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Consistent with its title, “An overview of the model container types in physical modeling of geotechnical problems” by Esmaeilpour et al. [1], the essence of the paper is literature review, and hence it is particularly important that the review is accurate. The authors have compiled an extensive list of papers relevant to the design of model containers used to study effects of seismic loading on soil behavior in shake table tests. Of course, many more container types exist for “physical modeling of geotechnical problems” beyond shake table testing. Both the paper and this discussion are focused on containers used to contain soils during shaking table tests, whether performed at 1g or on a centrifuge. Unfortunately, we noticed inaccuracies in the way that the authors have characterized the work of others. We present examples below. 

Biogeotechnics, specifically bio-mediated and bio-inspired geotechnical engineering, has matured rapidly over the past two decades, becoming one of the fastest growing subdisciplines within geotechnical engineering. As typical in most science and engineering fields, biogeotechnics relies on data from physical experiments and field observations to advance technology. Obtaining field data to drive advancement can pose unique challenges, and in many cases may be cost or logistically prohibitive. Physical experiments or models are often preferable and may offer the sole feasible pathway for technology development and upscaling. Hypergravity scaled modeling using centrifuges has been instrumental in biogeotechnics development to support the building of basic science knowledge, the validation of computational and theoretical models, and the advancement of emerging technologies towards field implementation. 

A reliable prediction of liquefaction-induced damage typically requires nonlinear deformation analyses with an advanced constitutive soil model calibrated to the site conditions. The calibration of constitutive models can be performed by relying primarily on a combination of commonly available properties and empirical or semi-empirical relationships, on laboratory tests on site-specific soils, on in-situ penetration tests, or a combination thereof. Chiaradonna et al. (2022) described a laboratory-based calibration approach of the PM4Sand constitutive model and evaluated the prediction accuracy against the response of a centrifuge experiment of a submerged slope. This paper addresses an alternate calibration approach in which the PM4Sand model is calibrated using centrifuge in-situ CPT data. The model performance for the resulting calibration is evaluated against the centrifuge experimental data and prior simulations from Chiaradonna et al. (2022). In this case, the CPT-based calibration resulted in more accurate estimations of the dynamic response and permanent displacements. 

This paper investigates and presents the numerical modeling and validation of the response of a uniform clean sand using monotonic and cyclic laboratory tests as well as a centrifuge model test comprised of a submerged slope. The dynamic response of the sand is modeled using a critical state compatible, stress ratio-based, bounding surface plasticity constitutive model (PM4Sand), implemented in the commercial finite-difference platform FLAC, and PM4Sand’s performance is evaluated against a comprehensive testing program comprised of laboratory data and a well-instrumented centrifuge model test. Three different calibrations informed by the lab and centrifuge data are performed and the goodness of the predictions is discussed. Conclusions are drawn with regards to the performance of the simulations against the laboratory and centrifuge data, and recommendations about the calibration of the model are provided. 

Measuring displacements in model tests typically involves contact-based sensors such as linear potentiometers, where contact between two moving parts occurs at the sensing point. The sensor's finite mass, the limited stiffness of the beams and the clamping mechanism, and the slippage and hinging of the sensor body could affect the object's response and lead to measurement errors. Also, the physical mounting rack required to hold these sensors often obstructs the view and makes significant areas unavailable for conducting some other essential investigations. The advancement in high-speed, high-resolution and reasonably priced rugged cameras makes it feasible to obtain better displacement measurements by image analysis. This paper introduces a non-contact method that works by video recording the projection of laser lines on a test object to measure static and dynamic vertical displacements. The technique produces a continuous settlement distribution along the laser line passing through multiple objects of interest. This paper presents the theory for converting laser line images to displacements. The new method's validity is demonstrated by comparing the results from other measurement techniques: hand measurements, linear potentiometers and three-dimensional stereophotogrammetry.