Hasan Hussain Abdullah’s scientific contributions

Dam projects require comprehensive studies and a careful implementation process; thus, the causes of the possible failure, during the construction or operation of dams, should be thoroughly investigated. Specifically, geotechnical analysis of seepage, static stability, and seismic stability is essential to be evaluated. Earthquakes shaking imposes additional hysteric and short-term loads in the two directions that may cause serious problems and may lead to dam failure due to settlement, piping, high pore water pressure, and soil liquefaction. In this study, Geo-Studio 2018 software was utilized to evaluate the slope stability and the seepage analysis of Al-Adhaim Dam in Iraq. The dynamic stability of the dam and the soil liquefaction were also evaluated as a result of applying earthquake shaking to the dam. The results obtained from the analysis indicated that the dam was stable in the static condition. Furthermore, the results of the dynamic condition indicated that an earthquake, with an acceleration value of 0.38g and 10 seconds period, caused a vertical displacement of the dam of 0.12 m and reduced the factor of safety to 1.01 which was less than the allowable value. Therefore, geotextile reinforcement was suggested to reduce the effect of the soil liquefaction that was observed in the front shell of the dam. As discussed herein, the reinforcement increased the dam stability as the factor of safety of the dam increased to 1.946 which was within the allowable values.

The design of dams requires comprehensive studies to ensure the safety and feasibility of these important engineering projects, as any possible failure case may lead to considerable losses in human life and properties. Specifically, analyses should be performed to evaluate seepage, slope stability, and soil liquefaction of large earth dams. In this study, numerical modeling, based on finite element methods, was used to analyze seepage, slope stability, and liquefaction of Makhoul Dam which is a large zoned dam, currently under construction on Tigris River in the north of Iraq. Earthquake shakings impose additional hysteric and short-term loads that may lead to dam failure due to high pore water pressure, piping, and soil liquefaction. Therefore, the dynamic stability of the dam and soil liquefaction were also evaluated, as a result of applying an earthquake shaking to the dam. For the static condition, the dam was safe against internal erosion and slope failure, as the calculated value of the safety factor was greater than the allowable value. However, the results obtained from the dynamic analysis indicated that a possible earthquake, with an acceleration of 0.38g and 10 seconds period, led to upstream slope failure, a relative displacement as high as 2 meters at the dam crest, and soil liquefaction at the upstream slope. As discussed herein, dam redesign or geotextile reinforcement may be considered to reduce the effects of earthquakes on the dam.