| 1. |
- Al-Mamoori, Sohaib Kareem, et al.
(författare)
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Chloride, Calcium Carbonate and Total Soluble Salts Contents Distribution for An-Najaf and Al-Kufa Cities’ Soil by Using GIS
- 2019
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Ingår i: Geotechnical and Geological Engineering. - : Springer. - 0960-3182 .- 1573-1529. ; 37:3, s. 2207-2225
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Tidskriftsartikel (refereegranskat)abstract
- The main objective of the paper is to create geotechnical maps for three soil chemical properties in An-Najaf and Kufa cities’ soil by utilizing of GIS tools. This properties are the chloride concentration, calcium carbonate (CaCO 3) and total soluble salts where they affect the durability of reinforced structural elements. This paper provides an easy accurate way to represent soil properties levels for different depths of soil and create reliable database that will help engineers and decision makers. The data included in this paper were collected for (464) boreholes with depths up to 35 m distributed on residential areas in all of An-Najaf and Kufa cities. Arc-Map of GIS 10.2.1 was used to produce the maps. It has been concluded that chloride content in the soil of the study area range from - 0.01 to 0.99% and with an average of 0.5. The maximum value found in at depth 4–6 m while the minimum value found in location at depth 4–6, 8–10 and 14–16 m. The chloride content in most of An-Najaf province has exceeded the permissible limit and for all, this required taking percussions to protect foundations. While calcium carbonate content in the soil of the study area range from 53 to 0.18 and with an average of 26.6. The maximum and the minimum values found at depth 4–6 m. Calcium carbonate content is within the permissible limits in most locations except in some locations.
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| 2. |
- Al Manmi, Diary Ali Mohammed Amin, et al.
(författare)
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Soil and Groundwater Pollution Assessment and Delineation of Intensity Risk Map in Sulaymaniyah City, NE of Iraq
- 2019
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Ingår i: Water. - : MDPI. - 2073-4441. ; 11:10
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Tidskriftsartikel (refereegranskat)abstract
- Groundwater and soil pollution caused by (PAHs) spills, mostly from the oil industry and petrol stations in urban areas, represent a major environmental concern worldwide. However, infiltration into groundwater is decreasing due to the natural attenuation processes of PAHs in the vadose zone, which protect invaluable groundwater resources against contamination. This study was conducted to evaluate the effect of improper management of the petroleum industry on the groundwater and soil surrounding the petrol station and an oil refinery unit and, furthermore, to prepare the polluted risk intensity (PRI) map. Fifty-one soil samples and twenty-five water samples were analyzed for Light Non-aqueous Phase Liquid (LNAPLs), and one soil sample for Dense Non-Aqueous Phase Liquid (DNAPLs); furthermore, six soil samples analyzed for Tetraethyl Lead (TEL) analysis. The results showed that seventeen wells were polluted with LNAPLs and the soils were highly contaminated with different DNAPLs components and mainly was in the form of Polycyclic Aromatic Hydrocarbons (PAHs). Seven factors introduced to the GIS platform to produce PRI map, which is the distance to source, depth to water table, slope, lineaments, lithology, soil, and recharge rate. The final map revealed that the eastern and western parts of the study area are at a very high-risk level, whereas the center is at a very low to low-risk level.
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| 3. |
- Abbas, Nahla, et al.
(författare)
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Flow Variation of the Major Tributaries of Tigris River Due to Climate Change
- 2019
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Ingår i: Engineering. - : Scientific Research Publishing. - 1947-3931 .- 1947-394X. ; 11:8, s. 437-442
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Tidskriftsartikel (refereegranskat)abstract
- Iraq relies greatly on the flow of the Euphrates and Tigris Rivers and their tributaries. Five tributaries namely Khabour, Greater Zab, Lesser Zab, AlAd- hiam and Daylia, which are the major tributaries of Tigris River, sustain Northern Iraq Region, a semi-arid, mainly a pastureland. These tributaries contribute about 24 km3 of water annually. The discharge in the tributaries, in recent times, has been suffering increasing variability contributing to more severe droughts and floods apparently due to climate change. This is because there were no dams constructed outside Iraq previously. For an appropriate appreciation, Soil Water Assessment Tool (SWAT) model was used to evaluate the impact of climate change on their discharge for a half-centennial lead time to 2046-2064 and a centennial lead time to 2080-2100. The suitability of the model was first evaluated, and then, outputs from six GCMs were incorporated to evaluate the impacts of climate change on water resources under three emission scenarios: A1B, A2 and B1. The results showed that wa-ter resources are expected to decrease with time.
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| 4. |
- al Amli, Ali Sabah, et al.
(författare)
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Behavior of Reinforced Concrete Beams with effect of Stiffened Plates
- 2019
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Ingår i: Civil Engineering Journal. - Iran : Salehan Institute of Higher Education. - 2676-6957 .- 2476-3055. ; 5:12, s. 2569-2578
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Tidskriftsartikel (refereegranskat)abstract
- This study presents experimental work including an investigation conducted on five simply supported reinforced concrete beams under pure torsion. First beam without strengthening as a control beam. The other four beams were strengthened externally by bolted thin steel plates. For this test the load was applied gradually. The torque was increased gradually up to failure of the beam. The variables were the thickness and height of the steel plate that was externally connected to both sides of the rectangular reinforced concrete beam. The test results for the beams discussed are based on torque-twist behavior. The experimental results show that the attachment of thin steel plates by mechanical means to beams provides a considerable improvement in the torsional behavior of the reinforced concrete beams. Comparable to the reference beam, the maximum increase in the cracking and the ultimate torque of the composite beam was recorded for the reinforced concrete beam that strengthen by steel plate of 150 mm height, 2 mm thickness and 50 mm spacing between shear connectors (B1). The results revealed that the cracking torque, ultimate torque, global stiffness of beam and beam ductility for all composite beams increase with the increase of the plate's thickness, plate's height.
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| 5. |
- Al Amli, Ali Sabah, et al.
(författare)
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Study Numerical Simulation of Stress-Strain Behavior of Reinforced Concrete Bar in Soil using Theoretical Models
- 2019
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Ingår i: Civil Engineering Journal. - Iran : C EJ PUBLISHING GROUP. - 2476-3055. ; 11:5, s. 2349-2358
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Tidskriftsartikel (refereegranskat)abstract
- Nonlinear analysis for reinforced concrete members (R.C.) with two types of bars also with unsaturated and saturated soils was used to represent the models. To control the corrosion in the steel bar that used in R.C. member and decrease the cost, the geogrid with steel bar reinforcement are taken in this study to determine the effect of load-deflection and stress-strain relationships. The finite element method is used to model the R.C. member, bars and soil. A three-dimensional finite element model by ABAQUS version 6.9 software program is used to predict the load versus deflection and stress versus strain response with soil. The results for the model in this study are compared with the experimental results from other research, and the results are very good. Therefore, it was concluded that the models developed in this study can accurately capture the behavior and predict the load-carrying capacity of such R.C. members with soil and the maximum stresses with strains. The results show plastic strain values in the R.C. member with saturated soil are larger than their values in unsaturated soil about (54%, 58%, and 55% and 52%) when the geogrid ratios are (without geogrid, 60%, 40% and 20%) respectively, with the same values of stresses.
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| 6. |
- Al-Ani, Thair, et al.
(författare)
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Crystal Chemistry and Geochronology of Thorium-Rich Monazite from Kovela Granitic Complex, Southern Finland
- 2019
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Ingår i: Natural Resources. - USA : Scientific Research Publishing. - 2158-706X .- 2158-7086. ; 10:6, s. 230-269
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Tidskriftsartikel (refereegranskat)abstract
- Abundant porphyritic granites, including Grt-bearing and Bt-bearing porphyritic granites, and porphyritic potash-feldspar granite (trondhjemite-granitic composition) are widely distributed within the Kovela granitic complex Southern Finland, which associated with monazite-bearing dikes (strong trondhjemite composition). The investigated monazite-bearing dikes are dominated by a quartz + K-feldspar + plagioclase + biotite + garnet + monazite assemblage. The monazite forms complexly zoned subhedral to euhedral crystals variable in size (100 - 1500 μm in diameter) characterized by high Th content. The chemical zoning characterised as: 1) concentric, 2) patchy, and 3) intergrowth-like. Textural evidence suggests that these accessory minerals crystallized at an early magmatic stage, as they are commonly associated with clusters of the observed variations in their chemical composition are largely explained by the huttonite exchange , and subordinately by the cheralite exchange with proportions of huttonite (ThSiO4) and cheralite [CaTh(PO4)2] up to 20.4% and 9.8%, respectively. Textural evidence suggests that these monazites and associated Th-rich minerals (huttonite/thorite) crystallized at an early magmatic stage, rather than metamorphic origin. The total lanthanide and actinide contents in monazite and host dikes are strongly correlated. Mineral compositions applied to calculate P-T crystallization conditions using different approaches reveal a temperature range of 700°C - 820°C and pressure 3 - 6 kbars for the garnet-biotite geothermometry. P-T pseudo-section analyses calculated using THERMOCALC software for the bulk compositions of suitable rock types, constrain the PT conditions of garnet growth equilibration within the range of 5 - 6 kbars and 760°C - 770°C respectively. Empirical calculations and pseudo-section approaches indicate a clockwise P-T path for the rocks of the studied area. 207Pb/206Pb dating of monazite by LA-MC-ICPMS revealed a recrystallization period at around 1860 - 1840 Ma. These ages are related to the tectonic-thermal event associated with the intense crustal melting and intra-orogenic intrusions, constraining the youngest time limit for metamorphic processes in the Kovela granitic complex.
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| 7. |
- Al Dahaan, Saad A.M., et al.
(författare)
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Salinity functions for groundwater at Safwan, South Iraq
- 2019
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Ingår i: Journal of Environmental Hydrology. - Canada : International Association for Environmental Hydrology. - 1058-3912 .- 1996-7918. ; 27:7, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Function type between electrical conductivity and total dissolved solids is polynomial and the exponential which are taken according to the water quality classification for irrigation. These functions relate the EC in ds/m to the salinity in term of part per million or to the half salinity in equivalent per million directly or in form of logarithmic transformation. A statistical test for best fit is considered for the selection of the type of a representative function. The irrigation salinity classification is taken as index of grouping extended to moderately sensitive vegetable crop tomato as salinity tolerance rating up to 15 ds/m groundwater salinity used for irrigation at Safwan area of arid climate. All fitted type of functions is programmed within a flow model computer of basic language by which the output from of both methods is an average final value. Thus the coast of analysis is reduced. This type of functions is standard for groundwater and so designed to involve the water type. The involved parameter for Safwan area is 0.5 for more than 5 ds/m in case of ppm half total and it is 1.3 for less than 5ds/m salinity, or using the direct model.
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| 8. |
- Al-Jabban, Wathiq, et al.
(författare)
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A Comparative Evaluation of Cement and By-Product Petrit T in Soil Stabilization
- 2019
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Ingår i: Applied Sciences. - Switzerland : MDPI. - 2076-3417. ; 9:23
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Tidskriftsartikel (refereegranskat)abstract
- This study presents a comparison between the effectiveness of adding low binder amounts of industrial by-product Petrit T as well as cement to modify and improve fine-grained soil. Binder amount was added by soil dry weight; cement at 1%, 2%, 4% and 7% and Petrit T at 2%, 4% and 7%. The unconfined compressive strength (UCS) was used as an indicator of soil strength. In addition, the consistency limits, laser particle size analysis, and pH tests were also conducted on the treated soil. The samples were cured at 20 °C for different periods from 7 to 90 days before testing. Results indicate that cement is more effective at improving the physical and engineering properties of the treated soil. Soil plasticity index decreases after treatment and with time. Liquidity index and the water content to plastic limit ratio are introduced as new indices to define the improvement in the workability of treated soil. Soil particle size distribution is changed by reducing the clay size fraction and increasing the silt size fraction after treatment. The findings confirm that adding small binder contents improve soil properties, which subsequently reduce the environmental threats and costs that are associated with using a high amount of binder.
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| 9. |
- Al-Jabban, Wathiq, et al.
(författare)
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Effect of Disintegration Times of the Homogeneity of Soil prior to Treatment
- 2019
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Ingår i: Applied Sciences. - Switzerland : MDPI. - 2076-3417. ; 9:22
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents an experimental study to investigate the effect of various disintegration times on the homogeneity of pre-treated natural soil before mixing with cementitious binders. Various disintegration times were applied, ranging from 10 s to 120 s. Four different soils were used with different characteristics from high, medium and low plasticity properties. Visual and sieving assessment were used to evaluate the best disintegration times to allow for a uniform distribution of water content and small-sized particles that would produce a uniform distribution of the binder around the soil particles. Results showed that a proper mixing time to homogenize and disintegrate the soil prior to treatment depended on several factors: soil type, water content and plasticity properties. For high plasticity soil, the disintegration time should be kept as short as possible. Increasing the disintegration time ha negative effects on the uniformity of distribution of the binder around soil particles. The homogenizing and disintegration time were less important for low plasticity soils with low water content than for medium to high plasticity soils. The findings could assist various construction projects that deal with soil improvement through preparation of soil before adding a cementitious binder to ensure uniformity of distribution of the binder around soil particles and obtain uniform soil–binder mixtures
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| 10. |
- Al-Jabban, Wathiq Jasim
(författare)
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Soil Modification by adding small amounts of binders : A laboratory study
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Soil stabilization through addition of a hydraulic binder is a method frequently used to modify and improve engineering properties of soft soils. Additives like cement and lime are typically used as stabilizers. More recently, industrial by-products, such as fly ashes, cement kiln dust, blast furnace slags and other slags have been used. The chemical reaction between the soil and the stabilizer alters the physical and engineering properties of the soil and thus desired strength and durability are obtained. The choice of appropriate type and quantity of stabilizer (binder) depends largely on factors such as soil type, moisture content, organic content, sulfate content, curing conditions (time and temperature) and the desired improvement.The objective of this thesis is to increase knowledge and understanding of how small amounts of binders change various engineering properties of stabilized soils in short- and longtime perspective. Extensive laboratory and field programs have been carried out. They cover immediate and long-term effects on the engineering properties by adding various binders. Cement, Multicem, and by-products Petrit T and Mesa were used as binders. Binder was added to the soil at various quantities: 1%, 2%, 4%, 7% and 8% of soil dry weight. The field and laboratory investigation included tests of consistency limits, sieving and hydrometer, unconfined compressive strength, density, solidification, grain size distribution using laser particle size analyzer, leaching tests and pH value. The tests were carried out on the treated soil with different binder contents and after different curing times i.e. 7, 14, 28, 60, 90 days for laboratory tests and 7 and 35 days for field investigation.The unconfined compression tests were used to show the effects of different binders on the enhancement in strength and stiffness over time. Consistency limits were determined to investigate the effects of the binders on the consistency limits, directly after treatment and over time. Laser particle size analyzer tests were conducted to investigate the effects of different binders on the particle size distribution (PSD) before and after treatment. The pH tests were conducted to investigate the effects of different binders on the alkalinity of the soil immediately after treatment and over time. This was used to give an indication of soil-binder reactions. MRM leaching tests were conducted to investigate the acidification potential of soils before and after treatment. Freeze-thaw cycles were conducted to investigate the strength characteristics after freezing and thawing in short- and long-term perspectives. Visual observation and standard dry sieving tests were conducted to optimize the proper mixing times to disintegrate or homogenize the soils by decreasing the size of agglomerated soil particles.The results show, that the variation in soil strength and stiffness of the treated soils are linked to different chemical reactions. Cement is most effective in improving the physical and engineering properties compared to the other binders studied. The plasticity index of soil decreases after treatment and over time. Liquidity index and the ratio of water content to plastic limit are introduced as new indices to illustrate the improvement in workability of treated soil by measuring the reduction in the liquidity index. This is found directly after treatment and it increases with time when the liquidity index is within the plastic range or when the water/plastic vi limit ratio is more than one. Increase of binder content and using longer curing times result in increase of soil density and decrease of water content. Particle size distribution of soil is changed by reducing the clay size fraction and increasing the silt size particles after treatment. This shows that an aggregation of particles take place resulting in coarser material than the initial. The cement-treated soils exhibit a more brittle failure in the unconfined compression tests compared to soils treated with other binder types where a more ductile behavior is observed. Applying freezing-thawing-cycles reduces the strength and stiffness of the treated soil.The appropriate length of time to homogenize and disintegrate the natural soil prior to treatment depends on several factors, such as soil type, water content, and plasticity properties of soil. For high plasticity soil, the disintegration time should be kept as short as possible. The homogenizing and disintegration time is less important for low plasticity soils with low water content than for medium to high plasticity soils.The acidification potential of soils are related to the addition of cementitious binders. The effect is found directly after treatment and over time. The treated soil exhibits higher resistance to decrease in pH value. The strength and stiffness properties found in the field investigation agree in general with those obtained from the laboratory investigation for the same binder type.
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