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Job No.:

Project: LOGO

Subject: Calculation of Vert Modulus of Subgrade Reaction

Prepared:

Sheet:

Rev.:

Date:

Checked:

LOGO

CALCULATION OF VERTICAL MODULUS OF SUBGRADE REACTION (Reference: Foundation Analysis and Design, 5th Edition by Joseph E. Bowles) L= B= D=

3.7 3.3 2.8

m m m

Length Width Depth

Soil Profile Layer

Type

Thickness

Depth

(m) Very Stiff Hard Silty Sand to Sandy Silt Firm Clay to Silty Clay Very Stiff

1

2 3

Clayey Silt to Silty Clay Medium Dense to

4

Dense Sand

Soil Density, Friction Cohesion, γb cu Angle, Ø (kN/m3) (degrees) (kPa)

0-2.5m

2.50

18.50

25

158

2.5-12.25m

9.75

17.50

20

34.6

12.25-14m

1.75

18.00

25

184

14-16.50m

2.50

18.50

30

249

sc

Shape Factors sq

sγ

1.44 1.36

1.22 1.18

1.22 1.18

to Silty Sand Reference for soil profile:

Meyerhof's Factors Layer 1 2

Nc

Bearing Capacity Factors Nq Nγ

20.72 14.83

Layer 1 2 q= qu = FOS = qall =

dc

10.66 6.40 Depth Factors dq

1.27 1.24 51.50 1339.69 3.0 447

6.77 2.87

1.13 1.12

Kp 2.46 2.04 Angle, α

dγ 1.13 1.12

(degrees) 0 0

ic 1.00 1.00

Inclination Factors iq iγ 1.00 1.00

kPa

Effective overburden pressure at foundation level

kPa

Ultimate bearing capacity Factor of safety

kPa

Allowable soil bearing capacity

1.00 1.00

Calculation of vertical modulus of subgrade reaction is provided below: ks = Vertical modulus of subgrade reaction (ks = 40 x FOS x qall) 53,640 kPa/m