I am quoting here an explanation from TAIEBAT and CARTER 2010
"The modified swipe loading is applied , where the foundation is loaded vertically to failure and then, in the second portion of loading, the incremental vertical displacement, v, reduces from its maximum value (downwards positive) using a cosine function. The incremental horizontal displacement, h, and the incremental rotation, theta, increase from zero using a sine function. When v reaches zero, h and theta reach their maximum values. After this stage v becomes negative (upwards) while h and theta reduce to zero at the end of the analysis. Different ratios of h/theta can be used to obtain various load paths that cover most of the failure surface."
Anyone please, I need a clarification on this procedure. Thank you!