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This paper examines the accuracy of a new elastic–thermoviscoplastic (E-TVP) constitutive model developed based on critical state soil mechanics. The model can be used for simulating the temperature-dependent and strain-rate-dependent behavior of clay soils. The study compares the E-TVP behavior of a single soil element with previously published thermo-mechanical experimental results performed on saturated clay specimens at different temperatures. Suggestions regarding unloading and reloading at constant temperatures as well as thermal consolidation under constant loads are presented. A modification for unloading–reloading adds a new criterion to the volumetric thermoviscoplastic strain rate formulation. A physics-based term is added to the current specific volume of the soil to include the viscous effect induced by temperature change. These modifications improve the convergence of laboratory data and simulated model responses. Comparisons of results from an earlier E-TVP model and the newly improved model provide evidence of improved predictive capabilities. [ABSTRACT FROM AUTHOR]

2 of the original paper" and that "For soils and rocks under undrained condition, HT ht has been proven theoretically to be equal to 0.5 when the Skempton ([22]) HT ht parameter is equal to 1 at fully saturated conditions." For instance, for very stiff clays at high confining pressures, the theoretical HT ht value may barely exceed 0.9 even at fully saturated conditions. The Skempton HT ht parameter depends on both the degree of saturation and the stiffness of the soil skeleton. 1, HT ht is more affected by changes in degree of saturation and confining pressure at small strain conditions compared to large strain conditions (e.g., [10]). [Extracted from the article]

The unconfined compressive strength (UCS) of soils is essential for both researchers and practitioner geotechnical engineers. UCS is well-understood and standardized for laboratory and field tests. Nevertheless, the large number of environmental and physical governing factors makes the reasonable prediction of UCS complicated. In this paper, a deep learning approach using the multilayer perceptron regressor (MLP) method along with the genetic expression programming (GEP) are used to assess nine variables that contribute to form a reflective multivariate formulation of the UCS. These variables include clay mineral percent (CF), specific gravity (Gs), dry unit weight (γd), saturated unit weight (γsat), natural unit weight (γt), moisture content (MC), void ratio (e), degree of saturation (S), and porosity (n). MLP and GEP are implemented to classify, correlate, rank, and reduce the number of variables that govern the UCS through the application of classification algorithms, importance analysis, interrelations and interdependency analysis of the variables, and functional indicators that shape the UCS. The changes of UCS in line with the variations of void ratio are analytically formulated according to both the critical state soil mechanics and the inverse proportionality between the voided area and soil strength. Moreover, the validity of the UCS principle is examined as opposed to the variation of the clay percent in the soil. Findings show that there shall be a breakpoint (clay percentage) after which the concept of UCS is radically changed due to the presence of a significant amount of frictional and drainable materials in the soil. The breakpoint appears to be centralized between 40% and 55%. The study is concluded by identifying the fundamental soil parameters, providing practical models to evaluate UCS, developing fundamental relationships between UCS and void ratio, and defining the breakpoint of clay content. [ABSTRACT FROM AUTHOR]

The writers appreciate the discussers' recognition of the pioneering and novel nature of the original work, which provides a unified effective stress equation for all types of soils under all saturation conditions. However, the discussers fail to appreciate the importance of the roles of soil water adsorption mechanisms in soil water retention and effective stress, given the ample experimental evidence presented in our work and other previously published work. Instead, they raise some points, which are academically thought-provoking notions that are largely reflections of the misunderstanding of the importance of the soil sorptive potential (SSP) concept and the roles of SSP in the effective stress in soils, as detailed subsequently, following the order outlined by the discussers. The discussers consider that the sole mechanical energy in soil water is capillary pressure as they state "That [capillary water] is presumably why many researchers have previously suggested that capillary water, solely, plays a role in the mechanical behavior of unsaturated soil.". [Extracted from the article]

Theoretical curves for different values of HT ht , 0.6, 0.8, and 1.0 are superimposed on the graph and can be seen to encapsulate the data. Yet, even without these separate curves, Wroth ([14]) noted that the parameter HT ht would track well with I ' i alone according to CSSM, and recommended the approximation HT ht (5) Graph: Fig. [Extracted from the article]

The authors focus on research into deep building foundations and its behavior under axial and lateral loading. They mention that the prediction of load-transfer curves, both for side resistance and for end bearing, allow for the analysis of deep foundations under a range of conditions. They talk about soil properties around deep foundations after installation and how the pile capacity under axial load differs depending on if the pile was driven into consolidated clay or loose cohesionless soil. They state that research can lead to an improvement of design methods of deep foundations.