The theory of viscoelasticity and its application in the modelling of flexible pavement is well d... more The theory of viscoelasticity and its application in the modelling of flexible pavement is well documented in literature. This paper demonstrates the use of the Burger model, a constitutive rheological model to investigate the linear visco-elastic (LVE) behavior of bituminous layers. The effect of temperature on viscoelastic bituminous layers is also studied. A simple pavement section as per the guidelines of Indian Roads Congress (IRC):37-2012 has been chosen to show the creep formation behavior of bituminous layers. The pavement responses obtained from the computer program, KENLAYER, shows three stages in strain; an instantaneous elastic strain, a delayed elastic strain and viscous creep strain for various temperatures from 20° to 40°C. A comparison of the effect of temperature variation on the horizontal tensile strain at the bottom of the bituminous layer is done by considering the bituminous layer as elastic and viscoelastic, separately. Results show that the viscoelastic chara...
Recently, composite reinforcements in which combinations of materials and material forms such as ... more Recently, composite reinforcements in which combinations of materials and material forms such as strips, grids, and strips and anchors, depending on requirements, have proven to be effective in various ground improvement applications. Composite geogrids studied in this paper belong to the category of composite reinforcements and are useful for bearing capacity improvement. The paper presents evaluation of results of bearing capacity tests conducted on a composite geogrid, made of composite reinforcement consisting of steel and cement mortar. The study shows that the behavior of composite reinforcements follows the general trends observed in the case of conventional geogrids, with reference to the depth of first layer below the footing, number of layers of reinforcement, and vertical spacing of the reinforcement. Results show that the performance is comparable to that of a conventional polymer geogrid.
International Journal of Geotechnical Earthquake Engineering, 2010
Using additional dynamic parameters in the pseudo-static method like shear wave and primary wave ... more Using additional dynamic parameters in the pseudo-static method like shear wave and primary wave velocities of soil, phase change in the shear and primary waves, and soil amplification for seismic accelerations, one can benefit from another useful tool called pseudo-dynamic method to solve the problem of earth pressures. In this study, the pseudo-dynamic method is used to compute the seismic passive earth pressures on a rigid gravity retaining wall by considering both the planar failure and composite failure (log-spiral and planar) mechanisms. To validate the present formulation, passive earth pressure computed by the present method are compared with those given by other authors. Seismic passive earth pressure coefficients are provided in tabular form for different parameters. The sliding and rotational displacements are also computed and results of the comparative study showed that the assumption of planar failure mechanism for rough soil-wall interfaces significantly overestimates...
The sealing effect and containment of moisture in landfill covers and liners containing geosynthe... more The sealing effect and containment of moisture in landfill covers and liners containing geosynthetic clay liners (GCLs) are largely influenced by moisture retention, swelling, and the self-healing behaviour of bentonite used in GCLs. The method of binding of GCLs also significantly affects the behaviour. To examine these aspects, percent swell and swell pressure tests under different effective pressures were conducted on two sodium-based GCLs. Permittivity tests were performed on GCL specimens with different hole diameters and also on specimens dried at 20 and 60°C. The test results are presented and discussed. The study shows that the GCLs considered have a good self-healing capacity for the case of desiccation cracks or punctures. In addition, the method of binding the GCL components, i.e., stitch-bonded or needle-punched, has a significant influence.
The component and system reliability based design of bridge abutments under earthquake loading is... more The component and system reliability based design of bridge abutments under earthquake loading is presented in the paper. Planar failure surface has been used in conjunction with pseudo‐dynamic approach to compute seismic active earth pressures on an abutment. ...
The paper presents a new formulation for the use of pseudo‐dynamic method to compute the passive ... more The paper presents a new formulation for the use of pseudo‐dynamic method to compute the passive earth pressure coefficients of bridge abutment gravity retaining walls by using composite (combination of log‐spiral and planar) failure mechanism in the framework of limit ...
Geotechnical Engineering for Disaster Mitigation and Rehabilitation - Proceedings of the 1st International Conference, 2005
Evaluation and design of shore protection works in the case of tsunamis assumes considerable impo... more Evaluation and design of shore protection works in the case of tsunamis assumes considerable importance in view of the impact it had in the recent tsunami of 26th December 2004 in India and other countries in Asia. The fact that there are no proper guidelines have made in the ...
Recycling plastic water bottles has become one of the major challenges world wide. The present st... more Recycling plastic water bottles has become one of the major challenges world wide. The present study provides an approach for the use of plastic waste as reinforcement material in soil, which can be used for ground improvement, subbases, and subgrade preparation in road construction. The experimental results are presented in the form of stress-strain-pore water pressure response and compression paths. On the basis of experimental test results, it is observed that the strength of soil is improved and compressibility reduced significantly with the addition of a small percentage of plastic waste to the soil. In this paper, an analytical model is proposed to evaluate the response of plastic waste mixed soil. It is noted that the model captures the stress-strain and pore water pressure response of all percentages of plastic waste adequately. The paper also provides a comparative study of failure stress obtained from different published models and the proposed model, which are compared with experimental results. The improvement in strength attributable to the inclusion of plastic waste can be advantageously used in ground improvement projects.
The evaluation and design of coastal shore protection works for tsunamis assumed considerable imp... more The evaluation and design of coastal shore protection works for tsunamis assumed considerable importance following the impact of the 26th December 2004 tsunami in India and other countries of Asia. The lack of proper guidelines made matters worse ...
... Back analysis of the Chang dam section in the Kachchh region of Gujarat, India. Babu, Sivakum... more ... Back analysis of the Chang dam section in the Kachchh region of Gujarat, India. Babu, Sivakumar and Amit Srivatsava, GL (2009) Back analysis of the Chang dam section in the Kachchh region of Gujarat, India. In: International ...
The main objective in the design of a machine foundation is to restrict the maximum amplitude of ... more The main objective in the design of a machine foundation is to restrict the maximum amplitude of the foundation motion to within the safety limits. When the underlying soil is poor, pile foundations are generally used to reduce the amplitude of foundation motion in machine foundations. Analysis results pertaining to a field example in which the foundation response of a foundation for a generator was improved using a reinforced soil technique are presented herein. The numerical simulations with regard to the response of the foundation on the reinforced soil confirm the efficacy of the method adopted. The results show that reinforced soil foundations are viable alternatives to improve foundation response due to dynamic loading.
Coir, a natural biodegradable material, is abundantly available in most parts of south-west India... more Coir, a natural biodegradable material, is abundantly available in most parts of south-west India, Sri Lanka, and other Asian countries, and is cheap. The use of coir in geotechnical construction started in the early 1990s, and it is found in many applications, such as drainage and filtration, erosion control, and the improvement of surficial stability of embankments in the form of sheets and mats in some of these areas. A few attempts are also made to use coir as random reinforcing material, in which some percentage of fibre is added to obtain an improvement in performance, and laboratory tests indicate that the strength increases considerably with the inclusion of coir fibres. However, there is a lack of a proper methodology for quantifying the strength and stiffness of soil due to the inclusion of fibres. This paper discusses a few experimental results, different methods for evaluating the strength of fibre-reinforced soil, and the application of these methods to predict the stre...
ABSTRACT. A large part of Central India and a portion of South India are covered with black cotto... more ABSTRACT. A large part of Central India and a portion of South India are covered with black cotton soils. These soils have high swelling and shrinkage characteristics and shear strength is extremely low; hence, there is need for improvement of these properties. Coir is a ...
Journal of Geotechnical and Geoenvironmental Engineering, 2013
The current study analyzes the leachate distribution in the Orchard Hills Landfill, Davis Junctio... more The current study analyzes the leachate distribution in the Orchard Hills Landfill, Davis Junction, Illinois, using a two-phase flow model to assess the influence of variability in hydraulic conductivity on the effectiveness of the existing leachate recirculation system and its operations through reliability analysis. Numerical modeling, using finite-difference code, is performed with due consideration to the spatial variation of hydraulic conductivity of the municipal solid waste (MSW). The inhomogeneous and anisotropic waste condition is assumed because it is a more realistic representation of the MSW. For the reliability analysis, the landfill is divided into 10 MSW layers with different mean values of vertical and horizontal hydraulic conductivities (decreasing from top to bottom), and the parametric study is performed by taking the coefficients of variation (COVs) as 50, 100, 150, and 200%. Monte Carlo simulations are performed to obtain statistical information (mean and COV) of output parameters of the (1) wetted area of the MSW, (2) maximum induced pore pressure, and (3) leachate outflow. The results of the reliability analysis are used to determine the influence of hydraulic conductivity on the effectiveness of the leachate recirculation and are discussed in the light of a deterministic approach. The study is useful in understanding the efficiency of the leachate recirculation system. (C) 2013 American Society of Civil Engineers.
Journal of Geotechnical and Geoenvironmental Engineering, 2010
In the present study, results of reliability analyses of four selected rehabilitated earth dam se... more In the present study, results of reliability analyses of four selected rehabilitated earth dam sections, ie, Chang, Tapar, Rudramata, and Kaswati, under pseudostatic loading conditions, are presented. Using the response surface methodology, in combination with first order ...
The theory of viscoelasticity and its application in the modelling of flexible pavement is well d... more The theory of viscoelasticity and its application in the modelling of flexible pavement is well documented in literature. This paper demonstrates the use of the Burger model, a constitutive rheological model to investigate the linear visco-elastic (LVE) behavior of bituminous layers. The effect of temperature on viscoelastic bituminous layers is also studied. A simple pavement section as per the guidelines of Indian Roads Congress (IRC):37-2012 has been chosen to show the creep formation behavior of bituminous layers. The pavement responses obtained from the computer program, KENLAYER, shows three stages in strain; an instantaneous elastic strain, a delayed elastic strain and viscous creep strain for various temperatures from 20° to 40°C. A comparison of the effect of temperature variation on the horizontal tensile strain at the bottom of the bituminous layer is done by considering the bituminous layer as elastic and viscoelastic, separately. Results show that the viscoelastic chara...
Recently, composite reinforcements in which combinations of materials and material forms such as ... more Recently, composite reinforcements in which combinations of materials and material forms such as strips, grids, and strips and anchors, depending on requirements, have proven to be effective in various ground improvement applications. Composite geogrids studied in this paper belong to the category of composite reinforcements and are useful for bearing capacity improvement. The paper presents evaluation of results of bearing capacity tests conducted on a composite geogrid, made of composite reinforcement consisting of steel and cement mortar. The study shows that the behavior of composite reinforcements follows the general trends observed in the case of conventional geogrids, with reference to the depth of first layer below the footing, number of layers of reinforcement, and vertical spacing of the reinforcement. Results show that the performance is comparable to that of a conventional polymer geogrid.
International Journal of Geotechnical Earthquake Engineering, 2010
Using additional dynamic parameters in the pseudo-static method like shear wave and primary wave ... more Using additional dynamic parameters in the pseudo-static method like shear wave and primary wave velocities of soil, phase change in the shear and primary waves, and soil amplification for seismic accelerations, one can benefit from another useful tool called pseudo-dynamic method to solve the problem of earth pressures. In this study, the pseudo-dynamic method is used to compute the seismic passive earth pressures on a rigid gravity retaining wall by considering both the planar failure and composite failure (log-spiral and planar) mechanisms. To validate the present formulation, passive earth pressure computed by the present method are compared with those given by other authors. Seismic passive earth pressure coefficients are provided in tabular form for different parameters. The sliding and rotational displacements are also computed and results of the comparative study showed that the assumption of planar failure mechanism for rough soil-wall interfaces significantly overestimates...
The sealing effect and containment of moisture in landfill covers and liners containing geosynthe... more The sealing effect and containment of moisture in landfill covers and liners containing geosynthetic clay liners (GCLs) are largely influenced by moisture retention, swelling, and the self-healing behaviour of bentonite used in GCLs. The method of binding of GCLs also significantly affects the behaviour. To examine these aspects, percent swell and swell pressure tests under different effective pressures were conducted on two sodium-based GCLs. Permittivity tests were performed on GCL specimens with different hole diameters and also on specimens dried at 20 and 60°C. The test results are presented and discussed. The study shows that the GCLs considered have a good self-healing capacity for the case of desiccation cracks or punctures. In addition, the method of binding the GCL components, i.e., stitch-bonded or needle-punched, has a significant influence.
The component and system reliability based design of bridge abutments under earthquake loading is... more The component and system reliability based design of bridge abutments under earthquake loading is presented in the paper. Planar failure surface has been used in conjunction with pseudo‐dynamic approach to compute seismic active earth pressures on an abutment. ...
The paper presents a new formulation for the use of pseudo‐dynamic method to compute the passive ... more The paper presents a new formulation for the use of pseudo‐dynamic method to compute the passive earth pressure coefficients of bridge abutment gravity retaining walls by using composite (combination of log‐spiral and planar) failure mechanism in the framework of limit ...
Geotechnical Engineering for Disaster Mitigation and Rehabilitation - Proceedings of the 1st International Conference, 2005
Evaluation and design of shore protection works in the case of tsunamis assumes considerable impo... more Evaluation and design of shore protection works in the case of tsunamis assumes considerable importance in view of the impact it had in the recent tsunami of 26th December 2004 in India and other countries in Asia. The fact that there are no proper guidelines have made in the ...
Recycling plastic water bottles has become one of the major challenges world wide. The present st... more Recycling plastic water bottles has become one of the major challenges world wide. The present study provides an approach for the use of plastic waste as reinforcement material in soil, which can be used for ground improvement, subbases, and subgrade preparation in road construction. The experimental results are presented in the form of stress-strain-pore water pressure response and compression paths. On the basis of experimental test results, it is observed that the strength of soil is improved and compressibility reduced significantly with the addition of a small percentage of plastic waste to the soil. In this paper, an analytical model is proposed to evaluate the response of plastic waste mixed soil. It is noted that the model captures the stress-strain and pore water pressure response of all percentages of plastic waste adequately. The paper also provides a comparative study of failure stress obtained from different published models and the proposed model, which are compared with experimental results. The improvement in strength attributable to the inclusion of plastic waste can be advantageously used in ground improvement projects.
The evaluation and design of coastal shore protection works for tsunamis assumed considerable imp... more The evaluation and design of coastal shore protection works for tsunamis assumed considerable importance following the impact of the 26th December 2004 tsunami in India and other countries of Asia. The lack of proper guidelines made matters worse ...
... Back analysis of the Chang dam section in the Kachchh region of Gujarat, India. Babu, Sivakum... more ... Back analysis of the Chang dam section in the Kachchh region of Gujarat, India. Babu, Sivakumar and Amit Srivatsava, GL (2009) Back analysis of the Chang dam section in the Kachchh region of Gujarat, India. In: International ...
The main objective in the design of a machine foundation is to restrict the maximum amplitude of ... more The main objective in the design of a machine foundation is to restrict the maximum amplitude of the foundation motion to within the safety limits. When the underlying soil is poor, pile foundations are generally used to reduce the amplitude of foundation motion in machine foundations. Analysis results pertaining to a field example in which the foundation response of a foundation for a generator was improved using a reinforced soil technique are presented herein. The numerical simulations with regard to the response of the foundation on the reinforced soil confirm the efficacy of the method adopted. The results show that reinforced soil foundations are viable alternatives to improve foundation response due to dynamic loading.
Coir, a natural biodegradable material, is abundantly available in most parts of south-west India... more Coir, a natural biodegradable material, is abundantly available in most parts of south-west India, Sri Lanka, and other Asian countries, and is cheap. The use of coir in geotechnical construction started in the early 1990s, and it is found in many applications, such as drainage and filtration, erosion control, and the improvement of surficial stability of embankments in the form of sheets and mats in some of these areas. A few attempts are also made to use coir as random reinforcing material, in which some percentage of fibre is added to obtain an improvement in performance, and laboratory tests indicate that the strength increases considerably with the inclusion of coir fibres. However, there is a lack of a proper methodology for quantifying the strength and stiffness of soil due to the inclusion of fibres. This paper discusses a few experimental results, different methods for evaluating the strength of fibre-reinforced soil, and the application of these methods to predict the stre...
ABSTRACT. A large part of Central India and a portion of South India are covered with black cotto... more ABSTRACT. A large part of Central India and a portion of South India are covered with black cotton soils. These soils have high swelling and shrinkage characteristics and shear strength is extremely low; hence, there is need for improvement of these properties. Coir is a ...
Journal of Geotechnical and Geoenvironmental Engineering, 2013
The current study analyzes the leachate distribution in the Orchard Hills Landfill, Davis Junctio... more The current study analyzes the leachate distribution in the Orchard Hills Landfill, Davis Junction, Illinois, using a two-phase flow model to assess the influence of variability in hydraulic conductivity on the effectiveness of the existing leachate recirculation system and its operations through reliability analysis. Numerical modeling, using finite-difference code, is performed with due consideration to the spatial variation of hydraulic conductivity of the municipal solid waste (MSW). The inhomogeneous and anisotropic waste condition is assumed because it is a more realistic representation of the MSW. For the reliability analysis, the landfill is divided into 10 MSW layers with different mean values of vertical and horizontal hydraulic conductivities (decreasing from top to bottom), and the parametric study is performed by taking the coefficients of variation (COVs) as 50, 100, 150, and 200%. Monte Carlo simulations are performed to obtain statistical information (mean and COV) of output parameters of the (1) wetted area of the MSW, (2) maximum induced pore pressure, and (3) leachate outflow. The results of the reliability analysis are used to determine the influence of hydraulic conductivity on the effectiveness of the leachate recirculation and are discussed in the light of a deterministic approach. The study is useful in understanding the efficiency of the leachate recirculation system. (C) 2013 American Society of Civil Engineers.
Journal of Geotechnical and Geoenvironmental Engineering, 2010
In the present study, results of reliability analyses of four selected rehabilitated earth dam se... more In the present study, results of reliability analyses of four selected rehabilitated earth dam sections, ie, Chang, Tapar, Rudramata, and Kaswati, under pseudostatic loading conditions, are presented. Using the response surface methodology, in combination with first order ...
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Papers by G L Babu