A finite element method is useful tools to be applicable in many geotechnical engineering topics. In this paper the pore water pressure development within the clay core of MOSUL earth dam were investigate considering the saturated/unsaturated conditions using GEO-SLOP software. Three selected sections through the dam were chosen for the analysis ( in the middle, right, and left sides of the dam to cover the dam body). The investigation of the dam body response to the earthquakes with many values of the maximum horizontal acceleration was done. Normal, maximum, and minimum operation water levels with possibility of rapid drawdown of water level during (8,21,30) days were also consider. Transient and steady state analysis of pore water pressure was performed, finally the results were compared with the actual field data.
Results indicated that, the maximum pore water pressure was occurred for the nodes in the upstream near of the core base at the time during and after the end of earthquake shaking. The results of the study also presented a positive pore water pressure development in the lower part of the core when the water was at maximum, normal, and minimum operation levels, with negative values near the crest of the dam. high pore water pressure was record through sec6 and sec4, for the rapid drawdown of water level at time 8 days. Finally, nearly identical pore water pressure results are obtained from the numerical analysis and the recorded field piezometers readings data.