- I am Maki Jafar Mohammed Al-Waily, a faculty member since a 25 years ago at the Technical College-Mussaib ( Al-Furat ... moreI am Maki Jafar Mohammed Al-Waily, a faculty member since a 25 years ago at the Technical College-Mussaib ( Al-Furat Al-Awsat Technical University-Iraq). I taught Soil Mechanics for third class and Foundation Engineering for fourth class of under graduated students in civil engineering derangement . I Have a PhD in Geotechnical Engineering from the University of Technology in Baghdad. Seventeen research papers have been published in international and local journals and the following books 1. Iraqi Code for Foundation and Retaining Wall (2015) 2. Fundamentals of Soil Mechanics and its Engineering Application. (2017). 3. Fundamentals of Foundation Engineering (under preparing)edit
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The current investigation used 16 model tests with two alternative foundation shapes, one strip and the other square, for a total of eight model tests for each foundation type. A model test was conducted only on natural soils to evaluate... more
The current investigation used 16 model tests with two alternative foundation shapes, one strip and the other square, for a total of eight model tests for each foundation type. A model test was conducted only on natural soils to evaluate the two types of foundation and both circumstances of improvement utilizing RAP. The model square footing was laid on a layer of (RAP), with the varied widths (1.25B and 1.75B) and different thicknesses (0.25 B, 0.50 B, and 0.75 B in which B=footing width). Six model tests are tested in two widths (1.25B and 2.50B) in model strip footing treated (RAP), and three thicknesses (0.50B, 1B, and 1.5B) in each width are done. The settlement improvement factor was utilized to show the (RAP) layer's influence.The data suggested that the (RAP) layer beneath the foundations influenced settlement significantly. The RAP material in a square footing with a depth of 0.75 B offered the most efficient settlement reduction, with the lowest settlement improvemen...
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This study used a finite element analysis approach employing Plaxis 3D to analyze the stress concentration ratio, a critical parameter in geotechnical engineering, to examine stresses operating on stone columns and soft soils. This study... more
This study used a finite element analysis approach employing Plaxis 3D to analyze the stress concentration ratio, a critical parameter in geotechnical engineering, to examine stresses operating on stone columns and soft soils. This study also looked at the effect of the stiffness ratio between the stone column and the neighboring soil. With the same length and three different diameters, 0.8 m, 1.0 m, and 1.2 m, or three area replacement ratios ranging from 7% to 16%, respectively, floating and end-bearing stone columns were used. The influence of soft soil undrained cohesion, cu ranging from 6 kPa to 40 kPa, was also considered in the current study. The stiffness ratio for columns to adjacent soil, end bearing or floating stone column, and area ratio all have a significant impression on the performance of the stone column in treating soft soil and stress transmission mechanisms in the enhanced soil body, according to parametric studies. The average stress concentration ratio in soil...
With many prime construction sites already developed, less desirable locations with poor soil conditions are increasingly being considered for future projects. Soil enhancement techniques enable construction in areas previously deemed... more
With many prime construction sites already developed, less desirable locations with poor soil conditions are increasingly being considered for future projects. Soil enhancement techniques enable construction in areas previously deemed unsuitable and allow for the modification of existing soils to achieve desired engineering properties. Moreover, the reuse of waste materials and industrial byproducts can help conserve valuable natural resources. This study investigates the potential of calcined agricultural and industrial waste products, namely cardboard, dry-date kernels, and rice husks, as soil stabilizers. The waste materials were calcined at three different temperatures (500, 700, and 900℃) and for three distinct durations (1, 2, and 4 hours). The ASTM C618 standard recommends conducting XRD and XRF chemical tests to determine the oxide content of the resulting fly ashes. Notable oxides included SiO2, Al2O3, and FeO2, with rice husks serving as a control byproduct material. The combustion of cardboard and dry-date kernels yielded over 60% of the measured oxides. Optimal combustion efficiency was achieved for cardboard and dry-date kernels at 500℃ for four hours, while rice husks exhibited optimal combustion at 900℃ for two hours. The oxide percentages resulting from the combustion of cardboard and dry-date kernels were close to 60%, aligning with the ASTM C618 and AASHTO M295 classifications for class C fly ash. In contrast, rice husks demonstrated high oxide concentrations, accounting for more than 95% of the total raw material.
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In this work, laboratory experiments have been carried out to study the bearing capacity ratio which is defined as ratio of the bearing capacity of treated soil with granular pile to the bearing capacity of untreated soil at a given... more
In this work, laboratory experiments have been carried out to study the bearing capacity ratio which is defined as ratio of the bearing capacity of treated soil with granular pile to the bearing capacity of untreated soil at a given settlement for the foundation. A laboratory setup was used electronic load cell to measure the applied load to the soil-granular pile system and used the displacement transducer to measure the settlement. Granular piles made of crushed stone or gravel or sand with a diameter of 50 mm were installed in very soft clays having undrained shear strength ranging between 13 and 21 kPa. Two ratios of the length to diameter were tried, namely 5.2 and 4. The experimental tests showed that the granular pile using crushed stone as backfill material provided a highest bearing capacity ratio equal to 1.6 and 1.5 for the soil having a shear strength = 13 kPa at the two ratios of length to diameter respectively.
Research Interests: Materials Science, Geotechnical Engineering, Experimental Analysis of Behavior, IEEE, Ground Improvement by Stone Columns, and 13 moreGeotechnics, Stone Column, Soil Improvement by Stone Column Method, Granular Material, Shear Strength, Bearing Capacity, Pile, Soft Clay, Soil Shear Strength, Bearing Capacity of Soil, Soft Clay Reinforced by Sand Columns, granular pil, and bearing caapacity of soft
In the present study, 24 laboratory models on soft clay treated with stone columns were carried out. The results for each case are analysed for the purpose of constructing a statistical model linking the variables studied. The experiments... more
In the present study, 24 laboratory models on soft clay treated with stone columns were carried out. The results for each case are analysed for the purpose of constructing a statistical model linking the variables studied. The experiments showed that the stress concentration and bearing capacity of soil treated with stone column increase with increasing the undrained shear strength (cu), number of columns and L/d ratio. The models represent a single stone column and a group of stone columns. The studied variables are three dependent variables, the stress concentration ratio (n), bearing capacity of soil treated with stone column (q) and the settlement improvement ratio (Sr) due to the existence of stone columns. The independent variables are six: the undrained shear strength of clay soil, with three values (6, 9 and 12 kPa), the number of stone columns (1, 2, 3 and 4 columns) and the length (L) to the diameter (D) of the stone column or (L/D) ratio in two values (6 and 8). Besides, ...
Research Interests: Geology, Geotechnical Engineering, Statistical Modeling, Soft soils, Ground Improvement by Stone Columns, and 9 moreGeotechnics, Stone Column, Soil Improvement by Stone Column Method, STRESS CONCENTRATION FACTOR, Stress Concentration, Bearing Capacity of Foundation, Bearing Capacity of Soil, Stress concentration ratio Settlement ratio, and Soft soil settlement
The emphasis of current work is on assessing the settlement improvement ratio, which is described as the ratio between the settled soils treated with a stone column and the settlement of the non-treated soil (Sr = Streated/Suntreated).... more
The emphasis of current work is on assessing the settlement improvement ratio, which is described as the ratio between the settled soils treated with a stone column and the settlement of the non-treated soil (Sr = Streated/Suntreated). The research was conducted using a 300 mm diameter and 300 mm high stone-column container testing model. On 14 modeled stone columns made only from crush stones and using various backfill content, model tests including static axial compression tests were performed. The substance used in the stone backfill column had been changed by sand or lime or cement percentages. The shear strength prepared by the containers varied between 5.5 kPa and 13.5 kPa. Results show that the settlement ratio values, Sr achieved with crush stone, crushed stone +50% sand, crushed stone +5% dry lime, crushed stones +10% dry lime, crushed stone +2.5% cement +5.0% crushed stone +5.0% cement, respectively, was 0.23, 0.12, 0.16, 0.15 and 0.09. In other words, there is a drop in the settlement from 77% to 91%.
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Herein, an experimental investigation of the plugging impact on the capacity of open-ended piles installed in clayey soil is presented. Model tests involving static axial compression load tests are carried out on four open-ended modeled... more
Herein, an experimental investigation of the plugging impact on the capacity of open-ended piles installed in clayey soil is presented. Model tests involving static axial compression load tests are carried out on four open-ended modeled piles with different diameters (12.5, 19, 25, and 50 mm). In the same manner, four closed-ended modeled piles are tested to make a comparison. A load cell system is used to determine the resistance acting on the piles, with an instrumented transducer on the outside walls of the pile. The eight steel model piles are tested in the circular steel tank with a diameter of 350 mm and 400 mm in length. Three undrained shear strengths of the clay sample, 5 KPa, 10 kPa, and 18 kPa, are used in model tests. The outcomes of the tested models uncover that the pipe pile capacity is mainly mobilized at the low shear strength. In addition, it is realized that the soil plugging in the small diameter has an impact on pipe pile capacity. Based on experimental results, five statistical models are established to achieve relations between the maximum load for the closed-ended pipe. It is realized that the value of Qexp is highly correlated with the diameter and Qcalc..
Research Interests: Geology, Geotechnical Engineering, Statistical Modeling, Experimental Analysis of Behavior, Soft soils, and 10 morePiles, Geotechnics, Bearing Capacity, Arabian Journal of Geosciences, Plugin, Ultimate Bearing Capacity, Soft Clays, Bearing Capacity of Foundation, Soft Soil Engineering, and Model tests
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This paper aims to examine the effect of partial replacement with crushed concrete as a recycled material to enhance the bearing capacity and to decrease the settlement of soft clay. To clarify the effect of scale factor, four cubic steel... more
This paper aims to examine the effect of partial replacement with crushed concrete as a recycled material to enhance the bearing capacity and to decrease the settlement of soft clay. To clarify the effect of scale factor, four cubic steel soil tank with four dimensions of (250 x 250 x 250) mm; (300 x 300 x 300) mm;(400 x 400 x 400) mm; and (500 x 500 x 500) mm are used to carry out the experimental works, by using a foursizes for each square and strip footings with varying the depth of replacement (0.2, 0.4 and 0.6 width of square footing) and (0.33, 0.67 and 1 width of strip footing).The effect of replacement wasevaluated with regard to settlement control and bearing capacity. It is found from results of experimental works that a significant decreasing in settlement and increasing in bearing capacity of treated soil with increasing the depth of the partial replacement layer for both square and strip footing compared to untreated soil. The study also shows that the use of partial re...
Research Interests: Geotechnical Engineering, Modeling, Multidisciplinary, Experimental Research, Experimental Analysis of Behavior, and 13 moreSoft soils, Recycled Materials, Geotechnics, Bearing Capacity, Soft Soil Stabilization, Iop, Soft Soil Engineering, Soft Soil Improvement, Bearing Capacity of Soil, Model tests, Soft soil settlement, Crushed Concrete Aggregate, and soft soil improvements
This paper aims to examine the effect of partial replacement with crushed concrete as a recycled material to enhance the bearing capacity and to decrease the settlement of soft clay. To clarify the effect of scale factor, four cubic steel... more
This paper aims to examine the effect of partial replacement with crushed concrete as a recycled material to enhance the bearing capacity and to decrease the settlement of soft clay. To clarify the effect of scale factor, four cubic steel soil tank with four dimensions of (250 x 250 x 250) mm; (300 x 300 x 300) mm;(400 x 400 x 400) mm; and (500 x 500 x 500) mm are used to carry out the experimental works, by using a foursizes for each square and strip footings with varying the depth of replacement (0.2 , 0.4 and 0.6 width of square footing) and (0.33, 0.67 and 1 width of strip footing).The effect of replacement wasevaluated with regard to settlement control and bearing capacity. It is found from results of experimental works that a significant decreasing in settlement and increasing in bearing capacity of treated soil with increasing the depth of the partial replacement layer for both square and strip footing compared to untreated soil. The study also shows that the use of partial r...
Research Interests: Geotechnical Engineering, Modeling, Multidisciplinary, Experimental Research, Experimental Analysis of Behavior, and 13 moreSoft soils, Recycled Materials, Geotechnics, Bearing Capacity, Soft Soil Stabilization, Iop, Soft Soil Engineering, Soft Soil Improvement, Bearing Capacity of Soil, Model tests, Soft soil settlement, Crushed Concrete Aggregate, and soft soil improvements
The main purpose of this experimental study is to know the effect of improvement of soft soil by mixing it with granular materials on the properties of soft soil. The soil model was brought from a one construction project in Karbala,... more
The main purpose of this experimental study is to know the effect of improvement of soft soil by mixing it with granular materials on the properties of soft soil. The soil model was brought from a one construction project in Karbala, Iraq. Routine tests were carried out on the soft soil model alone, as well as for soft soil with specific percentage of granular materials. The model of cylindrical shape laboratory dimensions of 250 mm in diameter with a height of 300 mm. Eight different shear strength were used for laboratory model tests. Static loading tests were carried out on these model tests. It was found from results of model tests of improved soil that the averaged value of settlement reduction is 0.61 for all model tests, where the bearing capacity is increased by 31%.
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In this work, laboratory experiments have been carried out to study the value of the stress concentration ratio, n, which is defined as the ratio of vertical stress acting on the stone column to that acting on the surrounding soil. A... more
In this work, laboratory experiments have been carried out to study the value of the stress concentration ratio, n, which is defined as the ratio of vertical stress acting on the stone column to that acting on the surrounding soil. A laboratory setup was manufactured in which two proving rings are used to measure the total load applied to the soil-stone column system and the individual load carried directly by the stone column. The foundation steel plates have 220 mm diameter and 5 mm thickness. These plates contain 1, 2, 3, and 4 holes. The spacing between all the holes equals twice the stone column diameter, D, center to center. The stone columns made of crushed stone were installed in very soft clays having undrained shear strength ranging between 6 and 12 kPa. Two length to diameter ratios L/D were tried, namely, L/D=6 and 8. The testing program consists of 30 tests on single, two, three, and four columns to study the stress concentration ratio and the bearing improvement ratio ...
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The emphasis of current work is on assessing the settlement improvement ratio, which is described as the ratio between the settled soils treated with a stone column and the settlement of the non-treated soil (Sr = Streated/Suntreated).... more
The emphasis of current work is on assessing the settlement improvement ratio, which is described as the ratio between the settled soils treated with a stone column and the settlement of the non-treated soil (Sr = Streated/Suntreated). The research was conducted using a 300 mm diameter and 300 mm high stone-column container testing model. On 14 modeled stone columns made only from crush stones and using various backfill content, model tests including static axial compression tests were performed. The substance used in the stone backfill column had been changed by sand or lime or cement percentages. The shear strength prepared by the containers varied between 5.5 kPa and 13.5 kPa. Results show that the settlement ratio values, Sr achieved with crush stone, crushed stone +50% sand, crushed stone +5% dry lime, crushed stones +10% dry lime, crushed stone +2.5% cement +5.0% crushed stone +5.0% cement, respectively, was 0.23, 0.12, 0.16, 0.15 and 0.09. In other words, there is a drop in the settlement from 77% to 91%.
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The present work is focused towards the evaluation of bearing capacity improvement ratio q r , determined trough the confined compression tests carried out on stone column penetrated in soft clay soil. The investigation was carried out... more
The present work is focused towards the evaluation of bearing capacity improvement ratio q r , determined trough the confined compression tests carried out on stone column penetrated in soft clay soil. The investigation was carried out using model tests of stone column performed inside cylindrical container of 300 mm in diameter and 350 mm in height. The undarined shear strength of the soil prepared in the containers ranged from 5.5 kPa to 13.5 kPa. The models ware tested immediately after preparation and some of the models were left to cure 10 days after preparation. It can be noticed from results that the treated soil loaded after 10 days shows an increase in bearing improvement ratio mare than that of treated soil loaded immediately.
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Herein, an experimental investigation of the plugging impact on the capacity of open-ended piles installed in clayey soil is presented. Model tests involving static axial compression load tests are carried out on four open-ended modeled... more
Herein, an experimental investigation of the plugging impact on the capacity of open-ended piles installed in clayey soil is presented. Model tests involving static axial compression load tests are carried out on four open-ended modeled piles with different diameters (12.5, 19, 25, and 50 mm). In the same manner, four closed-ended modeled piles are tested to make a comparison. A load cell system is used to determine the resistance acting on the piles, with an instrumented transducer on the outside walls of the pile. The eight steel model piles are tested in the circular steel tank with a diameter of 350 mm and 400 mm in length. Three undrained shear strengths of the clay sample, 5 KPa, 10 kPa, and 18 kPa, are used in model tests. The outcomes of the tested models uncover that the pipe pile capacity is mainly mobilized at the low shear strength. In addition, it is realized that the soil plugging in the small diameter has an impact on pipe pile capacity. Based on experimental results, five statistical models are established to achieve relations between the maximum load for the closed-ended pipe. It is realized that the value of Q exp is highly correlated with the diameter and Q calc. .
Research Interests: Geotechnical Engineering, Statistical Modeling, Experimental Analysis of Behavior, Soft soils, Piles, and 9 moreGeotechnics, Bearing Capacity, Experimental Statistics: Statistical Analysis of Experiments, Plugin, Ultimate Bearing Capacity, Soft Clays, Bearing Capacity of Foundation, Soft Soil Engineering, and Model tests
In the present study, 24 laboratory models on soft clay treated with stone columns were carried out. The results for each case are analysed for the purpose of constructing a statistical model linking the variables studied. The experiments... more
In the present study, 24 laboratory models on soft clay treated with stone columns were carried out. The results for each case are analysed for the purpose of constructing a statistical model linking the variables studied. The experiments showed that the stress concentration and bearing capacity of soil treated with stone column increase with increasing the undrained shear strength (cu), number of columns and L/d ratio. The models represent a single stone column and a group of stone columns. The studied variables are three dependent variables, the stress concentration ratio (n), bearing capacity of soil treated with stone column (q) and the settlement improvement ratio (Sr) due to the existence of stone columns. The independent variables are six: the undrained shear strength of clay soil, with three values (6, 9 and 12 kPa), the number of stone columns (1, 2, 3 and 4 columns) and the length (L) to the diameter (D) of the stone column or (L/D) ratio in two values (6 and 8). Besides, the bearing capacity of the soil treated (q) with stone columns and the settlement improvement ratio were used in some statistical models as independents. After regression analysis, a set of equations that correlate the previous variables have been suggested. The incepted values for dependent variables are close to the laboratory results.
Research Interests: Geotechnical Engineering, Statistical Modeling, Soft soils, Ground Improvement by Stone Columns, Geotechnics, and 8 moreStone Column, Soil Improvement by Stone Column Method, STRESS CONCENTRATION FACTOR, Stress Concentration, Bearing Capacity of Foundation, Bearing Capacity of Soil, Stress concentration ratio Settlement ratio, and Soft soil settlement
This paper aims to examine the effect of partial replacement with crushed concrete as a recycled material to enhance the bearing capacity and to decrease the settlement of soft clay. To clarify the effect of scale factor, four cubic steel... more
This paper aims to examine the effect of partial replacement with crushed concrete as a recycled material to enhance the bearing capacity and to decrease the settlement of soft clay. To clarify the effect of scale factor, four cubic steel soil tank with four dimensions of (250 x 250 x 250) mm; (300 x 300 x 300) mm;(400 x 400 x 400) mm; and (500 x 500 x 500) mm are used to carry out the experimental works, by using a foursizes for each square and strip footings with varying the depth of replacement (0.2 , 0.4 and 0.6 width of square footing) and (0.33, 0.67 and 1 width of strip footing).The effect of replacement wasevaluated with regard to settlement control and bearing capacity. It is found from results of experimental works that a significant decreasing in settlement and increasing in bearing capacity of treated soil with increasing the depth of the partial replacement layer for both square and strip footing compared to untreated soil. The study also shows that the use of partial replacement layer with a depth of 0.4 B for strip footings results
in reducing the settlements by an averaged percentage of 72 % and increasing the bearing capacity with an average of 96%. Also the results demonstrates that clear increasing in bearing capacity for all depth of replacement under square footing with indistinct in settlement
in reducing the settlements by an averaged percentage of 72 % and increasing the bearing capacity with an average of 96%. Also the results demonstrates that clear increasing in bearing capacity for all depth of replacement under square footing with indistinct in settlement
Research Interests: Geotechnical Engineering, Modeling, Experimental Research, Experimental Analysis of Behavior, Soft soils, and 11 moreRecycled Materials, Geotechnics, Bearing Capacity, Soft Soil Stabilization, Soft Soil Engineering, Soft Soil Improvement, Bearing Capacity of Soil, Model tests, Soft soil settlement, Crushed Concrete Aggregate, and soft soil improvements
The main purpose of this experimental study is to know the effect of improvement of soft soil by mixing it with granular materials on the properties of soft soil. The soil model was brought from a one construction project in Karbala,... more
The main purpose of this experimental study is to know the effect of improvement of soft soil by mixing it with granular materials on the properties of soft soil. The soil model was brought from a one construction project in Karbala, Iraq. Routine tests were carried out on the soft soil model alone, as well as for soft soil with specific percentage of granular materials. The model of cylindrical shape laboratory dimensions of 250 mm in diameter with a height of 300 mm. Eight different shear strength were used for laboratory model tests. Static loading tests were carried out on these model tests. It was found from results of model tests of improved soil that the averaged value of settlement reduction is 0.61 for all model tests, where the bearing capacity is increased by 31%.
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This study investigated the effect of using nano CaCO 3 and nano SiO 2 as partial replacement of cement on the mechanical properties, durability and flowability of concrete. Nano materials were added in four different dosages of 1%, 2%,... more
This study investigated the effect of using nano CaCO 3 and nano SiO 2 as partial replacement of cement on the mechanical properties, durability and flowability of concrete. Nano materials were added in four different dosages of 1%, 2%, 3% and 4% by weight of cement in concrete mixture. Mechanical properties of hardened concrete (compressive strength, flexural strength and split tensile strength) have been done after 28 days of water curing. Also water absorption test was carrying out for obtaining the durability properties of concrete specimen. slump flow for fresh concrete was measured for all mixes. Binary combination of nanoCaCO 3 + nanoSiO 2 were also studied the combined effect of the nano particles. The results showed that incorporation of nano CaCO 3 and nano SiO 2 particles lead to increase the packing and enhance the mechanical properties and durability of concrete. A significant performance was observed in case of nano silica addition to the concrete in comparing with nano CaCO 3. The results showed that the workability of fresh concrete was decreased by increasing the content of nano particles.
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... Al-Musaib Technical Institute/ Al-Musaib. 1673 Laboratory Investigation on Efficiency of Model Stone Column Groups Dr. Kais T. Shlash*, Dr. Mohammed Y. Fattah* & Dr. Maki J. MohammedAl-Waily** Received on: 6 / 4 / 2008 Accepted... more
... Al-Musaib Technical Institute/ Al-Musaib. 1673 Laboratory Investigation on Efficiency of Model Stone Column Groups Dr. Kais T. Shlash*, Dr. Mohammed Y. Fattah* & Dr. Maki J. MohammedAl-Waily** Received on: 6 / 4 / 2008 Accepted on: 5 / 3 / 2009 ...
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In this work, laboratory experiments have been carried out to study the bearing capacity ratio which is defined as ratio of the bearing capacity of treated soil with granular pile to the bearing capacity of untreated soil at a given... more
In this work, laboratory experiments have been
carried out to study the bearing capacity ratio
which is defined as ratio of the bearing capacity of treated soil
with granular pile to the bearing capacity of untreated soil at a
given settlement for the foundation. A laboratory setup was used
electronic load cell to measure the applied load to the soilgranular
pile system and used the displacement transducer to
measure the settlement. Granular piles made of crushed stone or
gravel or sand with a diameter of 50 mm were installed in very
soft clays having undrained shear strength ranging between 13
and 21 kPa. Two ratios of the length to diameter were tried,
namely 5.2 and 4. The experimental tests showed that the
granular pile using crushed stone as backfill material provided a
highest bearing capacity ratio equal to 1.6 and 1.5 for the soil
having a shear strength = 13 kPa at the two ratios of length to
diameter respectively.
carried out to study the bearing capacity ratio
which is defined as ratio of the bearing capacity of treated soil
with granular pile to the bearing capacity of untreated soil at a
given settlement for the foundation. A laboratory setup was used
electronic load cell to measure the applied load to the soilgranular
pile system and used the displacement transducer to
measure the settlement. Granular piles made of crushed stone or
gravel or sand with a diameter of 50 mm were installed in very
soft clays having undrained shear strength ranging between 13
and 21 kPa. Two ratios of the length to diameter were tried,
namely 5.2 and 4. The experimental tests showed that the
granular pile using crushed stone as backfill material provided a
highest bearing capacity ratio equal to 1.6 and 1.5 for the soil
having a shear strength = 13 kPa at the two ratios of length to
diameter respectively.
Research Interests: Geotechnical Engineering, Experimental Analysis of Behavior, Ground Improvement by Stone Columns, Geotechnics, Stone Column, and 9 moreSoil Improvement by Stone Column Method, Shear Strength, Soft Clay, Soil Shear Strength, Bearing Capacity of Soil, Soft Clay Reinforced by Sand Columns, Stone Columns, Soft Cay, Clay Minerals. , granular pil, and bearing caapacity of soft
This investigational study was directed to establish the correlation between piled raft foundation and two soil improvement techniques, stone columns and lime columns to evaluate the bearing improvement ratio BCR for the soft clay soil... more
This investigational study was directed to establish the correlation between piled raft foundation and two soil improvement techniques, stone columns and lime columns to evaluate the bearing improvement ratio BCR for the soft clay soil with three values of undrained shear strength, 8 kPa,10 kPa and 12 kPa. The 12 model tests was conducted in the present work, three models of untreated soil, three models of soil with piled raft, three models of soil treated with stone columns and three models of soil treated with lime columns. The container used in experimental works was made of steel with plane area of 500 mm * 500 mm and 500mm in height. The thickness of soil sample inside the container was 400 mm. The study showed that the piled raft was more efficient in the bearing capacity improvement than the two soil improvement techniques. The bearing improvement ratio were 3.39, 3.27 and 2.78 in the three model tests of piled-raft for three samples of soil, respectively, while the lime columns provided the lowest values of the bearing improvement ratio were 1.64, 1.67 and 1.8 respectively.
15 model tests were conducted to evaluate the settlement improvement factor (which is defined as the ratio between the settlement of untreated soil and the settlement of the soil treated with stone column) at various area replacement... more
15 model tests were conducted to evaluate the settlement improvement factor (which is defined as the ratio between the settlement of untreated soil and the settlement of the soil treated with stone column) at various area replacement ratio (which is defined as the ratio between the cross-sectional area of stone column and the area of soil surrounding it). All the model tests in this study were prepared by removing the soil from a hole and fill it by crushed stone. The stone columns are constructed in soft clays having three shear strengths (cu=11, 16 and 22 kPa) with various area ratios 0.042, 0.099, 0.333 and 0.563. The results of experimental tests showed that the crushed stone with the previous area ratio values provided a settlement improvement ratio (1.16, 1.25, 2.85 and 5.82) respectively, for the soil having a shear strength cu = 11 kPa. These results were good agreement with Priebe's semi-empirical method for estimating the settlement of soil treated by stone column. Stone column, Settlement improvement, soil treated
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This experimental study was conducted to demonstrate the relationship between the bearing improvement ratio (which is defined as the ratio between the bearing capacity of the soil treated with stone column to the bearing capacity of... more
This experimental study was conducted to demonstrate the relationship between the bearing improvement ratio (which is defined as the ratio between the bearing capacity of the soil treated with stone column to the bearing capacity of untreated soil at the same settlement level) or (q treated /q untreated) and the area replacement ratio (which is defined as the ratio between the area of cross-section of stone column and the area of soil surrounding it). The investigation was carried out using model tests of stone column with different diameters (20, 30, 50 and 60 mm) or area replacement ratio (Ar) (0.042, 0.099, 0.333 and 0.563) performed inside the container with dimensions of 240 mm x 240 mm and in height of 260 mm. The undrained shear strength of the soil prepared in the containers ranged from 11 kPa to 22 kpa The study showed that the bearing improvement ratio were 1.16, 1.29, 1.64 and 2.29 for the soil having (cu = 16 kPa) treated with stone columns of (Ar = 0.042, 0.099, 0.333 and 0.563) respectively. Introduction Stone columns and sand compaction piles represent the most known column-type technique for improving soft soils. They possess high compressive strength and stiffness relative the soft soil. They do not only serve the function of reinforcement and drainage, but they also increase the bearing capacity and reduce the settlement of the soft ground. Depending on the type of installation method, the soil around the column is compacted due to the displacement of the soil during installation, and hence improved stiffness of the soil. Various installation methods are used worldwide , for instance, the vibroreplacement method, the vibro-compaction method, the vibro-composer method and ramming by dropping hammer (15 to 20 kN). The effectiveness of the load redistribution to the columns mainly depends on the lateral support from the surrounding soft soil. The lateral support is expressed by means of the undrained shear strength. According to German regulations, the application of stone columns is generally limited to soils with undrained shear strength cu = 15-25 kN/m² (FGSV 1979). Stone columns are also occasionally used in very
The main objective of this paper is to find an experimental base for the value of the stress concentration ratio by manufacturing a model of a single stone column with rigid instrumented loading plates such that the total load applied to... more
The main objective of this paper is to find an experimental base for the value of the stress concentration ratio by manufacturing a model of a single stone column with rigid instrumented loading plates such that the total load applied to the model footing, and the load applied to the stone column can be measured alone. Model tests of soil treated with a single stone column and groups of two, three and four stone columns were tested. In addition, model tests were prepared with 10% cement as additive to backfill material for the columns. The backfill material was also modified by mixing 30% sand by weight with 70% crushed stone. It was found that the addition of the sand to the crushed stone indicated a marginal effect on stress concentration ratio in soil of shear strength cu 5 12 kPa, but no clear effect was noticed during addition of sand to stone in treated soil having a shear strength cu 5 6 kPa.
In this work, laboratory experiments have been carried out to study the value of the stress concentration ratio, n, which is defined as the ratio of vertical stress acting on the stone column to that acting on the surrounding soil. A... more
In this work, laboratory experiments have been carried out to study the value of the stress concentration ratio, n, which is defined as the ratio of vertical stress acting on the stone column to that acting on the surrounding soil. A laboratory setup was manufactured in which two proving rings are used to measure the total load applied to the soil-stone column system and the individual load carried directly by the stone column. The foundation steel plates have 220 mm diameter and 5 mm thickness. These plates contain 1, 2, 3, and 4 holes. The spacing between all the holes equals twice the stone column diameter, D, center to center. The stone columns made of crushed stone were installed in very soft clays having undrained shear strength ranging between 6 and 12 kPa. Two length to diameter ratios L/D were tried, namely, L/D=6 and 8. The testing program consists of 30 tests on single, two, three, and four columns to study the stress concentration ratio and the bearing improvement ratio (q treared / q untreated) of stone columns. The experimental tests showed that the stone columns with L/D=8 provided a stress concentration ratio n of 1.4, 2.4, 2.7, and 3.1 for the soil having a shear strength cu=6 kPa, treated with single, two, three, and four columns, respectively. The values of n were decreased to 1.2, 2.2, 2.5, and 2.8 when the L/D=6. The values of n increase when the shear strength of the treated soil was increased to 9 and 12 kPa.
In this work, laboratory experiments have been carried out to study the value of the stress concentration ratio, n, which is defined as the ratio of vertical stress acting on the stone column to that acting on the surrounding soil. A... more
In this work, laboratory experiments have been carried out to study the value of the stress concentration ratio, n, which is defined as the ratio of vertical stress acting on the stone column to that acting on the surrounding soil. A laboratory setup was manufactured in which two proving rings are used to measure the total load applied to the soil-stone column system and the individual load carried directly by the stone column. The foundation steel plates have 220 mm diameter and 5 mm thickness. These plates contain 1, 2, 3 and 4 holes, respectively. The spacing between all holes equals twice the stone column diameter (D), center to center.
As in piles, the efficiency of a group (E g) of stone columns is defined as the ratio between the capacity of the group to the capacity of each stone column in the group multiplied by single stone column capacity. In this paper, the group... more
As in piles, the efficiency of a group (E g) of stone columns is defined as the ratio between the capacity of the group to the capacity of each stone column in the group multiplied by single stone column capacity. In this paper, the group efficiency of 24 model stone columns installed in soft clay is considered. These groups consist of 2, 3 and 4 columns. The tests were conducted on stone columns with length to diameter ratio (L/D) of 6 and 8. A laboratory setup was manufactured in which two proving rings were used to measure the total load applied to the soil-stone column system and the individual load carried directly by the stone column. The foundation steel plates have 220 mm diameter and 5 mm thickness. These plates contain 1, 2, 3 and 4 holes, respectively. The spacing between all holes equals twice the stone column diameter (D), center to center. The stone column capacity is taken as the load corresponding to a settlement equals to 50% of the diameter of stone column. The results illustrated that the group efficiency decreases with increasing the number of stone columns, also the stone columns with L/D of (8) provided higher efficiency than those with L/D of (6).