Waves can cause significant accumulation of pore water pressure and liquefaction in seabed soils, leading to instability of foundations of marine hydrokinetic devices (MHKs). Geostatic shear stresses (existing around foundations, within slopes, etc.) can substantially alter the rate of pore pressure buildup, further complicating the liquefaction susceptibility assessments. In this study, the development of wave-induced residual pore water pressure and liquefaction within sandy seabed slopes supporting MHK structures is evaluated. Unlike most earlier studies that excluded the impact of shear stress ratios (SSR) on the residual pore pressure response of sloping seabeds, asymmetrical cyclic loadings are considered herein for a range of SSRs. To obtain wave-induced loading in the seabed (and cyclic shear stress ratios, CSRs), the poroelasticity equations governing the seabed response, coupled with those for fluid and structure domains, are solved simultaneously. Utilizing an experimental model based on anisotropic cyclic triaxial test data that includes CSR and SSR impacts, an equation for the rate of pore pressure buildup is developed and added as a source term to the 2D consolidation equation. Numerical investigations were performed by developing finite element models in time domain. The models were calibrated using particle swarm optimization method and validated against wave flume experimental data. The results indicate that the consideration of static shear stresses has led to sudden rise in residual pore pressures followed by fast dissipations at early and late time steps, respectively, beneath the structure. The exclusion of SSR is shown to cause significant overestimation of pore pressure accumulations at late cycles, potentially causing significant overdesign of MHK foundations. The impact of proximity to the free drainage boundary, CSR amplitude, and loading frequency on the accumulation of residual pore pressure is illustrated. The residual liquefaction susceptibility of the seabed is shown to decline by increase of the seabed slope angle.

Societal Impact StatementSolar parks enable renewable energy production at a large scale, thereby reducing greenhouse gas emissions. However, the effects of this change in land use on vegetation and soil health are still largely unknown. In this study, we determined the impacts of solar parks on vegetation, soil biota and soil carbon between and below solar panels. We found lower plant and microbial biomass below the panels, while no differences in soil carbon pools were observed. The results stress the urgent need to design future solar parks that prevent soil degradation while still producing the renewable energy needed to combat climate change.Summary Solar parks, large-scale arrays of photovoltaic panels, are a unique land use and play an important role in the renewable energy transition. However, the solar panels create shade and change the microclimate, potentially affecting plant growth and carbon inputs to the soil. These changes can influence key soil properties critical to long-term carbon storage and overall soil health. This study investigated the impact of commercial solar parks on plant productivity and the colonisation of roots by mycorrhizal fungi, soil organic matter (SOM), soil microbial community biomass and composition and litter decomposition in 17 solar parks with contrasting shading levels across the Netherlands. Soil samples and plant biomass samples were collected between and below the solar panels. The microclimate (temperature, moisture) was measured continuously over the growing season and cumulative solar irradiation during the growing season in relation to the solar panels was modelled. Results show that above- and below-ground plant biomass as well as mycorrhizal colonisation were significantly lower below than between panels, while we did not find differences for SOM, carbon stocks and hot water extractable carbon. Plant productivity related negatively to the extent of light interception by the panels. Furthermore, fungal and bacterial biomass and the F:B ratio were lower below compared to between the panels while decomposition rates did not differ. The severe decrease of plant biomass inputs in combination with maintained rates of decomposition are expected to result in decreased SOM stocks and soil health over time and suggest the need for guidelines for ecologically sound solar park designs to prevent soil damage.

Marine and underwater structures, such as seawalls, piers, breakwaters, and pipelines, are particularly susceptible to seismic events. These events can directly damage the structures or destabilize their supporting soil through phenomena like liquefaction. This review examines advanced numerical modeling approaches, including CFD, FEM, DEM, FVM, and BEM, to assess the impacts of earthquakes on these structures. These methods provide cost-effective and reliable simulations, demonstrating strong alignment with experimental and theoretical data. However, challenges persist in areas such as computational efficiency and algorithmic limitations. Key findings highlight the ability of these models to accurately simulate primary forces during seismic events and secondary effects, such as wave-induced loads. Nonetheless, discrepancies remain, particularly in capturing energy dissipation processes in existing models. Future advancements in computational capabilities and techniques, such as high-resolution DNS for wave-structure interactions and improved near-field seismoacoustic modeling show potential for enhancing simulation accuracy. Furthermore, integrating laboratory and field data into unified frameworks will significantly improve the precision and practicality of these models, offering robust tools for predicting earthquake and wave impacts on marine environments.