The macroscopic yield pressure of brittle granular soils is experimentally known to depend on the size particles. In this paper connection established theoretically within a unified framework that integrates principles fracture mechanics, breakage mechanics and Weibull's weakest link theory. particular, work input at which continuum begins comminute linked specific energy single particle fails, reveals an intrinsic length scale in form mean grain initial assembly. then connected with both...

A complete thermodynamic theory is presented that capable of explaining the dependence yielding on degree saturation in brittle granular aggregates. Historically, constitutive models represented this coupling between mechanics and hydraulics only phenomenologically, by way incorporation loading collapse curve concept. This was done both for fine-grained soils, and, latter case, without embodying physical connection to elasticity, as motivated fracture mechanics. Here, captured breakage...

Experimental evidence indicates that granular soils under high confining stress accumulate deformation over time, with processes such as creep, relaxation and strain-rate sensitivity being controlled by the growth of internal flaws delayed fracture individual particles. In this paper, a connection between theory subcritical crack propagation continuum modelling crushable is established exploiting an analogy promote energy release upon single particles those are responsible for comminution in...

The size-dependent strength of individual particles controls several key aspects the constitutive response brittle granular materials. Capturing this factor in numerical analyses is essential to accurately model mechanical behavior assemblies with different size. In study, a three-dimensional discrete element method (DEM) proposed reproduce size dependence particle by means bonded framework. Particle fragmentation modeled explicitly through disintegration agglomerates made elementary...

This work uses synchrotron X-ray tomography to quantify the role of particle shape on interaction between collective comminution and individual grain fracture. Two sands (subrounded Ottawa subangular Q-ROK#2) were compressed beyond their pressure imaged at microscale. An algorithm was developed track sequence breakage events stemming from compression, as well evolving morphology resulting fragments. The results show that degree evolution depends initial particles, with subrounded particles...

The influence of particle shape on the mechanics sand is widely recognized, especially in mineral processing and geomechanics. However, most existing continuum theories for engineering applications do not encompass morphology grains its evolution during comminution. Similarly, relatively few models accounting grain-scale processes tend to idealize particles as spheres, with their diameters considered primary sole geometric descriptor. This paper inspires a new generation constitutive laws...

Faults are complex structures that substantially influence the mechanical behavior and hydraulic connectivity of rock formations. Therefore, studying faults is important for a variety disciplines such as geoscience, civil, geotechnical, reservoir engineering, material science among others. Researchers from these have considered different aspects faults, namely geometry, petrophysical properties mechanics. Until now, studies evolved separately at scales, making it difficult to connect...

Discrete element modelling (DEM) analyses are conducted to quantify how the statistical dispersion of particle morphology influences stress transmission and strain energy storage granular materials. DEM samples prepared with both linear bimodal size distributions compressed isotropically. In addition, mixtures shapes used by covering a wide range aspect ratios. The results indicate that contact dynamics influenced significantly dispersion, fine particles in system tending not transmit...

ABSTRACT The framework of poromechanics is generalized to simulate the multiscale behavior porous media subjected internal loadings stemming from growth solid inclusions. This generalization designed enable study anisotropic stress generation within pores, while recovering isotropic fluid‐induced loading as a particular case. For this purpose, mathematical strategy define constitutive tensors in thermodynamically consistent form proposed, thus offering new opportunities for determining...

Nonlocal gradient continua are a reliable way to regularise numerical models of boundary value problems affected by strain localisation. However, the determination additional parameters such formulations, including those controlling length scale potential shear bands, is not straightforward, in that it interplay among stress–strain relations and band morphology. To address this challenge, study proposes parameter strategy for nonlocal strain-softening Mohr–Coulomb model based on...

Abstract The paper presents a theoretical approach to deal with mechanical instabilities in unsaturated soils. Towards this goal, the concept of test controllability is extended hydro‐mechanically coupled framework. A constitutive based on introduction hydraulic generalized stress–strain variables first adopted, order better describe suction effects behaviour soil. mathematical consequences hydro‐mechanical coupling are presented next and two indices defined identify onset an instability....

Abstract The volumetric compaction due to wetting processes is a phenomenon observed quite often in unsaturated soils. Under certain circumstances, saturation events can result into sudden and unexpected collapse of the system. These phenomena are usually referred as wetting‐induced collapses, without providing any detailed theoretical justification for this terminology. In order predict general fashion occurrence coupled instabilities induced by processes, generalization approaches employed...

This paper illustrates an application of the theory material stability to analysis unsaturated slopes. The main goal is contribute understanding rainfall-induced flow slides. For this purpose, a coupled hydromechanical constitutive model combined with simplified approach for infinite Simple shear-test simulations are used evaluate triggering perturbations and investigate role both initial suction stress anisotropy in activation slope failures. numerical clearly show that different mechanisms...

The paper presents a methodology to evaluate flow slide susceptibility in potentially liquefiable sandy slopes. proposed approach accounts for both contractive and dilative volumetric behaviour during shearing using the MIT-S1 constitutive model. As result, it is possible distinguish among different types of undrained response induced by rapid shear perturbation. first part describes general infinite slopes, providing an index stability incipient static liquefaction shallow deposits....

This paper examines the influence of initial state sands on potential for undrained instability. The main goal is to illustrate how advanced constitutive modeling sand behavior can be used evaluate susceptibility static liquefaction. methodology based concept latent instability, in which collapse contingent particular boundary conditions. A generalized effective stress soil model, MIT-S1, support analysis and combined with a theoretical approach identifying loss control owing shear...

Abstract The paper presents a strainhardening constitutive model for unsaturated soil behaviour based on energy conjugated stress variables in the framework of superposed continua. proposed law deals with hydro‐mechanical coupling phenomena. main purpose is to develop within consistent that can deal possible mechanical instabilities occurring partially saturated materials. loss capillary effects during wetting processes can, fact, play central role unstable processes. Therefore, it will be...

Gassy soils are a special case of unsaturated soils, for which the gas phase exists in form occluded bubbles size that allows to fit within void spaces without distorting soil structure. The applicability original Terzaghi's effective stress principle was tested this class soils. A series globally undrained tests on gassy specimens, as well drained path (ESP) fully saturated presented validate hypothesis. In test, stresses were computed with assumption valid. an ESP obtained from experiment...