This paper presents an overview of constitutive modelling of unsaturated soils and the numerical algorithms for solving the associated boundary value problems. It first discusses alternative stress and strain variables that can be used in constitutive models for unsaturated soils. The paper then discusses the key issues in unsaturated soil modelling and how these issues can be incorporated into...

Existing stochastic models of unsaturated flow and transport are usually developed using the simple Gardner-Russo constitutive relationship though it is generally accepted that the more complex van Genuchten and Brooks-Corey relationships may perform better in describing experimental data. In this paper, we develop first-order stochastic models for gravity-dominated flow in second-order station...

Liquefaction is a phenomenon in which the strength and stiffness of a soil is reduced by earthquake shaking or other rapid cyclic loading. Liquefaction and related phenomena have been responsible for huge amounts of damage in historical earthquakes around the world. Modeling of soil behavior is the main step in soil liquefaction prediction process. Nowadays, several constitutive models for sand...

In this study we develop a first-order, nonstationary stochastic model for steady state, unsaturated flow in randomly heterogeneous media. The model is applicable to the entire domain of a bounded vadose zone, unlike most of the existing stochastic models. Because of its nonstationarity, we solve it by the numerical technique of finite differences, which renders the flexibility in handling diff...

biomechanical properties of soft tissue, such as liver, are important in modeling computer aided surgical procedures. experimental evidences show that liver tissue is transversely isotropic. in this article, considering the liver tissue as an incompressible fiber-reinforced composite with one family of fibers, an exponential strain energy function (sef) is proposed. the proposed sef is based on...

Key words: soil-water transport, van Genuchten model, petroleum hydrocarbons In modeling a phytoremediation strategy, the transport and fate processes of soil water are influenced by subsurface groundwater flow, precipitation events, microbial activity, and transpiring vegetation. This transport is modeled in a variably saturated environment in a vertical dimension and is represented by a Richa...

A novel SPH model aimed at solving the coupled water-soil problems is proposed based on mixture theory. This method featured with spatially overlapped dual continua for both fluid and solid phases. The water phase modeled as a weakly-compressible Newtonian fluid, soil using an elastoplastic constitutive model. benchmark problem, fully submerged subjected to gravity , examined validate this Fina...

The frictional behaviours between unsaturated soils and structure are controlled mainly by the complex phenomena that develop within a thin soil layer close to contact area. constitutive model for soil-structure interfaces (SSI) must be established predict performance of related soil-structuresystems accurately. Multi-stage suction-controlled ring shear (RS) tests with three different upper ann...