As a consequence of the global health emergency in early 2020, universities had to tackle a sudden shift in their teaching–learning strategies so that the preset competences could be fulfilled. This study presents the learning outcomes of the implemented tasks, student experiences, and feedback, as well as some reflections from the instructors with a holistic perspective of the courses due to the adopted measures and adaptations. Six courses taught at civil engineering degrees of three universities, two from Spain and one from Peru, were analyzed. The teaching and evaluation strategies are described, and some reflections are made by comparing the student’s performance with the previous course. Though the shift to online learning had to be made from day to day, with no time for preparation, the experience has proved that online learning can be beneficial in some aspects and has probably come to stay, although some other aspects are difficult to replace with respect to face-to-face learning, especially students’ engagement and motivation. The significance of this study relies on a description of the challenges that arose due to the global public health and an assessment of the results of the implemented strategies to account for both teaching and evaluation in modules of civil engineering. After the acquired experience, new questions have arisen, e.g., what type of content is (and what is not) adequate or suitable for online exams? What features have come to stay? Has higher education taken a step forward to tomorrow’s education?

Earthquake ruptures in poroelastic media involve a suite of complex phenomena arising from stick‐slip frictional instabilities and thermo‐hydromechanical couplings. In this study we propose a fully implicit, time‐adaptive, and monolithically coupled finite element model to simulate dynamic earthquake sequences in poroviscoelastic media. We consider a Kelvin‐Voigt viscoelastic material and characterize the impact of inertial effects on injection‐induced earthquakes. We present, for the first time, dynamic simulations of ruptures in rate‐and‐state faults in poroelastic media. Our simulations resolve the full earthquake cycle, including the interseismic, spontaneous earthquake nucleation, and dynamic rupture phases. We compare dynamic simulations with quasi‐dynamic ones, in which inertial effects are neglected and the slip singularity is resolved through a radiation damping approximation. Viscous dissipation models the physical process of seismic wave attenuation: As viscous damping increases, the patch size and the maximum fault slip become smaller, hence decreasing the expected earthquake magnitude. From a computational perspective, viscoelasticity helps avoid spurious high‐frequency oscillations during wave propagation. By including inertial effects, the dynamic model accounts for transient fluctuations of pressures and solid stresses during rupture, which are neglected in the quasi‐dynamic approach. Understanding these transient perturbations may shed light on the role of pore pressure in the mechanism of dynamic earthquake triggering. The poroviscoelastic dynamic approach is a good compromise between the inviscid, fully dynamic model, and the quasi‐dynamic one. A small amount of viscous damping allows us more efficient calculations, while preserving the most relevant features of dynamic ruptures, in particular slip velocities, accumulated slip, and seismic moment released.

Changes in pore pressure due to the injection or extraction of fluids from underground formations may induce potentially damaging earthquakes and/or increase the sensitivity of injection sites to remote triggering. The basic mechanism behind injection‐induced seismicity is a change in effective stress that weakens a preexisting fault. The seismic potential of a given fault is controlled by the partitioning between seismic and aseismic slip events, which emerge as a manifestation of stick‐slip instabilities. Through fully coupled hydromechanical simulations, with fault frictional contact described by the Dieterich‐Ruina “aging” law, we investigate the evolution of slip due to pore pressure increase in an underground injection model. For the same flow conditions and rock mechanical properties, different constitutive parameters lead to a variety of stick‐slip patterns, ranging from stable sliding or a sequence of many small slip events, to a single, larger coseismic event after significant aseismic slip has occurred. Our results suggest that good characterization of fault frictional properties and coupled geomechanical simulations are essential to assess the seismic hazard associated with underground flow processes.

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Modeling injection-induced earthquakes requires coupling porous media flow, rock mechanics, and fault friction. Highly nonlinear laboratory-derived constitutive laws for fault friction pose a major challenge for computational models that couple flow and geomechanics. We present a finite element formulation to simulate injection-induced earthquake sequences in rate-and-state faults embedded in poroelastic media. We simulate all phases of the stick-slip cycle: from fault reactivation as pressure accumulates near the fault, to earthquake nucleation phase, coseismic rupture propagation and interseismic periods. Our simulations are quasi-dynamic: we neglect inertia, and adopt the so-called radiation damping approximation. We perform validation and verification tests based on a simple spring-block analog that allows straightforward comparison between our 2-D finite element model and the single-degree-of-freedom dynamics. We also verify our frictional contact algorithm by simulating injection-induced earthquakes on a slip-weakening strike-slip fault. We finally study the impact of different rate-and-state laws (aging and slip laws), as well as the role of the degree of poroelastic coupling, by varying the Biot coefficient. We characterize the undrained pressure response triggered by the fast propagation of rupture fronts. Undrained pressure changes during rupture act as an additional coseismic weakening mechanism, controlling the propagation or arrest of the rupture fronts. We find that this feedback between pore pressure and slip propagation, which is absent in uncoupled simulations, leads to distinctively asymmetric rupture patterns in induced earthquakes in poroelastic media. Our results show that capturing the coupling between fault frictional processes and rock poroelastic behavior requires well-resolved and fully coupled simulations.A recent increase in seismicity rates has drawn attention toward injection-induced earthquakes and their potentially

Fault reactivation induced by pore pressure changes involves complex frictional phenomena because effective normal stresses vary in space and time due to fluid flow and rock deformation. The impact of time-varying normal stresses on fault friction has been characterized in stress-step laboratory experiments and modeled through extended rate-and-state laws that incorporate a stressing-rate dependence of the state variable. Building on these rate-and-state models, we use 2-D poroelastic simulations to understand how the evolution of pore pressures due to fluid injection affects fault strength and reactivation. A sharp increase in pore pressure, associated with fluid injection, leads to an increase in friction coefficient and to a delayed weakening of the fault. Conversely, a sharp pressure decrease during extraction leads to a delayed strengthening. Stressing-rate effects emerge as a purely frictional mechanism that delays or accelerates the onset of fault slip, suggesting that reactivation under fluid injection may occur long after flow rates have decreased and pore pressures have stabilized at the fault. Hence, earthquakes induced by injection may ensue as a deferred process triggered several days later than predicted by simple estimates based on constant friction. The duration of the delay depends on the type of rate-and-state law used in calculations and on a characteristic relaxation time: The memory time over which the state variable evolves under stationary contact. Our results help understand the connection between injection protocols and frictional weakening mechanisms, suggesting that injection processes can be engineered to minimize the risk of induced seismicity for a given injected volume.

The classroom closure during the first semester of 2020 entailed decisive changes in higher education. Universities have become more digital in both the availability of e-resources and pervasive devices and how students communicate with lecturers and classmates. Learners adapted their study habits with a growing role of self-paced, internet-based strategies. Some flipped learning approaches have proven their efficacy under the remote-teaching physical constraints. This study aimed to appraise the outcomes from the implementation of various web-based, learning-aid tools on flipped teaching approaches in engineering modules. The open educational resources (OER) performed satisfactorily during the lockdown period in three universities from two countries with similar higher education models. Such resources encompassed classroom response systems and web-based exercise repositories, designed for diverse purposes such as autonomous learning, self-correction, flipped classroom, peer assessment, and guided study. The acquired experiences reveal that OER helped students to enhance their engagement, reach the deeper levels of the cone of learning, and widen their range of learning abilities. This procedure is easily attainable for architecture, engineering, and construction (AEC) courses and lifelong learning settings. Feedback from students, instructors’ perceptions, and learning outcomes show the suitability and effectiveness of the web-based learning assistant procedure presented here.