Sizing of Pile Caps(Part-1)

*Sizing of Pile Caps(Part-1)*
The size of the pile cap depends
on pile spacing and soil type.

ဆိုတ့ဲ အတိုင္း Pile Cap Design ရဲ႕
အ ေရးၾကီးတ့ဲအခ်က္ေတြထဲက ၂ ခုက
(1)Soil Type နဲ႕(2)Pile spacing ပါ
Junior မ်ား အတြက္(2)Spacing of
Pile ကို အဓိက ေဆြးေႏြးခ်င္ ပါတယ္
The spacing of the piles in a group
is an extremely complicated
subject as it is related to the
sub-soil properties....ဆိုသလိုပဲ
Pile ေတြရဲ႕ spacing ကလဲ
Site ရဲ႕ Soil ေပၚမူတည္ျပန္ပါတယ္
က်ေနာ္က ေတာ့ Soil အ ေၾကာင္း
မကြ်မ္းက်င္ လို႕ မ ေဆြးေႏြးလိုပါ ..
Structural designer မ်ားအ ေနနဲ႕
က ေတာ့ ဒီ stage မွာ Geotect ရဲ႕
Consultation ကို ယူရမွာပါ
နည္းပညာေက်ာင္းသား/သူမ်ားအ ေနနဲ႕
Minimum spacing ကိုေတာ့သိထားဖို႕
လိုအပ္ပါတယ္ ... ဆရာၾကီးဦးညီလွငယ္
ျပဳစုေရးသားထားတ့ဲ စာအုပ္မွာေတာ့
A centre to centre spacing of
about ‪#‎3times‬ the butt (top)
diameter of the pile, ‪#‎but‬ not
less than 2.5 ft is customary.
e.g. if pile diameter is - 16"
minimum spacing = 3 x 16 = 48"
Note - ရိုက္ထားတ့ဲ Pile တစ္ခုရဲ႕
AllowableReaction=30to70tons
ဆိုရင္ 3 ft ေလာက္ျခားေလ့ရွိပါတယ္
‪#‎Spacing‬ က 2.5 ft ထက္ စိတ္ ရင္ Pile တစ္ခုထပ္ ရိုက္တ့ဲအခါ Pile တစ္ခုကို
သြားျပီးရိုက္ခ်ိဳးသလိုျဖစ္တတ္ပါတယ္ ..
#Spacing က်ဲလြန္းရင္ လဲ Cap ရဲ႕
Area က မလိုပဲက်ယ္လာတတ္ပါတယ္
Economic design မျဖစ္ဘူးေပါ့ဗ်ာ
e.g-4 piles are located in single
row with c/c spacing of 7 ft, its
cap will be over (3 x 7 ft) 21 ft.
Reference:page-50, Chapter(9)
Footings and Foundations, by
Saya U Nyi Hla Nge
Engineering မွာပံုေသမွတ္လို႕မရပါဘူး
က်ေနာ္ စာေရးတိုင္းေျပာေလ့ရွိပါတယ္
Engineering Work ေတြမွာအ ေျဖနဲ႕
အယူအဆ ေလးေတြ အနည္းဆံုး(2)မ်ိဳး
ရွိတတ္ပါတယ္ .. သူမ်ားေျပာသမွ်
ပံုေသမမွတ္ပဲ ‪#‎ပံုရွင္‬ မွတ္ေပးပါလို႕!
ဟုတ္က့ဲ .. PE တစ္ေယာက္ျဖစ္တ့ဲ
ဆရာၾကီး Ruwan Rajapakse က
minimum spacing ကို #3times
မဟုတ္ပဲ ... 2.5 to 3times ယူပါတယ္
Typically,
engineers use 2.5d to 3d.
If centre to centre distance
is too small, piles will damage
each other.
But, if the piles are too far,
the pile cap will be too large
and the cost will increase.
If the site contains heavy
obstructions, such as rocks or
boulders, it is advisable to use
a larger spacing.
Reference:pg.415-Chapter(29)
Pile Design for Structural and
Geotechnical Engineers, by
Ruwan Rajapakse. OCM, P E
ကဲ..2 မ်ိဳးဆိုေရာမွာစိုးလို႕3မ်ိဳးျဖစ္ေအာင္
နည္းနည္းပိုျပီးကြဲျပားတ့ဲ Reference
ဆရာၾကီး John A.Baker ကိုေပးပါမယ္
19.2-Spacing of Piles
For ‪#‎preliminary‬ drawing work,
it is recommended that the
minimum spacing between the
piles should be as follows:
(1) for ‪#‎EndBearing‬ Piles,
not less than 2ft 6in c/c or
twice the width/diameter of pile
(3) for ‪#‎SkinFriction‬ Piles,
not less than 3ft 6in c/c or the
perimeter if the pile, whichever is greater.
Bearing Pile ေတြကို 2times
Friction Pile ေတြကို 4times
Reference:Chapter(19)Pile Caps
Reinforced Concrete Detailing
by John A.Baker
တန္ဖိုးရွိတ့ဲ အခ်ိန္ေတြေပးျပီး
ဖတ္တာ ေက်းဇူးတင္ ပါတယ္
မွ်ေဝတယ္ဆိုတာ မဂၤလာတစ္ပါးပါ
Aung Myat Thu(TU-Taunggyi)
Millimetre-Training & Design Group
10:25PM, 9-11-2014(Sunday)