900 mm

Static Stiffness Calculation of Pile :

Dia. Of Pile ( D ) =900mmArea of Pile (A) =0.636m2Length of Pile ( L )=20mModulus of elsticity (E) =29580N/mm2 =29580000kN/m2Moment of Inertia (I) =0.0322m4

Pile Dia. (mm)Allowable Pile LoadCompression (T)Shear (T)Tension (T)9002500125350

Vertical Stiffness :

KFY =Load for unit deflection in vertical direction=A.E/L=94089.91T/mNote : The value is increased by 15% considering frictional resistance from surrounding soil.

Hence,KFY,mod =108203.401763379T/m

Horz. Stiffness :

[Ref. IS: 2911(Part1/Sec2)-1979; Amendment No.3 (Aug 1987) Appendix C]From Fig.2 -For , L1 =0mLf /T =2.15(for fixed head pile in sand & normally loaded clay)K1 =0.525kg/cm3 ( for medium Sand) From Table : 15-Jan=5250kN/m3Hence ,

=2.830m

Therefore, Depth of Fixity (Lf) =6.08m

For clay (Cu ) =0.2kg/cm2[Assumed] K2 = 7.75kg/cm2[As per Table-2]= 775KN/m2

Hence,

=5.921m

Therefore, Depth of Fixity (Lf) =12.73m

Consider Depth of Fixity = Avg. of two above Lf =9.4073159009m

KFX = KFZ = 12 EI/ (L1+Lf) 3

=13731.63kN/m

Therefore stiffnesses for 900 mm diameter piles are as follows:Vertical =108203.401763379T/mHorizontal =1373.16T/m

Sheet2

Sheet3