Pub Date : 2022-04-19DOI: 10.1080/17486025.2022.2064553
A. Kalogeropoulos, T. Michalakopoulos
ABSTRACT In this study, actual laboratory rock cutting tests on sandstone specimens that were performed at NTUA’s Laboratory of Excavation Engineering were simulated numerically with the use of a 3D bonded particle DEM model implemented in Yade. The numerical assembly was calibrated to closely match the macroscopic strength, Young’s modulus, and brittleness of the real material, by controlling the grain interlocking through careful selection of the appropriate value for the interaction range coefficient. The calibrated model was then used to examine the effect of the microparameters’ values on the cutting force history and the failure mechanism. The Fast Fourier Transformation was used to compare the characteristics of the simulated cutting force data with those from the actual cutting tests. It was found that for high values of the interaction range coefficient the numerical model showed a more brittle behaviour, while for low values the simulation behaved more realistically for the specific type of rock. It is concluded that the use of the interaction range coefficient can substantially provide more realistic simulations of the cutting process by capturing both the rock-cutting tool interaction and the failure mechanism.
{"title":"The effect of grain interlocking in discrete element modelling of rock cutting","authors":"A. Kalogeropoulos, T. Michalakopoulos","doi":"10.1080/17486025.2022.2064553","DOIUrl":"https://doi.org/10.1080/17486025.2022.2064553","url":null,"abstract":"ABSTRACT In this study, actual laboratory rock cutting tests on sandstone specimens that were performed at NTUA’s Laboratory of Excavation Engineering were simulated numerically with the use of a 3D bonded particle DEM model implemented in Yade. The numerical assembly was calibrated to closely match the macroscopic strength, Young’s modulus, and brittleness of the real material, by controlling the grain interlocking through careful selection of the appropriate value for the interaction range coefficient. The calibrated model was then used to examine the effect of the microparameters’ values on the cutting force history and the failure mechanism. The Fast Fourier Transformation was used to compare the characteristics of the simulated cutting force data with those from the actual cutting tests. It was found that for high values of the interaction range coefficient the numerical model showed a more brittle behaviour, while for low values the simulation behaved more realistically for the specific type of rock. It is concluded that the use of the interaction range coefficient can substantially provide more realistic simulations of the cutting process by capturing both the rock-cutting tool interaction and the failure mechanism.","PeriodicalId":46470,"journal":{"name":"Geomechanics and Geoengineering-An International Journal","volume":"18 1","pages":"394 - 417"},"PeriodicalIF":1.3,"publicationDate":"2022-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41640818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-17DOI: 10.1080/17486025.2022.2065036
V. T. Vu
ABSTRACT The article presents the optimisation of gravity retaining walls under bounded uncertainties using Differential Evolution method. This problem is a two-level optimisation, i.e. main loops for the objective function optimisation and inside loops for the most disadvantaged circumstances of constraints, which are the wall sliding, the wall overturning and the soil bearing capacity. The uncertainties are of the surcharge intensity, the backfill soil and the ground soil properties. Since the constraints are continuous and monotonic functions of uncertainties, the search of the worst condition of constraints in inside loops can limit at vertices of the feasible region defined by the lower and upper bounds of uncertainties instead of the whole region. Four cases of the wall heights are illustrated for this approach.
{"title":"Optimisation of gravity retaining walls under bounded uncertainties","authors":"V. T. Vu","doi":"10.1080/17486025.2022.2065036","DOIUrl":"https://doi.org/10.1080/17486025.2022.2065036","url":null,"abstract":"ABSTRACT The article presents the optimisation of gravity retaining walls under bounded uncertainties using Differential Evolution method. This problem is a two-level optimisation, i.e. main loops for the objective function optimisation and inside loops for the most disadvantaged circumstances of constraints, which are the wall sliding, the wall overturning and the soil bearing capacity. The uncertainties are of the surcharge intensity, the backfill soil and the ground soil properties. Since the constraints are continuous and monotonic functions of uncertainties, the search of the worst condition of constraints in inside loops can limit at vertices of the feasible region defined by the lower and upper bounds of uncertainties instead of the whole region. Four cases of the wall heights are illustrated for this approach.","PeriodicalId":46470,"journal":{"name":"Geomechanics and Geoengineering-An International Journal","volume":"18 1","pages":"418 - 425"},"PeriodicalIF":1.3,"publicationDate":"2022-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44140553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-27DOI: 10.1080/17486025.2022.2056642
Mehran Karimpour Fard, Erfan Ashouryan, Ghazal Rezaie Soufi, S. Machado
ABSTRACT Employing Expanded PolyStyrene, EPS has become common in the construction industry, however, their compressibility creates complexities in effective stress analysis. In this paper, the compressibility of EPS beads and the overall compressibility of sand–EPS beads mixtures have been evaluated. Drained and undrained one-dimensional compression tests along with CD and CU triaxial tests were performed on the mixtures to evaluate the classic effective stress equation. Modified versions of the effective stress equation were applied to results and pore pressure correction factors were obtained from both data series based on two different effective stress analysis approaches (volume change and shear strength related) and compared. Results showed that the two sets of correction factors are consistent. Therefore, correction factors obtained based on the compressibility parameters of the mixtures can be used in the effective stress analysis of CU triaxial tests. Pore pressure factors obtained from the oedometer data were used to analyze results of CU triaxial tests. It is shown that a better agreement between CD and CU stress path results is obtained when the EPS compressibility is considered, leading to similar effective strength parameters in both conditions.
{"title":"Experimental review on the effective stress equation in sand–EPS mixtures","authors":"Mehran Karimpour Fard, Erfan Ashouryan, Ghazal Rezaie Soufi, S. Machado","doi":"10.1080/17486025.2022.2056642","DOIUrl":"https://doi.org/10.1080/17486025.2022.2056642","url":null,"abstract":"ABSTRACT Employing Expanded PolyStyrene, EPS has become common in the construction industry, however, their compressibility creates complexities in effective stress analysis. In this paper, the compressibility of EPS beads and the overall compressibility of sand–EPS beads mixtures have been evaluated. Drained and undrained one-dimensional compression tests along with CD and CU triaxial tests were performed on the mixtures to evaluate the classic effective stress equation. Modified versions of the effective stress equation were applied to results and pore pressure correction factors were obtained from both data series based on two different effective stress analysis approaches (volume change and shear strength related) and compared. Results showed that the two sets of correction factors are consistent. Therefore, correction factors obtained based on the compressibility parameters of the mixtures can be used in the effective stress analysis of CU triaxial tests. Pore pressure factors obtained from the oedometer data were used to analyze results of CU triaxial tests. It is shown that a better agreement between CD and CU stress path results is obtained when the EPS compressibility is considered, leading to similar effective strength parameters in both conditions.","PeriodicalId":46470,"journal":{"name":"Geomechanics and Geoengineering-An International Journal","volume":"18 1","pages":"380 - 393"},"PeriodicalIF":1.3,"publicationDate":"2022-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49496159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-23DOI: 10.1080/17486025.2022.2052193
M. K. Pradhan, Praveen Kumar, V. S. Phanikanth, D. Choudhury, K. Srinivas, Homi K. Bhabha
ABSTRACT Pile foundations are provided for structures, where soil at the top layers possesses low bearing capacity. A comprehensive understanding of pile foundation located in liquefiable soils is a key requirement to enable designer to arrive at an economic design and for safe performance of structure during its intended service life. The failure of various structures on pile foundation system in liquefied soil subjected to earthquake load shows limitation of present methodologies available for design. Hence, study of pile foundations in liquefiable soil under earthquake loading attracted attention of researchers over many years. In addition, many governing factors, as compiled by researchers during analysis and design of pile foundation in liquefiable soils, need to be critically analysed. Therefore, in present paper comparative aspects of various issues addressed by different researchers are presented. It briefs about various International Codes followed in design and analysis. This review article also provides analytical study/numerical model developments, and experimental works performed by various researchers with an effort to bring out the progress in analysis and design. The current paper also discussed various behavioural issues, design aspects, recommendations by researchers dealing with proablems of pile foundation considering liquefaction condition of soil and some exemplary cases.
{"title":"A review on design aspects and behavioral studies of pile foundations in liquefiable soil","authors":"M. K. Pradhan, Praveen Kumar, V. S. Phanikanth, D. Choudhury, K. Srinivas, Homi K. Bhabha","doi":"10.1080/17486025.2022.2052193","DOIUrl":"https://doi.org/10.1080/17486025.2022.2052193","url":null,"abstract":"ABSTRACT Pile foundations are provided for structures, where soil at the top layers possesses low bearing capacity. A comprehensive understanding of pile foundation located in liquefiable soils is a key requirement to enable designer to arrive at an economic design and for safe performance of structure during its intended service life. The failure of various structures on pile foundation system in liquefied soil subjected to earthquake load shows limitation of present methodologies available for design. Hence, study of pile foundations in liquefiable soil under earthquake loading attracted attention of researchers over many years. In addition, many governing factors, as compiled by researchers during analysis and design of pile foundation in liquefiable soils, need to be critically analysed. Therefore, in present paper comparative aspects of various issues addressed by different researchers are presented. It briefs about various International Codes followed in design and analysis. This review article also provides analytical study/numerical model developments, and experimental works performed by various researchers with an effort to bring out the progress in analysis and design. The current paper also discussed various behavioural issues, design aspects, recommendations by researchers dealing with proablems of pile foundation considering liquefaction condition of soil and some exemplary cases.","PeriodicalId":46470,"journal":{"name":"Geomechanics and Geoengineering-An International Journal","volume":"18 1","pages":"347 - 379"},"PeriodicalIF":1.3,"publicationDate":"2022-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49668544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-16DOI: 10.1080/17486025.2022.2048092
Diptesh Chanda, R. Saha, S. Haldar, Barmavath Chandrababu Nayak, E. V. Kumar
ABSTRACT Considerable research has been endeavoured to examine the responses of piled raft foundation (PRF) under gravity load. In reality, PRF often encounters combined vertical (V), horizontal (H) and moment (M) load simultaneously due to wind, earthquake and wave load along with dead load of the structure, and vertical soil pressure. Present study aims at a scaled-model test on the PRF subjected to V-H-M loads to investigate the lateral responses of PRF due to the interaction of loadings. The scaled model tests are conducted in Agartala sand with a relative density of 30%. Effects of relative stiffness raft with respect to soil, the length and spacing to diameter ratio of the pile, number of piles in a group and non-uniform pile length configuration on the lateral response of PRF are studied. Results indicate that the V load in V-H-M loading has a significant influence on the lateral response of PRF. Further, a substantial influence of other parametric variations on lateral response is also observed. Furthermore, a numerical model is also developed and validated based on experimental results that substantiate investigation on prototype foundation. Finally, the load-sharing behaviour of prototype PRF is also studied through the validated numerical model.
{"title":"Scaled Modeled Tests and Finite Element Numerical Study on Lateral Responses of PRF System under V-H-M Loading","authors":"Diptesh Chanda, R. Saha, S. Haldar, Barmavath Chandrababu Nayak, E. V. Kumar","doi":"10.1080/17486025.2022.2048092","DOIUrl":"https://doi.org/10.1080/17486025.2022.2048092","url":null,"abstract":"ABSTRACT Considerable research has been endeavoured to examine the responses of piled raft foundation (PRF) under gravity load. In reality, PRF often encounters combined vertical (V), horizontal (H) and moment (M) load simultaneously due to wind, earthquake and wave load along with dead load of the structure, and vertical soil pressure. Present study aims at a scaled-model test on the PRF subjected to V-H-M loads to investigate the lateral responses of PRF due to the interaction of loadings. The scaled model tests are conducted in Agartala sand with a relative density of 30%. Effects of relative stiffness raft with respect to soil, the length and spacing to diameter ratio of the pile, number of piles in a group and non-uniform pile length configuration on the lateral response of PRF are studied. Results indicate that the V load in V-H-M loading has a significant influence on the lateral response of PRF. Further, a substantial influence of other parametric variations on lateral response is also observed. Furthermore, a numerical model is also developed and validated based on experimental results that substantiate investigation on prototype foundation. Finally, the load-sharing behaviour of prototype PRF is also studied through the validated numerical model.","PeriodicalId":46470,"journal":{"name":"Geomechanics and Geoengineering-An International Journal","volume":"18 1","pages":"321 - 345"},"PeriodicalIF":1.3,"publicationDate":"2022-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47980998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-11DOI: 10.1080/17486025.2022.2046873
A. Hanna, M. Khalifa
ABSTRACT Stone columns are widely used around the world as cost-effective soil improvement techniques for highways and embankments. They are also used as drainage to expedite the consolidation period, and accordingly to increase the allowable pressure, reduce settlement, and reduce the liquefaction potential for shallow foundations. Currently the design of these columns is based on the unit cell or homogenised material concepts, which neglect the effect of the interaction of the columns. This paper presents a 3-D numerical model using the finite element technique and the commercial software ‘ABAQUS’ to simulate the case of a group of stone columns installed in soft clay. The model is capable of capturing the interaction between columns and the surrounding soil and of establishing the mode of failure of the system. After validating the model with the available experimental results, it was used to predict the allowable pressure and the failure mechanism of groups of stone columns for given geometry/soil conditions. An improvement factor was introduced ‘IF’, which is defined as the ratio of the capacity of the improved to the unimproved soft clay. The results of this investigation are presented in the form of design charts to assist the engineer to determine the level of improvement needed to achieve a given allowable pressure for the foundation.
{"title":"Numerical models for shallow foundation on soft clay reinforced with a group of stone columns","authors":"A. Hanna, M. Khalifa","doi":"10.1080/17486025.2022.2046873","DOIUrl":"https://doi.org/10.1080/17486025.2022.2046873","url":null,"abstract":"ABSTRACT Stone columns are widely used around the world as cost-effective soil improvement techniques for highways and embankments. They are also used as drainage to expedite the consolidation period, and accordingly to increase the allowable pressure, reduce settlement, and reduce the liquefaction potential for shallow foundations. Currently the design of these columns is based on the unit cell or homogenised material concepts, which neglect the effect of the interaction of the columns. This paper presents a 3-D numerical model using the finite element technique and the commercial software ‘ABAQUS’ to simulate the case of a group of stone columns installed in soft clay. The model is capable of capturing the interaction between columns and the surrounding soil and of establishing the mode of failure of the system. After validating the model with the available experimental results, it was used to predict the allowable pressure and the failure mechanism of groups of stone columns for given geometry/soil conditions. An improvement factor was introduced ‘IF’, which is defined as the ratio of the capacity of the improved to the unimproved soft clay. The results of this investigation are presented in the form of design charts to assist the engineer to determine the level of improvement needed to achieve a given allowable pressure for the foundation.","PeriodicalId":46470,"journal":{"name":"Geomechanics and Geoengineering-An International Journal","volume":"18 1","pages":"309 - 320"},"PeriodicalIF":1.3,"publicationDate":"2022-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48750690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-02-26DOI: 10.1080/17486025.2022.2044076
Abdellah Cherif Taiba, Y. Mahmoudi, Hamou Azaiez, M. Belkhatir
ABSTRACT This research aims to establish accurate correlations between critical state characteristics and particle shape parameters in terms of overall regularity (OR), considering the gradation and packing density aspects of natural sands. For this purpose, a database of physical and mechanical characteristics [sphericity ‘S’, aspect ratio ‘AR’, convexity ‘Cx’, overall regularity ‘OR’, mean grain size ‘D50’, critical state intercept ‘eГ’, critical state gradient ‘λ’ and critical state friction angle ‘φcs’] related to 21 sands have been compiled from the existing literature. The evaluation and analysis of the collected data indicate that the overall regularity parameter is found to be a suitable factor for the prediction of the critical state parameters (‘eГ’, ‘φcs’) compared to the critical state gradient ‘λ’ of the compiled sands. Moreover, this study gains an insight on the prediction of the overall regularity through the packing density (emax and emin) and gradation (D50 and Cu) of the compiled data to be estimated of physical characteristics of sandy soils. In addition, this research gives the intention to help scientists and researchers to use systematically the proposed expressions in their researches to explore the influence of the overall regularity parameter on the macro and micro-mechanical response of granular soils.
{"title":"Impact of the overall regularity and related granulometric characteristics on the critical state soil mechanics of natural sands: a state-of-the-art review","authors":"Abdellah Cherif Taiba, Y. Mahmoudi, Hamou Azaiez, M. Belkhatir","doi":"10.1080/17486025.2022.2044076","DOIUrl":"https://doi.org/10.1080/17486025.2022.2044076","url":null,"abstract":"ABSTRACT This research aims to establish accurate correlations between critical state characteristics and particle shape parameters in terms of overall regularity (OR), considering the gradation and packing density aspects of natural sands. For this purpose, a database of physical and mechanical characteristics [sphericity ‘S’, aspect ratio ‘AR’, convexity ‘Cx’, overall regularity ‘OR’, mean grain size ‘D50’, critical state intercept ‘eГ’, critical state gradient ‘λ’ and critical state friction angle ‘φcs’] related to 21 sands have been compiled from the existing literature. The evaluation and analysis of the collected data indicate that the overall regularity parameter is found to be a suitable factor for the prediction of the critical state parameters (‘eГ’, ‘φcs’) compared to the critical state gradient ‘λ’ of the compiled sands. Moreover, this study gains an insight on the prediction of the overall regularity through the packing density (emax and emin) and gradation (D50 and Cu) of the compiled data to be estimated of physical characteristics of sandy soils. In addition, this research gives the intention to help scientists and researchers to use systematically the proposed expressions in their researches to explore the influence of the overall regularity parameter on the macro and micro-mechanical response of granular soils.","PeriodicalId":46470,"journal":{"name":"Geomechanics and Geoengineering-An International Journal","volume":"18 1","pages":"299 - 308"},"PeriodicalIF":1.3,"publicationDate":"2022-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44689059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-02-24DOI: 10.1080/17486025.2022.2043455
B. Ta'negonbadi, R. Noorzad, Mehran Ta’Negonbadi
ABSTRACT In this work, the influence of lignosulfonate (LS), which is a by-product of timber and paper industries, on the cyclic characteristics of expansive clay was investigated by conducting cyclic triaxial tests. Test findings showed that cyclic stress ratio (CSR) substantially influenced liquefaction resistance of treated soil samples such that, at CSR = 0.2, none of the specimens were liquefied, whereas, at CSR = 0.4, all of the specimens were liquefied. Furthermore, liqueaction resistance was enhanced by decreasing the sample moisture content. Due to a stabilisation effect, the secant shear modulus increased by up to about 64%, and the damping ratio decreased by up to about 22%.
{"title":"Cyclic undrained properties of stabilised expansive clay with lignosulfonate","authors":"B. Ta'negonbadi, R. Noorzad, Mehran Ta’Negonbadi","doi":"10.1080/17486025.2022.2043455","DOIUrl":"https://doi.org/10.1080/17486025.2022.2043455","url":null,"abstract":"ABSTRACT In this work, the influence of lignosulfonate (LS), which is a by-product of timber and paper industries, on the cyclic characteristics of expansive clay was investigated by conducting cyclic triaxial tests. Test findings showed that cyclic stress ratio (CSR) substantially influenced liquefaction resistance of treated soil samples such that, at CSR = 0.2, none of the specimens were liquefied, whereas, at CSR = 0.4, all of the specimens were liquefied. Furthermore, liqueaction resistance was enhanced by decreasing the sample moisture content. Due to a stabilisation effect, the secant shear modulus increased by up to about 64%, and the damping ratio decreased by up to about 22%.","PeriodicalId":46470,"journal":{"name":"Geomechanics and Geoengineering-An International Journal","volume":"18 1","pages":"284 - 298"},"PeriodicalIF":1.3,"publicationDate":"2022-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43969670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-02-21DOI: 10.1080/17486025.2022.2040606
Mohsen Salehi, M. Bayat, Mohsen Saadat, M. Nasri
ABSTRACT So far, a limited number of studies have been published on utilisation of crushed stone waste, cement, lime and pozzolan as stabilisers for soil stabilisation. The research conducts soil engineering properties and strength test for various contents of crushed stone waste, cement, lime and pozzolan under various curing times. Increasing the pozzolan or cement content resulted in an increase in UCS; however, the UCS increased as the lime content increased from 0% to 5% and then decreased as lime content violated from 5%. An increase in the granite crushed stone content from 0% to 10% resulted in an increase in the UCS value. The unsoaked CBR and UCS values are almost 1.37 and 1.24 times more than the corresponding soaked ones for all cases, respectively. The CBR value increased with the increase in the pozzolan, lime or cement content. The cement content has more important influence on the increase in CBR value than the lime or pozzolan content. The multi-layer perceptron (MLP) neural network and non-linear regression (NLR) techniques are employed to develop models to predict the CBR and UCS values of the stabilised specimens.
{"title":"Prediction of unconfined compressive strength and California bearing capacity of cement- or lime-pozzolan-stabilised soil admixed with crushed stone waste","authors":"Mohsen Salehi, M. Bayat, Mohsen Saadat, M. Nasri","doi":"10.1080/17486025.2022.2040606","DOIUrl":"https://doi.org/10.1080/17486025.2022.2040606","url":null,"abstract":"ABSTRACT So far, a limited number of studies have been published on utilisation of crushed stone waste, cement, lime and pozzolan as stabilisers for soil stabilisation. The research conducts soil engineering properties and strength test for various contents of crushed stone waste, cement, lime and pozzolan under various curing times. Increasing the pozzolan or cement content resulted in an increase in UCS; however, the UCS increased as the lime content increased from 0% to 5% and then decreased as lime content violated from 5%. An increase in the granite crushed stone content from 0% to 10% resulted in an increase in the UCS value. The unsoaked CBR and UCS values are almost 1.37 and 1.24 times more than the corresponding soaked ones for all cases, respectively. The CBR value increased with the increase in the pozzolan, lime or cement content. The cement content has more important influence on the increase in CBR value than the lime or pozzolan content. The multi-layer perceptron (MLP) neural network and non-linear regression (NLR) techniques are employed to develop models to predict the CBR and UCS values of the stabilised specimens.","PeriodicalId":46470,"journal":{"name":"Geomechanics and Geoengineering-An International Journal","volume":"18 1","pages":"272 - 283"},"PeriodicalIF":1.3,"publicationDate":"2022-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46409275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-02-18DOI: 10.1080/17486025.2022.2040605
Arunava Ray, Ashutosh Kumar Bharati, Harshal Verma, R. Rai, T. Singh
ABSTRACT The bioengineering technique of slope stabilisation, which has been developed as a sustainable alternative to traditional civil engineering structures, requires more scientific research and a good understanding of the factors that influence its effectiveness since many a time it fails to provide the desired outcome. The present study discusses the importance of understanding the variable root distribution and root-soil-slope relationship before implementation. The probabilistic analysis was used to take into account the natural variability of root features, which includes root length, strength, branching and orientation along with heterogeneity of slope material. It was observed that the mean rooting depth plays a vital role in deciding the utility of the bioengineering technique. Though its effect in gentle slopes is negligible, in the case of moderate to steep slopes, it can significantly affect the overall stability. Improper planning can lead to aggravation of the situation leading the slope more vulnerable to failure. Furthermore, the stabilisation using vegetation is best suitable for moderate slope inclinations, and the maximum shear strength increase is obtained for slope inclining around 50°. A gradual reduction in overall stability was observed with the reduction of mean rooting depth and an increase in the spacing of the plants.
{"title":"Numerical study of the utility of bioengineering technique for slope stabilisation","authors":"Arunava Ray, Ashutosh Kumar Bharati, Harshal Verma, R. Rai, T. Singh","doi":"10.1080/17486025.2022.2040605","DOIUrl":"https://doi.org/10.1080/17486025.2022.2040605","url":null,"abstract":"ABSTRACT The bioengineering technique of slope stabilisation, which has been developed as a sustainable alternative to traditional civil engineering structures, requires more scientific research and a good understanding of the factors that influence its effectiveness since many a time it fails to provide the desired outcome. The present study discusses the importance of understanding the variable root distribution and root-soil-slope relationship before implementation. The probabilistic analysis was used to take into account the natural variability of root features, which includes root length, strength, branching and orientation along with heterogeneity of slope material. It was observed that the mean rooting depth plays a vital role in deciding the utility of the bioengineering technique. Though its effect in gentle slopes is negligible, in the case of moderate to steep slopes, it can significantly affect the overall stability. Improper planning can lead to aggravation of the situation leading the slope more vulnerable to failure. Furthermore, the stabilisation using vegetation is best suitable for moderate slope inclinations, and the maximum shear strength increase is obtained for slope inclining around 50°. A gradual reduction in overall stability was observed with the reduction of mean rooting depth and an increase in the spacing of the plants.","PeriodicalId":46470,"journal":{"name":"Geomechanics and Geoengineering-An International Journal","volume":"18 1","pages":"253 - 271"},"PeriodicalIF":1.3,"publicationDate":"2022-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47437740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：