This document analyzes the effects of blast loads applied below ground level on pile foundations supporting a 9-story building. Computer models are used to analyze stresses in the soil and displacements of piles for different blast weights and depths. Key findings include: 1) Stresses in the soil decrease as standoff distance increases but increase with deeper pile lengths and higher blast weights. 2) Pile displacements also decrease with greater standoff distances but increase with deeper pile lengths and higher blast weights. 3) For the building, displacements and drifts decrease as pile length increases, improving structural performance under blast loads.