Chapter 12
Footings
1Acknowledgement
This Powerpoint presentation was
prepared by Dr. Terry Weigel,
University of Louisville. This work
and other contributions to the text
by Dr. Weigel are gratefully
acknowledge
...
Chapter 12
Footings
1Acknowledgement
This Powerpoint presentation was
prepared by Dr. Terry Weigel,
University of Louisville. This work
and other contributions to the text
by Dr. Weigel are gratefully
acknowledged.
2Footings
3
Design for load transfer to soil uses
unfactored loads
Support structural members and transfer
loads to the soil
Structural members are usually columns
or walls
Structural design of footing is done with
factored loadsFootings
4
Typically, bottom of footing must be
located below frost line
Footings must be designed to prevent
bearing failure, sliding and overturning
Footings must be designed to prevent
excessive settlement or tilting
Excavation may be required to reach a
depth where satisfactory bearing
material is locatedWall Footing
5
Wall footings – enlargement of the bottom
of the wallIsolated Square Footing
6
Isolated or single column square footing –
loads relatively light and columns not
closely spacedCombined Footing
7
Combined footings – support two or more
columns – heavily loaded columns;
closely spaced columns; columns near
property lineMat Footing
8
Mat or raft foundation – continuous concrete
slab supporting many columns; soil
strength relatively low; large column
loads; isolated spread footings would
cover more than 50 percent of area;
reduce differential settlementPile Cap
9
Pile caps – distribute column loads to
groups of pilesSoil Pressure
10
Soil pressure is assumed to be uniformly
distributed beneath footing if column
load is applied at the center of gravity
of the footing
Footings supported by sandy soils
Footings supported by clayey soils
Footings supported eccentric loadsAssumed Soil Pressure
11Soil Pressur
[Show More]