Aims/hypothesis One of the critical mechanisms determining creep in granular materials is the bre... more Aims/hypothesis One of the critical mechanisms determining creep in granular materials is the breakage of soil particles. This study aims at evaluating the time-dependent creep deformation of calcareous sand at low effective stress conditions. Methods K 0 creep tests were performed for both calcareous and silica sands at low stresses of 65 and 120 kPa, and the results of creep tests were compared with the results of constant rate of strain (CRS) tests at high stress levels up to 12 MPa. For a quantitative evaluation of the effect of the particle breakage on the creep deformation of calcareous sand, the relative breakage ( $$B_{r}$$ B r ) was determined based on the results of sieve analyses. Results The results demonstrate that Tunisia calcareous sand experiences significant particle breakage during creep and the consequent creep deformation at low stress level. The determined $$B_{r}$$ B r after creep at low stress level is comparable with that after the CRS test at high stress lev...
Soil particle shape analysis was conducted on two calcareous sands from Dissa and Matmata in Tuni... more Soil particle shape analysis was conducted on two calcareous sands from Dissa and Matmata in Tunisia and one silica sand from Jumunjin in Korea using an image analysis method. This technique uses complex Fourier shape descriptors and image analysis of sand grains SEM photographs to provide accurate quantification of particle morphology and texture. The Fourier descriptors, denoted “Signature Descriptors”, provide measures of Elongation, Triangularity, Squareness, and Asymmetry and identify the overall shape of soil particles. A summary of higher-order descriptors provides textural information linked up to local roughness and texture characteristics. After analyzing the Fourier descriptors, elongation was found to be the major characteristics of the three sands, mainly for the Dissa and Matmata carbonate sands. In addition, the elongation signature descriptors for the Dissa and Matmata sands have very high values compared to those of Ras Alkhair (Saudi Arabia) and Dog’s bay (Ireland)...
Soil particle shape analysis was conducted on two calcareous sands from Dissa and Matmata in Tuni... more Soil particle shape analysis was conducted on two calcareous sands from Dissa and Matmata in Tunisia and one silica sand from Jumunjin in Korea using an image analysis method. This technique uses complex Fourier shape descriptors and image analysis of sand grains SEM photographs to provide accurate quantification of particle morphology and texture. The Fourier descriptors, denoted “Signature Descriptors”, provide measures of Elongation, Triangularity, Squareness, and Asymmetry and identify the overall shape of soil particles. A summary of higher-order descriptors provides textural information linked up to local roughness and texture characteristics. After analyzing the Fourier descriptors, elongation was found to be the major characteristics of the three sands, mainly for the Dissa and Matmata carbonate sands. In addition, the elongation signature descriptors for the Dissa and Matmata sands have very high values compared to those of Ras Alkhair (Saudi Arabia) and Dog’s bay (Ireland)...
The present experimental investigation aims at investigating the small strain stiffness of calcar... more The present experimental investigation aims at investigating the small strain stiffness of calcareous sand as a function of applied stress. The calcareous sand was sampled at Tunisia's Dejebel Dahar region, and the shear wave velocity (Vs) of calcareous sand was measured using modified oedometer cell equipped with bender elements. The results of this study demonstrate that the Vs of the tested calcareous sand is smaller than that of silica sand with minimal crushable particles at relatively low applied stress (σ); however, Vs of calcareous sand is greater than that of silica sand at high σ, reflecting strong dependency of calcareous sand on σ. The applied stress dependency of soils can be expressed as a power function of applied stress (Vs = α (σ / 1 kPa)β, where α = Vs at σ = 1 kPa and β = stress exponent). Generally, the single α-β can capture the dependency of Vs on σ, and the typical β value for sand is around 0.25. The measured β of tested silica sand was around 0.20; while...
L'objectif de ce travail consiste à étudier le comportement des argiles molles de Tunis (amT)... more L'objectif de ce travail consiste à étudier le comportement des argiles molles de Tunis (amT) et la détermination des caractéristiques physiques et mécaniques relevantes. En effet, l'identification des paramètres physiques, minéralogiques, sédimentologiques et mécanique, d'une part, et l'étude du comportement mécanique des amT, d'autre part, a permis dans un premier volet d'estimer le degré de sensibilité de divers argiles molles de Tunis et suggérer le processus qui a conféré à ces argiles leur métastabilité. Un modèle physique de développement de la sensibilité dans les amT a été élaboré. Les classifications (selon la sensibilité) suggérées par plusieurs auteurs, montrent une divergence des résultats. La proposition d'une classification propre aux amT a été élaborée. Dans un deuxième volet l'étude du comportement mécanique des amT a permis d'abord de confirmer le caractère métastable de ces argiles; ensuite de trouver l'impact de la sensibil...
Aims/hypothesis One of the critical mechanisms determining creep in granular materials is the bre... more Aims/hypothesis One of the critical mechanisms determining creep in granular materials is the breakage of soil particles. This study aims at evaluating the time-dependent creep deformation of calcareous sand at low effective stress conditions. Methods K 0 creep tests were performed for both calcareous and silica sands at low stresses of 65 and 120 kPa, and the results of creep tests were compared with the results of constant rate of strain (CRS) tests at high stress levels up to 12 MPa. For a quantitative evaluation of the effect of the particle breakage on the creep deformation of calcareous sand, the relative breakage ( $$B_{r}$$ B r ) was determined based on the results of sieve analyses. Results The results demonstrate that Tunisia calcareous sand experiences significant particle breakage during creep and the consequent creep deformation at low stress level. The determined $$B_{r}$$ B r after creep at low stress level is comparable with that after the CRS test at high stress lev...
Soil particle shape analysis was conducted on two calcareous sands from Dissa and Matmata in Tuni... more Soil particle shape analysis was conducted on two calcareous sands from Dissa and Matmata in Tunisia and one silica sand from Jumunjin in Korea using an image analysis method. This technique uses complex Fourier shape descriptors and image analysis of sand grains SEM photographs to provide accurate quantification of particle morphology and texture. The Fourier descriptors, denoted “Signature Descriptors”, provide measures of Elongation, Triangularity, Squareness, and Asymmetry and identify the overall shape of soil particles. A summary of higher-order descriptors provides textural information linked up to local roughness and texture characteristics. After analyzing the Fourier descriptors, elongation was found to be the major characteristics of the three sands, mainly for the Dissa and Matmata carbonate sands. In addition, the elongation signature descriptors for the Dissa and Matmata sands have very high values compared to those of Ras Alkhair (Saudi Arabia) and Dog’s bay (Ireland)...
Soil particle shape analysis was conducted on two calcareous sands from Dissa and Matmata in Tuni... more Soil particle shape analysis was conducted on two calcareous sands from Dissa and Matmata in Tunisia and one silica sand from Jumunjin in Korea using an image analysis method. This technique uses complex Fourier shape descriptors and image analysis of sand grains SEM photographs to provide accurate quantification of particle morphology and texture. The Fourier descriptors, denoted “Signature Descriptors”, provide measures of Elongation, Triangularity, Squareness, and Asymmetry and identify the overall shape of soil particles. A summary of higher-order descriptors provides textural information linked up to local roughness and texture characteristics. After analyzing the Fourier descriptors, elongation was found to be the major characteristics of the three sands, mainly for the Dissa and Matmata carbonate sands. In addition, the elongation signature descriptors for the Dissa and Matmata sands have very high values compared to those of Ras Alkhair (Saudi Arabia) and Dog’s bay (Ireland)...
The present experimental investigation aims at investigating the small strain stiffness of calcar... more The present experimental investigation aims at investigating the small strain stiffness of calcareous sand as a function of applied stress. The calcareous sand was sampled at Tunisia's Dejebel Dahar region, and the shear wave velocity (Vs) of calcareous sand was measured using modified oedometer cell equipped with bender elements. The results of this study demonstrate that the Vs of the tested calcareous sand is smaller than that of silica sand with minimal crushable particles at relatively low applied stress (σ); however, Vs of calcareous sand is greater than that of silica sand at high σ, reflecting strong dependency of calcareous sand on σ. The applied stress dependency of soils can be expressed as a power function of applied stress (Vs = α (σ / 1 kPa)β, where α = Vs at σ = 1 kPa and β = stress exponent). Generally, the single α-β can capture the dependency of Vs on σ, and the typical β value for sand is around 0.25. The measured β of tested silica sand was around 0.20; while...
L'objectif de ce travail consiste à étudier le comportement des argiles molles de Tunis (amT)... more L'objectif de ce travail consiste à étudier le comportement des argiles molles de Tunis (amT) et la détermination des caractéristiques physiques et mécaniques relevantes. En effet, l'identification des paramètres physiques, minéralogiques, sédimentologiques et mécanique, d'une part, et l'étude du comportement mécanique des amT, d'autre part, a permis dans un premier volet d'estimer le degré de sensibilité de divers argiles molles de Tunis et suggérer le processus qui a conféré à ces argiles leur métastabilité. Un modèle physique de développement de la sensibilité dans les amT a été élaboré. Les classifications (selon la sensibilité) suggérées par plusieurs auteurs, montrent une divergence des résultats. La proposition d'une classification propre aux amT a été élaborée. Dans un deuxième volet l'étude du comportement mécanique des amT a permis d'abord de confirmer le caractère métastable de ces argiles; ensuite de trouver l'impact de la sensibil...
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