Bio web of conferences/BIO web of conferences, 2024
The L-shaped retaining walls (L-SRWs) are considered one of the important earth retaining structu... more The L-shaped retaining walls (L-SRWs) are considered one of the important earth retaining structures (ERSs). The investigation of L-SRWs mainly depends on factors directly related to the design process. Reviewing these factors represents the key matter in the design of ERSs, and this is the main purpose of this paper. This review showed that, in the design of L-SRWs, there are important issues to be considered. Some of them are related to the backfill and foundation soils e.g. the dependency of soil stiffness on the state of stresses, information related to soil behavior, inclination and quality of backfill, and settlement of foundation soil. Other issues are related to the wall itself such as the wall dimensions, failure mechanism, and flexural failure mode. In the design processes of L-SRWs, structural and geotechnical design requirements should be considered. L-SRWs should be designed to be proportional in their dimensions, the width of the wall base and its height should be designed to meet a specific ratio. Considerations related to the "conjugate rupture planes", the displacement pattern, and flexural failure mode should be included in the design process of L-SRWs.
The L-shaped retaining walls (L-SRWs) are considered one of the important earth retaining structu... more The L-shaped retaining walls (L-SRWs) are considered one of the important earth retaining structures (ERSs). The investigation of L-SRWs mainly depends on factors directly related to the design process. Reviewing these factors represents the key matter in the design of ERSs, and this is the main purpose of this paper. This review showed that, in the design of L-SRWs, there are important issues to be considered. Some of them are related to the backfill and foundation soils e.g. the dependency of soil stiffness on the state of stresses, information related to soil behavior, inclination and quality of backfill, and settlement of foundation soil. Other issues are related to the wall itself such as the wall dimensions, failure mechanism, and flexural failure mode. In the design processes of L-SRWs, structural and geotechnical design requirements should be considered. L-SRWs should be designed to be proportional in their dimensions, the width of the wall base and its height should be designed to meet a specific ratio. Considerations related to the "conjugate rupture planes", the displacement pattern, and flexural failure mode should be included in the design process of L-SRWs.
Expansive soils are difficult soils for construction purposes because of their cyclic swell/shrin... more Expansive soils are difficult soils for construction purposes because of their cyclic swell/shrink behavior. These soils undergo significant expansion when subjected to an increase in water content or shrink under evaporation condition (when water out). Bulging soils can be improved in several ways. Either by adding materials such as cement, lime, sand and adding river mixture soil. or these soils treated with chemical additives. When added to expansive soils in the proper quantities, these materials aim to improve engineering properties of soils such (i.e. texture , strength, plasticity, etc.). In addition to these traditional materials, solid wastes were also used as one of the stabilization methods (non-traditional methods) to improve the engineering characteristics of expansive soils and to make these soils suitable in construction. From the geotechnical engineering perspective, fly ash, quarry waste, silica fume, cement kiln dust, tire rubber, rice husk, etc. represent the waste materials having effectual features required by excellent soil admixtures. Soils stabilization by using these wastes are one of the different methods of treatment to improve soils geotechnical properties and make them more suitable for construction. Different stabilization methods were reviewed and discussed in the present paper.
Cracking, shrinkage, and curling of soils, in general, take place due to drying. These deformatio... more Cracking, shrinkage, and curling of soils, in general, take place due to drying. These deformations lead to many problems include the development of main paths for water flow and pollutant transport, reduction of soil strength (and impact on other mechanical properties of soils), erosion in slopes, landslides, increase infiltration capacity of the soil and the differential settlement problems. Few studies have investigated the effect of wetting-drying (W-D) cycles on desiccation cracks of soils. The effect of multiple wetting-drying cycles in the cracking behavior was investigated in this research by performing several wetting-drying (W-D) cycles on the initially saturated samples (of pure kaolinite and a mixture of kaolinite with bentonite) under the lab atmosphere (24 ± 1 °C, and 52 ± 2% of RH). The weight of each sample was monitored using a computerized scale (with an accuracy of 0.01 g) connected to the computer. During the test, the water evaporation path with the development of surface cracks and volume shrinkage was monitored by means of digital images. It was observed that the crack patterns changed during the initial cycles, but there was an equilibrium state in the third and fourth W-D cycles. Additionally, it was observed that the main cracks formed in the first dry path were virtually closed after 10 minutes of the second wetting path; in the meantime, small cracks (fissures) were initiated after this wetting process. It was, also, detected that soils with high plasticity required more W-D cycles to reach the equilibrium condition than soils with low plasticity. The results of these experiments are useful for understanding the effect of different seasons on soil behavior.
Iraq is not secure from seismic hazards. Earthquakes are likely to happen and may cause substanti... more Iraq is not secure from seismic hazards. Earthquakes are likely to happen and may cause substantial damage. Actually, such hazards were happened and recorded after the last earthquake in November 2017 (Halabjah earthquake). Unfortunately, there is a lack of studies concerns the assessment of the earthquake hazard on the soil in Iraq. The available research efforts directed toward the earthquakes and their effects on bridge piers, and traditional commercial buildings of Iraq. A historical view of earthquakes that struck Iraq was presented in this paper. Evaluation of liquefaction susceptibility of poorly graded sand at the southwest of Baghdad, Iraq was studied considering the last earthquake. The NCEER, 1997 workshop procedure using shear wave velocity was used to evaluate liquefaction susceptibility of soil. The variation of safety factor with depth had been investigated at different earthquake magnitudes and accelerations. The study revealed that the soil had a high tendency to liquefaction if subjected to earthquake magnitudes within the ranges that hit Iraq in November 2017. Large attention should be given to the effect of the earthquake on soil foundation in the future for all engineering project that constructed in Iraq.
Geotechnical and Geological Engineering, May 23, 2020
In geotechnical engineering, there is a significant potential of using image analysis technique t... more In geotechnical engineering, there is a significant potential of using image analysis technique to study cracking soils by quantifying the characteristics of the crack network. In the current work, the image analysis process was used to obtain comprehensive information about the cracking mechanism and shrinkage during drying. Artificial soil samples investigated in the lab via desiccation tests under different boundary and environment conditions. Soil specimens with smooth and rough bottom contact surfaces were allowed to desiccate under opened and closed environments with specific pressure and temperature conditions. Digital photos were regularly taken during the tests then processed with image j software to characterize the crack patterns. The investigated effects were expressed in terms of crack intensity factor, CIF, and total crack intensity factor, (CIF) tot . The friction of the bottom contact surface, the environment, and the exposition to a saturated salt solution affect cracks formation and affect the cracking mechanism and shrinkage during drying. Smooth and rough boundaries showed significant differences at the end. For rough bottom contact surface, the difference between the values of suction under the opened environment and the closed one may have a small or insignificant effect on (CIF)tot, also the pattern of the cracks did not differ that much. CIF increases with an increase in the friction of the bottom contact surface. Also, samples dried under the open environment exhibit higher CIF and (CIF)tot than those under a closed environment. However, (CIF)tot decreases with an increase in the friction of the bottom surface. For the rough boundary condition under the open environment, the samples exposed to a salt solution had lower CIF and (CIF)tot in comparison with the other one not exposed. Since the orthogonal intersections are more dominant than others, it could be observed that the tensile stresses have a significant effect on desiccation cracks under the investigated conditions.
Sand raining is among the popular techniques used in the laboratory for preparing sand samples. F... more Sand raining is among the popular techniques used in the laboratory for preparing sand samples. Factors like the deposition intensity (DI) and the falling height (HF) affect the produced relative density (RD) in this technique. Studies showed that the RD increase as the HF increases. This is, however, applicable up to a critical HF beyond which the RD seems unaffected. According to previous experiments, the maximum RD achieved using the sand raining is about (70 ± 5)%. The preparation of samples with higher RD is a prerequisite required in many experimental models. In the present article, a new raining system, which is capable to prepare sand samples with a very high RD and with a fast sand flow, is introduced. The new system was used to examine the relationship between the HF and the RD under different trapped air pressures and using rain nozzles with three different opening diameters. The new system was found appropriate for reconstituting SP-SM with very dense specimens (RD > ...
Information about soil consolidation is essential in geotechnical design. Because of the time and... more Information about soil consolidation is essential in geotechnical design. Because of the time and expense involved in performing consolidation tests, equations are required to estimate compression index from soil index properties. Although many empirical equations concerning soil properties have been proposed, such equations may not be appropriate for local situations. The aim of this study is to investigate the consolidation and physical properties of the cohesive soil. Artificial Neural Network (ANN) has been adapted in this investigation to predict the compression index and compression ratio using basic index properties. One hundred and ninety five consolidation results for soils tested at different construction sites in Baghdad city were used. 70% of these results were used to train the prediction ANN models and the rest were equally divided to test and validate the ANN models. The performance of the developed models was examined using the correlation coefficient R. The final mo...
Most of the soils suffered from significant geotechnical problems dependent on factors like the t... more Most of the soils suffered from significant geotechnical problems dependent on factors like the type of soil, soil composition and mineralogy. Specifically, the problems related to mechanical and physical properties of soils. Several studies have been used to mitigate the adverse effects of soils through using either additive conventional materials such as cement, lime or these soils blending with produced material and chemical materials. This paper focuses on stabilizing or improving different soils using sustainable materials. These materials provided environmental and economic benefits while mitigating a health hazard, storage problems, and a potential pollution source. They can be classified according to these sources into four groups: industrial waste (by-products), agriculture waste, domestic waste and mineral waste. According to the results of this review, compaction characteristics, California bearing ratio and unconfined compressive strength have been studied and discussed ...
Cracking, shrinkage, and curling of soils, in general, take place due to drying. These deformatio... more Cracking, shrinkage, and curling of soils, in general, take place due to drying. These deformations lead to many problems include the development of main paths for water flow and pollutant transport, reduction of soil strength (and impact on other mechanical properties of soils), erosion in slopes, landslides, increase infiltration capacity of the soil and the differential settlement problems. Few studies have investigated the effect of wetting-drying (W-D) cycles on desiccation cracks of soils. The effect of multiple wetting-drying cycles in the cracking behavior was investigated in this research by performing several wetting-drying (W-D) cycles on the initially saturated samples (of pure kaolinite and a mixture of kaolinite with bentonite) under the lab atmosphere (24 ± 1 °C, and 52 ± 2% of RH). The weight of each sample was monitored using a computerized scale (with an accuracy of 0.01 g) connected to the computer. During the test, the water evaporation path with the development ...
Bio web of conferences/BIO web of conferences, 2024
The L-shaped retaining walls (L-SRWs) are considered one of the important earth retaining structu... more The L-shaped retaining walls (L-SRWs) are considered one of the important earth retaining structures (ERSs). The investigation of L-SRWs mainly depends on factors directly related to the design process. Reviewing these factors represents the key matter in the design of ERSs, and this is the main purpose of this paper. This review showed that, in the design of L-SRWs, there are important issues to be considered. Some of them are related to the backfill and foundation soils e.g. the dependency of soil stiffness on the state of stresses, information related to soil behavior, inclination and quality of backfill, and settlement of foundation soil. Other issues are related to the wall itself such as the wall dimensions, failure mechanism, and flexural failure mode. In the design processes of L-SRWs, structural and geotechnical design requirements should be considered. L-SRWs should be designed to be proportional in their dimensions, the width of the wall base and its height should be designed to meet a specific ratio. Considerations related to the "conjugate rupture planes", the displacement pattern, and flexural failure mode should be included in the design process of L-SRWs.
The L-shaped retaining walls (L-SRWs) are considered one of the important earth retaining structu... more The L-shaped retaining walls (L-SRWs) are considered one of the important earth retaining structures (ERSs). The investigation of L-SRWs mainly depends on factors directly related to the design process. Reviewing these factors represents the key matter in the design of ERSs, and this is the main purpose of this paper. This review showed that, in the design of L-SRWs, there are important issues to be considered. Some of them are related to the backfill and foundation soils e.g. the dependency of soil stiffness on the state of stresses, information related to soil behavior, inclination and quality of backfill, and settlement of foundation soil. Other issues are related to the wall itself such as the wall dimensions, failure mechanism, and flexural failure mode. In the design processes of L-SRWs, structural and geotechnical design requirements should be considered. L-SRWs should be designed to be proportional in their dimensions, the width of the wall base and its height should be designed to meet a specific ratio. Considerations related to the "conjugate rupture planes", the displacement pattern, and flexural failure mode should be included in the design process of L-SRWs.
Expansive soils are difficult soils for construction purposes because of their cyclic swell/shrin... more Expansive soils are difficult soils for construction purposes because of their cyclic swell/shrink behavior. These soils undergo significant expansion when subjected to an increase in water content or shrink under evaporation condition (when water out). Bulging soils can be improved in several ways. Either by adding materials such as cement, lime, sand and adding river mixture soil. or these soils treated with chemical additives. When added to expansive soils in the proper quantities, these materials aim to improve engineering properties of soils such (i.e. texture , strength, plasticity, etc.). In addition to these traditional materials, solid wastes were also used as one of the stabilization methods (non-traditional methods) to improve the engineering characteristics of expansive soils and to make these soils suitable in construction. From the geotechnical engineering perspective, fly ash, quarry waste, silica fume, cement kiln dust, tire rubber, rice husk, etc. represent the waste materials having effectual features required by excellent soil admixtures. Soils stabilization by using these wastes are one of the different methods of treatment to improve soils geotechnical properties and make them more suitable for construction. Different stabilization methods were reviewed and discussed in the present paper.
Cracking, shrinkage, and curling of soils, in general, take place due to drying. These deformatio... more Cracking, shrinkage, and curling of soils, in general, take place due to drying. These deformations lead to many problems include the development of main paths for water flow and pollutant transport, reduction of soil strength (and impact on other mechanical properties of soils), erosion in slopes, landslides, increase infiltration capacity of the soil and the differential settlement problems. Few studies have investigated the effect of wetting-drying (W-D) cycles on desiccation cracks of soils. The effect of multiple wetting-drying cycles in the cracking behavior was investigated in this research by performing several wetting-drying (W-D) cycles on the initially saturated samples (of pure kaolinite and a mixture of kaolinite with bentonite) under the lab atmosphere (24 ± 1 °C, and 52 ± 2% of RH). The weight of each sample was monitored using a computerized scale (with an accuracy of 0.01 g) connected to the computer. During the test, the water evaporation path with the development of surface cracks and volume shrinkage was monitored by means of digital images. It was observed that the crack patterns changed during the initial cycles, but there was an equilibrium state in the third and fourth W-D cycles. Additionally, it was observed that the main cracks formed in the first dry path were virtually closed after 10 minutes of the second wetting path; in the meantime, small cracks (fissures) were initiated after this wetting process. It was, also, detected that soils with high plasticity required more W-D cycles to reach the equilibrium condition than soils with low plasticity. The results of these experiments are useful for understanding the effect of different seasons on soil behavior.
Iraq is not secure from seismic hazards. Earthquakes are likely to happen and may cause substanti... more Iraq is not secure from seismic hazards. Earthquakes are likely to happen and may cause substantial damage. Actually, such hazards were happened and recorded after the last earthquake in November 2017 (Halabjah earthquake). Unfortunately, there is a lack of studies concerns the assessment of the earthquake hazard on the soil in Iraq. The available research efforts directed toward the earthquakes and their effects on bridge piers, and traditional commercial buildings of Iraq. A historical view of earthquakes that struck Iraq was presented in this paper. Evaluation of liquefaction susceptibility of poorly graded sand at the southwest of Baghdad, Iraq was studied considering the last earthquake. The NCEER, 1997 workshop procedure using shear wave velocity was used to evaluate liquefaction susceptibility of soil. The variation of safety factor with depth had been investigated at different earthquake magnitudes and accelerations. The study revealed that the soil had a high tendency to liquefaction if subjected to earthquake magnitudes within the ranges that hit Iraq in November 2017. Large attention should be given to the effect of the earthquake on soil foundation in the future for all engineering project that constructed in Iraq.
Geotechnical and Geological Engineering, May 23, 2020
In geotechnical engineering, there is a significant potential of using image analysis technique t... more In geotechnical engineering, there is a significant potential of using image analysis technique to study cracking soils by quantifying the characteristics of the crack network. In the current work, the image analysis process was used to obtain comprehensive information about the cracking mechanism and shrinkage during drying. Artificial soil samples investigated in the lab via desiccation tests under different boundary and environment conditions. Soil specimens with smooth and rough bottom contact surfaces were allowed to desiccate under opened and closed environments with specific pressure and temperature conditions. Digital photos were regularly taken during the tests then processed with image j software to characterize the crack patterns. The investigated effects were expressed in terms of crack intensity factor, CIF, and total crack intensity factor, (CIF) tot . The friction of the bottom contact surface, the environment, and the exposition to a saturated salt solution affect cracks formation and affect the cracking mechanism and shrinkage during drying. Smooth and rough boundaries showed significant differences at the end. For rough bottom contact surface, the difference between the values of suction under the opened environment and the closed one may have a small or insignificant effect on (CIF)tot, also the pattern of the cracks did not differ that much. CIF increases with an increase in the friction of the bottom contact surface. Also, samples dried under the open environment exhibit higher CIF and (CIF)tot than those under a closed environment. However, (CIF)tot decreases with an increase in the friction of the bottom surface. For the rough boundary condition under the open environment, the samples exposed to a salt solution had lower CIF and (CIF)tot in comparison with the other one not exposed. Since the orthogonal intersections are more dominant than others, it could be observed that the tensile stresses have a significant effect on desiccation cracks under the investigated conditions.
Sand raining is among the popular techniques used in the laboratory for preparing sand samples. F... more Sand raining is among the popular techniques used in the laboratory for preparing sand samples. Factors like the deposition intensity (DI) and the falling height (HF) affect the produced relative density (RD) in this technique. Studies showed that the RD increase as the HF increases. This is, however, applicable up to a critical HF beyond which the RD seems unaffected. According to previous experiments, the maximum RD achieved using the sand raining is about (70 ± 5)%. The preparation of samples with higher RD is a prerequisite required in many experimental models. In the present article, a new raining system, which is capable to prepare sand samples with a very high RD and with a fast sand flow, is introduced. The new system was used to examine the relationship between the HF and the RD under different trapped air pressures and using rain nozzles with three different opening diameters. The new system was found appropriate for reconstituting SP-SM with very dense specimens (RD > ...
Information about soil consolidation is essential in geotechnical design. Because of the time and... more Information about soil consolidation is essential in geotechnical design. Because of the time and expense involved in performing consolidation tests, equations are required to estimate compression index from soil index properties. Although many empirical equations concerning soil properties have been proposed, such equations may not be appropriate for local situations. The aim of this study is to investigate the consolidation and physical properties of the cohesive soil. Artificial Neural Network (ANN) has been adapted in this investigation to predict the compression index and compression ratio using basic index properties. One hundred and ninety five consolidation results for soils tested at different construction sites in Baghdad city were used. 70% of these results were used to train the prediction ANN models and the rest were equally divided to test and validate the ANN models. The performance of the developed models was examined using the correlation coefficient R. The final mo...
Most of the soils suffered from significant geotechnical problems dependent on factors like the t... more Most of the soils suffered from significant geotechnical problems dependent on factors like the type of soil, soil composition and mineralogy. Specifically, the problems related to mechanical and physical properties of soils. Several studies have been used to mitigate the adverse effects of soils through using either additive conventional materials such as cement, lime or these soils blending with produced material and chemical materials. This paper focuses on stabilizing or improving different soils using sustainable materials. These materials provided environmental and economic benefits while mitigating a health hazard, storage problems, and a potential pollution source. They can be classified according to these sources into four groups: industrial waste (by-products), agriculture waste, domestic waste and mineral waste. According to the results of this review, compaction characteristics, California bearing ratio and unconfined compressive strength have been studied and discussed ...
Cracking, shrinkage, and curling of soils, in general, take place due to drying. These deformatio... more Cracking, shrinkage, and curling of soils, in general, take place due to drying. These deformations lead to many problems include the development of main paths for water flow and pollutant transport, reduction of soil strength (and impact on other mechanical properties of soils), erosion in slopes, landslides, increase infiltration capacity of the soil and the differential settlement problems. Few studies have investigated the effect of wetting-drying (W-D) cycles on desiccation cracks of soils. The effect of multiple wetting-drying cycles in the cracking behavior was investigated in this research by performing several wetting-drying (W-D) cycles on the initially saturated samples (of pure kaolinite and a mixture of kaolinite with bentonite) under the lab atmosphere (24 ± 1 °C, and 52 ± 2% of RH). The weight of each sample was monitored using a computerized scale (with an accuracy of 0.01 g) connected to the computer. During the test, the water evaporation path with the development ...
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Papers by Abbas J . Al-Taie