The study discusses the potential use of geosynthetics in isolating the ground vibration emanated... more The study discusses the potential use of geosynthetics in isolating the ground vibration emanated from the vertical mode dynamic excitation. A field study was conducted to investigate the screening efficacy of reinforced foundation beds. In the field study, vibration was generated using a mechanical oscillator. Four different cases, namely, unreinforced, single layer geogrid, two layers of geogrid, and geocell reinforced cases were considered. The isolation efficacy was studied in terms of peak particle velocity and amplitude reduction ratio. The resonance response of different reinforced conditions was studied by varying the dynamic force, and frequency of the excitation. The effectiveness of the reinforced soil system was examined by comparing the performance of the reinforced system with the unreinforced system. From the field test results, a significant reduction in ground vibration was observed in the presence of
Proceedings of the Institution of Civil Engineers - Engineering Sustainability
The growing depletion of natural geomaterials has forced scientists and engineers to look for alt... more The growing depletion of natural geomaterials has forced scientists and engineers to look for alternate sustainable backfill materials for large-scale practical applications. This study presents an experimental and numerical investigation of the performance of two sustainable backfills – namely, steel slag and construction and demolition waste (CDW) – for possible mechanically stabilised earth (MSE) wall backfill application. A detailed characterisation followed by the performance evaluation of the materials using extensive laboratory experiments, encompassing strength and drainage criteria, is presented. Results of the triaxial and California bearing ratio strength tests highlighted the superior performance of the sustainable backfill materials compared with that of the traditional backfill material. The adequate drainage capacity of slag and CDW reflected the encouraging possibility of utilising the materials as alternate backfills. Additionally, the strength enhancement options o...
The concept of using Reinforced Earth (RE) walls for rail corridors is gaining popularity. As of ... more The concept of using Reinforced Earth (RE) walls for rail corridors is gaining popularity. As of now, very few nations have successfully adopted the RE walls for Railway infrastructure. These structures require good quality granular materials like sand for backfilling. However, due to the scarcity of good quality natural sand, research efforts are being made to look for cost effective alternatives to sand in backfill applications. The present study examines the possibilities of using the two sustainable materials, namely steel slag and construction and demolition waste (CDW), as backfills in RE walls subjected to harmonic train-induced load. In total, 63 separate full-scale numerical models of RE walls have been analyzed to understand the wall behavior with sustainable backfills subjected to different train speeds. The backfill materials were simulated with three different material models, namely, linear elastic, Mohr-Coulomb and Hardening Soil, for comparison. The results showed th...
The present chapter describes the results of large-scale field vibration tests and cyclic plate l... more The present chapter describes the results of large-scale field vibration tests and cyclic plate load tests conducted on geosynthetics reinforced soil beds. A series of vertical mode block resonance tests are conducted over a rigid concrete footing resting on different reinforced soil conditions. The tests are performed in a test pit of size 2 m × 2 m × 0.5 m using a concrete footing of size 0.6 m × 0.6 m × 0.5 m. Four different conditions, namely unreinforced, single-layer geogrid reinforced, two-layer geogrid reinforced and geocell reinforced conditions were considered. The tests are performed under six different dynamic force levels using a Lazen-type mechanical oscillator. In total, 38 number of field tests are conducted. The dynamic response is studied in terms of reduction in resonant amplitude, peak particle velocity (PPV) and improvement in dynamic properties of the soil. Experimental results revealed that the displacement amplitude of vibration significantly reduced in the presence of geosynthetics. The maximum reduction is observed in the presence of geocell reinforcement as compared to other conditions. In the presence of geocell reinforcement, the resonant amplitude is decreased by 61% and the natural frequency of the soil system is increased by 1.38 times as compared to the unreinforced condition. In addition, the geocell reinforcement found to reduce the PPV by 48% at a distance of 0.5 m from the footing face. The elastic uniform compression of the foundation bed is improved by 91% in the presence of geocell reinforcement. From the cyclic plate load test results, four times improvement in natural frequency of the foundation soil system and 92% reduction in amplitude of the vibration were observed by the combined utilization of geocell and geogrid.
Over the years, geosynthetic reinforcements have been used in various civil engineering applicati... more Over the years, geosynthetic reinforcements have been used in various civil engineering applications. These materials are available in different shapes and forms to suit specific applications. Geosynthetics have replaced the use of conventional reinforcement materials like metallic products and steel bars. Among the different forms, geocells are relatively new and known for offering economical, efficient, and environmentally friendly solutions. Several studies reported the potential benefits of using geocells in the field of geotechnical engineering through field and laboratory studies (Hegde 2017).
In the last few years, the use of geocell reinforcements in various infrastructural projects has ... more In the last few years, the use of geocell reinforcements in various infrastructural projects has gained importance due to its positive benefits. Due to an increased use of geocells in the infrastructure projects, there exists an expansive scope for further research to understand the material better. Hence, the present chapter provides the wide spectrum of knowledge about the geocell reinforcement ranging from characterization to the field implementation. The chapter has been broadly divided into different sections covering detailed characterization, reinforcement mechanisms, design methods, analytical solutions, and the construction practices. The brief summary about the various factors, which influence the behavior of geocell reinforced system, is presented. Further, a detailed note about the field installation procedure and the equipment requirement has been discussed.
This chapter presents the results of the laboratory model tests and the numerical studies conduct... more This chapter presents the results of the laboratory model tests and the numerical studies conducted on small diameter PVC pipes, buried in geocell reinforced sand beds. The aim of the study was to evaluate the suitability of the geocell reinforcement in protecting the underground utilities and buried pipelines. In addition to geocells, the efficacy of only geogrid and geocell with additional basal geogrid cases was also studied. A PVC (Poly Vinyl Chloride) pipe with external diameter 75 mm and thickness 1.4 mm was used in the experiments. The vehicle tire contact pressure was simulated by applying the pressure on the top of the bed with the help of a steel plate. Results suggest that the use of geocells with additional basal geogrid considerably reduces the deformation of the pipe as compared to other types of reinforcements. Further, the depth of placement of pipe was also varied between 1B and 2B (B is the width of loading plate) below the plate in the presence of geocell with add...
This paper describes the results of laboratory static plate load tests conducted on small diamete... more This paper describes the results of laboratory static plate load tests conducted on small diameter PVC (polyvinyl chloride) pipes buried in geocell and geogrid reinforced soft clay bed. The aim of the study was to evaluate the suitability of the combination of geocell and geogrid reinforcement system in protecting the underground utilities and buried pipelines. Commercially available neoweb geocells and biaxial geogrids were used as the reinforcements. A pipe with external diameter 75 mm and thickness 1.4 mm was used in the experiments. Results suggest that the use of the combination of geocell and the geogrid reinforcement system considerably reduces the deformation of the pipe as compared to unreinforced bed. More than 40% reduction in the pressure and more than 60% reduction in the strain in the pipe were observed in the presence of reinforcements as compared to the unreinforced bed. Conversely, the performance of the foundation bed was also found to be marginally influenced by t...
This chapter presents the results of the laboratory investigation performed on clay bed reinforce... more This chapter presents the results of the laboratory investigation performed on clay bed reinforced with natural (bamboo) and commercial (geosynthetics) reinforcement materials. 3D cells (similar to geocells) and 2D grids (similar to geogrids) were formed using bamboo known as bamboocells and bamboogrids, respectively. The performance of bamboocells and bamboogrids reinforced clay beds were compared with that of reinforced geocells and geogrids. Bearing capacity of the clay bed is increased by 6 times due to the provision of combination of geocell and geogrid. The ultimate bearing capacity of the bamboocell and bamboogrid reinforced clay bed was found to be 1.3 times that reinforced with geocell and geogrid. Also, substantial reduction in the footing settlement and the surface deformation was observed. The tensile strength and surface roughness of the bamboo were found to be 9 times and 3 times higher than geocell materials. The bamboo was treated chemically to increase the durabilit...
The study discusses the potential use of geosynthetics in isolating the ground vibration emanated... more The study discusses the potential use of geosynthetics in isolating the ground vibration emanated from the vertical mode dynamic excitation. A field study was conducted to investigate the screening efficacy of reinforced foundation beds. In the field study, vibration was generated using a mechanical oscillator. Four different cases, namely, unreinforced, single layer geogrid, two layers of geogrid, and geocell reinforced cases were considered. The isolation efficacy was studied in terms of peak particle velocity and amplitude reduction ratio. The resonance response of different reinforced conditions was studied by varying the dynamic force, and frequency of the excitation. The effectiveness of the reinforced soil system was examined by comparing the performance of the reinforced system with the unreinforced system. From the field test results, a significant reduction in ground vibration was observed in the presence of
Proceedings of the Institution of Civil Engineers - Engineering Sustainability
The growing depletion of natural geomaterials has forced scientists and engineers to look for alt... more The growing depletion of natural geomaterials has forced scientists and engineers to look for alternate sustainable backfill materials for large-scale practical applications. This study presents an experimental and numerical investigation of the performance of two sustainable backfills – namely, steel slag and construction and demolition waste (CDW) – for possible mechanically stabilised earth (MSE) wall backfill application. A detailed characterisation followed by the performance evaluation of the materials using extensive laboratory experiments, encompassing strength and drainage criteria, is presented. Results of the triaxial and California bearing ratio strength tests highlighted the superior performance of the sustainable backfill materials compared with that of the traditional backfill material. The adequate drainage capacity of slag and CDW reflected the encouraging possibility of utilising the materials as alternate backfills. Additionally, the strength enhancement options o...
The concept of using Reinforced Earth (RE) walls for rail corridors is gaining popularity. As of ... more The concept of using Reinforced Earth (RE) walls for rail corridors is gaining popularity. As of now, very few nations have successfully adopted the RE walls for Railway infrastructure. These structures require good quality granular materials like sand for backfilling. However, due to the scarcity of good quality natural sand, research efforts are being made to look for cost effective alternatives to sand in backfill applications. The present study examines the possibilities of using the two sustainable materials, namely steel slag and construction and demolition waste (CDW), as backfills in RE walls subjected to harmonic train-induced load. In total, 63 separate full-scale numerical models of RE walls have been analyzed to understand the wall behavior with sustainable backfills subjected to different train speeds. The backfill materials were simulated with three different material models, namely, linear elastic, Mohr-Coulomb and Hardening Soil, for comparison. The results showed th...
The present chapter describes the results of large-scale field vibration tests and cyclic plate l... more The present chapter describes the results of large-scale field vibration tests and cyclic plate load tests conducted on geosynthetics reinforced soil beds. A series of vertical mode block resonance tests are conducted over a rigid concrete footing resting on different reinforced soil conditions. The tests are performed in a test pit of size 2 m × 2 m × 0.5 m using a concrete footing of size 0.6 m × 0.6 m × 0.5 m. Four different conditions, namely unreinforced, single-layer geogrid reinforced, two-layer geogrid reinforced and geocell reinforced conditions were considered. The tests are performed under six different dynamic force levels using a Lazen-type mechanical oscillator. In total, 38 number of field tests are conducted. The dynamic response is studied in terms of reduction in resonant amplitude, peak particle velocity (PPV) and improvement in dynamic properties of the soil. Experimental results revealed that the displacement amplitude of vibration significantly reduced in the presence of geosynthetics. The maximum reduction is observed in the presence of geocell reinforcement as compared to other conditions. In the presence of geocell reinforcement, the resonant amplitude is decreased by 61% and the natural frequency of the soil system is increased by 1.38 times as compared to the unreinforced condition. In addition, the geocell reinforcement found to reduce the PPV by 48% at a distance of 0.5 m from the footing face. The elastic uniform compression of the foundation bed is improved by 91% in the presence of geocell reinforcement. From the cyclic plate load test results, four times improvement in natural frequency of the foundation soil system and 92% reduction in amplitude of the vibration were observed by the combined utilization of geocell and geogrid.
Over the years, geosynthetic reinforcements have been used in various civil engineering applicati... more Over the years, geosynthetic reinforcements have been used in various civil engineering applications. These materials are available in different shapes and forms to suit specific applications. Geosynthetics have replaced the use of conventional reinforcement materials like metallic products and steel bars. Among the different forms, geocells are relatively new and known for offering economical, efficient, and environmentally friendly solutions. Several studies reported the potential benefits of using geocells in the field of geotechnical engineering through field and laboratory studies (Hegde 2017).
In the last few years, the use of geocell reinforcements in various infrastructural projects has ... more In the last few years, the use of geocell reinforcements in various infrastructural projects has gained importance due to its positive benefits. Due to an increased use of geocells in the infrastructure projects, there exists an expansive scope for further research to understand the material better. Hence, the present chapter provides the wide spectrum of knowledge about the geocell reinforcement ranging from characterization to the field implementation. The chapter has been broadly divided into different sections covering detailed characterization, reinforcement mechanisms, design methods, analytical solutions, and the construction practices. The brief summary about the various factors, which influence the behavior of geocell reinforced system, is presented. Further, a detailed note about the field installation procedure and the equipment requirement has been discussed.
This chapter presents the results of the laboratory model tests and the numerical studies conduct... more This chapter presents the results of the laboratory model tests and the numerical studies conducted on small diameter PVC pipes, buried in geocell reinforced sand beds. The aim of the study was to evaluate the suitability of the geocell reinforcement in protecting the underground utilities and buried pipelines. In addition to geocells, the efficacy of only geogrid and geocell with additional basal geogrid cases was also studied. A PVC (Poly Vinyl Chloride) pipe with external diameter 75 mm and thickness 1.4 mm was used in the experiments. The vehicle tire contact pressure was simulated by applying the pressure on the top of the bed with the help of a steel plate. Results suggest that the use of geocells with additional basal geogrid considerably reduces the deformation of the pipe as compared to other types of reinforcements. Further, the depth of placement of pipe was also varied between 1B and 2B (B is the width of loading plate) below the plate in the presence of geocell with add...
This paper describes the results of laboratory static plate load tests conducted on small diamete... more This paper describes the results of laboratory static plate load tests conducted on small diameter PVC (polyvinyl chloride) pipes buried in geocell and geogrid reinforced soft clay bed. The aim of the study was to evaluate the suitability of the combination of geocell and geogrid reinforcement system in protecting the underground utilities and buried pipelines. Commercially available neoweb geocells and biaxial geogrids were used as the reinforcements. A pipe with external diameter 75 mm and thickness 1.4 mm was used in the experiments. Results suggest that the use of the combination of geocell and the geogrid reinforcement system considerably reduces the deformation of the pipe as compared to unreinforced bed. More than 40% reduction in the pressure and more than 60% reduction in the strain in the pipe were observed in the presence of reinforcements as compared to the unreinforced bed. Conversely, the performance of the foundation bed was also found to be marginally influenced by t...
This chapter presents the results of the laboratory investigation performed on clay bed reinforce... more This chapter presents the results of the laboratory investigation performed on clay bed reinforced with natural (bamboo) and commercial (geosynthetics) reinforcement materials. 3D cells (similar to geocells) and 2D grids (similar to geogrids) were formed using bamboo known as bamboocells and bamboogrids, respectively. The performance of bamboocells and bamboogrids reinforced clay beds were compared with that of reinforced geocells and geogrids. Bearing capacity of the clay bed is increased by 6 times due to the provision of combination of geocell and geogrid. The ultimate bearing capacity of the bamboocell and bamboogrid reinforced clay bed was found to be 1.3 times that reinforced with geocell and geogrid. Also, substantial reduction in the footing settlement and the surface deformation was observed. The tensile strength and surface roughness of the bamboo were found to be 9 times and 3 times higher than geocell materials. The bamboo was treated chemically to increase the durabilit...
Geotechnical Engineering Journal of the SEAGS & AGSSEA, 2018
The foundation beds are often subjected to dynamic loads due to many circumstances, such as earth... more The foundation beds are often subjected to dynamic loads due to many circumstances, such as earthquakes, traffic loads, and the machine vibrations in the case of the machine foundations. Excessive vibrations caused by the dynamic sources can lead to the structural damage of the foundation soil. Over the years, geosynthetics have been effectively used in reducing the settlement of the foundations under static loads. However, the performance of geosynthetics is not fully analyzed under the dynamic loads. In the present study, the numerical analyses have been carried out to understand the performance of the machine foundations resting on the geocell reinforced beds. The analyses were carried out by using finite element software PLAXIS 2D. The hypothetical case of the circular machine foundation of 1 m diameter resting on the saturated silty sand was analyzed. Mohr-Coulomb failure criteria was used to simulate the behavior of the soil. Initially, the numerical model was validated with the existing results reported in the literature. The validated numerical model was further used to investigate the performance of the machine foundations. Three different cases, namely, unreinforced, geogrid reinforced and geocell reinforced were considered. The response of all the cases was studied by varying the frequency of dynamic excitation and maintaining the constant force amplitude. The depth of the placement of the geocell and geogrid was also varied. At the optimum location of geocell, 61% reduction in the displacement amplitude was observed as compared to unreinforced foundation bed. Similarly, as compared to geogrid, more than 50% reduction in the displacement was observed in the presence of geocell. In addition, 40% reduction in peak particle velocity was observed in the presence of geocell at the center of the footing. The resonant frequency was found to vary with the reinforcement system. Furthermore, 163% increase in the damping ratio of the soil was observed in the presence of geocell. In this way, the study highlights the possible new applications of geocell in supporting the machine foundations.
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