Happy New Year! Time flies when we are having fun - we are in 2015 - 15 years into the 21st century. Here's to making 2015 happy and prosperous for all!
Without further ado, here are the first programs for 2015!
Without further ado, here are the first programs for 2015!
Wind-Chill Factor
The equation, provided by NOA 2011, to determine wind chill
is:
W = 35.74 + .6215*T – 35.75*V^.16 + .4275*T*V^.16
Where:
T = air temperature (°F)
V = speed of the wind (mph)
Program WINDCHIL
: Input “AIR TEMP IN °F:”, T
: Input “WIND SPEED (MPH):”, V
: 35.75+.6215*T-35.75*V^.16+.4275*T*V^.16→W
: Disp “WIND CHILL FACTOR:”, W
Example 1:
V = 25 mph, T = 50°F.
Result: W = 42.75596219
V = 40 mph, T = 20°F.
Result: W = -.9093161248
Source: Thomas J.
Glover. “Pocket Ref: 4th Ed” –
2012. Sequoia Publishing, Inc.: Littleton, CO
Boiling Point at
Various Elevations
Using data from
Pocket Ref, the boiling point of water at certain elevations can be estimated by
the following equation:
Y »
211.99262 – (1.94802*10^-3)*X + (7.17273*10^-9)*X^2
X = elevation in feet
Y = boiling point of water in °F
Program BOILH20:
: Input “ELEV. IN FEET:”, X
: 211.99262-(1.94802E-3)*X+(7.17273E-9)*X^2→Y
: Disp “APPROX BAIL PT. (°F):”, Y
Examples:
|
X = elevation (feet)
|
Y = boiling point (°F)
|
|
250
|
211.5060633
|
|
1000
|
210.0517727
|
|
2750
|
206.6898088
|
Source: Thomas J.
Glover. “Pocket Ref: 4th Ed” –
2012. Sequoia Publishing, Inc.: Littleton, CO
Velocity of P-Waves
and S-Waves
In measuring seismic waves (earthquakes) of p-waves (primary
waves) and s-waves (secondary waves), the following equations can be used:
(I)
First Lamé Parameter:
λ = (v*E)/((1+v)*(1-2*v))
Where:
v = ratio of soil.
The following parameters are stated from the Foundation Engineering
Handbook:
|
Type of Soil
|
v =
|
|
Clay, above the water table
|
0.4
|
|
Saturated Clay, below the water table
|
0.5
|
|
Wet Sand
|
0.35
|
|
Dry Sand or Rock
|
0.25
|
E = elasticity of the soil, measured in thousand-feet per
pound
(II)
Shear Modulus (modulus of rigidity)
‘μ = E/(1 + v)
(III) Velocity
of the P-Wave (feet/second)
P = √((λ+2μ)*g*1000/w)
w = specific
soil weight, in pounds per cubic foot
g = Earth’s gravity
constant, g = 32.1740486 ft/s^2
(IV) Velocity
of the S-Wave (feet/second)
S = √(μ*1000*g/w)
Program SEISMIC
: Disp “ELASTICITY (1000 LB/FT)”
: Prompt E
: Disp “SPEC. SOIL WEIGHT”, “(LB/FT^3)”
: Prompt W
: Menu(“SOIL TYPE”, “CLAY”, 1, “BELOW H20 TABLE”, 2, “WET
SAND”, 3,
“DRY SAND/ROCK”, 4)
: Lbl 1
: .4→V
: Goto 5
: Lbl 2
: .5→V
: Goto 5
: Lbl 3
: .35→V
: Goto 5
: Lbl 4
: .25→V
: Goto 5
: Lbl 5
: (EV)/((1+V)(1-2V))→L
: E/(2(1+V))→M
: √((L+2M)*32174.0486/W)→P
: √(M*32174.0486/W)→S
: Disp “P-WAVE (FT/S)”,P
: Disp “S-WAVE (FT/S)”,S
Example:
Input:
E = 3000 pounds per square foot
w = 120 pounds per cubic foot
Type of soil: Clay (v=.4)
Output:
P-Wave Velocity »
1312.863186 ft/s
S-Wave Velocity »
535.9741515 ft/s
Sources:
Hsai-Yang Fang. “Foundation
Engineering Handbook” Springer Science & Business Media. 1990.
Indrahil Goswami,
Ph.D. P.E. “Civil Engineering PE Breadth and Depth, Exam Guide. 2nd Edition” McGraw Hill. 2014
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This blog is property of Edward Shore. 2015.
