Contents lists available at ScienceDirect Computers and Geotechnics journal homepage: www.elsevier.com/locate/compgeo Review Implementation of a model of elastoviscoplastic consolidation behavior in Flac 3D Verónica M. Giraldo Zapata ⁎ , Eduardo Botero Jaramillo, Alexandra Ossa Lopez Instituto de Ingeniería, Universidad Nacional Autónoma de Mexico (UNAM), Ciudad de México, Mexico ARTICLE INFO Keywords: Elastoviscoplastic Finite difference 3D consolidation ABSTRACT The implementation of an elastoviscoplastic three-dimensional model (EVP3D) with the finite difference method is presented using the Flac3D analysis platform. This numerical model allows the time-dependent stress-strain behavior of soil to be studied while incorporating its viscous characteristics. An algorithm for solving the constitutive equations is developed and programmed using the centered finite difference method varying in time. The historical case of the construction of Tarsuit Island in the Beaufort Sea in the Arctic Ocean is studied to calibrate and validate the model. A finite difference model that represents the construction stages is developed, and the short- and long-term behaviors are obtained. The model was calibrated and validated with the data record from an electric piezometer that was installed in the foundation of the artificial island, and the results of the algorithm are compared with the recorded data. The results are satisfactory and comparable to the mea- surements that were recorded for a year on the island, which demonstrates the applicability and validity of the model and its constitutive hypotheses. 1. Introduction Traditional behavior models that have been developed for soft soils have mainly focused on the elasto-plastic component and neglected the viscous component. According to several researchers (e.g., [5,3,21,11,13]), in compressible soils such as clays, the deformation over time has a strong influence on the stress-strain behavior of soils; therefore, ignoring this effect can lead to unrealistic analysis. Some authors (e.g. Mesri (1975), Wehnert and Neher [23], Ovando [16], Gonzalez et al. [10]) have been reported evidence of elastoviscoplastic behavior of highly compressible clays. The first elastoviscoplastic models were presented by Bjerrum [3], Adachi and Oka (1982), Leroueil et al. [13], Borja and Kavazanjian (1985) and Yin and Graham [25], and they used different approaches for determining the time-dependent stress-strain behavior. This study involves the development of the elastoviscoplastic model in three di- mensions (EVP3D) that was proposed by Yin and Graham [28,29], which began with the one-dimensional model formulated by those authors in 1994 and 1996. The EVP model referred to in this article is based on Perzyna's theory of viscoplasticity (1963) [17], the concept of instantaneous and delayed compression that was proposed by Bjerrum [3] and a new concept called the equivalent timeline, which represents the creep be- havior of soil under the application of a constant load [26,27] and is considered to be an extension of the Modified Cam Clay model that was defined by Roscoe and Burland [18]. The model was initially validated through triaxial tests on soil samples made with a mixture of Sand and Bentonite [28,29] getting good approximations between the numerical model and the laboratory test results. In this study, we adopt the model proposed by [28,29] and the approach for generating a model coupled with the three-dimensional consolidation model proposed by Biot [2] to obtain the equations that relate the increase of excess pore pressure with the increasing volu- metric deformations obtained from the EVP model [28,29]. Finally, the equations are solved using a finite difference scheme. Each of the constitutive equations from the coupled model is programmed in the Flac 3D platform to take advantage of the graphical interface and the storage capacity in addition to the constitutive models that have been programmed. 2. Elastoviscoplastic model in three dimensions (EVP3D) The EVP model, which was developed by Yin and Graham [28,29], is a model of soil behavior that involves two important aspects: the first is related to elastic behavior under a limited range of stresses, and the second is inelastic behavior that depends on the stress trajectories and time. Traditional geotechnical models are plastic models that do not include the influence of time; as such, they mainly depend on the https://doi.org/10.1016/j.compgeo.2017.11.011 Received 4 April 2017; Received in revised form 17 November 2017; Accepted 26 November 2017 ⁎ Corresponding author. E-mail address: vgiraldoz@iingen.unam.mx (V.M. Giraldo Zapata). Computers and Geotechnics 98 (2018) 132–143 0266-352X/ © 2017 Elsevier Ltd. All rights reserved. T