- document
-
Bayraktaroglu, H. (author), Gonzalez Acosta, J.L. (author), van den Eijnden, A.P. (author), Korff, M. (author), Hicks, M.A. (author)Natural soil deposits may possess a highly anisotropic nature. The fabric anisotropy of soils which is induced during the soil formation process can lead to severe variation in field scale responses. Although the influence of fabric on the response of sands is well known and several advanced constitutive models have been developed to account for...conference paper 2023
- document
-
Gonzalez Acosta, J.L. (author), Varkey, D. (author), van den Eijnden, A.P. (author), Hicks, M.A. (author)Free-field site response analysis is a standard technique used to predict soil deposit dynamic response and liquefaction susceptibility. Such analyses are typically carried out by implementing periodic boundaries to guarantee the same speed of the dynamic waves travelling across them. However, when using random fields to consider the impact of...conference paper 2023
- document
-
Yu, Beiyang (author), Varkey, D. (author), van den Eijnden, A.P. (author), Rongier, G. (author), Hicks, M.A. (author)This research focuses on investigating the relative performance of a range of machine learning algorithms, namely the artificial neural network, support vector machine, Gaussian process regression, random forest, and XGBoost, for predicting the undrained shear strength from cone penetration test data. This is to assess how machine learning could...conference paper 2023
- document
-
Varkey, D. (author), van den Eijnden, A.P. (author), Hicks, M.A. (author)Geological uncertainty can significantly influence the computed response of a geotechnical structure. For example, ignoring the presence of a weak soil layer embedded within a stronger layer and assuming a deterministic stratigraphic boundary can significantly underestimate the probability of failure. In this paper, the coupled Markov chain...conference paper 2023
- document
-
Gonzalez Acosta, J.L. (author), van den Eijnden, A.P. (author), Hicks, M.A. (author)Soil liquefaction is investigated considering a saturated soil deposit and by implementing standard techniques of random field theory to distribute initial void ratio values and assess liquefaction risk. The soil domain is represented in a 2-dimensional (2D) random finite element model for the dynamic analysis of coupled behavior. Multiple...conference paper 2023
- document
-
Do, Phuong Chinh (author), Vardon, P.J. (author), Gonzalez Acosta, J.L. (author), Hicks, M.A. (author)The material point method (MPM) is gaining an increasing amount of attention due to its capacity to solve geotechnical problems involving large deformations. Large deformations in geotechnics usually involve the failure process and therefore dynamic analyses are often carried out. However, simulating the (infinite) continuous domain using...conference paper 2023
- document
-
Bayraktaroglu, H. (author), Hicks, M.A. (author), Korff, M. (author)In this paper, a state-dependent semi-micromechanical framework for anisotropic sands is proposed. A simple constitutive model based on critical state theory and bounding surface (BS) plasticity is used to describe idealized micro-level soil behaviour, and a slip theory based multilaminate framework employed to create a link between the micro...conference paper 2023
- document
-
Varkey, D. (author), Hicks, M.A. (author), van den Eijnden, A.P. (author)The stability of six regional dyke cross-sections in the Netherlands was re-assessed using the random finite element method (RFEM), which explicitly accounts for the spatial variability of strength parameters. The RFEM assessments of the cross-sections were shown to result in significantly narrower response distributions than those obtained...conference paper 2023
- document
-
Hicks, M.A. (author)The spatial variability of soil properties influences material behaviour and the performance of geotechnical structures. It also leads to uncertainty in design, because one can never be certain about what the ground conditions are at every location across a site. This article introduces the concept and implications of spatial variability, and...conference paper 2022
- document
-
Gonzalez Acosta, J.L. (author), van den Eijnden, A.P. (author), Hicks, M.A. (author)1D soil column techniques are widely used to evaluate the potential of liquefaction in a system of soil layers. This approach generally leads to large inaccuracies since (1) soil layers are hardly homogeneous and perfectly horizontal and (2) horizontal effects are neglected. To demonstrate the limitation of 1D strategies and the need for 2D...conference paper 2022
- document
-
Golchin, A. (author), Vardon, P.J. (author), Hicks, M.A. (author), Coombs, William M. (author), Pantev, I.A. (author)The numerical implementation of a recently developed thermomechanical constitutive model for fine-grained soils based on hyperelasticity-hyperplasticity theory (Golchin et al. 2020), is presented. A new unconventional implicit stress return mapping algorithm, compatible with elasticity derived from Gibbs (complementary) energy potential, in...conference paper 2021
- document
-
Zheng, X. (author), Gonzalez Acosta, J.L. (author), Remmerswaal, G. (author), Vardon, P.J. (author), Pisano, F. (author), Hicks, M.A. (author)The material point method (MPM) shows promise for the simulation of large deformations in history-dependent materials such as soils. However, in general, it suffers from oscillations and inaccuracies due to its use of numerical integration and stress recovery at non-ideal locations. The development of a hydro-mechanical model, which does not...conference paper 2021
- document
-
Remmerswaal, G. (author), Hicks, M.A. (author), Vardon, P.J. (author)The material point method (MPM) is used to model both rotational and horizontal sliding failure mechanisms of dykes under external (water) loading. To model the different failure mechanisms, an external hydrostatic water pressure has been applied on the canal side of the dyke by applying a newly developed boundary condition. The boundary...conference paper 2019
- document
-
Duvvuru Mohan, V.K. (author), Vardon, P.J. (author), Hicks, M.A. (author), van Gelder, P.H.A.J.M. (author)Bayesian networks are proposed as a tool to integrate reliability and influential variables relating to the slope stability of an idealized embankment. The site investigation (extent) and slope geometry, as well as the material properties and their spatial variability, are considered within a Bayesian network. The random finite element method ...conference paper 2019
- document
-
Varkey, D. (author), Hicks, M.A. (author), Vardon, P.J. (author)An improved method for the reliability analysis of 3D slopes has been proposed based on the semi-analytical method of Vanmarcke (1977). Comparing the predicted responses of an idealised 3D slope obtained by the more general, albeit computationally intensive, random finite element method (RFEM), and the original semi-analytical method showed that...conference paper 2019
- document
-
de Gast, T. (author), Vardon, P.J. (author), Hicks, M.A. (author)Measuring soil variability has many challenges. One of the challenges is soil deformation, which can change the spatial correlation structure arising from the original geological processes. In particular, this is important in the assessment of existing structures. In this paper, the effect of existing structures on the horizontal spatial...conference paper 2019
- document
-
Remmerswaal, G. (author), Bolognin, M. (author), Vardon, P.J. (author), Hicks, M.A. (author), Rohe, A. (author)This paper describes current work on the implementation of non-trivial boundary conditions (BCs) for improving the general applicability of the Material Point Method (MPM) to geotechnical boundary values problems. It summarises novel boundary treatments (non-trivial BCs) in MPM for (i) flow conditions, as well as (ii) the application of a...conference paper 2019
- document
-
Gonzalez Acosta, J.L. (author), Zheng, X. (author), Vardon, P.J. (author), Hicks, M.A. (author), Pisano, F. (author)Stress oscillations in the material point method (MPM) are one of the major reasons unrealistic results are obtained. In this paper an investigation of the stress oscillations occurring when using one- and two-phase approaches is performed. Specifically, an axisymmetric benchmark and a two-dimensional plane strain problem are used to demonstrate...conference paper 2019
- document
-
de Gast, T. (author), Vardon, P.J. (author), Hicks, M.A. (author)The variability of soil is well known to affect the geotechnical performance of structures. As probabilistic design methods become more commonly used, the ability to measure the variability of soil becomes more important. However, by using only the point statistics of soil parameters in design (e.g. the mean and standard deviation), typically an...conference paper 2018
- document
-
Gonzalez Acosta, J.L. (author), Vardon, P.J. (author), Hicks, M.A. (author), Pantev, I.A. (author)In geotechnical engineering, proper design of retaining structures is of great importance, since failure of these structures can lead to catastrophic consequences. Nowadays, the finite element method is seen as a reliable numerical technique to analyze soil behaviour and is widely used to assess the interaction be-tween soil and rigid structures...conference paper 2018