Overturning moment on core walls supported by raft

[fracture_point]

I have four core walls surrounding a staircase that is subject to tension/compression in opposite walls under seismic loading. The walls will be supported on a raft foundation. What is the best way to model the tension piles to determine the distribution of axial force into each pile? I do not want to assume the axial force distributes even to each piles, because some piles are directly under the wall and others adjacent.

Any resources for me to read over the weekend would be great!

Cheers