The existence of rock weathering products has an important effect on the infiltration of water in the soil. Understanding the mechanism of water infiltration in a mixed soil and weathered rock debris medium is highly important for soil science and hydrology. The purpose of this study is to explore the effects of mudstone hydrolysis on water infiltration in the soil under different mixing ratios (0-70 %) of weathered mudstone contents. Soil column experiments and numerical modelling were used to study the processes of hydrolysis of weathered mudstone and water infiltration in the mixed medium. The results revealed that water immersion can cause the dense mudstone surface to fall off, thus forming pores, and that the amount of these pores first increase but then decrease over time. The disintegration of post-hydrolysis mudstone debris occurs mainly among particles ranging from 2-2000 mu m, predominantly transforming sand particles into finer fractions. Increasing the mudstone content in the soil from 0 % to 50 % enhances the infiltration rate and cumulative infiltration volume. However, when the mudstone content exceeds 50 %, these parameters decrease. The mudstone weathering products promote water infiltration in the soil within a certain range of mudstone contents, but as the ratio of weathered products increases, excessive amounts of mudstone hinder the movement of water in the soil. The identified transformation phenomenon suggests that the infiltration capacity of mixed soil will not scale linearly with mudstone content. The findings enable some mitigation strategies of geologic hazards based on the hydrological stability in heterogeneous environments.
Forests are increasingly impacted by climate change, affecting tree growth and carbon sequestration. Tree-ring width, closely related to tree growth, is a key climate proxy, yet models describing ring width or growth often lack comprehensive environmental data. This study assesses ERA5-Land data for tree-ring width prediction compared to automatic weather station observations, emphasizing the value of extended and global climate data. We analyzed 723 site-averaged and detrended tree-ring chronologies from two broadleaved and two gymnosperm species across Europe, integrating them with ERA5-Land climate data, CO2 concentration, and a drought index (SPEI12). A subset was compared with weather station data. For modelling interannual variations of tree-ring width we used linear models to assess parameter importance. ERA5-Land and weather-station-based models performed similarly, maintaining stable correlations and consistent errors. Models based on meteorological data from weather stations highlighted SPEI12, sunshine duration, and temperature extremes, while ERA5-Land models emphasized SPEI12, dew-point temperature (humidity), and total precipitation. CO2 positively influenced the growth of gymnosperm species. ERA5-Land facilitated broader spatial analysis and incorporated additional factors like evaporation, snow cover, and soil moisture. Monthly assessments revealed the importance of parameters for each species. Our findings confirm that ERA5-Land is a reliable alternative for modeling tree growth, offering new insights into climate-vegetation interactions. The ready availability of underutilized parameters, such as air humidity, soil moisture and temperature, and runoff, enables their inclusion in future growth models. Using ERA5-Land can therefore deepen our understanding of forest responses to diverse environmental drivers on a global scale.
The Augmented Kalman Filter (AKF) has been applied previously for input-state estimation of offshore wind turbines (OWT). However, the accuracy of the estimated results depend on the chosen model, for which various complexities exist, making this a challenging task. Two of which are the lack of information required to model the Rotor-Nacelle Assembly (RNA), and the high uncertainty associated with the soil-structure-interaction (SSI). Therefore, the primary focus of this work is to avoid these limitations by considering a suitable substructure which eliminates the need to model the RNA and the SSI, thus significantly reducing uncertainties. The substructure is obtained by 'cutting' the OWT at the top of the tower and at the ground level. To define the model, the resulting substructure then only requires geometries and material properties for the monopile and tower; information which is often known with greater certainty. A numerical case study is presented to investigate the accuracy of the proposed approach for input-state estimation of a 15 MW OWT. A series of commonly used setups involving accelerometers and inclinometers are used and the effects on the predicted fatigue life of the structure are discussed. Additionally, a simple approximation of the wave loading is considered to estimate and account for its contribution to the dynamics of the substructure. The proposed approach is shown to be an effective solution for input-state estimation of OWTs when the RNA or SSI are unknown or associated with significant uncertainty.
Soil-plant-atmosphere interaction (SPAI) plays a significant role on the safety and serviceably of geotechnical infrastructure. The mechanical and hydraulic soil behaviour varies with the soil water content and pore water pressures (PWP), which are in turn affected by vegetation and weather conditions. Focusing on the hydraulic reinforcement that extraction of water through the plant roots offers, this study couples advances in ecohydrological modelling with advances in geotechnical modelling, overcoming previous crude assumptions around the application of climatic effects on the geotechnical analysis. A methodology for incorporating realistic ecohydrological effects in the geotechnical analysis is developed and validated, and applied in the case study of a cut slope in Newbury, UK, for which field monitoring data is available, to demonstrate its successful applicability in boundary value problems. The results demonstrate the positive effect of vegetation on the infrastructure by increasing the Factor of Safety. Finally, the effect of climate change and changes in slope vegetation cover are investigated. The analysis results demonstrate that slope behaviour depends on complex interactions between the climate and the soil hydraulic properties and cannot be solely anticipated based on climate data, but suctions and changes in suction need necessarily to be considered.
In recent years, there has been an increased focus on the research of earthen construction, driven by the rising demand for low-cost and sustainable building materials. Numerous studies have investigated the properties of compressed earth blocks (CEBs), however, very few have examined the properties of earth-based mortar. Mortar is an essential component and further investigation is required to enhance the mechanical performance of CEB structures. The study focuses on raw earth mortar (REM), which is a rudimentary mix of water with natural earth consisting of sand, silt and clay. Through experimental investigation, the fresh and hardened properties of three REM mixes were examined to determine the influence of cement stabilisation and jute fibre reinforcement. Shear triplet CEB assemblages were manufactured and tested to determine the initial shear strength of each mortar mix. The addition of 20 mm jute fibre at 0.25 % by weight increased the compressive and flexural strength of cement-stabilised raw earth mortar by 12 % and 20 % respectively. The addition of jute fibre also enhanced the initial shear strength, angle of internal friction and coefficient of friction during shear triplet testing. Finite element analysis (FEA) was undertaken to model the failure mechanism of the CEB assemblages, employing the use of cohesive zone modelling. The results of the FEA provided a satisfactory correspondence to the behaviour observed during experimental analysis and were within +/- 5.0 % of the expected values. The outcome of this investigation demonstrates the potential of REM and contributes to the development of low-cost and sustainable earth construction.
Transversely isotropic rocks (TIRs) are widespread in geological formations, and understanding their mechanical behavior is crucial for geotechnical and geoengineering applications. This study presents the development of a novel analog material that reproduces the directional mechanical properties of TIRs. The material is composed of quartz sand, mica flakes, and gelatin in adjustable proportions, allowing control over strength and stiffness anisotropy. Uniaxial compressive strength (UCS) and direct shear tests were conducted to evaluate mechanical responses across different anisotropy angles. Results show that the analog material replicates key features of natural TIRs, including directional variations in strength and fracture modes. In UCS tests, the anisotropy angle (beta) governs the transition between tensile and shear failure. In direct shear tests, the orientation angle (alpha) significantly affects shear strength. Higher gelatin concentrations increase cohesion and Young's modulus without changing the internal friction angle, while mica content reduces overall strength and stiffness. Comparisons with published data on sedimentary and metamorphic rocks confirm the mechanical representativeness of the material. Its simplicity, tunability, and reproducibility make it a useful tool for scaled physical modeling of anisotropic rock behavior in the laboratory. This approach supports the experimental investigation of deformation and failure mechanisms in layered rock masses under controlled conditions.
This article presents the findings of a comprehensive assessment of the predictive capabilities and limitations of advanced geotechnical numerical tools utilizing two sophisticated constitutive models for sands: the hardening soil model with small strains and hypoplasticity with intergranular strain. The evaluation is based on simulations of laboratory and centrifuge tests under monotonic and cyclic loading conditions. Initially, these models were calibrated and assessed using an experimental database on Fontainebleau sand. This database encompasses a range of laboratory results, including isotropic compression, drained monotonic triaxial, and undrained cyclic triaxial tests with varying initial conditions. The models, in general, provided good representation for monotonic experiments while some discrepancies were observed in undrained cyclic experiments. Subsequently, the calibrated models were employed to replicate a series of centrifuge tests involving a pile embedded in the same sand. The pile was subjected to various episodes of monotonic and cyclic lateral loading. In general, the models accurately replicated the experimental observations from tests conducted under monotonic loading conditions. Some small discrepancies were found in pile tests subjected to cyclic loading, these were however minor when compared to issues in predicting cyclic element tests at undrained conditions.
The dynamic response of piles is a fundamental issue that significantly affects the performance of pile foundations under vertical cyclic loading, yet it has been insufficiently explored due to the limitations of experimental methods. To address this gap, a hydraulic loading device was developed for centrifuge tests, capable of applying loads up to 2.5 kN and 360 Hz. This device could simulate the primary loading conditions encountered in engineering applications, such as those in transportation and power machinery, even after the amplification of the dynamic frequency for centrifuge tests. Furthermore, a design approach for model piles that considers stress wave propagation in pile body and pile-soil dynamic interaction was proposed. Based on the device and approach, centrifuge comparison tests were conducted at 20 g and 30 g, which correspond to the same prototype. The preliminary results confirmed static similarity with only a 1.25% deviation in ultimate bearing capacities at the prototype scale. Cyclic loading tests, conducted under various loading conditions that were identical at the prototype scale, indicated that dynamic displacement, cumulative settlement, and axial forces at different burial depths adhered the dynamic similarity of centrifuge tests. These visible phenomena effectively indicate the rationality of centrifuge tests in studying pile-soil interaction and provide a benchmark for using centrifuge tests to investigate soil-structure dynamic interactions.
Floods and erosion are natural hazards that present a substantial risks to both human and ecological systems, particularly in coastal regions. Flooding occurs when water inundates typically dry areas, causing widespread damage, while erosion gradually depletes soil and rock through processes driven by water and wind. This study proposes an innovative approach that integrates Deep Neural Decision Forest (DeepNDF), Feedforward Neural Network (FNN), autoencoders, and Bidirectional Recurrent Neural Networks (Bi-RNN) models for flood prediction, enhanced through transfer learning for erosion mapping in coastal environments. Utilizing multi-source datasets from the United States Geological Survey (USGS), Climate Hazards Group InfraRed Precipitation with Station (CHIRPS), the National Algerian Institute of Cartography, and Sentinel-2 imagery, the key conditioning factors using Geographic Information System (GIS) were generated. The conditioning factors included elevation, slope, flow direction, curvature, distance from rivers, distance from roads, hillshade, topographic wetness index (TWI), stream power index (SPI), geology, and land use/land cover (LULC), as well as rainfall. To ensure the modeling reliability, the performance was rigorously evaluated using multiple statistical metrics, including the Area Under the Curve-Receiver Operating Characteristic (AUC-ROC), Precision, Recall, and F1 Score. The DeepNDF model achieved the highest performance for flood prediction with an AUC-ROC of 0.97, Precision of 0.93, Recall of 0.92, and an F1 Score of 0.925, while the transfer learning approach significantly improved erosion prediction, reaching an AUC-ROC of 0.92, Precision of 0.90, Recall of 0.92, and an F1 Score of 0.91. The analysis indicated that flood risks predominantly affected rangeland (18.68%) and bare ground (20.48%), while cropland was found to face the highest erosion risk, affecting approximately 3,471 km2. This research advances predictive modelling in hydrology and environmental science, providing valuable insights for disaster mitigation and resilience planning strategies in coastal areas.
Precast driven piles are extensively used for infrastructure on soft soils, but the buildup of excess pore water pressure associated with pile driving is a challenging issue. The process of soil consolidation could take several months. Measures are sought to shorten the drainage path in the ground, and permeable pipe pile is a concept that involves drainage channels at the peak pore pressure locations around the pile circumference. Centrifuge tests were conducted to understand the responses of permeable pipe pile treated ground, experiencing the whole pile driving, soil consolidating, and axially loading process. Results show that the dissipation rate of pore pressures can be improved, especially at a greater depth or at a shorter distance from the pile, since the local hydraulic gradient was higher. Less significant buildup of pore pressures can be anticipated with the use of permeable pipe pile. For this, the bearing capacity of composite foundation with permeable pipe pile can be increased by over 36.9%, compared to the case with normal pipe pile at a specific time period. All these demonstrate the ability of permeable pipe pile in accelerating the consolidation process, mobilizing the bearing capacity of treated ground at an early stage, and minimizing the set-up effect. (c) 2025 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/ 4.0/).