Saturated Soil Research Articles

Stability analysis of unsaturated–saturated soil slopes under rainfall infiltration using the rigorous limit equilibrium method

Stability analysis of unsaturated–saturated soil slopes under rainfall infiltration using the rigorous limit equilibrium method

Stresses in Saturated and Unsaturated Subgrade Layer Induced by Railway Track Vibration

The theoretical and practical studies of the cyclic loads resulting from the movement and passage of trains on the unsaturated subgrade to determine the effect of the degree of saturation and moisture content on the foundations and infrastructure of the railway lines, especially the settlement in the railway lines as a result of the development of the train loads. Thirty-six laboratory experiments were carried out using models that simulate a railway with nearly half the scale of the real one, using an iron box of (1.5 × 1.0 × 1.0) meters and a layer of clay soil with a thickness of 0.5 m representing the base layer, were constructed inside it. Above it, there is a layer of crushed stone representing a 0.2 m thick ballast, topped by a rail line of 0.8 m long installed on three sleeper beams with dimensions of 0.9 m (0.1 × 0.1 m). The subgrade layer has been constructed at different saturation degrees as follows: 100, 80, 70, and 60%. The tests were carried out using different load amplitudes and frequencies. These experiments investigated the effect of the subgrade degree of saturation on the value of the stresses generated on the surface and the middle (vertical and lateral stresses) and the settlement of the subgrade. In the case of unsaturated subgrade soil, an increase in load frequency has a clear effect on increasing the generated stresses in the subgrade layer, especially with lower saturation levels. However, the results and measurements of these experiments found that the load frequency almost had no effect on the values of the stresses generated on the surface and inside the subgrade layer with a 100% degree of saturation. The results of the investigation demonstrated that, while load frequency had a minimal effect on track-panel settlement, it increased with the load amplitude and subgrade soil saturation degree. The change of settlement of the track panel with the number of cycles has a high rate at the beginning; after a while from that, it decreases gradually until, after some value of the number of cycles, the settlement changes at a very low rate and gradually.

Fractional derivative modelling for consolidation of multilayered saturated soils with interfacial thermal contact resistance subjected to time-dependent heating and loading

In this paper, the one-dimensional rheological consolidation characteristics of multilayered saturated soil foundations under time-dependent loading and heating are investigated by considering the semi-permeability and the interface thermal resistance. By introducing the fractional derivative model and the thermos-elastic theory, a thermo-mechanical coupling model is established to describe the rheological properties of saturated soils. Semi-analytical solutions for strain, temperature increment, pore water pressure and settlement were derived through the Laplace transform and its inverse. The accuracy of the solutions proposed in this paper has been verified by comparing with existing solutions. The effects of different thermal contact models of the interface on the rheological properties of saturated soils under semi-permeable boundary are discussed, and the effects of fractional derivative order, constitutive material parameters, and thermal conductivity of soil on the thermal consolidation process are investigated. The results show that: neglecting the thermal resistance effect can result in an overestimates of the impact of rheological properties on the thermal consolidation process of saturated soils under semi-permeable boundaries; As the thermal resistance coefficient increases, the influence of soil thermal conductivity on settlement decreases.

Influence of stress history on thermal conductivity of saturated fine-grained soils

This research investigated variations in thermal conductivity <i>k</i> for normally consolidated (NC) and overconsolidated (OC) saturated fine-grained soils at different levels of vertical effective stress. A series of undrained heating tests were performed using a specially designed consolidometer with central radial heating arrangement and temperature measurements within a soil specimen. For different soils investigated in this research, <i>k</i> correlated well with soil consolidation characteristics (compression index <i>λ</i> and swelling index <i>κ</i>) and vertical effective stress <i>σ</i><sub>v</sub>ʹ at both NC and OC states. However, the rates of increment of steady- and transient-state values of <i>k</i> (<i>k</i><sub>st</sub> and <i>k</i><sub>tr</sub>, respectively) with <i>σ</i><sub>v</sub>ʹ differed from one soil to another. For OC clays, both <i>k</i><sub>tr</sub> and <i>k</i><sub>st</sub> increased with preconsolidation stress <i>σ</i><sub>c</sub>ʹ. A set of equations were proposed to estimate both <i>k</i><sub>st</sub> and <i>k</i><sub>tr</sub> for saturated fine-grained soils as functions of <i>σ</i><sub>v</sub>ʹ, <i>λ</i>, <i>κ</i>, and stress history. At a particular value of <i>σ</i><sub>v</sub>ʹ, the dependence of <i>k</i> on overconsolidation ratio (OCR) and <i>σ</i><sub>c</sub>ʹ marked the importance of considering stress history in the determination of <i>k</i>. The influence of soil mineral composition on <i>k</i> was also explored. Quantification of soil mineralogical composition and available data on mineral thermal conductivity enabled prediction of <i>k</i><sub>tr</sub> with reasonable accuracy.

Investigation of Unsaturated Soil Hydraulic Properties for Subgrade Improvement using Marble Dust Waste

Introduction The distribution of suction, which has implications for seepage and shear strength, plays a crucial role in determining the stability of unsaturated soil. The Air Entry Value (AEV) and Residual Water Contents (RWC) change over time to create the Soil-Water Characteristic Curve (SWCC), which is very important for figuring out how the suction is distributed. During a flood occurrence, the subgrade becomes inundated with water, leading to adverse effects on the AEV and RWC of the subgrade. Consequently, the performance of the subgrade is diminished. This study focuses on the use of Marble Dust Waste (MDW) as an addition to the subgrade to improve the strength of the subgrade. Aims This study aims to investigate the variations in air AEV in relation to the optimal MDW in unsaturated soil found in Malaysia. Methods The study uses control samples and soil that has been mixed with different amounts of MDW: 5%, 10%, 15%, 20%, and 25%. The SWCC is generated using the pressure plate extractor device. Results The results indicate a significant increase in the AEV for the mixed soil sample when compared to the control sample. While the soil-MDW mixture containing 5% of this material has an AEV value of 23 kPa, the control sample's value is 10 kPa. Conclusion The findings of the study suggest that the utilization of MDW yields a beneficial influence on the AEV, hence potentially improving the performance of the subgrade. The researchers aim to evaluate the potentially dangerous waste and convert it into a substance that is appropriate for engineering applications. This study provides empirical evidence that aligns with the objectives outlined in Chapter 8 of the 12th Malaysia Plan for the period 2021–2025. The topic under discussion pertains to environmental sustainability, specifically focusing on enhancing the ability to withstand the adverse effects of climate change and disasters, as well as the Green Technology Master Plan Malaysia 2017–2030, with a specific emphasis on Chapter 6, which addresses the issue of waste management.

Understanding front-rear track effect of seabed mining vehicle and traction performance optimization

The dual-tracked deep-sea mining vehicles used for sea trials generally cannot meet the demands of large-scale manganese nodules production due to their inadequate load bearing and traction performance. Various seabed mining organizations have gradually started four-tracked mining vehicles as seabed traveling ore collection machines to meet the demand for enhanced tractive performance. A notable challenge encountered is the significant front-rear track effect observed when these vehicles navigate soft-cohesive sediments. Addressing this, our study introduces a novel design concept that involves setting the grouser heights with a deviation between the front and rear tracks, coupled with the development of a traction force-slip rate model inspired by this innovative approach. This model facilitates an in-depth analysis of the front-rear track effect, including phenomena such as deep sinkage and an increase in pitch angle experienced by vehicles on soft-cohesive terrains. It is calculated that the front and rear grouser deviation height of only 2 cm can improve the traction force by 21%. Utilizing the multi-body dynamics (MBD) method, we validated the effectiveness of this grouser height adjustment in mitigating front-rear track effects, demonstrating its potential to reduce sinkage by at least 30 mm and pitch angle by at least 0.3 degrees, thereby guiding the optimization strategy. Finally, through optimization simulation, we present optimized track structural parameter sets suitable for three types of seabed pavement, concluding that for soft silty soil, saturated high cohesive soil, and saturated soft sandy soil, the grouser deviation heights should be approximately 5.3, 4.1, and 2.0 cm, respectively. After applying the optimized track structural parameter sets, traction performance evaluation indexes, such as traction force and the traction force-disturbing area ratio, improved by at least 23.4% and 3.3%, respectively. Meanwhile, static sinkage was reduced by at least 21.4% across the three types of pavements.

Effect of mixed plant roots on saturated hydraulic conductivity and saturated water content of soil in the loess region

Soil hydraulic properties are essential for understanding soil hydrological and erosion processes. The importance of roots on soil hydraulic parameters has been widely recognized, but current studies have focused mainly on the root effect of a single plant species. However, few studies have been carried out to investigate the effect of mixed plant roots on soil hydraulic parameters. Undisturbed soil samples were collected from three natural sampling sites with single plant types and four sites with mixed plant types. Both soil hydraulic parameters were measured: soil saturated hydraulic conductivity (Ks) and soil saturated water content (SW). Then the root effects on Ks and SW were subsequently evaluated. The results showed that the Ks and SW at the sites with mixed plants were higher than those at the sites with a single plant species. At all the sites, Ks and SW both exhibited a decreasing-increasing-decreasing trend with increasing root density. The critical root density for the above change was quantified. When fibrous roots were mixed with tap roots, Ks was mainly affected by tap roots, while SW was mainly affected by fibrous roots. The influence of roots on Ks and SW was mainly achieved by affecting soil organic matter, not by directly affecting Ks and SW. Based on the root density, the herbaceous coverage with optimal saturated hydraulic conductivity and water content was estimated to be 66.71%.

Application of cohesive soil flow limit and slope critical flow angle

To investigate the relationship between moisture content in cohesive soils during spontaneous liquefaction and their corresponding critical slope failure angles. This study modified the liquid limit test apparatus originally developed by A. Atterberg in 1911, adapting it into a liquid-flow limit test apparatus. On-site soils from three actual cases of slope failures in Xiaolin Village, Jiasian District, Kaohsiung City, as well as soils from slope failures along the banks of Meilong River and Zengwun River were used for experiments involving different soil moisture content and slope failure angles. Based on the experimental findings, the moisture content which cohesive soils undergo spontaneous liquefaction was designated as the Flow Limit (FL), corresponding to the downslope angle at which circular failure occurs. This value represents the critical sliding angle at which spontaneous liquefaction occurs as a results of soil saturation. It also represents the maximum slope angle for exposed mudrock or clay slopes, and establishes the critical slope angle for vegetated slopes. Beyond this critical FL angle, all vegetation is susceptible to loss due to soil liquefaction. Furthermore, this study conducted FL tests on soils from thirteen tree holes in Kaohsiung City, two mountain slopes in Fengshan District, and the silty clay responsible for property damage and injuries during a landslide in Yanchao District on September 29, 2016, as a means of validation. The consistent test results observed reaffirm that different soils exhibit similar spontaneous liquefaction angles and flow limit behavior. These FL test results demonstrate a consistent pattern, reinforcing the notion of distinct curve characteristics that can be replicated across diverse soil compositions.

Interactive effects of environmental factors and fertilization practices on soil nitrate leaching and tea productivity in Tianmu Lake Basin, China

Although the effects of fertilization practices and environmental factors on tea yield and NO3−–N leaching have been acknowledged, the interactive effects of these influencing factors remain unknown. These effects were investigated in this study using the denitrification–decomposition (DNDC) model, which was validated using field data collected from a typical tea garden hillslope in the Tianmu Lake Basin, China. Environmental factors such as temperature, precipitation intensity, slope, saturated hydraulic conductivity (Ksat), and fertilization practices (fertilizer amount and type) were combined to construct 1080 scenarios. The results revealed that DNDC achieved acceptable performance in simulating NO3−–N leaching under the application of a compound fertilizer (CF) and a slow-release fertilizer (SF). During the calibration period, the Nash–Sutcliffe efficiency (NSE) values were 0.48 and 0.24. During the validation period, the NSE values were 0.71 and 0.67. Scenario analysis indicated that precipitation intensity (p < 0.001), saturated soil hydraulic conductivity (Ksat) (p < 0.001), fertilizer amount (p < 0.001), and fertilizer type (p < 0.001) significantly influenced the leaching flux of NO3−–N and tea yield. The interactive effects of different factors also varied across the different types of fertilizers. The amount of fertilizer had the most significant impact on NO3−–N leaching, with relative contribution rates of 70% and 53% for compound and SFs, respectively. As CF application increased, there was a significant increase (93%) in the average flux, whereas SF application resulted in an increase of only 76%. The highest contribution rate in terms of tea yield was observed for the amount of fertilizer under CF application at 44%. However, the highest contribution rate under SF application was attributed to Ksat at 51%. The application of SFs resulted in a higher yield improvement rate than that of CFs as the fertilizer amount increased, with respective rates of 15% and 8%. Additionally, environmental factors, excluding temperature, exerted opposite effects on tea production and NO3−–N leaching flux. These findings contribute to optimizing fertilization management in tea plantations by integrating multiple environmental factors to control nonpoint nitrogen loss. Future research should conduct long-term monitoring of tea garden yield and nitrogen loss to accurately assess the impact of SF application on the ecological and economic benefits of tea gardens.

Advancing landslide early warning systems through saturation monitoring and prediction

Landslides most commonly occur in the rainy season, resulting in damage to infrastructure and human lives. An early prediction framework for landslides would clearly help to mitigate damage. In this work, a prediction framework for shallow landslide initiation was developed and validated with a real case study. To assess the reliability of the prediction framework, back-analysis of a landslide that occurred in Malin village, Maharashtra, India on July 2014 was performed. Relations of landslide stability with soil saturation were established through a physically based approach using GeoStudio software. A leaky barrel algorithm was developed for the study location to monitor the effect of rainfall' on soil saturation. Simulation results of landslide stability were compared with the rainfall–soil saturation algorithm based on the leaky barrel. The presented framework was found to have good predictability of shallow landslide occurrence and is therefore recommended for real-time monitoring of landslide-prone locations.

Analytical solution for the seismic response of a nearly saturated sloping seabed: Weak interlayer

Sloping seabeds often exist in offshore areas with complex structures. It is difficult to accurately analyze the seismic response characteristics of sloping seabeds based on the assumptions used for horizontal seabeds. The degree of saturation in nearly saturated soil notably affects the seismic response of seabeds. Therefore, we developed an analytical solution for the seismic response of a sloping, nearly saturated multilayer seabed. Using this solution, we analyzed the effects of the slope angle and soil saturation degree on the seismic response of the seabed. The results show that the seafloor inclination may has a minor impact on the seismic motion at a specific point, but it has a very significant effect on the overall site. A weak interlayer refers to a layer of material that has lower strength and/or permeability compared to the surrounding soil or rock. This layer can reduce the natural frequency of the seabed and increase the amplitude of long-period seismic components. In addition, the presence of a weak interlayer can lead to increased pore water pressure, decreased effective stress, and increased susceptibility to shear failure. These factors combine to reduce the stability of submarine slopes, highlighting the importance of understanding and managing the effects of weak interlayers in geotechnical engineering and coastal defense projects.

Virus decay and community composition in virus-amended sterile soil under slurry and unsaturated conditions

Soil viruses are abundant and diverse. The available research suggests viruses play a significant role in shaping the structure and function of soil microbial communities. Their effects are modulated by various environmental factors, including soil temperature, moisture, and geochemical conditions. This study investigated the persistence/inactivation of naturally occurring soil viruses added to sterilized soil, providing insights into virus decay under abiotic conditions. Soil microcosm experiments under saturated (slurry) conditions (5 g:12 mL) and unsaturated conditions (60% of field capacity) revealed a consistent decline in viral abundance over time. Under saturated conditions, there was a reduction of over 90% in viral abundance after 10 d, a steeper decline than the 55% reduction observed under unsaturated conditions during the same length of incubation. Notably, the composition of viruses also changed over time, and the remaining viruses demonstrated infectious capabilities for up to 13 d in saturated and 16 d in unsaturated soil, evidenced by changes in viral abundance upon the addition of live bacteria. Introducing live bacteria reduced the net viral dissipation in saturated soil but resulted in a net increase in viral abundance in unsaturated soil from 4.49 × 108 to 6.76 × 109 within 3 days. The increase in viral abundance in the unsaturated soil was partly due to the emergence of new viruses from prophage induction. This research presents a preliminary exploration into extracellular persistence of soil viruses under varying moisture conditions.

An effective medium theory-based unified model for estimating thermal conductivity of unfrozen and frozen soils

Soil thermal conductivity (STC) is a crucial parameter in modeling land surface processes. However, the current STC models are developed separately for unfrozen and frozen soils, leading to inconsistent understanding. In this study, we propose a unified model based on the work of Ghanbarian and Daigle (2016) originally developed for unfrozen soils. The unified model comprises three parameters: critical volume fraction (ϕc), scaling exponent (t), and a compensating factor (α), and considers dry soil as the low-conductivity component (weighted by air volume fraction) and saturated soil as the high-conductivity component (weighted by volumetric liquid content for unfrozen state and total water content for frozen state). Specifically, ϕc represents a critical point where high-conductivity component begins to govern the behavior of effective STC, characterized by t. α allows for accurate calibration of saturated STC. Using a dataset of 90 unfrozen samples (693 measurements) and 74 frozen samples (255 measurements), pedotransfer functions (PTFs) for the three parameters were trained. The unified model successfully reproduces the sharp rise in STC at low moisture conditions during wetting and the increase during freezing. Compared to an empirical model (Côté and Konrad, 2005a) and a theoretical model (Tian et al., 2016), the unified model demonstrates higher predictive skill for unfrozen and frozen soils, achieving Nash-Sutcliffe efficiency coefficients of 0.96 and 0.90, respectively. This work contributes to a more consistent and comprehensive understanding of STC in cold environments and has the potential to be integrated into land surface models.

Heat and mass transfer based on the low-temperature thermal treatment of hydrocarbons-impacted soil: A numerical simulation and sandbox validation

Thermal treatment can be an effective method for soil remediation, and numerical models play a crucial role in elucidating the underlying processes that affect efficacy. In this study, experiments were conducted to examine the low-temperature thermal treatment for removing n-hexane and n-octane from soil. The results showed that the removal of two alkanes followed the pseudo-first-order kinetics. Additionally, a quantitative relationship between kinetics constant and temperature was established. Based on experimental results, a simple mathematical model was presented via COMSOL Multiphysics 6.0. The processes considered in the model incorporated conductive and convective heat transfer, the vaporization latent heat, and the removal of organic contaminants which was quantified using an advection-dispersion equation combined with a pseudo-first-order kinetic. The developed model was first validated by a thermal treatment in a soil column, demonstrating conformity with the measured temperature and concentration values. Subsequently, the temporal and spatial changes in soil temperature and contaminant levels were evaluated for different heating temperatures. It was found that thermal conduction dominated heat transfer, whereas thermal convection caused by the migration of liquid water intensified when the temperature was higher than the boiling point. The completion time exhibited a correlation with the heating temperature. It was predicted that the time required to achieve a 90% removal efficiency could be shortened from 14 h to 9.5 h by elevating the heating temperature from 80 ℃ to 120 ℃. The study also investigated the impact of the initial water content on heat transfer. It was observed that the saturated soil showed the slowest heating rate and the longest boiling stage.

Novel approach to the derivation of dam breach parameters in 2D hydrodynamic modeling of earthquake induced dam failures

Current methods of dam breach analyses adopt a deterministic approach. Applying these methods to Concrete Faced Rockfill Dams (CFRD) is fraught with huge levels of uncertainty, especially in the context of natural hazards. The frequency and magnitude of rainfall and earthquakes are higher in today's world. In the literature, the complete collapse of dams is modelled on dam breach parameters that define the dam break outflow but are not related to the return periods of natural hazards. As more new dams are constructed to control the floods in intra-plate seismic regions, this study presents a novel approach to the derivation of generalized dam break parameters for CFRD based on the structural analysis of Finite Element Model (FEM) simulations for peak ground accelerations corresponding to 475 and 2475 year return periods. Furthermore, the occurrence of rainfall and earthquake for different return periods are modelled using 2D hydrodynamic simulations. Results show the significance of generalized dam breach parameters for planning and managing CFRDs during earthquakes. The study emphasizes the utilization of structural analysis outputs for the hydraulic modeling of dam breaks, which will result in more specific and accurate dam break parameters. Additionally, the study has shown that the flood risk and the severity will increase with the intensity of earthquake and rainfall magnitudes. Disaster mitigation strategies can be optimized by considering the integrated occurrence of rainfall and earthquakes based on the probability of occurrence, demonstrated using a case-study dam. Another significant outcome of the study is the effect of soil saturation condition during a dam break, which reveals that areas within 40 km of the dam breach location might be worst affected.

Numerical Analysis of Bridge Foundation in Dry and Saturated Soils with Effect of Halabjah Earthquake (Case Study)

The importance of this study comes from the expected risks as the bridge foundations is exposed and their effects on the lives of users. So, the aim of this study is to investigate the influence of earthquakes loading on the bridge foundation subjected to combined loading as a case study for Al-Shareef Bridge/ Diyala province in Iraq. The numerical analysis highlights the foundation settlement firstly, in flat ground and secondly, in slope ground with applied different value of axial loads starts from the zero-working load (no loading) to maximum working load. All cases were investigated in dry and saturated soil under effect of Halabjah earthquake. Plaxis 3D is one of the finite element programs that had been used to simulate the soil foundation interaction by Mohr-Coulomb failure criteria for the soil model and linear elastic for concrete materials. The conclusions of this study showed that the settlement of pile group is increased in saturated soil about 5% more than the dry soil under the effect of static loads for both groups, but, the settlement in group (2) is increased about 10% more than the group (1) in dry and saturated condition. The settlement in saturated soil is increased to 12% more than the dry soil when Halabjah earthquake loads is applied.

Elastoplastic constitutive model of gravelly soil and its validation through numerical analysis of the Kobe Port Island liquefaction

The liquefaction of gravelly soil has been demonstrated in many earthquakes, but the constitutive model to predict its liquefaction behavior is limited. The dilatancy equation plays an important role in establishing elastoplastic models of geotechnical materials. Recognizing the unique dilatancy characteristics of gravelly soil, this study introduces an improved nonlinear dilatancy equation into the generalized plasticity model. Consequently, a unified elastoplastic constitutive model is proposed, aimed at accurately predicting both the monotonic and cyclic behaviors of saturated gravelly soil under diverse drainage conditions. A series of drained and undrained triaxial tests of gravelly soil under monotonic and cyclic loadings are carried out to validate the model performance. In addition, the model performance is also examined through monotonic and liquefaction tests of gravelly soil obtained from prior publications. Furthermore, the proposed model is implemented into the nonlinear finite element program GEODYNA and applied to the numerical simulation of the Kobe Port Island liquefaction to better validate the capabilities of the proposed model. From the comprehensive analysis of triaxial tests and numerical simulations, the proposed model performs well in predicting mechanical behavior of gravelly soil and can provide a powerful tool for seismic liquefaction analysis of gravelly soil sites.

Study on the gas phase migration and distribution characteristics in horizontal well air sparging remediation

Horizontal well air sparging (AS) technology has been proven to be efficient in remediating saturated soils and groundwater contaminated with volatile organic compounds (VOCs). Nevertheless, the airflow patterns and the mechanisms governing uniformity in the horizontal well AS process remain elusive, and a quantitative characterization of the zone of influence (ZOI) has yet to be determined. In this study, we employed both model experiments and numerical simulations to investigate the distribution patterns of lateral airflow in horizontal air sparging tubes within a porous medium. The influence of parameters such as air sparging pressure, groundwater flow, the inclination angle of the air sparging tubes, and the diameter of the medium particles on the distribution patterns of gas-phase transport in horizontal well AS was analyzed. The results show that both groundwater flow and the inclination of air sparging tubes disrupt the uniformity of gas distribution. The ZOI area of AS is observed as an oblong shape in the horizontal plane and a parabolic contour along the boundaries. Additionally, a mutual influence is identified between groundwater flow and AS airflow. Furthermore, the inclination of air sparging tubes results in the formation of preferential flow near the air source end. The ZOI of horizontal AS demonstrates a positive correlation with air sparging pressure and a negative correlation with medium particle diameter. All of the results elucidated above provide valuable information for the design and theoretical modelling of AS within horizontal wells for groundwater remediation.

A Unified Phenomenological Model Captures Water Equilibrium and Kinetic Processes in Soil

AbstractSoil water sustains life on Earth, and how to quantify water equilibrium and kinetics in soil remains a challenge for over a century despite significant efforts. For example, various models were proposed to interpret non‐Darcian flow in saturated soils, but none of them can capture the full range of non‐Darcian flow. To unify the different models into one overall framework and improve them if needed, this technical note proposes a theory based on the tempered stable density (TSD) assumption for the soil‐hydraulic property distribution, recognizing that the underlying hydrologic processes all occur in the same, albeit very complex and not measurable at all the relevant scales, soil‐water system. The TSD assumption forms a unified fractional‐derivative equation (FDE) using subordination. Preliminary applications show that simplified FDEs, with proposed hydrological interpretations and TSD distributed properties, effectively capture core equilibrium and kinetic water processes, spanning non‐Darcian flow, water retention, moisture movement, infiltration, and wetting/drying, in the soil‐water system with various degrees and scales of system heterogeneity. Model comparisons and evaluations suggest that the TSD may serve as a unified density for the properties of a broad range of soil‐water systems, driving multi‐rate mass, momentum, and energy equilibrium/kinetic processes often oversimplified by classical models as single‐rate processes.

Prediction of Damping Ratio and Shear Modulus of Saturated Clay Soil under Rotating Machine

Developing countries' industrial growth necessitates innovative machine foundation design and resilient infrastructure. Meanwhile, soil properties play a significant role in the satisfactory design of machine foundations. The paper presents an experimental work to determine accurately the damping ratio and shear modulus by equations. The paper studies the effect of different parameters (embedded depth of foundation, shape of footing, and changing operating frequency of machine) on the damping ratio and shear modulus of saturated clay soil. Moreover, mathematical expressions are derived from statistical analysis to predict the damping ratio for rectangular and circular footing on saturated clay. The physical model results reveal that the damping ratio inside the soil will be increased with an increase in the depth of the point inside the soil for all cases. The damping ratio tends to decrease with an increase in operating frequency. The maximum damping ratio has occurred below a rectangular foundation with a 16.6 Hz operating frequency in saturated clay. The damping ratio is a function of many factors, such as embedment depth, degree of saturation, shape of foundation, and operation frequency of the machine.