This preview shows pages 1–2. Sign up to view the full content.
CE 3120
Fall 2008
Thought Problem 12
Footing Loads
Suppose that a foundation engineer wanting to estimate the longterm settlement of a
footing states that the total sustained load on the footing is the sum of the dead load of the
structure (the weight of the structure itself) plus the occupancy load (e.g. the weight of
the furniture, people, etc.) Since each is the sum of many small relatively small weights,
the engineer suggests that the dead load, X, and the occupancy load, Y, can be reasonably
modeled as normal random variables. Unable to see any important correlation between
them, the engineer also suggests that X and Y be treated as independent random
variables.
Data from numerous buildings of similar type suggest that
μ
X
= 100 kips,
σ
X
= 10 kips
μ
Y
= 40 kips,
σ
Y
= 10 kips
a.
What is the distribution of the total sustained load?
b.
A reasonable design load might be that load for which the probability of
excedance is 5% or less. Determine such a design load.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentCE 3102
Fall 2008
This is the end of the preview. Sign up
to
access the rest of the document.
 Spring '11

Click to edit the document details