Square Foundation Design steps (with Moment)

 

 

           

Square Foundation Design steps (with Moment)

 

 

نوت: در صورت موجودیت مومنت  عن المرکزیت (e)Eccentricity به وجود آمده و به اندازه (e) عمل قوه به سمت x  و y انتقال (shift) می گردد.

Step 1:-

          

           Calculation of loads = W_T = W_c + W_F = W_c + 10% W_c

 

Step 2:-

 

           Calculation of Foundation Area (A) = W_T/p’           p’= Bearing capacity of soil

 

Step 3:-

 

           Calculation of upward pressure (p) = W_c /A

 

Step 4:-

 

           Calculation of projection 

       

           a1 = (L-b)/2 + e

           a2 = (L-b)/2 - e

 

 

 

Step 5:-

 

          Calculation of Depth of Foundation (D)

           

a)     B.M. consideration :

b)     Punching shear consideration :

 

 

a)       B.M. consideration :

 

(B.M)_max = Resisting Moment

 

pL (a)²/2 = k b d²  or  Q b d²  

 

Q=0.185 * f’c *(.09) (permissible stress/Mark of concrete )

 

d=

D = d + cover + dia . of bars

 

b)  Punching shear consideration:

 

Punching load = punching resistance

 

W_c – pL² = 4 b D q              (q) _all = 10 kg/cm²    D = (W_c – pL² ) / 4 b D q             

 

 

 

Step 6:-

 

            As = M / fy z              (As)_min = ρ_min b d

 

Step 7:-

 

            Nos. of bars:-

           

            Number of bars = As / Area of selected bars

 

 

Square Foundation Design steps (without Moment)

 

 

Square Foundation Design steps (without Moment)

 

 

 

Step 1:-

          

           Calculation of loads = W_T = W_c + W_F = W_c + 10% W_c

 

Step 2:-

 

           Calculation of Foundation Area (A) = W_T/p’           p’= Bearing capacity of soil

 

 

 

Step 3:-

 

           Calculation of upward pressure (p) = W_c /A

 

Step 4:-

 

           Calculation of projection 

       

            a = (L – b) / 2

 

Step 5:-

 

          Calculation of Depth of Foundation (D)

           

a)     B.M. consideration :

b)     Punching shear consideration :

 

 

a)     B.M. consideration :

 

(B.M)_max = Resisting Moment

 

pL (a) ( a /2) = k b d²  or  Q b d²  

 

Q=0.185 * f’c *(.09) (permissible stress/Mark of concrete )

 

d=

D = d + cover + dia . of bars

 

b)  Punching shear consideration:

 

Punching load = punching resistance

 

W_c – pL² = 4 b D q              (q) _all = 10 kg/cm²    D = (W_c – pL² ) / 4 b D q             

 

 

 

Step 6:- calculation of steel area (As)

 

 

            As = M / fy z              (As)_min = ρ_min b d  = 0.005 bd  

 

 

Step 7:- calculation of bar number

 

             

           

            Number of bars = As / Area of selected bars

           

 

Structural Loads

 

Structural Loads

Ultimate Limit States (ULS) ----------------include exceeding the loading-carrying capacity, overturning, sliding, and fracture.

Serviceability Limit States (SLS) ---------include deflection, vibration, permanent deformation and local structure damage such as cracking.

  D ...... Dead load - a permanent load dure to the weight of building components.
  E ...... Earthquake load and effects - a rare load due to an earthquake.
  H ...... a permanent load due to lateral earth pressure.
  L ...... Live load - a variable load due to intended use and occupancy.
  P ...... Permanent effects caused by pre-stress.
  S ...... Variable load due to snow, including ice and associated rain.
  T ...... Effects due to contraction, expansion, or deflection caused by teperature change, shrinkage, moisture change, creep, ground settlement, or a combination thereof.
  W ...... Wind load - a variable load due to wind.

Load Combinations for ULS

 

Case	Principal Loads	Companion Loads
1	1.4 D	-
2	(1.25D or 0.9D) + 1.5L	0.5S or 0.4W
3	(1.25D or 0.9D) + 1.5S	0.5L or 0.4W
4	(1.25D or 0.9D) + 1.4W	0.5L or 0.4S
5	1.0D + 1.0E	0.5L + 0.25S

 

 

Open Channel Hydraulics

Open Channel Hydraulics

 

The capacity of ditches and channels is calculated using Manning's equation.

The minimum velocity of flow should be 0.6 m/s in order to prevent the settling of solids.

for concrete sewers, the maximum velocity should be 3 m/s in order to prevent continuous and grit erosion, for other materal, see following table.

 

Closed storm sewers should be designed to flow full for the design storm.

 

For circular shapes:
 circular shapes, wetted perimeter WP = 3.14 D, wetted cross sectional area = 3.14 D²/4
 
Reference:

Chow, Ven Te. Open-Channel Hydraulics   McGraw-Hill Book Company. New York

 

 

Maximum Design Velocity of Ditches

 

Material	Velocity (m/sec)
Fine Sand	0.45
Silt loam or silt	0.45
Fine gravel	0.76
Sandy clay or clay	0.9
Sod	0.9
Stiff clay or ordinary gravel soil	1.25
Coase gravel,hardpan,shale,soft rock	1.8
Hard rock	3.0
Lined: Asphalt, concrete or gunite	3.0

 

 

Roughness Coefficient for Closed Sewers

 

Material	n
Polyvinyl chloride pipe	0.01
steel	0.011
ductile iron	0.013
cast iron	0.013
cement lined pipe	0.015
concrete pipe	0.013
vitrified clay pipe	0.013
fiberglass reinforced plastic	0.01
corrugated metal pipe	0.024
HDPE, smooth interior	0.01
HDPE,corrugated interior(4-6 in)	0.015
HDPE,corrugated interior(8 in)	0.016
HDPE,corrugated interior(10 in)	0.017
HDPE,corrugated interior(12-15 in)	0.018
HDPE,corrugated interior(18-24 in)	0.02

 

 

 

 

 

 

Roughness Coefficient for Ditches and Channels

 

Material	n
poured concrete	0.014
short Crete	0.016
asphalt	0.014
rip rap	0.035
crushed rock	0.025
grass	0.03
fine sand, silt	0.02
sand, gravel	0.025
coarse gravel	0.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Storm Drainage Design

 

Storm Drainage Design

1. Rational Method:

    a). The intensity of the rainfall is constant and is applied to the entire watershed
    b). The runoff coefficient remains constant throughout the storm event
    c). The frequency of the peak flow is equal to the frequency of the rainfall intensity

   Rational Formula:

   Q = 10 C.i.A

     Q - peak runoff, m³/hr 

     C - runoff coefficient

     i - rainfall intensity, mm/hr

     A - Tributary area, hectares (10⁴ m²)

   runoff Coefficient:

     Concrete pavement = 1.0

     Asphalt = 1.0

     Lawns = 0.2

     Uncompacted soil = 0.2

     Natural soil, grass cover = 0.4

     Compacted sand soil = 0.4

     Uncompacted gravel = 0.5

     Natural bare soil = 0.6

     Compacted gravel = 0.7

     Oiled compacted soil = 0.8

     Compacted impervious soil = 0.6

     Composite runoff coefficient:

    C = (A₁.C₁+ A₂.C₂ + ...) / (A₁+A₂ + ...)

2. time of Concentration

   This is the time it takes for water to flow from the most remote point in the watershed to the point of discharge

  Intial time of concentration for sheet flow:  t_c = 7 n^0.6 . L^0.6 / ( i^0.4 . s^0.3)

     t_c - the time of concentration, minutes

     n - Manning resistance coefficient

     L - the distance from the upper end of the plane to the point of interest in meters

     i - rainfall intensity, mm/hr

     s - slope of the surface

   Minimum time of concentration: for paved areas, 5 minutes; for unpaved area, 10 minutes

   Manning's Resistance Coefficient (n):

     Concrete,asphalt = 0.01-0.013

     Sand = 0.01-0.016

     Lawns = 0.2-0.3

     Bare clay = 0.012-0.033

     Gravel = 0.012-0.03


3. Intensity-Duration-Frequency Curve(IDF):

   i = a / (t + b)

     i - intensity of rainfall, mm/hr

     t - duration of rainfall, hr

     for example:

    i₁ = 72mm/hr, t₁ = 0.25 hr,

    i₂ = 3 mm/hr, t₂ = 24 hr;

    then, a =72.2, b = 0.753;

    If t = 1 hr, then, i = 72.2 /(1+0.753) = 41 mm/hr


4. Travel Time:

  Time of flow in one reach + Initial time of concentration of the area


5. Storm Runoff at Junctions

   For tributary area with longer time of concentration, Q₁, T₁, i₁
   For tributary area with shorter time of concentration, Q₂, T₂, i₂

    If T₁ = T₂,     Q = Q₁ + Q₂,     T = T₁

    If T₁ > T₂,     Q = Q₁ + Q₂.i₁/i₂,     T = T₁

    If T₁ < T₂,     Q = Q₂ + Q₁.i₂/i₁,     T = T₂

Reference: Chow, Ven Te. Handbook of Applied Hydrology, Mcgraw Hill Inc. New York Chow Ven Te. Open-Channel Hydraulics, Mcgraw Hill Inc. New York

 

Foundations for Vibrating Machines

 

Foundations for Vibrating Machines

1. Trial Sizing of Block Foundation:

  The bottom of the block foundation should be above the water table, wherever possible. In addition, block foundation should not rest on backfilled soil or on soil sensitive to vibration.

  Block foundation resting on soil should have a mass of 2 or 3 times the supported mass for centrifugal machines, and 3 to 5 times for reciprocating machines.

  Top of the block foundation is usually kept 300 mm above the finished floor to prevent damage from surface water runoff.

  The thickness of the block foundation should not be less than 600 mm, or as dictated by the length of the anchor bolts. In any case, the thickness of the block shall not be less than 1/5 of the least dimension and 1/10 of the largest dimension of the foundation in plan, whichever is greater.

  The block foundation should be widened to increase damping in rocking mode. The minimum width should be 1 to 1.5 times the vertical distance from the machine base to the machine center line.

  The plan dimensions shall be such that the block foundation extends at least 300 mm beyond the edge of machine for maintenance purposes.

  The length and width of the block foundations shall be such that plan view eccentricities between the center of gravity of combined machine-foundation system and the center of resistance (center of stiffness) should be less than 5% of plan dimensions of the foundation

  Should the dynamic analysis predict resonance with the machine frequency, the mass of the block foundation shall be increased or decreased so that the modified foundation is over-tuned or under-tuned for reciprocating and centrifugal machines respectively.

  The footing area shall be such that the soil bearing pressure under the combined dead load of the machine and foundation shall not exceed 50% of the allowable value.

  Combined static and dynamic loads shall not create a bearing pressure greater than 75% of the allowable soil pressure given in the geotechnical report.

2. Equivalent static loading method: (for design of foundations for machines weighing 10,000 lb (45 kN) or less

  Static Loads:

  Reciprocating Machines:

  The weight of the machine and the self weight of foundation block, the live load of platforms and any other loads on the foundation.

  Unbalanced forces and couples supplied by machine manufacturer.

  Centrifugal Machines:

  Vertical pseudodynamic design force is applied at the shaft, it can be taken as 50% of the machine assembly dead weight.

  Lateral pseudodynamic forces representing 25% of the weight of each machine, including its base plates, applied normal to its shaft at mid point between end bearings.

  Longitudinal pseudodynamic forces representing 25% of the weight of each machine, including its base plates, applied along the longitudinal axis of the machine shaft.

  Vertical, lateral, and longitudinal forces are not considered to act concurrently.


3. Dynamic Analysis:

  Velocity = 6.28 f (cycles per second) x displacement amplitude. Compare with limitation values for 'good' operating condition.

  Magnification Factor (applicable for machines generating unbalanced forces). The calculated value of M or Mr should be less than 1.5 at resonant frequency.

  Resonance: The acting frequencies of the machine should not be within a 20% of the resonant frequency (damped or un-damped).

  Transmissibility Factor: It is usually applied to high frequency, spring-mounted machines. The value of transmissibility factor should be less than 3%.

  Resonance of individual components (supporting structure without the footing) shall be avoided by maintaining the frequency ratio either less than 0.5 or greater than 1.5.

  For pile foundations, the effects of embedment are often neglected. Floating piles have lower stiffness but higher damping than end-bearing piles

  Unbalanced forced for centrifugal machines:

  1). from balance quality by manufacturer:
    e = Q / w   (mm)
    F₀ = m_r.e.w².S_f / 1,000   (N)

    F₀ - dynamic force (N)
    m_r - rotating mass (kg)
    e - mass eccentricity (mm)
    w - circular operating frequency (rad/s)
    S_f - service factor, = 2
    Q - Balance quality, i.e.   for G6.3, Q = 6.3

  2). from empirical formula:
    F₀ = W_r.f₀ / 6,000
    f₀ - operating speed   (rpm)
    W_r - weight of rotor   (N)

  For DYNA5, F^* = F₀ / w²

4. Drive torque:

  NT = 5250 (P_s) / f₀   (lb-ft)
  NT = 9550 (P_s) / f₀   (N.m)

  NT - normal torque   (m-N)
  P_s - power being transmitted by the shaft at the connection, horsepower(kilowatts)
  f₀ - operating speed,   (rpm)

5. Misc. items

  1 mil = 0.001 in. = 25.4 microns ( 1 micron = 10^-6)

  In foundation thicker than 4 ft (1.2m), the minimum reinforcing steel is used (ACI207.2R), or a minimum reinforcing of 3.1 lb/ft³ (50 kg/m³ or 0.64%) for piers and 1.91 lb/ft³(30 kg/m³ or 0.38%) foundation slabs. For compressor blocks, 1% reinforcing by volume.

  For dynamic foundation, epoxy grout should be used

  Anchor bolts should be as long as possible so that the anchoring forces are distributed lower in the foundation or ideally into concrete mat below the foundation pier

  For compressor foundation, post-tensionin anchor bolts are used to prevent the generation of crack. the embeded end is anchored by a nut with a diameter twice the rod diameter and a thickness 1.5 times the rod diameter, minimum anchor bolt clamping force of 15% of the bolt yield strength is required

  6. Reference: ACI351.3R

 

Foundations for Vibrating Machines

 

Design Criteria for Horizontal Equipment

1. Wind Load:

  a). Basic diameter = diameter O.D. + 2 ( shell thickness + insulation).
    effective projected area = height x I.F. x basic diameter.

  b). Intensification Factor (I.F.):

    Diameter ≤ 760 mm, I.F. = 1.50
    Diameter 900 to 1350 mm, I.F. = 1.40
    Diameter 1370 to 1960 mm, I.F. = 1.30
    Diameter 1980 to 2570 mm, I.F. = 1.20
    Diameter ≥ 2590 mm, I.F. = 1.18

  c). The vessel saddle to pier connection shall be considered fixed for transverse loads.

  d). Longitudinal winds shall be resisted by the fixed end pier only.

  e). The force required to remove tubes from heat exchanger shall be 100% of bundle weight, but ≥ 19kN.


2. Load Combinations:

  Empty Load (or Erection Load) + Wind (Seismic)
  Operating Load + Temperature + Live Load
  Operating Load + Wind (Seismic)
  Operating Load + Temperature + Wind (Seismic)
  Operating Load + Temperature + Live Load + Wind (Seismic)
  Test Load
  Test + 0.5 Wind (Seismic)
  Empty Load + Bundle Pull Load (applies to supports only)


3. Sliding Plates:

  Teflon plates are normally 25 mm smaller than the length and width of the saddle base leaving 12.5 mm margin all around.

  Vessel support and top Teflon plate shall have horizontal slotted holes to allow movement due to expansion and contraction.


4. Pier Design:

  Pier shall be designed as cantilever columns, k = 2.0.

  Pier width ≥ 10% of height or 300 mm, minimum concrete cover for anchor bolts shall be 100 mm.

  Normally, pier dimensions = saddle support base plate size + 100 mm.

  A double tie shall be placed at top of piers spacing 50mm and 125mm below top of concrete.

  Minimum vertical reinforcement = 0.25% times gross section area.


5. Footing Design:

  The common footing is used for pier spacing ≤ 4m.
  Use two separate spread footing when pier spacing > 4m, tie beam may be used.


6. Normally, the stability ratio is ≥ 1.5 for sliding and overturning.


7. Soil Bearing:

    e ≤ a/6     B.P._max = P/a [1 + 6e/a]         B.P._min = P/a [1 - 6e/a]
    e > a/6     B.P. = 2P / [3a(a/2 - e)]

 

 

Design Criteria for Vertical Equipment

Design Criteria for Vertical Equipment

1. Wind Load:

  Basic diameter = diameter O.D. + 2 (shell thickness + insulation),
    effective projected area = height x I.F. x basic diameter.

  For shape factor, rough surface is used.

  Gust factor > 2.0, for slender vessel, vortex shedding shall be considered.

  Intensification Factor (I.F.):

    Diameter ≤760 mm, I.F. = 1.50
    Diameter 900 to 1350 mm, I.F. = 1.40
    Diameter 1370 to 1960 mm, I.F. = 1.30
    Diameter 1980 to 2570 mm, I.F. = 1.20
    Diameter≥ 2590 mm, I.F. = 1.18

    For tall vessel (≥ 30 m), the strong wind 1/100 year wind pressure is used.


2. Load Combinations:

  Empty Load (Erection Load) + Wind (Seismic)
  Operating Load + Temperature + Live Load
  Operating Load + Wind (Seismic)
  Operating Load + Temperature + Wind (Seismic)
  Operating Load + Temperature + Live Load + Wind (Seismic)
  Test Load
  Test + 0.5 Wind (Seismic)


3. Anchor Bolts Design:

  Maximum tension = 4.M / (N x BC) - W / N.

    M - maximum overturning moment at base of vessel.
    N - number of bolts.
    BC - diameter of bolt circle.
    W - weight of vessel.

  The dead load factor for overturning is 0.85.

  Normally, for bearing type bolt shear capacity, only half of anchors actually transfer the shear load.

  If anchor bolt in tension and concrete pull-out capacity is not enough, vertical dowels are required to transfer tensile forces to foundations, for development length of rebars , check ACI351.3R 4.2.1

4. Pedestal Design:

  Pedestal shall be designed as cantilever columns, k = 2.0.

  The pedestal size ≤ 1.5m, square pedestal may be economical, normally, octagonal shape is used.

  Top of pedestal is 300 above grade.

  Face to face pedestal size:

  Bolt circle + 200 mm
  Bolt circle + 8 x bolt diameters.
  Bolt circle + Sleeve diameter + 150 mm
  Diameter of base plate + 100 mm.

  Maximum dowel tension = 4.M_u / (n x BD) - W_u / n.

    M_u - maximum overturning moment at base of pedestal.
    n - number of bars.
    BD - diameter of bar circle.
    W_u - Factored vertical load (factor =0.85).

  Minimum reinforcement:

    Octagon ≤ 2.7 m, 16 - 25M vertical with 10M ties at 400 mm maximum.
    Octagon 2.75 to 3.7m, 24 - 20M vertical with 15M ties at 250 mm maximum.
    Octagon > 3.7 m, 32 - 20M vertical with 15M ties at 250 mm maximum.
  Pedestal over 1.8m shall have a mesh at the top, 10M at 200mm spacing in both direction, minimum.


5. Footing Design:

  The footing size ≤ 1.5m, square footing may be economical, normally, octagonal shape is used.
  Minimum thickness is 300 mm.
  Minimum rebars 15M @ 300 c/c for top and bottom both direction.
Top of footing shall be minimum 300 mm above grade.


6. Normally, the stability ratio is = 1.5 for sliding and overturning, but for tall vessel (≥ 30m), 2.0 is used.


7. Soil Bearing:

  Allowable soil bearing pressure may be increased 33% for wind or seismic loading.

  Bearing pressure for square footing:

  For axis 1-1:
    B.P._max = [ 1 + 8.485e / a] P /a²
    B.P._min = [ 1 - 8.485e / a] P /a²

  For axis 2-2:
    e = a/6     B.P._max = P/a [1 + 6e/a]     B.P._min = P/a [1 - 6e/a]
    e > a/6     B.P. = 2P / [3a(a/2 - e)]

  Bearing pressure for octagonal footing:

    B.P._max = 1.2[ 1+ 8.19 e/D] / D²
    B.P._min = 1.2[ 1- 8.19 e/D] / D²


8. Foundamental Frequency:

  For a vessel with constant wall thickness, constant diameter, and a fixed base, the natural frequencies are those for a cantilever beam:

  n_i = k_i / H²[ E.I /M]^0.5

  n_i = frequency of mode i (Hertz)

  K_i = constant

    = 0.56 for mode 1
    = 3.51 for mode 2
    = 9.82 for mode 3
    = 19.2 for mode 4

    H = height of vessel(m)
    E = Modulus of elasticity (pa)
    I = moment of inertia of vessel(m⁴),   I = p.d³.t / 8
    M = mass of vessel per unit length. (kg per meter or N.s² /m per meter, = N / 9.81)
    d = inside vessel diameter (m)
    t = vessel wall thickness (m)


9. Tall vessel structural damping:

  It depends not only on the vessel itself, but also on the vessel soil-structure interaction.

    Concrete vessel: 0.0150 – 0.025
    Steel vessel: 0.005 – 0.015
    Unlined steel stack: 0.0016 – 0.006
    Gunite-lined steel stack: 0.003 – 0.012
    Concrete chimney: 0.004 – 0.020

    The lower values are appropriate for foundation on rock or piles, average values are appropriate for foundations on compacted soil,
    

 higher values are appropriate for vessels supported by elevated structures or soft soils.

وسلام

Design Criteria for Industrial Structures

 

 

Design Criteria for Industrial Structures

Pipe Supports:

1. General:

  Type and location of pipe supports including shoes, anchors, spring hangers, and guides shall be indicated on isometrics and/or orthographic piping drawing for 2 inch lines or larger. Support locations for 1.5 inch and smaller lines shall be shown when such lines are critical.


2. Pipe Support Shoes:

  Hot-insulated lines 2 inch and larger, and all steam-traced lines, shall be provided with support shoes at all support locations.

  Shoes supporting stress-relieved lines shall be clamp-on type. Standard lengths of support shoes:

    12 inch for up to 3 inch thermal movement in each direction.
    18 inch for up to 6 inch thermal movement in each direction.
    24 inch for 6 in. to 9 inch thermal movement in each direction.
    36 inch for 9 inch to 15 inch thermal movement in each direction.

  Cold-insulated lines shall have support shoes strapped to the outside of the insulation at the support points.

  Guides and anchors designed for small to medium forces may be used with shoes strapped on to the outside of the cold-insulation of piping.


3. Lines from Vertical Vessels:

  Support brackets for 6 inch and smaller lines will be designed as single-bracket.
  For lines 8 inch and larger, double-bracket type as required.

4. Lines over Exchangers:

  Supports shall be attached to the exchanger saddle, shell flange or its foundation.


5. Lines from Horizontal Drums:

  Lines from nozzles on top of vessels to grade may be supported from grade guided near the center of the vessel.


6. Piping at Pumps and Turbines:

  Piping 3 inch and larger shall be supported by adjustable base supports to the structural members or by non-adjustable types supported to grouted-in base plate.

  If possible pavement frost heave or settlements, base supports shall rest on the pump foundation or a structural member attached to its foundation.


7. Relief Valves:

  Piping connected to relief valves shall be supported.


8. Mechanical Support Devices:

  Variable spring supports shall be used for supporting lines and equipment with a vertical thermal movement up to 3 inch.

  Constant supports shall be used for supporting lines and equipment with a vertical thermal movement more than 3 inch.


9. Tank field Piping:

  Lines connected to tanks subject to settlement shall have the first support located at sufficient distances from the tank to avoid excessive stress.
For large settlement, the lines shall be supported from the tank or by adjustable or spring supports from grade.


Pipe Rack Design:


1. Basic Design:

  Braced bay should be located away from bays where pumps or similar equipment are to be located in the vicinity of column line.
  To provide flexibility for future expansion, no piping should run on the center line of columns except flare line.
  Pipe rack bents are spaced 20 feet on centers, the others carrying small tubing or electrical conduit may be 10 feet.


2. Transverse Beams:

  Unbraced length of the compression flange should be between points of inflection.
  Effects of torsion should be considered for anchor forces.


3. Longitudinal Beams:

  Beam struts should be designed for 50% of gravity loading on the most heavily loaded transverse pipe support beam.
  The above load should not be added to the design load for column or footing.


4. Vertical Bracing:

  The maximum spacing of braced bay should be 200 feet, normally 120 feet.


5. Column for Weak Axis:

  The unbraced length is from the base to the first longitudinal beam.
  Effective length factor k =1.0 for pinned base, k=0.7 for fixed base.


6. Column for Strong Axis (Sway Frames):

  The unbraced length is from the base to the first transverse beam.
  Rigid frame with pinned base, for effective length factor (k=2.5), GL=10.
  Rigid frame with fixed base, for effective length factor (k=1.5), GL =1.
  Knee frame with pinned base, for effective length factor (k=3.0), GU =10 and GL =10, but KL does not need to exceed the KL if the frame was designed as a moment connected rigid frame.
  Knee frame with fixed base, for effective length factor (k=1.9), GU =10 and GL =1, but KL does not need to exceed the KL if the frame was designed as a moment connected rigid frame.


7. Structure Sway:

  a). Pipe rack frames:

    For 30 years wind, Height / 150.
    For 10 years wind, Height / 180.
    1.2 inch for support 18 feet above grade.
    2.0 inch for support 30 feet above grade.

  b). Equipment Support Structures:

    For 30 years wind, Height / 200.
    For 10 years wind, Height / 240.
    2.3 inch at the equipment floor 46 feet above grade.
    3.0 inch at the equipment floor 60 feet above grade.

  c). Industrial Building Frames:

    For 30 years wind, Height / 170.
    For 10 years wind, Height / 200.
    2.4 inch at the top of a 40 feet tall building frame.
    2.0 inch for support 30 feet above grade.

  d). Vertical deflection of platform:

    Vertical deflection of platform framing beams = span / 300.
    Vertical deflection of equipment support points due to the 50% live load and the operating liquid weight = 3/8 inch.


8. Deflection Limits:

  a). Cable tray and pipe supports:

    Horizontal, Height / 200.
    Vertical, Height / 180.

  b). Platform and walkways: Length / 180.


Foundation and Grout:

1. Foundation:

  a). Foundations shall be placed a minimum of 10 feet below grade or shall be insulated to reduce the frost penetration to less than the depth of the underside of the foundation.

  b). The supports for all tanks, vessels and pipes shall be designed for hydrotest.

  c). Foundations supporting rotating equipment not as a heavy one shall be:

    The ratio of weight of concrete to weight of equipment shall not be less than 3 to 1 for rotary, 5 to 1 for reciprocating one.
    Min. 2 rows of ties provided around anchor bolts in the top of pedestals, A horizontal layer of temperature steel provided in the top of pedestals.

  d). All graded-supported concrete paving slab shall be isolated from columns and foundations by expansion joints.

  e). Top of concrete piers for structures or equipment shall be = 8 inch above HPFS (high point of finished surface).

  f). Foundation or pedestal inside buildings shall be = 6 inch above HPFS.

  g). Anchor bolt sleeves be provided at foundations for Spheres, Coker, Vertical Vessels, Pumps, Compressors, Heaters, and Boilers, free standing stacks, etc.

  h). Two nuts be provided at crane columns and at base of structures having vibrating and reversal loads.

  i). Frost adhesion for the foundation surfaces: Concrete 65 kPa, Steel 100 kPa.


2. Grout:

  a). Non-shrink cementitious grout, Compressive strength 30 MPa to 55 MPa :

    Centrifugal equipment less than 100 HP (except use in hydrocarbon).
    Constant wet environment will not exist.
    Wet-dry cycling associated with exterior use will not occur.

  b). Non-shrink epoxy grout, Compressive strength 55 MPa to 80 MPa :

    Reciprocating or centrifugal equipment greater than 100 HP.
    Constant wet environment will exist.
    Wet-dry cycling associated with exterior use will occur.

  c). Non-shrink high-temperature grout, Compressive strength 35 MPa: High-temperature up to 500 degree.

  d). Grout holes for placement of the grout should be located so that grout does not travel more than about 48 in. (1.2m).

    Holes for pumping grout are typically 3/4 to 2 in. (19 to 50 mm) in diameter.

  Grout holes for free-pouring grout are typically 3 to 6 in. (75 to 150 mm) in diameter.

    e). If anchor bolt sleeves are to be grouted, anchor bolt sleeves and holes should be grouted before pouring grout under the plate.

    For post-tensioned anchor bolts with sleeves, sleeves shall be not grouted, a greese or mastic type filler should be filled inside the sleeves

  f). For hydraulic cement grouts, the concrete surface should be continuously saturated with water for at least 24 hours just prior to grouting

    For epoxy grout, the surface should be dry unless otherwise specified by the manufacturer.

Design Loads:

1. Loads for Pipeway:

  a). Load for piping and cable tray shall be dead load.

  b). The actual vertical load from pipes be used but shall be = 2.0 kPa on each level, the effects of large pipes and snow load shall also be considered.

  c). For miscellaneous pipe supports, minimum load = 1.2 kPa.

  d). Thermal expansion forces shall be:

    10% of total operating weight of all pipes.
    30% of the operating weight of the largest pipe.
    On supports having three lines or less, 20% of the total pipe weight.
  e). Anchor loads 9kN shall be considered to act at 1/4 points of the beam.

  f). For electrical loads, a minimum weight of 1.0 kPa shall be used for single tray, 2.0 kPa shall be used for double tray.


2. Thermal Forces:

  a). Friction coefficients:

    Steel to steel = 0.3
    Steel to concrete = 0.5
    Teflon to Teflon = 0.1
    Teflon to steel = 0.1
    Graphite to graphite = 0.15
    Lubrite plate on steel (temperature = 250) = 0.2
    Lubrite plate on steel (temperature < 250) = 0.15
    Lubrite plate on steel (bearing stress < 3.5 MPa) = 0.18

  b). Teflon shall not be used if temperature exceeds 260 degree, stainless steel or lubrite shall be provided. Lubrite shall only be used if bearing and/or temperature ratings are exceeded on Teflon.


3. Maintenance Load (live load):

  a). Tube bundle removal horizontal force for exchanger equal to the empty bundle weight or 8.9 kN whichever is greater.

  b). The force is applied at the centroid of the tube bundle.



4. Impact Loads (increased percentage):

  a). Hand operated cranes and monorail:

    Vertical = 10%.
    Lateral = 20%
    Longitudinal = 10%

  b). Electrically operated cranes and monorail:

    Vertical = 25%
    Lateral = 20%
    Longitudinal = 10%

  c). Davits, lifting Eyes and Supporting Structures:

    Vertical = 50%
    Lateral = 20%
    Longitudinal = 10%

  d). Vibrating Equipment:

    Elevator supports or Light machinery = 20%
    Heavy and reciprocating machinery = 50%
    Motor turbine driven equipment supports = 200%


5. Module Lifting and Transportation Load:

  a). The impact force due to lifting shall be 30% of weight of the module, therefore, the load combination 1.25(1.3V).

  b). The horizontal forces during transportation shall be:

  i) Off-Site:

    Longitudinal impact factor is 0.3g
    Transverse impact factor is 0.2g
    Vertical impact factor is 0.2g.
    Thus: load combinations: 1.25 (1.2V + 0.3L) and 1.25 (1.2V + 0.2T)

  ii) On-Site:

    Longitudinal impact factor is 0.1g
    Transverse impact factor is 0.05g
    Vertical impact factor is 0.
    Thus: load combinations: 1.25 (1.0V + 0.1L) and 1.25 (1.0 V +0.05 T)

  c). For lifting lug design, the applied loads including impact shall be multiplied by a factor 3 as a minimum (ASD).


6. Load Combination:

  Friction and wind or seismic loads are not combined,friction loads relieve themselves during wind and earthquake. Anchor load is different from friction loads, it should be combined with wind or seismic load

  Wind and earthquake loads are not considered to act simultaneously.

  Test load + live load + wind load shall be considered.

 

 

 

اهمیت مهندسی راه وساختمان (عمران)

 طوریکه به همه معلوم است سرپناه از جمله نیازهای اساسی و اولیه نوع بشر است که در دوره­های مختلف زندگی او بصورتهای مختلفی به این نیاز پاسخ داده شده است. انسانهای اولیه از غارها که بصورت طبیعی ساخته پدیده­های زمین شناسی بودند استفاده می­کردند. ولی آیا انسان بلند پرواز که همواره سعی در بدست آوردن و رام کردن طبیعت دارد، می­توانست به این مکانهای محدود و بی روح بسنده کند؟

انسانها با بکارگیری ابزارهای دست ساز خود و استفاده از منابعی که طبیعت در اختیار آنها قرار می­داد، اقدام به ساخت محلی برای زندگی خود کردند. با پیدایش اولین سرپناه دست ساز بشر پایه و اساس مهندسی عمران بوجود آمد. با بزرگتر شدن جوامع و نیاز آنها به سرپناههای بزرگتر، و تلاش بشر در جهت مهار و رام کردن طبیعت در جهت رفع نیازهای خود همانند ساختن سدها و پلها و ... رفته رفته نقش مهندسی عمران در زندگی بشر پررنگ و پررنگتر شد.

پیشرفتهای بزرگی که امروزه شاهد آن هستیم در سایه آرامش و ایمنی ایجاد شده توسط مهندسی عمران حاصل گردیده­است. مهار قهر طبیعت همانند سیل و زلزله و طوفانهای وحشتناک، هدیه­هایی هستند که مهندسی عمران به جامعه امروزی عطا کرده است. از طرف دیگر سرکهای  ارتباطی که همچون شریانهای حیاتی جامعه هستند، سدهای عظیمی که برق را به ارمغان می­آورند، تونلهایی که دل کوهها را می­شکافند و ... همگی شواهدی بر اهمیت این رشته مهندسی دارند.

در زبان انگلیسی به مهندسی عمران Civil Engineering اطلاق میشود که Civil به معنی تمدن و از همان ریشه کلمه Civilization است. پس میتوان نتیجه گرفت همانطور که از اسم این رشته پیداست، مهندسی عمران یعنی مهندسی تمدن! و تقریبا بیش از سایر رشته­های مهندسی به جامعه نزدیکتر است.

در افغانستان رشته مهندسی عمران بنام انجینری سیول  یاد شده ومدت تحصیلی آن ۵ سال می باشد.

انجینری سیول در فاکولته انجینری کابل شامل بخش های ذیل می باشد:

۱- ساختمان 

۲-سرک 

۳- پل 

۴- بند ونهر 

۵- واتر سپلای و فاضلاب