><br />For slabs, modeling showed that thinner LTPs can substantially increase tensile stress. The presenters recommend checking slab capacity when the LTP is less than roughly 2–3 feet thick, particularly over soft soils.<br /><br />For spread footings, modeled moments were generally no greater than under uniform bearing, though some layouts increased shear. Recommendations include circular element layouts, placing an inclusion near the footing center, and keeping elements within one-quarter of the footing width from its center where possible. When uncertain, analyze the system and consult the structural engineer.

Keywords

rigid inclusions

ground improvement

load-transfer platform

slab tensile stress

spread footing design

structural coordination