X hits on this document

PDF document

Practical Advice for Foundation Design – Micropiles for Structural Support - page 6 / 25

195 views

0 shares

0 downloads

0 comments

6 / 25

#10 Bar

#11 Bar

#14 Bar

#18 Bar

#20 Bar

#28 Bar

Bar diameter, in

1.25

1.375

1.75

2.25

2.5

3.5

Area (A), in2

1.27

1.56

2.25

4

4.91

9.61

Moment of Inertia (I), in4

0.13

0.19

0.40

1.27

1.92

7.35

I/A2

0.08

0.08

0.08

0.08

0.08

0.08

Pile factor (PF), in2/kip

1.64

1.64

1.64

1.64

1.64

1.64

Yield strength, kip

92

133

180

236

368

722

Casing OD, in

5.5

7

7

9.625

Wall thickness, in

0.36

0.5

0.73

0.47

Area (A), in2

5.83

10.17

14.38

13.58

Moment of Inertia (I), in4

19.3

54.1

71.6

142.6

I/A2

0.57

0.52

0.35

0.77

Pile factor (PF), in2/kip

10.3

9.5

6.3

14

Yield strength, kip

466

814

1150

1086

30/16

32/20

40/20

52/26

73/53

103/51

1.18/0.63

1.26/0.79

1.57/0.79

2.04/1.02

2.87/2.09

4.06/2.0 0 8.53 10.08 0.14 2.86 612.8

0.59 0.06 0.17 3.39 40.5

0.69 0.09 0.19 3.96 47.2

1.00 0.16 0.16 3.23 96.7

2.08 0.61 0.14 2.92 160.8

2.53 1.88 0.29 6.07 218.1

5½ -inch casing

6–inch casing

8-inch casing

10¾ -inch casing

Casing OD, in

5.56

6.625

8.00

10.75

Wall thickness, in

0.5

0.5

0.5

0.63

Area (A), in2

7.95

9.62

11.82

19.91

Moment of Inertia (I), in4

25.7

45.4

83.4

256.2

I/A2

0.41

0.49

0.6

0.65

Pile factor (PF), in2/kip

36.4

43.9

53.5

57.8

Yield strength, kip

286

346

425

717

GSP 131 Contemporary Issues in Foundation Engineering

CASING FY= 36 KSI

BAR FY=75 KSI

INJECTION BORE PILES FY=75 KSI (CON-TECH SYSTEMS)

Bar diameter, O.D./I.D. (mm) Bar diameter, O.D./I.D. (in) Area (A), in2 Moment of Inertia (I), in4 I/A2 Pile factor (PF), in2/kip Yield strength, kip

Step 5: Final Design

5.1 Design for Geotechnical Strength Limit States. Bond length design is most usually based on the assumptions that load is transferred by skin friction only and that this distribution is uniform. The first assumption is nearly always accurate; the second assumption is nearly always false. Nevertheless, it is conservative, although it does tend to confuse inexperienced analyzers of detailed load-movement test data. Table 4 provides ultimate stress transfer values commonly used for pre-construction designs. The nominal factor of safety on the ultimate bond value varies typically from 2 to 2.5, the lower extreme only being considered when the bond zone is in

5½ -INCH

7-INCH CASING

9-INCH

CASING

CASING

CASING FY= 80 KSI

Table 3. Typical properties and pile factors of micropile reinforcement used in the

U.S.A. (Cadden and Gómez, 2002)

6

Document info
Document views195
Page views227
Page last viewedWed Dec 07 16:49:01 UTC 2016
Pages25
Paragraphs981
Words9391

Comments