Differential settlement caused by variable soil types

Structure · Problems · printed page 35 (PDF page 36)

Book index entries

Differential Settlement Caused by Soils Settlement – Differential caused by Soils Soil Conditions – Causing Differential Settlement Footings – and Foundations Foundation – and Footing

Text in the illustration

if footings are designed for sandy soil, the footings for the portion of the house over silty soil may be undersized
this could lead to differential settlement
sandy soil - good bearing capacity
silty soil - poor bearing capacity

Generated explanation

The illustration shows a house with its foundation and footing bearing partly on sandy soil and partly on a pocket of silty soil. The sandy soil is identified as having good bearing capacity, while the silty soil has poor bearing capacity. The footing slopes downward on the silty-soil side, with a large downward arrow indicating settlement. Cracks extend through the foundation wall and brick wall above on that side of the house. The annotation explains that footings designed for sandy soil may be undersized where they bear on silty soil, leading to differential settlement.