Namran Faris Hamad AL-Maliki

H2S is one of the principal odor gases released from sewer networks and understanding the rate of H2S release into sewer air space and ventilation to the atmosphere is crucial for preventing or minimizing odor and corrosion issues in sewer systems. TOXCHEM model was used to simulate the fate of H2S gas in roads for this study. The model was calibrated for the spring and summer seasons and validated for the remainder of the seasons. The predicted behavior showed good correlation to measurements on real samples following statistical analysis, with R2, R, and RMSE results between (0.93–0.97), (0.8–0.82), and (0.000438–0.000838), respectively. A sensitivity study was performed to assess the effect of various pH values, drop heights, tailwater depths, stream widths, and sewer ventilation rate levels. The results showed that the emissions concentrations for winter, spring, summer, and autumn reached 3500, 5044, 6425, and 4045 ppm respectively. All the emissions levels from this DS can be considered hazardous, and this was particularly evident during the summer months. This study has helped to clarify the fate and emission of hydrogen sulfide gas at the DS by simulation using a TOXCHEM model.

Abstract: In this research, a finite element software (ANSYS) has been used to simulate one of the important problems of most hydraulic structures which is seepage and piping under Kufa barrage in Iraq. A Sheet pile would be used to control it and would discuss several cases for location and number of sheet piles under floor of structure. After simulation, the cases of sheet piles and analysis by ANSYS was measured uplift pressure and exit gradient. In the case of no sheet pile provided, the uplift pressure is =6.072 Kn/m, the thickness of impervious floor to equivalent uplift pressure is=4.89 m, exit gradient=0.283. In the case of one sheet pile provided at upstream, the uplift pressure, thickness of floor and exit gradient would be reduced by 50%, 51% and 47.7% respectively. In the case of two sheet piles provided at upstream and downstream, the uplift pressure and thickness of floor would be increased by 43.9% and 43% and exit gradient would be reduced by 36.8%. In the case of three sheet piles provided at upstream, intermediate and downstream, the uplift pressure and thickness of floor would be increased by 3.67% and 2.8% and exit gradient would not change considerably. The last case of four sheet piles one at both of upstream and downstream and two at intermediate, the changes would not be considerable in the uplift pressure, thickness of floor and exit gradient. According to the results, Using of one sheet pile under floor for Kufa regulator will be the perfect case. Keywords: Barrages, sheet piles, seepage control under barrages, ANSYS analysis, uplift pressure, Kufa Barrage