PILE ROTATIONAL STIFFNESS

[chadegani]

I HAVE MODELED A PILE FOUNDATION IN SAFE WITH COLUMN SUPPORT BENEATH THE FOUNDATION. PILES TOP CONNECTION IN PILE CAP ARE FIX .

FOR FILLING OF SPRING CONSTANT WE USE AXAIL STIFFNESS FROM PILE AXIAL COMPRESSION TEST ( SOIL REPORT DATA ). BUT I DON'T NOW HOW I CAN FILL THE ROTATIONAL STIFFNESS TEXT BOX CORRECTLY (X & Y DIRECTION ).

ADDITIONALLY I HAVE THE RESULT OF PILE LATERAL TEST DATA SUCH AS ( LATERAL LOAD-DISPLACEMENT CURVE ).

 

[kickabeeaaaammm]

I have encountered this situation in the past. The way I did it was to go back to matrix structural analysis principles. Look at the rotational stiffness of a frame element of length L. If you imagine that the pile is effectively fixed at some distance into the ground, and you know this distance say it's 2T or you find it using a program like LPile, you know what your length L is. It's the distance from the soffit down to this point of fixity in the ground. Now from matrix structural analysis the rotational stiffness is 4EI/L. So you just need your I about x and I about y and you're done.

Hope this helps.