TÝnh to¸n ®é chèi theo c«ng thøc ®éng hilley.
Calculation penetration resistance follow hilley
0
5,0 e
Q
HWe
e
u
ff
Trong ®ã :
f
e
- HiÖu suÊt c¬ häc cña bóa ®ãng cäc;
Coefficient of mechanical efficiency of drop hammer ;
Víi bóa §iezen
f
e
= 0,8.
With diesel hammer
f
e
= 0,8.
H - chiÒu cao r¬i bóa;
stroke dropping free height
H = 2,4m.
r
W
- Träng lîng bóa ®ãng;
Weight of hammer
Víi cäc kÝch thíc 300x300 vµ 350x350 th×
r
W
= 3,5 T.
With pile 300x300 & 350x350 :
r
W
= 3,5 T.
Víi cäc kÝch thíc 200x200 vµ 250x250 th×
r
W
= 2,5 T.
With pile 200x200 & 250x250 :
r
W
= 2,5 T.
u
Q
- Kh¶ n¨ng mang t¶i cùc h¹n cña cäc, lÊy víi hÖ sè an toµn
s
F
=
3;
Ultimate carrying capacity of pile, with factor of safety
s
F
= 3;
Víi cäc kÝch thíc 350x350 ,
u
Q
= 152x3 = 456 T.
With pile 350x350,
u
Q
= 152x3 = 456 T.
Víi cäc kÝch thíc 300x300 ,
u
Q
= 112x3 = 336 T.
With pile 300x300 ,
u
Q
= 112x3 = 336 T.
Víi cäc kÝch thíc 250x250 ,
u
Q
= 75x3 = 225 T.
With pile 250x250 ,
u
Q
= 75x3 = 225 T.
1
Víi cäc kÝch thíc 200x200 ,
u
Q
= 45x3 = 135 T.
With pile 200x200 ,
u
Q
= 45x3 = 135 T.
0
e
- ®îc tÝnh theo c«ng thøc :
Calculation with formula :
e
prf
FE
LHWe
e2
0
p
L
- chiÒu dµi cäc,
p
L
= 42m.
length of penetration (of pile)
F - diÖn tÝch tiÕt diÖn cäc :
Area of section
Víi cäc kÝch thíc 350x350 , F = 0,35x0,35 = 0,1225
2
m
.
With pile 350x350, F = 0,35x0,35 = 0,1225
2
m
.
Víi cäc kÝch thíc 300x300 , F = 0,30x0,30 = 0,09
2
m
.
With pile 300x300, F = 0,30x0,30 = 0,09
2
m
.
Víi cäc kÝch thíc 250x250 , F = 0,25x0,25 = 0,0625
2
m
.
With pile 250x250 , F = 0,25x0,25 = 0,0625
2
m
.
Víi cäc kÝch thíc 350x350 , F = 0,20x0,20 = 0,04
2
m
.
With pile 200x200, F = 0,20x0,20 = 0,04
2
m
.
e
E
- modun ®µn håi cña vËt liÖu lµm cäc.
Elastic module of pile material .
Víi cäc Bªt«ng Grade 45 ,
e
E
= 3.250.000 T/
2
m
.
With concrete Grade 45 ,
e
E
= 3.250.000 T/
2
m
.
Thay vµo c«ng thøc ,®îc b¶ng tÝnh ®é chèi cña cäc theo c«ng thøc
Hilley :
2
Pile 350x350 300x300 250x250 200x200
e (mm) 2,7 2,8 2,8 3,0
3