| 1. |
- Al-Hashimi, Shaymaa A.M., et al.
(författare)
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Flow over Broad Crested Weirs: Comparison of 2D and 3D Models
- 2017
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Ingår i: Journal of Civil Engineering and Architecture. - : David Publishing Company. - 1934-7359 .- 1934-7367. ; 11:8, s. 769-779
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Tidskriftsartikel (refereegranskat)abstract
- The flow over broad-crested weirs was simulated by computational fluid dynamic model. The water surface profile over broad crested weir was measured in a laboratory model and validated using two and three dimensional Fluent programs. The Reynolds Averaged Navier-Stokes equations coupled with the turbulent standard (k-ε) model and volume of fluid method were applied to estimate the water surface profile. The results of numerical model were compared with experimental results to evaluate the ability of model in describing the behaviour of water surface profile over the weir. The results indicated that the 3D required more time in comparison with 2D results and the flow over weir changed from subcritical flow at the upstream (U/S) face of weir to critical flow over the crest and to supercritical flow at downstream (D/S). A reasonable agreement was noticed between numerical results and experimental observations with mean error less than 2 %.
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| 2. |
- Faisal, Ayad A.H., et al.
(författare)
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Using different materials as a permeable reactive barrier for remediation of groundwater contaminated with landfill’s leachate
- 2020
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Ingår i: Desalination and Water Treatment. - : Desalination Publications. - 1944-3994 .- 1944-3986. ; 175, s. 152-163
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Tidskriftsartikel (refereegranskat)abstract
- The present study investigates the utilization of the waterworks sludge by-product that generated from water supply treatment plant for the remediation of simulated groundwater contaminated with leachate spilled from the sanitary landfill by permeable reactive barrier (PRB) technology. Batch sorption experiments were conducted for describing the interaction between the acetogenic phase (pH=5.5±0.1) of leachate contaminated with cadmium (Cd(II)), ammonia nitrogen (NH3–N) or dissolved organic matter (COD) and waterworks sludge. Also, conventional sorbents such as the activated carbon and amberlite ion-exchange resin were tested to evaluate their ability in compar-ison with waterworks sludge in the remediation process. Results proved that the Langmuir model describes well the sorption data with maximum sorption capacities of 5.634, 14.908 and 3.938mg/g for Cd(II) onto sludge, NH3–N onto resin and COD onto activated carbon, respectively. The batch and column tests signified that the sludge, resin, and carbon can be used for removing Cd(II), NH3–N, and COD, respectively. The multi-layered bed of sorbents under consideration has a remarkable ability in the remediation of a leachate contaminated with Cd(II), NH3–N, and COD. Finally, the Yan model is more representative than Thomas and Belter models for characterization of the contaminants propagation in the column packed with single sorbent.
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| 3. |
- Al-Maliki, Hadi Naser Ghadhban, et al.
(författare)
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Structural Behavior Of Precast High Strength Reinforced Concrete Vierendeel Truss Walls : A Numerical Approach
- 2021
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Ingår i: International Journal of GEOMATE. - : The Geomate International Society. - 2186-2982 .- 2186-2990. ; 21:84, s. 137-150
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Tidskriftsartikel (refereegranskat)abstract
- Reinforced concrete (RC) walls have been widely used in different types of civil engineering projects. Therefore, their behaviour under several kinds of loading is of utmost importance. In this study, the main objective is to investigate the behaviour of RC Vierendeel walls under the applied loads by employing numerical analyses for the studied walls. Several assumptions are adopted in these analyses to simulate the actual behaviour of Vierendeel walls, which were experimentally studied in previous investigations. The numerical results showed that the simulated numerical behaviour has a very good agreement with the experimental results of the tested models. Statically, this agreement is validated and verified in terms of the mean and standard deviation values. Therefore, the proposed numerical models and assumptions are the suitable ones to simulate the structural behaviour of these walls under the applied conditions. The structural behaviour is presented in terms of load capacity, crack pattern, deflection, and mode of failure. The results show that the reactive powder concrete (RPC) models have more resistance under the applied load in terms of deflection, cracks, and ductility index than the models of normal strength concrete (NSC). Also, the openings are the main reason for the diagonal cracking at the corners of the RC walls. The deflection in all models is a single curvature. The mode of failure for all models is shear.
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| 4. |
- Al-Soud, Madhat Shakir, et al.
(författare)
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Sustainable Improvement Of Bentonite Clay Characteristics By Adding Pulverized Waste Glass
- 2022
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Ingår i: International Journal of GEOMATE. - : Geomate Interantional Society. - 2186-2982 .- 2186-2990. ; 23:95, s. 10-19
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Tidskriftsartikel (refereegranskat)abstract
- Bentonite clay is the soil that undergoes high volume changes (swelling) when its moisture content increases. The soil swelling may cause structural damage leading to damage to structural members like cracking in reinforced foundations and borders, curbs swelling, and eventually produces deformation indoors and on floors. In this study, Bentonite clay with expansive characteristics was used and mixed with various amounts of Pulverized waste glass PWG (0%, 5%, 10%, and 15%). Two types of PWG were prepared: fine glass (passing sieve No. 200) and coarse glass (passing sieve No. 2 mm). Laboratory experiments were performed on Bentonite specimens blended with different amounts of PWG. The results showed that the addition of 15% by Bentonite weight of 2 mm of PWG reduces the Atterberg limits considerably. Moreover, a noticeable reduction was observed in the Bentonite samples’ free swell and swelling pressure after being treated with different amounts of PWG. The observed advantages of adding the PWG to Bentonite clay soil by decreasing the volume changes and enhancing the overall properties of Bentonite clay reflect the suitability of using PGW as a good soil stabilizer. Besides reducing the impact of waste glass on the environment due to its non-biodegradable nature.
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| 5. |
- Ali, Asma Mahdi, et al.
(författare)
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Nonlinear Simulation Analysis of Mechanical Behaviour of Rubberized Concrete
- 2022
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Ingår i: International Journal of GEOMATE. - : GEOMATE International Society. - 2186-2982 .- 2186-2990. ; 22:90, s. 125-137
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Tidskriftsartikel (refereegranskat)abstract
- The main objective is to simulate the representation of rubber concrete with different percentages (0, 20, 40, 60, 80, 100%) of rubber using a finite element approach with ANSYS V.15 software to evaluate the behavior of concrete under the influence of mechanical force by using a standard cylinder to calculate its compressive strength, elasticity modulus and displacements for comparison with the previous experimental study, which showed a very close agreement of 5 to 12% when compared between them. The results showed that when the percentage of rubber increases, it leads to a decrease in the compressive strength, that is, its resistance, and an increase in the corresponding displacements and deformations that occur in them, as a result of the concentration of these stresses in the rubber limits. The results also showed that the meshing distribution of the analyzed elements by the ANSYS gave higher values of compressive strength and a decrease in the corresponding displacements when they were regular i.e. homogeneous compared to the irregular ones. Finally, through statistical analysis, it was found that the mean and arithmetic mean were acceptable and close when comparing the theoretical and practical results.
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| 6. |
- Alrammahi, Faris S., et al.
(författare)
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Earthen slope stability using dimensional analysis
- 2021. - 1
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 1895
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Konferensbidrag (refereegranskat)abstract
- Slope stability is an important aspect in the management of civil engineering projects. The stability of earth slopes is a significant concern for safety and the economy. There are several methods for finding the safety factor. Spencer's method is considered one of the most accurate methods for calculating the factor of safety but it depends on the others on dividing the slope geometry into the number of slices with complicated calculations. This paper introduced a new theoretical equation (using dimensional analysis) capable of defining and testing the slope stability of the natural and man-made slope of the earth without complicated calculations. The major and significant variables which affect and contribute to the stability of a slope will be listed and discussed. The Geo-SLOPE and SEEP software were used to present the stability analyses of the earth dam and compare the result. The derived equation shows the excellent relationship between the factor of safety concerning the ratio of internal friction angle over slope angle ∅/α and the hydraulic gradient. The main objective is to set a new rapid method for checking the stability of slopes instead of a complex calculation that can describe the slope stability of the natural earth slope.
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| 7. |
- Faisal, Ayad A. H., et al.
(författare)
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Modeling of Trichloroethylene Migration in Three-Dimensional Saturated Sandy Soil
- 2014
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Ingår i: Arabian Journal for Science and Engineering. - : Springer. - 2193-567X .- 2191-4281 .- 1319-8025. ; 39:11, s. 7763-7769
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Tidskriftsartikel (refereegranskat)abstract
- This study characterized the temporal and spatial distribution of trichloroethylene (TCE) dissolved plume from continuous source in 3D bench-scale sand aquifer. COMSOL Multiphysics 3.5a (2008) software based on the finite element numerical scheme taking into account the sorption process was used to interpreted the experimental results. A conservative tracer is employed for the determination of the longitudinal dispersivity. The sorption characteristics of TCE onto the aquifer sand are independently determined from batch equilibrium data. TCE concentrations at specific downstream locations within the aquifer for different periods of time are measured under flow rates values equal to 20, 40 and 100 ml/min. The predicted TCE concentrations were found to be reasonably agreed with the bench-scale experimental results with mean error <5%.
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| 8. |
- Ghadhban Al-Maliki, Hadi Naser, et al.
(författare)
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Nonlinear Simulation Analysis of Tapered Reinforced Concrete Column (Solid and Hollow) Behavior Under Axial Load
- 2021
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Ingår i: International Journal of GEOMATE. - : The Geomate International Society. - 2186-2982 .- 2186-2990. ; 21:86, s. 131-146
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Tidskriftsartikel (refereegranskat)abstract
- Tapered columns are a type of column that is used for different purposes, including architectural purposes or structural needs to take into account the changes that occur to moments along with the height of the column. For example, in highway bridges, tapered columns are used to reduce the number of moments transmitted to the base of the columns and from there to the foundation. This research studied the analysis of short reinforced concrete columns with variable cross-sections along the column in a linear manner by using the ANSYS V.15 software package. The variables that were studied included the type of section, solid or hollow, the ratio of longitudinal and transverse reinforcement, the ratio of the hollowness, and the comparison of numerical results with those obtained from the previous study. The results we obtained from the simulation of the numerical analysis of the models showed a very good agreement with the results of the experimental studies for them. This agreement can also be observed through statistical analysis using the arithmetic mean and standard deviation when compared. Thus, the proposed model by numerical analysis and hypotheses is suitable for formulating the behavior of these reinforced concrete tapered column models under the effect of axially applied load and other variables. The behavior of column models is based on applied loads, load-displacement curves, crack patterns, and failure modes. The results showed that increasing the ratio of longitudinal and transverse reinforcement increases the resistance of the R.C. column models and the ductility index with a decrease in the corresponding lateral displacement. This behavior is observed when changing the section from hollow to solid. Finally cracks pattern is represented in the concrete crushing and concrete spalling out of some parts at the end of the tapered and diagonal cracks in different places, especially at the end of the tapered.
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| 9. |
- Huda M., Madhloom, et al.
(författare)
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Geographical Information System and Remote Sensing for WaterResources Management Case Study : The Diyala River, Iraq
- 2018
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Ingår i: International J. of Civil Engineering and Technology. - India : IAEME Publication. - 0976-6308. ; 9:12, s. 971-984
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Tidskriftsartikel (refereegranskat)abstract
- Utilizing Geographical Information System (GIS) in the management of water resources, especially, in the quality of surface water, constiytutes a worthwile attempt made in the improvement and control the levels of pollution in the water. In this paper, GIS technology was used in conjunction with Water Quality Index (WQI) to assess the suitability for onsumption of water in the souther within Baghdad City for human needs based on the set of monthly measurements during the period from January to December 2016. The variables measured in seven monitoring stations along the studied reach of the river were: Total Di(T.D.S), Total Hardness (T.H), Sulphate ion (SO Biochemical Oxygen Demand (BODhigher than the permissible limits specified by Iraqi and WHO regulations for the dand wet seasons. The digital pollution maps showed that the pollution moved from extremely polluted zones near the outfalls of wastewater to low polluted zones near the confluence of the Diyala and Tigris techniques are among the most effective methods to display the seasonal variability onwater quality, which can be used by the decision makers.
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| 10. |
- Jawad, Faris Waleed, et al.
(författare)
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Liquefaction potential of layered soil under vertical vibration loads
- 2022
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Ingår i: INTERNATIONAL JOURNAL OF GEOMATE. - : Geomate Int Soc. - 2186-2982 .- 2186-2990. ; 23:99, s. 141-150
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Tidskriftsartikel (refereegranskat)abstract
- The risk of liquefaction phenomena increases during dynamic loading and can cause the shear failure of soil under foundations. Model tests for a small-scale model under vertical vibration loads are presented. The operating frequency was changed from 1000, 2500 to 3500 revolutions per minute and the amplitude of loading with time was applied as a sine wave. Several parameters were considered, such as the force-time history of the machine foundation, the final settlement of the foundation, the vertical stress inside the soil media, the excess pore water pressure and observed liquefaction phenomena. These observations were compared to the effect of the sub-base layer thickness under the footing and its ability to reduce the liquefaction phenomena. The results showed that the shape of the load-time history coincides with a sine wave and the increase in the operating frequency led to an increase in the measured vibration load. The settlement was observed to increase with increases in the operating frequency. The settlement depended on the state of the soil and the operating frequency applied. Increases in operating frequency of about 3 times led to an increase in the time interval of excess pore pressure and reached a maximum value. The phenomenon of liquefaction appeared clearly when sandy soil was in a loose state. When the soil changes to a medium state, the phenomena of liquefaction respond to the operating frequency more than the operating frequency in a loose state. No liquefaction occurs in a dense state. The use of a subbase layer more than 1.5 times the depth of the footing led to eliminating the liquefaction phenomena.
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