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This paper investigated the relationships of some physical and mechanical parameters of sediments and a typical clay during a natural dewatering process. Four sediments from different French river dams sampled by the Électricité De France group (EDF group) and a commercial kaolin clay used for comparative purposes were the focus of this study. Continuous dewatering was monitored in a laboratory by quantifying the percentage of water remaining in sediments or clay, drained and evaporated. Undrained shear strength was also assessed during the sediment or clay dewatering process, using the laboratory vane shear test. The samples were controlled along different dimensions during the dewatering process throughout the whole experiment. The results showed a certain interdependence between the physical parameters and the water content (ω), which was normalized by the liquidity limit (ω/LL) over time. This led to sigmoidal and exponential correlations when considering the percentage of water drained. The percentage of water remaining in the sediments or clay was characterized using the normalized water content, leading to exponential and power correlations. Both exponential and linear correlations were perfect for describing the evolution of the percentage of water evaporated. Other correlations were established for variations in void index, dry unit weight/solid unit weight ratio and undrained shear strength during the dewatering process. [ABSTRACT FROM AUTHOR]

The compression index C c , is one of the key properties of fine-grained soils. Several correlations exist in the literature linking this parameter to other geotechnical properties such as Atterberg limits, void ratio and porosity. This paper analyzes more than 300 data from the literature plotting C c against liquid limit, LL , plasticity index, PI , shrinkage index, SI , defined as the difference between liquid limit, LL , and the shrinkage limit, SL , plasticity ratio, R p , initial porosity, n 0 . Key words for the literature review analysis were "clays", "compression index", "liquid limit", "plastic limit", "plasticity index", "shrinkage index", "remolded", "undisturbed" and "correlations". The C c – LL relationships are considered taking into account the gradient, a , and intercept, b , of the said relationship and plotting several values of the literature to assess their origin. A new relationship between b and a , called Compression Liquid Limit was obtained. Besides, an overview regarding the undisturbed and remolded compression index, C c , as well as the correlation of predicted versus experimental C c values based on two available methods, i.e. the method of Park and Koumoto (J Geotech Geoenviron Eng 130(2):223–226, 2004) and the method of Sharma and Bora (Indian Geotech J 45:225–230, 2015. https://doi.org/10.1007/s40098-014-0128-0) is also presented. As a result, the Park and Koumoto (2004) method is capable of predicting approximately with the precision of 1/1.5 to 1.5 the measured compression index using the initial porosity of soil sample, irrespective of the disturbance state of the soil, soil types and clay minerals. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A mathematical framework for the description of structureless clay behaviour is proposed in this paper. It is based on the observation that there exists a biunique relationship between the radial stress path direction and the compression curve on the specific volume ( v = 1 + e)-mean effective stress ( σ or p) plane. The projection on the v − σ plane defines the Intrinsic Compression Curve ( ICC) of the corresponding radial stress path, which results in infinite possible ICC curves. Following a normalization procedure, a general methodology is presented, which can be applied to any mathematical formulation of the ICC curve. The constants included in this description are called intrinsic properties. This procedure can be easily implemented to anisotropic constitutive models. Its importance is based on the fact that modern constitutive models require a definition of the structureless state, as this state is the limiting reference state of the fully destructured material. In addition, the paper presents a set of correlations for the estimation of the intrinsic properties from the index properties, which helps on the preliminary selection of the material constants. [ABSTRACT FROM AUTHOR]

The small strain shear modulus, G max , is an important parameter for characterizing the seismic response of deposits to dynamic loading. The parameter is related to shear wave velocity (G max =ρV s 2 ) only via the soil density. Existing V s correlations established in the laboratory were compiled in this paper and grouped into different general forms. Laboratory V s measurements using the piezoelectric ring-actuator technique, P-RAT, incorporated in conventional oedometer cells, were performed for six Eastern Canadian clay deposits. Specific correlations were established between normalized shear wave velocities, V s1 , with the overconsolidation (OCR) and void ratios (e). The paper examines the applicability of existing correlations by comparing V s1 values obtained from P-RAT correlations to those predicted by published laboratory correlations. While several correlations can be used to predict V s for Eastern Canadian clay, the applicability of other correlations has however been questioned. The analysis reveals the importance of considering the effect of the percentage of fine particles (<2 μm). This effect changes the void ratio variation range, which in turn has a significant impact on V s values. Furthermore, two general correlations are suggested based on P-RAT results and considering the clay content of analyzed sites. These general correlations can be readily used to estimate V s1 values for low and high plasticity clays. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper was prepared based on in situ measurements carried out by the authors using the CPTu and DMT static penetration probes. The list of study sites includes seven specific locations in the northern parts of Croatia and one study site on the southern border of the country. The sites were selected based on the criterion of soil type, which falls into the category of soft to firm, slightly over-consolidated silty clays and silty sands. Intermediate soils are prevalent in the wider region, and most engineers deal with them in their everyday practice. For this reason, local characterization is of most importance for engineering purposes. In this investigation, results of in-situ tests are compared in order to validate the quality of the constrained modulus obtained from a CPT test to the one obtained by a DMT flat dilatometer. A comparison was made between the CPT test cone resistance Q t 1 and two DMT parameters—normalized modulus E D / σ ′ v 0 and horizontal stress index K D . Dependencies were analyzed for the main soil groups and intermediate data groups. Clay soils were divided into two subgroups based on the identification parameter I D , while silty soils were analyzed in three subgroups. The results for each subgroup differed significantly, and the analyses showed deviations from published values, especially for the intermediate soil groups. The usefulness of the application is demonstrated with examples at two sites, showing improvements over the most commonly used formula for the constrained modulus from the CPT test. [ABSTRACT FROM AUTHOR]

• Extensive experimental testing of unreinforced masonry behaviour under tensile and shear loads. • Probabilistic descriptions of the ratios between tensile and shear properties of unreinforced masonry. • Presentation of raw experimental data. • Consideration of the effects of net-section and stress-raisers for perforated masonry units. This paper presents the results of an extensive set of material characterisation tests performed on unreinforced clay brick masonry. The results of these experiments allow for the estimation of relationships between the measured material parameters. This study considers the relationships of flexural tensile bond strength to direct tensile bond strength, flexural to direct tensile strength of fired clay brick masonry units, and flexural tensile to shear bond strength. A mean ratio of flexural tensile bond strength to direct tensile bond strength of 2.06 and a COV of 31.5% were determined. For the flexural to direct tensile strength of fired clay brick masonry units, a mean ratio of 1.29 with a COV of 14.7% was estimated. Finally, considering the ratio of the shear bond to flexural tensile bond strengths, a mean ratio of 1.34 with a COV of 28.4% was found. In addition to these relationships, suitable probabilistic models were determined to describe the relationship between the flexural and direct tensile bond strengths, and the flexural tensile and shear bond strengths. These results may be used in future studies of URM structures, in particular finite element modelling and stochastic analyses of masonry. [ABSTRACT FROM AUTHOR]

The preconsolidation pressure and overconsolidation ratio profiles are the most important factors related to the mechanical behaviour of clay deposits. They are interpreted on the basis of a limited number of laboratory tests, but the near-continuous information provided by the piezocone can allow local data to be extrapolated to an entire site. Numerous methods have been proposed for relating piezocone data to preconsolidation pressure and the overconsolidation ratio, but their validity is still uncertain. In this paper, nine methods are compared on the basis of data collected on 31 sensitive clay sites in Quebec whose preconsolidation pressure profiles are well known. Each method is briefly presented and the most promising are identified. The simplest method, which directly relates preconsolidation pressure to net tip resistance, also appears to be the most effective.Key words: clay, preconsolidation pressure, overconsolidation ratio, piezocone, correlations.Les profils de pression de préconsolidation et du rapport de surconsolidation constituent les éléments les plus importants en ce qui concerne le comportement mécanique des dépôts argileux. Leur évaluation se fait par un nombre limité d'essais de laboratoire, mais les données fournies par le piézocône de manière presque continue peuvent permettre une extrapolation à l'ensemble du site de ces données locales. De nombreuses méthodes ont été proposées pour corréler les données du piézocône et la pression de préconsolidation ou le rapport de surconsolidation mais leur validité est encore incertaine. Dans le présent article, neuf méthodes sont examinées à partir de données provenant de 31 sites d'argile sensible de la province du Québec pour lesquels les profils de pression de préconsolidation sont bien connus. Chaque méthode est brièvement présentée et les méthodes les plus intéressantes sont identifiées. Il semble que la relation entre la pression de préconsolidation et la résistance en pointe nette, qui est la plus simple, est aussi la plus efficace.Mots clés : argile, pression de préconsolidation, rapport de surconsolidation, piézocône, corrélations. [ABSTRACT FROM AUTHOR]

Clay-rich shales form the overburden in many sedimentary basins and the seals to hydrocarbon accumulations in the subsurface. Their strength properties are not well understood and they are not often cored or carefully preserved to allow laboratory measurement of their properties. This paper presents the results of geomechanical tests carried out on a global suite of temporally and spatially diverse shales in terms of unconfined compressive strengths, cohesive strengths and friction coefficients. These shales were also extensively characterised in terms of their composition, porosity, physicochemical properties, grain size and rock physics response in order to derive empirical correlations to shale strength. The dataset was expanded using measurements published in the open literature along with some proprietary measurements. What might have been presumed to be good relationships such as strength with velocity or friction coefficient with clay content/porosity were found not to be the case. The best correlations were between strength and porosity or bulk cation exchange capacity. A correlation between friction coefficient and rigid grains was noted although the variables involved were not strictly independent. The relationship with cation exchange capacity may provide the opportunity of strength prediction from dielectric logs as dispersion of the dielectric constant is directly related to cation exchange capacity. [ABSTRACT FROM AUTHOR]

This paper was prepared based on in situ measurements carried out by the authors using the CPTu and DMT static penetration probes. The list of study sites includes seven specific locations in the northern parts of Croatia and one study site on the southern border of the country. The sites were selected based on the criterion of soil type, which falls into the category of soft to firm, slightly over-consolidated silty clays and silty sands. Intermediate soils are prevalent in the wider region, and most engineers deal with them in their everyday practice. For this reason, local characterization is of most importance for engineering purposes. In this investigation, results of in-situ tests are compared in order to validate the quality of the constrained modulus obtained from a CPT test to the one obtained by a DMT flat dilatometer. A comparison was made between the CPT test cone resistance Qt1 and two DMT parameters—normalized modulus ED/σ′v0 and horizontal stress index KD. Dependencies were analyzed for the main soil groups and intermediate data groups. Clay soils were divided into two subgroups based on the identification parameter ID, while silty soils were analyzed in three subgroups. The results for each subgroup differed significantly, and the analyses showed deviations from published values, especially for the intermediate soil groups. The usefulness of the application is demonstrated with examples at two sites, showing improvements over the most commonly used formula for the constrained modulus from the CPT test.

Shear wave velocity (Vs) and standard penetration test number (SPT-N) are important parameters for seismic site characterization. Shear wave velocity profiles have been evaluated in a grid size of 2 km × 2 km using Multichannel Analysis of Surface Waves (MASW) at 67 locations of Vadodara city. Shear wave velocity profiles for study region are developed at different depths to study the local site conditions. SPT-N values have been extracted from geotechnical details through 430 bore hole data which spread over entire region. SPT-N value maps are also generated at 5 m, 10 m, 15 m, and 20 m depths to understand the variation of soil properties with varying depth. The correlations between Vs and SPT-N values (uncorrected and energy corrected) have been developed for different categories of soil (all soil, clay, sand). Various statistical tools such as scaled relative error and cumulative frequency plot have been used to assess the accuracy of obtained correlations. Further, the comparison has also been made for proposed correlations with the existing correlations developed by other researchers. The study reveals that 90% of predicted velocities from uncorrected SPT-N values with proposed relations fall within ±20% error for all soil, clay and sand. It is observed that Vs and uncorrected SPT-N relationships give more accuracy as compare to Vs and energy corrected SPT-N relationships. The correlations will be further useful to develop shear wave velocity profiles for other regions having similar site conditions. [ABSTRACT FROM AUTHOR]