Questions of Interest
We seek answers to the following questions.
a) Set up equations for:
Duration of excavation work
Cost to contractor
Profit
Compute the values of each, using expected values for variable values. From the perspective
of a determinis
CIVL 520 Construction Planning & Control
SOME DRAFT NOTES ON RISK MANAGEMENT a work in progress
Topics to be treated:
The issue of discrete risks (may or may not happen) and consequences, versus uncertainty that
happens with certainty in variable values o
Central Limit Theorem
Under very general conditions, as the number of random variables in a sum becomes large, the
distribution of the sum of random variables will approach the normal distribution.
The theorem holds for most physically meaningful random v
Beta distribution
We start by requiring three time estimates for an activity duration, not just one estimate. (In what
follows, we suppress the subscript for ease of presentation. Also, we tend to consider an activity
on arrow network representation as op
Direct Cost of Excavation Work
Your firm has just been awarded a lump sum contract in the amount of $2,600,000 for the
excavation for a large hotel and convention complex that is to be constructed in a busy
downtown location. Dimensions of the site are 10
Attributes required of a general implementation
Attributes required of a general set of planning structures suitable for modeling projects with
both repetitive here
the original implementation distinguished between non-repetitive activities and repetitive
Family of planning structures the basic building blocks
Initial work limited the planning structures to two kinds non-repetitive and repetitive, with the
latter requiring work continuity. Extensive experience led to an enlarged family of structures,
and g
Expected event (path) times and their variances
*NOTE: Rather than compute as ,it has been argued that defining as, where a and b correspond to the 5 and 95
percentiles of the distribution, respectively, constitutes a more robust measure of . This is beca
Probability
Duration Range
T150 days
150<T175 days
175<T200 days
200<T
Liquidated Damages
0
75,000
225,000
475,000
Prob. of Occurrence
p1=0.500
p2=0.218
p3=0.141
p4=0.141
Sp= 1.000
Note: Probabilities of occurrence were determined assuming that T is logno
Example of quantifying risk
This distribution is not tabulated. What is tabulated is the standardized variable Z which has
mean 0 and variance 1. A table for standardized variable Z is appended.
Let Z =
We wish to show that this definition of Z correspond
Dewatering Methods - Wellpoints
The wellpoint consists of a slotted or perforated pipe which is covered with a screen mesh. At the foot of
this pipe is an orifice which permits jetting of the pipe into the ground during installation. A well-point
dewateri