PEER has just published Report No. 2021/02: "Implementation, Verification, and Validation of the PM4Sand Model in OpenSees." It was authored by Long Chen and Pedro Arduino, Department of Civil and Environmental Engineering, University of Washington.
Human and economic losses caused by earthquake-induced soil liquefaction underscore the importance of assessing liquefaction hazards, both by determining whether a soil is likely to liquefy and by estimating consequences these events may cause. Numerical simulations have proven to be useful for these purposes. Reliable numerical analysis requires that constitutive models represent the in situ soil behavior as well as general loading and drainage conditions. For this purpose, comprehensive verification and validation studies of material models are imperative for successful deployment of advanced numerical tools. In this context, the main objective of this research is to implement, verify, and validate a newly developed constitutive model, PM4Sand (Boulanger and Ziotopoulou, 2017), using the finite-element platform OpenSees (OpenSees, 2007). This model was developed for earthquake engineering applications and can achieve reasonable approximations of desired behavior (including pore pressure generation and dissipation, limiting strains, and cyclic mobility) using a straight-forward calibration process. After implementing PM4Sand in OpenSees, a parametric study was carried out to shed light on the model’s general behavior and calibration process. Next, a verification study was performed to compare the response of the model implemented in three different frameworks, OpenSees, FLAC, and PLAXIS, using point, element, and one-dimensional model analyses. Lastly, a few well known case histories were considered to validate and demonstrate the model’s ability to capture realistic soil behavior.