Chapter 6: Ultimate Bearing Capacity of Shallow Foundations: Special Cases

Why is it important to study bearing capacity in special soil conditions?

Soils may be anisotropic, layered, near slopes, or on rock; these conditions change stress distribution and failure behavior

What is the bearing capacity of a shallow foundation on anisotropic sand?

Depends on direction-dependent strength; anisotropy reduces capacity compared to isotropic assumptions

How is bearing capacity analyzed for an inclined foundation under normal load?

Inclination alters stress distribution and reduces effective bearing area

How is bearing capacity estimated for soil with limited thickness?

Failure may reach rigid base; capacity depends on thickness and underlying layer stiffness

How is bearing capacity evaluated for layered clay?

Controlled by properties of each layer; weakest layer often governs

What happens when a foundation is on a stronger layer over a weaker layer?

Punching shear can occur into weaker layer, reducing capacity

What happens when a foundation is on a weaker layer over a stronger layer?

Failure governed by weaker top layer

What is the bearing capacity of a foundation on a granular trench in soft clay?

Granular trench increases drainage and strength, improving capacity

How do two nearby shallow foundations affect bearing capacity?

Overlapping stress zones reduce capacity compared to isolated footings

How is bearing capacity estimated for a foundation on top of a slope?

Reduced due to less confinement and potential slope instability

How is bearing capacity affected for a foundation located on a slope?

Inclined ground reduces stability and bearing capacity

How does seismic loading affect bearing capacity?

Dynamic forces reduce soil strength and increase failure risk

How is bearing capacity estimated for a foundation on rock?

Depends on rock strength, fractures, and weathering; generally high capacity

What is the bearing capacity of a shallow wedge-shaped foundation?

Depends on geometry; wedge shape changes stress distribution and failure surface