RANDOM FORMULAS/TERMS Flashcards
Deals with
understanding the causes of accidents
at work and ways to prevent unsafe
acts and unsafe conditions in any
workplace.
Occupational Safety
A broad
concept which explains how the
different hazards and risks at work
may cause an illness and emphasizes
that health programs are essential in
controlling work related and/or
occupational diseases.
Occupational Health
The principle used in equations related to the deformation of axially loaded material
Hooke’s Law
It is the force which determines whether the body will be in equilibrium or will have a varying state of motion
Resultant
The ratio of the lateral to the longitudinal strain constant
Poissons’s Ratio
It is the constant proportionality that defines the linear relationship between stress and strain
Young’s Modulus
The stress is proportional to the strain within the elastic region
Hooke’s Law
A structural member that has the ratio of its least lateral dimension of not less than 3 and is used primarily to support axial load
Column
Retarding force acting opposite of the body in motion
Kinetic Friction
Term for the value beyond which the stress is no longer proportional to the strain
Proportional limit
Materials which have the same composition or compression at any point
Homogenous
Property of a material that enables it to undergo large permanent strains before failue
Ductility
Described as the loss of stress that takes place with the passage of time as concrete is held at a constant strain
Relaxation
Ability of a material to absorb energy in the elastic range
Resilience/ Modulus of Resilience
Ability of a material to absorb energy in the plastic range or rupture/fracture point
Toughness/ Modulus of Toughness
Property of a material which makes it return to its original dimension when the load is removed
Elasticity
Point on which the resultant of the resistance to the applied lateral force acts
Center of rigidity
Distance between the Center of rigidity and center of mass
Eccentricity
Ability of a material to deform/defuse in the plastic range without breaking
Ductility
Refers to flexibility of a structure
Inverse of stiffness
The material deforms considerable even with the slight increase in stress
Yielding
Measured by seismometer
Ground displacement
One in which the lateral stiffness is less than 70% of the stiffness of the story above
Soft story
A lateral displacement of one level relative to the level above or below is called
Story Drift
Sudden drop in the shear strength of soil
Liquefaction
It is a point through which the applied seismic force acts
Center of Mass
The material has the same composition at every point but the elastic may not be the same in all direction
Orthotropic
Besides epicenter it described the location of the earthquake
Focal Depth
It is measured by the Richter scale
Magnitude
A material subjected to repeated cycles of stress or strain, it causes structure to breakdown ultimately leading to fracture
Fatigue
Causes the material to continue to deform until fracture due to supporting a load for a long period of time
Creep
Condition of material to break down and deform permanently even due to slight increase in stress above elastic limit
Plasticity
Occurs when the structures center of mass does not coincide with its center of rigidity
Torsion
Stress at failure
Rupture strength
Ratio between volume of water and volume of voids
Degree of saturation
Weight of water to the weight of solids
Water content
Happens when there is lowering of water table
Decrease in lateral pressure
Value of surface tension at normal room temperature
0.064 N/m
The discharge passing a given cross section is constant with time
Steady Flow
Volume of liquid passing a cross section of a stream
Discharge
A ship floating is stable if metacentric height is
Above the center of gravity
If with steady flow the average velocity at every cross section is same in that reach, the flow is
Uniform
The NSCP provides that the slope of a cut surface shall be no steeper than safe for intended use and shall be no steeper than
1 vertical to 2 horizontal
The component of shear strength of a rock or soil that inter particle friction is called
Cohesion
Acording to USCS, soil particle greater than 75 mm is called
Cobbles
A cohesive soil deposit is considered soft if the unconfined compression strength in KPa is between
24 to 48
A pressure surge or wave caused when a fluid in motion is forced to stop or change direction suddenly is referred to as
Water Hammer
Temperature when water has maximum unit weight
4 degree celsius (1000kg/m3)
When path of individual particles of a flowing liquid are irregular curves and continually cross each other and form a complicated network is called
Turbulent
Fraction of soil passing which sieve number for Atterberg limit test
Sieve No. 40
A granular soil deposit is considered medium if the blow count of a standard penetration test is between
10-30
when at any instant, the number of particles passing every section of the stream are always equal
Continuous Flow
What would happen if the ground water table will be at the ground level
Decrease in vertical pressure
A line of joining the points of the highest elevation of water in series of vertical open pipes rising from a pipelines in which water flows in pressure
Hydraulic gradient
It is an abrupt rise in water surface which results from retarding water flowing at lower stage
Hydraulic jump
Most used property in soil properties
Void Ratio
A device used to determine the undrained shear strength of the soil which consist of four equal-sized thin steel plates
Shear Vane
Wave at a point where the water depth is equal to 1/2 the wavelength or greater to be expressed in terms of parameters of significant waves
Deep Water Wave
Inform and advice road users of directions, distances, routes, the location services, and points of interest
Guide sign
A continous structure built parallel to along the margin of the sea or alongside river where vessel may lie along side to receive o discharge cargo or disembark passenger s or lie at rest.
Wharf
Messages when painted on pavement is limited to how many words only
2 or less
Two angles whos sum is 360 degrees
Conjugate angle
Ratio of wave heigth to wavelength
Steepness
Formula sum of exponents
(sum exp inside)(n+t-1Ct)
Triangle circumscribing a circle
Area = rs
Triangle circumscribe by circle
Area = (abc)/4R
Sum of diagonals
(n/2)(n-3)
Area of Quadlirateral(diagonal)
A= 0.5(d1)(d2)sin(theta)
Formula for parallelogram
(d1)^2 +(d2)^2 = 2(a^2 +b^2)
Volume and Area of tetrahedron
V = (a^3)/6sqrt(2) : A = (a^2)sqrt(3)
Area of polar(integral)
(0.5)INTEGRAL(r^2)
Law of Cooling
T = Tm +Ce^(kt)
DBM
K = 1- nth root of (SV/FC)
DDBM
0 - FC; 1 - FC(1-2/n)
CC
FC + (FC-SV) or Mainte/(1+i)^k -1
Correction for Distances
Cd = (MD/TL)(error)
Correction for sag
(W^2L^3)/(24P^2)
Probable Error single measurement
0.6745(Sx)
Rate of Accident (Highway)
(# 100M)/(L N 365 ADT)
Impact factor
e + f =(v^2)/(gR)
Radius of Vertical Summit SSD
S^2/2(sqrtH1 + sqrtH2)^2
Vertical Sag L>S
L = (AS^2)/(122 + 3.5 S)
Horizontal Curve L>SD
R = (S^2)/8M
Horizontal Curve L<SD
R= (2SL - L^2)/8M
y (Dist from Ts to any point in Tangent)
L - (L^5)/(40 R^2 Ls^2)
Length of Spiral given velocity
Ls = (0.036V^3)/R
Centroid of parabolic shape from base
(1/3) of heigth
Rigidity of of Axial
AE
What is stiffness
Force or Moment/Deformation Rotation
Shape factor
Mp/Me or Z/S
Shear Flow
R/S or VQ/I
M/I is equivalent to
E/rho(radius of curvature)
Max y for simply supported beam supporting point load
(Pb*(3L^2 - 4b^2))/48EI
Max y for simply supported beam supporting uniform load
(5wL^4)/384EI
Allowable concrete stress
0.45 f’c
Allowable steel stress if Fy= 420 MPa
170 Mpa
Cracking Stress
fr = 0.62f’c
Modulus of elasticity of light weight concrete
0.043 (f’c^1.5) sqrt(f’c)
Cmax
(3/7) d
Av min with f’c
(0.062 sqrt(f’c) bw S)/fyt
Av min without f’c
(0.36 bw S)/fyt
Shear capacity of concrete
0.17 sqrt(f’c) bw d
Spacing formula for design of shear reinforcement
S= (Av fyt bw d)/ Vs
complex number exponential form
re^(theta i)
complex number trigonometric form
rcos(theta) + ir sin(theta)
period formula
P = 2pi/B
Median of triangle
4Ma^2 = 2c^2 + 2b^2 - a^2
Perimeter of ellipse
P= 2pi sqrt((a^2 + b^2)/2)
Volume of Spherical segment 1 Base
V = ((pi h^2)/3) (3R-h)
Volume of Spherical segment 2 Base
V = ((pi h)/6) (3a^2 +3b^2 + h^2)
Spherical zone area
2 pi r h
Latus rectum of parabola
LR= 4a
Exact DE solution Value of K(y)
INTEGRAL(N- partial(INTEG of M)) dy
Correction to slope
h^2 / 2S
Hcr
0,0675k^2
SD (Stadia method)
SD = (f/i)s cos(theta) +f+c
Sx
sigma x (n-1) (sample deviation)
Relative precision
RP = PE/mpv
Weight
1/ PE^2
MPV
average or Sum xW/W
Density
Vehicles/Length
Kjam
4qmax/Free flow
Peak hour Factor
sum of vehicles/(Max Xmin volume/ Xminute) *60 minute
Frog number
HL/HS or 0.5cot(theta/2)
Design of Pavement center dowel
sqrt(3W/4f)
Stopping SD
SSD= Vitr + (Vi^2)/(2g)(f+-G_
Vertical Sag R
R= (V^2)/6.5
Prismoidal Correction
L/12 (H1-H2)(C1-C2)
Deflection at any point X of cantilever beam
yEI= ((Px^2)/6) (3a - x) (fr. 0 to a)
Spacing for spiral column
S= (4As (Dc - db))/ DC^2 *rhossteel (FR. 25 - 75)
Wide beam shear stress
Vu/(0.75 bw d)
Pressure of Footing (Axial & Moment) if e actual > L/6
q= 2P/3aWidth
Purlins with sagrods 1 and 2
1/32 and 1/90 wL^2
Allowable buckling Axial load (Eulers)
(pi^2 EI) / (KL)^2
Allowable shear stress of steel
0.3Fu
Allowable bearing stress of steel
1.2Fu
Block Shear
P= 0.3FuAv + 0.5FuAt
Strenght based on Yielding
P = 0.6Fy Ag
Summation of errors
Esum = sqrt(squred of individual errors)
Product of errors (sample in Areas)
Ep= sqrt((b ERROR a)^2 +(a ERROR b)^2)
Service rate
(Time interval)/meter cycle
Benefit cost ratio
P Income/ P capital
Mean value thorem
F’c = (f(b) - f(a)) / (b-a)
Sum of roots
SOR= -b/a
Product of roots
POR= constant/ coeff of highest exp
Area of common shapes given sides
A= ns^2 / 4tan(180/n)
HP to Watts
1 HP = 746 watts
Metacentric height
MG = MB - GB (if stable)
MB formula floating boadies
MB = I/Vd
Height of paraboloid in rotating vessel
Y= w^2x^2 / 2g
Rectangular weir
Q= (2/3)C sqrt(2gH) ((H+Hv)^(3/2) - Hv^(3/2))
Triangular weir
Q= (8/15)Csqrt(2gH) tan(theta/2)H^(5/2)
Triangular weir if 90°
Q= 1.4H^(5/2)
Cipolleti weir (4V:1H)
Q= 1.859H^(5/2)
Volume of paraboloid
V= (pi r^2 h) /2
Reynolds number
Re = (Diameter Vavg)/kinetic viscosity ; K viscosity = dynamic viscosity/rho
Friction factor if laminar
f= 64/Re
coefficient of friction if turbulent
f= 0.3164/ 4th root of(Re)
Celerity of non rigid pipe
C = sqrt( Eb / (rho(1+ (Eb d / Es t))))
Time of closure
Tc = 2L/Celerity
Pressure in water hammer
P = rho C velocity
Composite bulk of elasticity
Inverse(Ec) = inverse(Eb) + d/Es t
Hydraulic jump
Fs1 + Fd1 = Fs2 + Fd2
Hydro dynamics
Fs= rho Q Velocity
Boundary shear stress
To = Rh gamma slope
Froudes number
FN = sqrt( T Q^2 / A^3 g)
Terzhagi equation
qu= 1.3CNc + Df gamma Nq + 0.4 B gamma Ngamma
Radius of summit curve
R = L/ (g1 - g2)
Main bar spacing(minimum)
Largest of (4/3) Agg size ; db ; 25 mm
Dimensions are adequate in shear if Vs is less than Vsmax of:
Vs max = 0.66sqrt(f’c) bw d
Load factor
LF = (W/Lm^3)/(W/Bm^3)
Shrinkage factor
SF = (W/Bm^3)/(W/CM^3)
Bank volume and compacted volume
BV = (cubic meter)(Load factor) ; CV = BV(Shrinkage factor)
Adjusted rate of inflation
If = i + f + i f
adj rate due to inflation
I adj. = (io - f)/(1+f)
Lenght of overhang for least possible moment
X= ((sqrt(2) - 1)/ 2 ) L
Eulers buckling load and stress
Pe = (pi^2 E Imin)/(KL)^2 Fe = (pi^2 E)/(Srmax)^2
Moment equation and shear for propped beam with support at end plastic analysis
Mp = ((3-2√2) / 2) wL^2 Vp = (2-√2)wL
Plastic moment if fixed qt both ends
Mp = (1/16) wL^2
Reaction at overhang support of cantilever beam
P = (3/8)wL
Volume of spherical triangle
V= (pi r^3)E/540°
Reduce live load (must be greater than 0.5LL)
Lo = L( 0.25 + 4.57/Atotal)
Deep water waves breaks when
H = L/7
Deepwater wave Period (d > 0.5 L)
T= (2pi/g) V
Deepwater wave length (d> 0.5L)
L = (2pi/g) V^2
Critical web yielding stress
N + 2.5k
If two vectors are perpendicular to each other their dot product is
0
If two vectors are parallel their cross product is
0
AVR (air void ratio)
AVR = (e - Se)/(1+e)
Hydraulic gradient critical
icr = (Gs-1)/(1+e)
Capillary height
h= C/eD10
Seepage force
F = i gamma water
Mas shear stress at hollow circular
Vstress = 2V/A
Residual water level
RWL= k(HWL-LWL) + LWL where k is 2/3 for pile and 1/3 for gravity type
Length of wave
L = V T(period)
Velocity of long wave
V= √(gd)
Velocity of shallow wave
V = (gT / 2 pi) tanh(2 pi d/L)
Velocity of deep wave
V = (gT)/2 pi
Palnned water depth
PWD = draft + DLT + allowance (0.5)
Half life of c-14
5730
Standard time
ST = (1+allowance) Rating HIGHEST OT
Swell
Swell % = 1/LF
