New in PLAXIS 3D 2024.2
New UDSM: Swelling Rock for PLAXIS 3D
The Swelling rock model was originally implemented by Prof. Thomas Benz of NTNU and further developed by Bert Schädlich of TUGraz for PLAXIS 2D as a User-Defined Soil Model (UDSM) several years ago. The model is based on previous work by Wittke-Gattermann & Wittke (2004), Anagnostou (1993), and Heidkamp & Katz (2002) and can account for the stress- and time dependency of swelling deformations. Recent advancements have further refined the Swelling rock model, enhancing its capabilities to accurately simulate swelling behaviour. These improvements include a 3D extension of the existing model, enabling the simulation of complex geological scenarios with greater accuracy and detail for PLAXIS 3D. Additionally, a novel swelling model has been developed based on the work of Hawlader et al. (2003) and Carvalho (2015), offering an alternative representation of swelling behaviour over time (linear in log(t) scale). This enhancement provides improved prediction for coupled swelling behaviour, contributing to a more comprehensive understanding of swelling phenomena. The user can now select between the original formulation and the log(t) version of the Swelling rock model during the material creation. Using this UDSM requires the Advanced or Ultimate licence tier and a valid Geotechnical SELECT Entitlement.
New UDSM: Clay And Sand Model (CASM)
The Clay And Sand Model (CASM) has been developed by Yu (1998) in the framework of Critical State Soil Mechanics (Schofield and Wroth, 1968) as a versatile constitutive model able to simulate the behaviour of both clays and sands. CASM can simulate static liquefaction, for example tailings dams, and has been successfully employed to analyse the Brumadinho (Arroyo and Gens, 2021) and Merriespruit dam failures (Mánica et al., 2022). CASM has been implemented as a User-Defined Soil Model (UDSM) in PLAXIS. Compared to the original formulation, this version of CASM includes Lode’s angle dependency, an alternative plastic potential equation (Arroyo and Gens, 2021) and the possibility to use it as either a rate-independent plastic model or as an elasto-viscoplastic model accounting for time-dependency (Manica et al., 2021). Using this UDSM requires the Advanced or Ultimate licence tier and a valid Geotechnical SELECT Entitlement.
Improved convergence for Fully coupled flow-deformation calculations
For the Fully coupled flow-deformation calculation type, a new setting called Include reference flow analysis is introduced. By default, this setting is unchecked and automatically excludes the calculation of a steady-state reference solution as was normally done in previous releases. In some cases, the calculation of this steady-state reference solution would not reach convergence and therefore the entire fully coupled flow-deformation analysis fails , this is now automatically averted. The excess pore pressures are also no longer calculated under this new default setting. By enabling the checkmark for Include reference flow analysis, users will be able to reproduce the behaviour as seen in previous releases where the steady-state reference solution was still calculated as well as the excess pore pressures. The Fully coupled flow-deformation calculation type is only available for the Ultimate license tier.