Chapter 8 Flashcards
What is a combined footing?
One footing supports the loading from several columns. Combined footings are typically used along the wall of the buildings at the property line or where two adjacent columns are close together.
What is a cantilever or strap footing?
Designed to support a wall column near its edge without causing non uniform soil bearing pressure.
What is a raft or mat foundation?
It is a combined footing that covers the entire area beneath a structure and supports all of the walls and columns.
When is a raft or mat foundation economical?
Raft foundations are used to reduce settlement of structures located above highly compressible deposits. Under these conditions, the depth at which the raft is established is sometimes made so great that the weight of the structure plus that of the raft is wholly compensated by the weight of the excavated soil.
What is a Deep foundation system?
A foundation system that typically goes down to bedrock or a different strong soil type, to limit the amount of differential settlement. Great is Seismic conditions.
What is a pile?
A structural member of small cross sectional area compared to their length and are usually installed by a driver consisting of a hammer or vibrator.
What force holds the pile in?
Friction
In deep foundation piles what is refusal?
When the pile can be driven no further.
T/F, Timber piles can not withstand stresses due to hard driving?
True
What is the difference between a pile and pier?
Piles are driven piers are drilled.
What is the function of the bell, in a belled pier?
The bell increases the bearing at the base.
