Increase In Suction Research Articles

Characterization of pore water distribution in unsaturated soils during drying process with NMR and soil-water characteristic curves

The soil–water characteristic curve, which illustrates the relationship between water content and matric suction, is crucial for both unsaturated soil theory and engineering applications. Since water content significantly affects unsaturated soil strength, experimentally examine the distribution of water within the soil matrix. First, three types of soil are prepared for nuclear magnetic resonance and pressure plate tests, conducted over a range of matric suctions from 0 to 1400 kPa. Then, the pressure plate testreveals that matric suction expels free water first, leaving bound water, which remains until reaching critical suction point. NMR test is also performed to analyze the dynamics of pore water distribution during drying process. As matric suction increases, the peak of signal amplitude decreases, shifting leftward, reflecting water drainage from larger to smaller pores. In addition, two drainage stages are identified, considering distinct ranges of matric suction. Large pores drain more quickly, while smaller pores retain water for a longer period, challenging simpler models of pore drainage. The dynamic distribution of pore water reveals the evolution of water expulsion from the soil over time. This sheds light on water distribution and drainage behavior, emphasizing the need for advanced models that account for pore connectivity and water retention mechanisms.

Understanding and mitigating settlement in gypseous soils: A comprehensive study on the role of saturation and soil stabilization techniques

This study examines the influence of saturation levels and soil additives on the load-settlement properties of gypseous soils, a significant geotechnical concern in regions like Iraq. The study analyzes the deficiencies of conventional oedometer testing, which often fail to adequately represent the true unsaturated conditions prevalent in these soils. The research investigates the impact of varying matric suction (Ψ) values on the compressibility of untreated, cement-treated, and CKD-treated gypseous soils. A modified oedometer apparatus, engineered to control and quantify matric suction, was used to replicate diverse moisture conditions. The experimental program investigated soils with varying gypsum contents (8.8%, 12.66%, and 30%), reflecting the diversity of gypseous soils seen in the field. The findings demonstrate that increased saturation levels significantly enhance settling in gypseous soils. As matric suction increases, settlement is markedly reduced due to elevated soil suction pressure and enhanced effective stress. The findings underscore the importance of unsaturated conditions in improving the load-bearing capacity of these soils. The study illustrates the advantageous impacts of cement and CKD treatments in reducing settling. The effectiveness of these methods is particularly apparent in partially saturated environments, emphasizing the need of including matric suction into design considerations. This research improves understanding of the complex behavior of unsaturated gypseous soils. The findings have practical importance for geotechnical engineering, including foundation design, ground improvement methods, and the development of effective solutions for settlement issues in areas with high gypsum concentrations.

Exploring Soil–Water Characteristic Curves in Transitional Oil Sands Tailings

Soil–water characteristics curves (SWCC) have proved useful in estimating parameters used in modeling unsaturated geotechnical properties of soils including permeability and strength. Either saturation, gravimetric, and instantaneous and initial volumetric water content designation can be used to develop SWCCs. Studies have shown that any of the designations will give good estimates for soils that do not undergo volume change with suction change whereas, for soils that undergo substantial volume change, only saturation and instantaneous volumetric water content designation obtained by incorporating shrinkage curves can give correct estimates. Transition oil sands tailings have fines content that cannot be categorized as sandy or fine materials, and research on volume change with suction change in these materials is limited. In this study, HyProps, Tempe cells, and a chilled-mirror water potential meter were used to measure suction and corresponding water contents for samples that were prepared by mixing coarse sand and Fluid Tailing by ratios that mimic transition zone tailings. Shrinkage tests were also performed to observe the extent of volume change with suction increase. Air Entry Values (AEV) estimated from SWCCs based on gravimetric water content were found to be lower than those estimated from saturation-based SWCCs due to substantial volume changes in these materials with suction increase. The use of saturation water content designation is recommended in estimating AEV for transitional oil sands tailings. This is useful information in predicting the long term unsaturated geotechnical behavior of these materials for environmental management and safety purposes.

Three-dimensional numerical modeling of soil-roots system based on X-ray computed tomography: Hydraulic effects study

Vegetation roots enhance soil stability by influencing saturation and pore structure, playing a pivotal role in stabilizing slopes, reducing erosion, and enhancing soil structure. However, current research on the hydraulic effects of roots on soil remains relatively limited. The micro-mechanisms of vegetation's impact on soil and the macro-level connections are not yet fully understood, which poses a challenge to the modeling of root-soil system. This study develops a three-dimensional (3D) finite element model of root-soil composites based on root computed tomography (CT) images and experimental results. Four different groups are modeled, including the rootless group, and those with Festuca arundinacea (FA) roots at various growth stages. The simulation results show that the saturation in the shallow layers significantly decreases in root-soil composite groups, and the rhizosphere water content is lower than that away from the roots, resulting in a net water flux toward the roots. The influence range of roots on suction is gradually amplified with increasing root growth process and root water uptake time. Higher levels of root development result in a stronger overall water uptake effect, leading to a more pronounced decrease in saturation. Closer proximity to the surface roots results in a more rapid increase in soil suction. Compared with one-dimensional root water uptake models, this model considers the effects of spatial heterogeneity of root structures on soil, which provides a comprehensive modeling basis for studying the effect of root system on soil.

Root tensile strength and suction-characteristic as indicators for screening species for slope stabilization in extreme climates

Root water potentials, essential for understanding drought tolerance and transpiration, can also influence root tensile strength, which is valuable for selecting plants for slope stabilization and erosion control in extreme wet and dry climates. This study investigated the relationships between root suction, water content, diameter and tensile strength of Cnidoscolus aconitifolius and Bougainvillea glabra to explore their potential for slope stabilization. Both species showed an increase in root water content and a decrease in suction with larger root diameter, despite their inherent difference in the tensile strength and suction relationship. The tensile strength versus suction plots clearly showed that Bougainvillea glabra can sustain higher load as root suction increases and is likely to perform better in extremely dry condition than Cnidoscolus aconitifolius. Observation of field performance indicated that this is the case which warrants further study on root suction for selecting species in stabilization of slopes in extreme climates.

Mechanical properties and durability analysis of CS-CG stabilized soil: Towards sustainable subgrade soil enhancement

In this study, carbide slag (CS) and coal gangue (CG) powder were utilized to enhance the properties of the subgrade soil. CS-CG stabilized soil underwent lab experiments to assess its mechanical properties and durability. Tests included unconfined compressive strength (UCS), compressive resilient modulus (CRM), and California bearing ratio (CBR) at stabilizer dosages of 5 %, 10 %, and 15 %. Additional tests, such as dry-wet cycling, salt solution immersion, permeability, leaching, thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscope (SEM) and mercury intrusion porosimetry (MIP), were conducted specifically for the 10 % dosage. The mechanical properties and durability were comprehensively analyzed, with a microscopic investigation into pore size. Furthermore, the soil-water characteristic curve (SWCC) of CS-CG stabilized soil is derived through MIP, providing insights into its impact on the material's strength. Results showcased favorable bearing capacity and durability of CS-CG stabilized soil. The optimal mixing dosage is 10 %, with the best ratio being CS: CG= 70: 30. After 6 dry-wet cycles, UCS loss rate was 18.6 %, comparable to 4 % Portland cement (PC) stabilized soil. Dry-wet cycle characteristics surpassed PC and Lime stabilized soils. Immersion in a 5 % NaCl solution for 30 days yielded a UCS of 3.8 MPa at 28-day age, while exposure to 5 % Na2SO4 solution led to an 11.6 % strength decrease compared to NaCl. Permeability coefficient indicated low permeability akin to PC and Lime stabilized soils. Heavy metal content met standards, with minimal increase during cycles. Hydration products mainly comprised C-S-H gel, Ca(OH)2 crystals, and carbonate modification. Analysis suggested capillary and transition pores predominantly, with minimal macropores presence. Dry-wet cycles induced a marginal increase in pore size, with negligible overall impact. SWCC predicted water content (θs) ranged from 30 % to 32 %, with a slight increase in matrix suction during dry-wet cycles. CS-CG stabilized soil shows favorable mechanical properties, durability, and environmental sustainability, indicating its potential as a substitute for traditional cement and lime treatments in subgrade soil reinforcement.

Thermal effects on the strain rate-dependent behavior of highly compacted GMZ01 bentonite

Investigation of thermal effects on the strain rate-dependent properties of compacted bentonite is crucial for the long-term safety assessment of deep geological repository for disposal of high-level radioactive waste. In the present work, cylindrical GMZ01 bentonite specimens were compacted with suction-controlled by the vapor equilibrium technique. Then, a series of temperature- and suction-controlled stepwise constant rate strain (CRS) tests was performed and the rate-dependent compressibility behavior of the highly compacted GMZ01 bentonite was investigated. The plastic compressibility parameter λ, the elastic compressibility parameter κ, the yield stress p0, as well as the viscous parameter α were determined. Results indicate that λ, κ and α decrease and p0 increases as suction increases. Upon heating, parameters λ, α and p0 decrease. It is also found that p0 increases linearly with increasing CRS in a double-logarithm coordinate. Based on the experimental results, a viscosity parameter α(s, T) was fitted to capture the effects of suction s and temperature T on the relationship between yield stress and strain rate. Then, an elastic-thermo-viscoplastic model for unsaturated soils was developed to describe the thermal effects on the rate-dependent behavior of highly compacted GMZ01 bentonite. Validation showed that the calculated results agreed well to the measured ones.

Semi-analytical solution of MHD free convective flow of a nanofluid over an exponentially stretching porous sheet in the presence of heat source/sink

In this study, the magnetohydrodynamic flow and heat transfer of electrically conducting nanofluid over an exponentially stretching porous sheet is investigated. By introducing similarity variables, the non-linear set of partial differential governing equations, are transformed into a system of ordinary nonlinear differential equations. The equations are solved semi-analytically by the Optimal Collocation Method (OCM) which is a powerful method to solve equations containing infinite boundary conditions. The accuracy of the OCM results is examined by the Richardson method. The effects of the different physical parameters such as magnetic field strength, nanofluid volume fraction, suction strength, and the heat sink/source value are discussed on the flow and heat transfer characteristics of the problem. The obtained results show that the velocity and temperature of nanofluid increase with the increase in volume fraction. Also, when suction increases, the thickness of the boundary layers decreases. As the strength of the magnetic field (Hartmann) increases, the temperature slightly increases but the flow rate of the nanofluid decreases. The skin friction coefficient and Nusselt number increase when the values of suction parameters, volume fraction, magnetic field, and the field angle increase.

Numerical solutions of steady radiative Maxwell-nanofluid flow toward a stretching sheet in the presence of magnetic field and porous medium

The study investigates the behavior of a Maxwellian nanofluid flowing steadily over an extending sheet in a permeable medium with a magnetic field. The energy equation includes the radiation, and the conservation of momentum equation considers the magnetic field and porous medium. The novelty of this study is in its examination of complex phenomena involving magnetic fields, radiation, Maxwell fluids, and nanoparticle suspensions in a porous medium via an exponential stretching sheet. The study of Maxwell fluids has been enriched by the substantial contributions made by researchers, delving into their rheological behavior, modelling, and applications. Their work has provided valuable insights into the complexities of these materials and has advanced the knowledge in this specialized area of fluid mechanics. The governing partial differential equations (PDEs) are converted into ordinary differential equations (ODEs) utilizing an appropriate similarity transformation. These resultant ODEs are then resolved by employing a numerical approach, specifically the finite element method. The numerical simulations provide valuable information regarding the distributions of velocity, temperature, and nanoparticle concentration. Furthermore, the presented tabulated outcomes display alterations in skin friction, mass transfer rate, heat transmission coefficients, and their reliance on different emerging parameters. The velocity diminishes as the magnetic field, suction, Maxwell fluid, and medium factors increase, while it enhances with the stretching sheet limitation. The temperature diminishes with the Prandtl number but upsurges with higher radiation, thermophoresis, and Brownian motion. As the thermophoresis limit increases, concentration rises, but it decreases with an upsurge in the Lewis and Brownian motion. The heat transfer rate rises with radiation, thermophoresis, and Brownian motion, but the mass transfer rate decreases with Lewes and Brownian motion. The outcomes of the study could have implications for various engineering and industrial applications that control and manipulate fluid flows and heat transfer.

Numerical study of hybrid binary Al2O3-Cu-H2O nanofluid coating boundary layer flow from an exponentially stretching/shrinking perforated substrate with Cattaneo-Christov heat flux, heat source, suction and multiple slip effects

Modern coating systems are increasingly deploying nanomaterials which offer improved thermal performance. The optimization of these systems can benefit from more elegant fluid dynamic models of the coating process. Inspired by these advancements, the present investigation introduces a novel mathematical model to analyze the boundary layer transport in Al2O3-Cu-H2O hybrid binary nanofluid coating deposition on an exponentially stretching porous substrate (sheet). Lateral mass flux (suction) at the wall is also considered a heat source (generation) for hot spot manufacturing effects. To add further sophistication to the thermal conduction model, a non-Fourier approach is adopted which accurately incorporates thermal relaxation effects i.e. the Cattaneo-Christov heat flux (CCHF) model. The Tiwari-Das volume fraction nanoscale formulation is implemented for different combinations of Alumina (Al2O3) and Copper (Cu) metallic nanoparticles in an aqueous base fluid (H2O). Hydrodynamic wall and thermal slip are also included as they feature in coating processes. The fundamental equations governing mass, momentum, and energy conservation, along with the corresponding conditions at the wall (substrate) and free stream, are made dimensionless through suitable scaling similarity transformations. The resulting nonlinear coupled ordinary differential boundary value problem is subsequently addressed using the efficient MATLAB bvp4c routine. Special cases of the non-Fourier model are validated against published results, and the general model is further confirmed through validation using an Adams-Moulton 2-step predictor-corrector algorithm (AMPC). Furthermore, dual solutions of the generalized model are extracted and visualized. A comprehensive study of the effects of key thermophysical key parameters on momentum and thermal characteristics (velocity, temperature, skin friction and local Nusselt number) is conducted and solutions are visualized graphically. The computations show that higher temperatures are present with intensification in the thermal relaxation parameter (Cattaneo-Christov hyperbolic model parameter), which predicts therefore larger temperatures than the classical Parabolic heat conduction model using Fourier analysis. Effectively, thermal relaxation is responsible for finite heat wave propagation and produces more accurate estimations of heat transfer than the Fourier model. An increase in stretching parameter enhances the skin friction coefficient and elevates the local Nusselt number. As the thermal relaxation parameter increases, the temperature magnitudes corresponding to the first and second solutions are both enhanced as are thermal boundary layer thicknesses. An increase in wall suction induces an escalation in the first solution for velocity whereas it reduces the second solution velocity. Stronger wall suction suppresses temperatures. With increasing thermal slip, the boundary layer is cooled i.e. temperature plummets and thermal boundary layer thickness is decreased. Strong deceleration is induced with greater hydrodynamic (velocity) slip. Both first and second solutions for skin friction are elevated with shrinking whereas they are depressed with stretching. With greater velocity slip both the first and second solutions for skin friction are depleted with greater velocity slip for the shrinking case, whereas they are generally enhanced for the very strong stretching case. The computations offer some new insights into multi-physical thermal fluid dynamics of nanofluid-based coating systems.

Influence of suction and injection on the electrical magnetohydrodynamic behavior of nano-fluid in a nonlinear radiative flow over an extending surface

The present communication aims to investigate the behavior of a radiative electrical MHD Casson nanofluid flowing over a stretched surface, under the influence of nonlinear thermal radiation, and suction/injection effects. The governing equations include parameters for temperature and concentration, which are adjusted based on the dependence of viscosity and thermal conductivity, thus enhancing the fluid flow properties. By using similarity transformations, the system of PDEs is converted to an ODE, which is then numerically solved using the well-known fourth-order Runge–Kutta integration strategy based on the shooting method. The impacts of operating parameters on velocity, temperature, and concentration profiles were explained and examined through tables and graphs. Temperature and concentration are increased as the injection ( S < 0 ) increases . However, they show decrement when the suction ( S > 0 ) increases . The novelty of this study focuses on the mathematical development of the flow problem with significant results and also investigating the impact of electric field on velocity of the fluid flow and shear stress. These results are applicable in manufacturing of stretchable materials.

Generalized vortex flow of nanoparticle shapes over a permeable disc surface with generalized slip conditions

This paper investigates the generalized vortex flow of nanofluid consisting of titanium dioxide (TiO2) with base fluid (H2O) over a permeable disk surface that generates a heat transfer process in the thermal boundary layer of the disk. Four types of non-spherical shapes of nanoparticles (blade, brick, cylinder and platelet) are considered for the research. The motion is produced when the fluid is far from the disk surface and rotates like a solid body with a constant angular velocity [Formula: see text]. The partial differential equations (PDEs) are obtained using boundary layer approximations and then converted into ordinary differential equations (ODEs) using suitable similarity transformations. These nonlinear ODEs are solved using the bvp4c MATLAB solver. The effect of different parameters (n, A, [Formula: see text], [Formula: see text], R and Pr) on the velocity components and temperature profile is shown graphically and in tabular results. This analysis concludes that for all non-spherical shapes, the velocity spectrum of all nanoparticles decreases when the values of factors such as power-law, suction, volume fraction and slip parameter increase. All non-spherical shapes of a nanofluid experience a decrease in fluid temperature due to the Prandtl number, while radiation numbers have the opposite effect.

Elastoplastic solution for cylindrical cavity contraction in unsaturated soils

This paper develops an elastoplastic solution for cylindrical cavity contraction in unsaturated soils under constant suction conditions. The elastoplastic cavity contraction problem is formulated into a set of first-order ordinary differential equations by introducing a new auxiliary variable, which is solved as an initial value problem. The new solution is validated by comparison with numerical simulation results. Finally, parametric studies show that, as soil suction increases, the internal support pressure decreases faster with cavity contraction, the unloading-induced plastic zone becomes narrower, and the changes in effective stresses are smaller for a given tunnel convergence.

Suction/Injection Influence on Electrical MHD Nano-Fluid on a Nonlinear Radiative Flow Over a Stretching Sheet

The current communication’s goal is to look at how a radiative electrical MHD Casson nanofluid moves through a stretched sheet while being affected by nonlinear thermal radiation and suction/injection. The controlling equations incorporate a temperature and concentration parameter that is modified viscosity/thermal conductivity dependent in order to enrich the blood flow. By using similarity transformations, the system of PDEs is converted to an ODE, which is then numerically solved using the well-known fourth-order Runge-Kutta integration strategy based on the shooting method. The impacts of operating parameters on velocity, temperature and concentration profiles were explained and examined through tables and graphs. Temperature and concentration are increased as the injection (S &lt; 0) increases. However, they show decrement when the suction (S &gt; 0) increases.

Shear strength model of unsaturated frozen soil based on soil freezing characteristic and soil water characteristic

The strength characteristics of unsaturated soil after freezing significantly influence the safety of engineering construction in frozen soil regions. In this study, the soil freezing characteristic curve (SFCC) and soil water characteristic curve (SWCC) of unsaturated lean clay were tested. Based on the similarity between SFCC and SWCC, the unfrozen water content of SFCC was used to replace the water content of the SWCC to obtain the expression for soil suction under different negative temperatures. A shear strength model of unsaturated frozen soil was established. According to unsaturated triaxial tests under different conditions, the effectiveness of the established unsaturated soil shear strength model was verified. The test results show that in the rapid freezing stage of the SFCC, the volumetric unfrozen water content with an initial matrix suction of 57 kPa exhibited the largest rate of change. The stress-strain curve of soil at positive temperature is strain hardening type, and that at negative temperature presents different types under the influence of temperature, initial matrix suction and confining pressure. The effective cohesion and internal friction angle of soil varied significantly under the influence of temperature and initial matrix suction. When the initial matrix suction was constant, the unsaturated shear strength of the soil increased nonlinearly with a decrease in temperature. When the temperature was ≥−5 °C, the shear strength increased with an increase in initial matrix suction, but decreased when the temperature was ≤−5 °C. The model fitting results were consistent with the measured results of the unsaturated triaxial test, which verifies the validity of the model. This research can provide a reference for studying the mechanical characteristics of unsaturated frozen soil under negative temperature.

Experimental and modeling study of shear strength of unsaturated fine-grained soils with bi-modal water-retention characteristics

The mechanical behavior and strength characteristics of unsaturated fine-grained soils with dual-porosity are of crucial importance in geotechnical designs. Nanyang fine-grained soils have been selected as typical dual-porosity structure soils to perform experimental tests under a wide range of suction and different initial densities while studying its stress-strain-strength properties constitute the main scope of this study. Axial translation and vapor equilibrium techniques are jointly employed to apply a wide suction range. Our data suggest that soil behavior transits from strain-hardening with shear-induced contraction to strain-softening with shear-induced dilation as suction and density increase. By exploiting a bi-modal soil–water retention curve (SWRC) explicitly separating capillarity and adsorption mechanisms, the shear strength is allowed to be analyzed in the capillary suction stress-shear stress space. The strength envelop exhibits bi-linear characteristics. Building upon these findings, we propose a bi-linear shear strength criterion specifically for dual-porosity fine-grained soils. We utilize the obtained test data to evaluate existing strength criteria based on effective stress and dual stress variables that consider the bi-modal SWRC characteristics. The comparison indicates that the proposed bi-linear shear strength criterion can more reasonably represent the variation of shear strength under a wide range of suction for unsaturated dual-porosity fine-grained soils.

A Numerical Simulation of Moisture Reduction in Fine Soil Subgrade with Wicking Geotextiles.

A new wicking geotextile is proposed to control the water content of fine-grained soil subgrade. By comparing the spatial distribution of volumetric water content and matric suction before and after the installation of the wicking geotextile, the effectiveness of the geotextile in controlling the subgrade humidity is evaluated. Firstly, the hydraulic parameters of the wicking geotextile are obtained through laboratory tests using a pressure plate apparatus. Then, a numerical model for water flow in the subgrade is established using COMSOL to obtain the spatial distribution characteristics of humidity in the subgrade under different groundwater levels (2~8 m). The results show the wicking geotextile exhibits strong hydrophilicity, low water retention, and high horizontal permeability. Compared to the subgrade without geotextile, the water content of the soil above the geotextile decreases significantly by 7.6~9.6% at groundwater levels of 4~8m, while the saturation decreases by 18.3~23.0%, and the matric suction increases by 2~2.3 times. The wicking fabric functions as an effective drainage material to serve as a capillary barrier in the cross-plane direction and an effective drainage tunnel to transport water in the in-plane direction. The dynamic resilient modulus of the subgrade increases by 23.2~43.6%. The wicking geotextile effectively absorbs and drains weakly bound water in unsaturated soil due to the matric suction difference and its horizontal drainage capacity to improve the bearing capacity of the subgrade. It suggests that using wicking geotextile for drainage and reinforcement in fine-grained soil subgrades with groundwater levels ranging from 4 to 8 m is beneficial.

Suppression of flow separation around a finite wall-mounted square cylinder by suction at the side leading edge

We investigate the control of three-dimensional flow separation around a finite wall-mounted square cylinder by applying suction at the side leading edge. Direct numerical simulations are conducted at a Reynolds number of 250, with suction ratios Γ of 0–2 (where Γ is the absolute value of the suction velocity divided by the free stream velocity). The effect of Γ on the aerodynamic forces acting on the cylinder is studied. The results show that suction reduces the aerodynamic forces, with the best control effect for the fluctuating lift coefficient (corresponding to a reduction of over 70%) achieved at Γ = 0.375. As the suction ratio increases, the pressure drag experienced by the square cylinder decreases. Simultaneously, the mean frictional drag force exerted on the square cylinder increases. The optimal mean drag coefficient (corresponding to a reduction of nearly 20%) is achieved at Γ = 1. The effect of the suction ratio on the flow topology in the wake is also investigated. Suction significantly suppresses the flow separation. As the suction ratio increases, the spanwise counter-rotating vortices in the streamwise and transverse directions decreases in size, and the downwash vortex shrinks, and shifts toward the free end of the square cylinder. The far-wake streamwise base vortex disappears when active suction is applied to the side leading edge. However, a new pair of base vortices splits from the original base vortex and persists into the far wake flow field, forming a quadrupole vortex structure with the tip vortex.

Jeffrey fluid flow past inclined stretchable sheet with magnetic dipole and suction/injection

Jeffrey fluid flow past an inclined stretchable sheet affected by magnetic dipole and suction/injection was investigated. The applicable equations were changed into nonlinear ordinary differential equations by similarity transformations. With the Chebyshev spectral collocation approach, solutions were obtained for fluid velocity and temperature. Considering the prescribed surface temperature (PST) and prescribed heat flux (PHF) heat processes, the effect of inclination angle, the Grashof number, and other parameters on the velocity and temperature of the fluid were documented by graphs and tables. Without the angle of inclination, the solutions from this paper were found to agree with those of the Generic algorithm and Nelder Mead method. The fluid is slower when the plate is inclined at a larger angle and this tends to allow for higher fluid temperature. The ferromagnetic interaction parameter and the ratio of relaxation to retardation time have the same effect on fluid velocity and temperature as the angle of inclination. The suction parameter and Prandtl number amplify the Nusselt number, while, as the suction increases, the skin friction increases for all inclination angles. With these results, engineers in chemical/polymer industries can make appropriate changes that can lead to more quality production.

Performance of stone columns in unsaturated soils: Numerical evaluation

Stone columns are often designed using the conventional framework of saturated soils, ignoring the influence of in-situ unsaturated soil conditions. Such an approach contributes to unrealistic and, in certain scenarios, over-conservative designs. The key objective of this paper is to quantify the influence of matric suction on the confining support offered by the surrounding soil towards stone columns. In addition, how this approach can be implemented through a numerical technique is also presented and discussed. The numerical analysis suggests that the load-carrying capacity of stone columns increased with an increase in the matric suction in the boundary effect, and the transition zone. However, the contribution of matric suction towards load-carrying capacity starts reducing from the residual zone of saturation. Furthermore, the performance of stone columns in unsaturated soils is strongly associated with the area replacement ratio. The results of the study are promising towards developing procedures that can be used in the rational design of stone columns in unsaturated soils.