Deviatoric Stress Research Articles

Mechanical properties and piecewise constitutive model of fine sandstone in mining area of western China

Owing to the differences in sedimentary environments in the mining areas of western China, the mechanical properties of rocks in this region are significantly different from those in the central and eastern regions. Therefore, uniaxial cyclic loading-unloading tests were conducted on fine sandstone found in many roof rocks to study the evolution laws of mechanical properties, deformation characteristics, acoustic emission (AE) parameters, and energy under cyclic loading and unloading conditions. The accumulated residual strain, dissipative energy, acoustic emission cumulative ringing counts, and cumulative energy were introduced to characterize the degree of rock damage. Based on this, a piecewise constitutive model was established for fine sandstone. The results indicate that (1) the cumulative ringing counts and cumulative energy of the AE increase in a stepwise manner with an increase in the cyclic loading and unloading times. Still, there is a sudden increase in the plastic failure and post-peak failure stages. (2) The fine sandstone specimens’ input energy, elastic energy, and dissipative energy density increased nonlinearly during the cyclic loading tests. Owing to the closure of the primary pores in the microfracture compaction stage, dominant matrix deformation in the elastic deformation stage, and development and expansion of cracks in the plastic failure stage, with an increase in the cyclic loading and unloading times, the dissipative energy ratio first decreased and then increased. (3) Based on the tangential modulus, residual strain, and Felicity ratio, fine sandstone’s cyclic loading and unloading stress-strain curves were divided into microfracture compaction, elastic deformation, and plastic failure stages. The piecewise constitutive model of fine sandstone constructed with accumulated AE energy was the closest to the real stress-strain curve of the rock, and the deviations of the peak stress and peak strain from the actual situation were 0.52% and 0.84%, respectively. The research results can provide theoretical support for identifying the degree of rock damage in western mining areas and ensure the safe and efficient development of coal resources.

Unlocking the Potential of RFA and Stabilizers in High Moisture Geotechnical Applications

In recent decades, rapid urbanization has generated a large amount of waste soft soil and construction debris, resulting in severe environmental pollution and posing significant challenges to engineering construction. To address this issue, this study explores an innovative approach that synergistically applies recycled fine aggregate (RFA) and soil stabilizers to improve the mechanical properties of soft soil. Through laboratory experiments, the study systematically examines the effects of different mixing ratios of RFA (20%, 40%, 60%) and soil stabilizers (10%, 15%, 20%) with red clay. After standard curing, the samples underwent water immersion maintenance for varying durations (1, 5, 20, and 40 days). Unconfined compressive strength (UCS) tests were conducted to evaluate the mechanical performance of the samples, and the mechanisms were further analyzed using scanning electron microscopy (SEM) and particle size distribution (PSD) analysis. The results indicate that the optimal performance is achieved with 20% RFA and 20% stabilizer, reaching the highest UCS value after 40 days of water immersion. This improvement is primarily attributed to the formation of a dense reticulated structure, where RFA particles are effectively encapsulated by clay particles and stabilized by hydration products from the stabilizer, forming a robust structural system. Unconsolidated undrained (UU) tests reveal that peak deviatoric stress increases with confining pressure and stabilizer content but decreases when excessive RFA is added. Shear strength parameter analysis demonstrates that both the internal friction angle (φ) and cohesion (c) are closely related to the content ratios, with the best performance observed at 20% stabilizer and 20% RFA. PSD analysis further confirms that increasing stabilizer content enhances particle aggregation, while SEM observations visually illustrate a denser microstructure. These findings provide a feasible solution for waste soft soil treatment and resource utilization of construction debris, as well as critical technical support and theoretical guidance for geotechnical engineering practices in high-moisture environments.

Deformation and Failure Mechanism and Control of Water-Rich Sandstone Roadways in the Huaibei Mining Area

The sandstone roof rock in the Huaibei mining area contains abundant water at depths of 2–3 m. Water–rock interactions in the rock-surrounding roadway can cause significant deformation, seriously threatening the safety of mine operations. Investigating the deformation and failure mechanisms of water-rich sandstone is therefore of critical importance. In this study, X-ray diffraction and scanning electron microscopy were used to analyze the composition and microstructure of water-rich sandstone. Based on the stress state during the roadway excavation, a true triaxial loading scheme with four different stress paths was designed to study the effects of different moisture contents and loading methods on the mechanical properties of the sandstone. The results show that the deviatoric stress decreased for all stress paths. Acoustic emission (AE) characteristics during the deformation and failure processes were also studied, which indicated that the AE b-value decreased, increased, and then decreased again corresponding to the primary compaction, elastic deformation, and plastic deformation evolutionary processes in the internal microstructure of the rock. The variation in the b-value reflected the development and expansion of internal fractures. These findings provide useful insights for controlling the stability of the surrounding rock in water-rich roadways in coal mines.

A study of the undrained monotonic behavior of geotextile reinforced sand-silt mixtures using triaxial tests

“Investigating the behavior of silty soils reinforced with geotextile layers in terms of shear strength and deformation in a laboratory setting is the study’s objective described in this paper. This work includes an experimental study based on a series of undrained monotonic triaxial tests, which were carried out on clean sand from Chlef, medium dense (Dr = 50%), mixed with silt content fluctuating between 0 and 30%. The mechanical behavior was examined and discussed in this paper by varying the number of geotextile layers (Ng = 1, 2, 3) and the fines content where the samples were consolidated under 100 kPa confining pressure. Experimental results on unreinforced and reinforced silt/sand soils by geotextile layers show that the quantity of geotextile layers is growing in the studied samples improves the shear strength characteristics of the soil, nevertheless, lessen the radial deformations cause the pore water pressure to rise instead. However, the pore water pressure increases while the deviatoric stress decreases as the percentage of fines increases.”

Discovering non-associated pressure-sensitive plasticity models with EUCLID

We extend (EUCLID Efficient Unsupervised Constitutive Law Identification and Discovery)—a data-driven framework for automated material model discovery—to pressure-sensitive plasticity models, encompassing arbitrarily shaped yield surfaces with convexity constraints and non-associated flow rules. The method only requires full-field displacement and boundary force data from one single experiment and delivers constitutive laws as interpretable mathematical expressions. We construct a material model library for pressure-sensitive plasticity models with non-associated flow rules in four steps: (1) a Fourier series describes an arbitrary yield surface shape in the deviatoric stress plane; (2) a pressure-sensitive term in the yield function defines the shape of the shear failure surface and determines plastic deformation under tension; (3) a compression cap term determines plastic deformation under compression; (4) a non-associated flow rule may be adopted to avoid the excessive dilatancy induced by plastic deformations. In contrast to traditional parameter identification methods, EUCLID is equipped with a sparsity promoting regularization to restrain the number of model parameters (and thus modeling features) to the minimum needed to accurately interpret the data, thus achieving a compromise between model simplicity and accuracy. The convexity of the learned yield surface is guaranteed by a set of constraints in the inverse optimization problem. We demonstrate the proposed approach in multiple numerical experiments with noisy data, and show the ability of EUCLID to accurately select a suitable material model from the starting library.

Macro-Micro Mechanics of Granular Soils Under Shear Considering Coupled Effects of Particle Size Distribution and Particle Morphology.

This paper investigates the effects of particle morphology (PM) and particle size distribution (PSD) on the micro-macro mechanical behaviours of granular soils through a novel X-ray micro-computed tomography (μCT)-based discrete element method (DEM) technique. This technique contains the grain-scale property extraction by the X-ray μCT, DEM parameter calibration by the one-to-one mapping technique, and the massive derivative DEM simulations. In total, 25 DEM samples were generated with a consideration of six PSDs and four PMs. The effects of PSD and PM on the micro-macro mechanical behaviours were carefully investigated, and the coupled effects were highlighted. It is found that (a) PM plays a significant role in the micro-macro mechanical responses of granular soils under triaxial shear; (b) the PSD uniformity can enhance the particle morphology effect in dictating the peak deviatoric stress, maximum volumetric strain, contact-based coordination number, fabric evolution, and shear band formation, while showing limited influences in the maximum dilation angle and particle-based coordination number; (c) with the same PSD uniformity and PM degree, the mean particle volume shows minimal effects on the macro-micro mechanical behaviours of granular soils as well as the particle morphology effects.

재한 유학생의 문화적응 스트레스와 대인관계 유능성이 대학생활 적응에 미치는 영향: 사회적 지지의 조절된 매개효과

Objectives The purpose of this study was to examine the moderated mediating effect of social support on the influence of acculturative stress and interpersonal competence on the adjustment to university life among international students in South Korea. Methods An online survey was conducted with 331 international students enrolled in universities located in the Jeonbuk region. The data were analyzed using SPSS 23.0 and SPSS Macro to explore the mediating effect of interpersonal competence in the relationship between acculturative stress and university life adjustment, as well as the moderated mediating effect of social support. Results When looking at the mean and standard deviation of acculturation stress, adaptation to college life, interpersonal competence, and social support, acculturation stress was 2.085 (SD=.549), interpersonal competence was 2.993 (SD=.451), and college life. Adaptation was 2.994 (SD=.599), and social support was 3.044 (SD=.513). Adaptation to college life and acculturation stress had a negative correlation of -.745 (P〈.01), and interpersonal competence and social support had a positive correlation of .225 (P〈.01) and .333 (P〈.01). It seemed. In the relationship between acculturation stress and adaptation to college life, interpersonal competence showed a mediating effect with b = .183 (P < .001), and social support had a moderated mediating effect with b = -.167 (P< .001). appeared. Conclusions This study confirmed that acculturative stress, interpersonal competence, and social support play critical roles in international students' adjustment to university life. In particular, higher social support enhances students' adjustment to university life, suggesting that improving interpersonal skills and reinforcing social support systems are essential for the successful adaptation of international students.

Influences of Different Factors and Sensitivity Analysis of Permeability of Gassy Coal

Influencing factors and sensitivity analysis of coal permeability are significant for reasonably setting coalbed methane (CBM) extraction parameters and increasing CBM output. Seepage tests were conducted on gassy coal using a seepage test system for damaged coal and rock mass under various conditions of axial pressure, confining pressure, and gas pressure. Moreover, the influences of different factors on the permeability of gassy coal and the sensitivity of permeability to these factors were analyzed. Research results show that under the same confining pressure, the relationship between permeability and axial pressure of gassy coal meets the quadratic polynomial function; under the same axial pressure, the permeability changes with the confining pressure as a power function. The permeability of gassy coal is far more sensitive to confining pressure than to axial pressure during axial seepage. Under the same axial pressure and confining pressure (same stress), the permeability of gassy coal reduces at first and then increases in a V-shaped trend with growing gas pressure. There is a turning point in the seepage tests, that is, the critical gas pressure. When the gas pressure is lower than the critical value, the slippage effect plays the leading role in the variation of permeability of the coal; on the contrary, effective stress plays the dominant role. In the non-isobaric deviatoric stress state, the permeability of gassy coal is most sensitive to the confining pressure, followed successively by gas pressure and axial pressure. The research results provide a theoretical basis for precise gas extraction and control in coal seams.

Analysis of mechanical properties and energy evolution mechanism of frozen calcareous clay under multi-factor interaction

Research investigating the complex mechanical properties and energy evolution mechanisms of frozen calcareous clay under the influence of multiple factors is crucial for optimizing the artificial ground freezing method in shaft sinking, thereby enhancing construction quality and safety. In this study, a four-factor, four-level orthogonal test was devised, taking into account temperature, confining pressure, dry density, and water content. The complex nonlinear curvilinear relationship between deviatoric stress, volume strain, and axial strain of frozen calcareous clay under different interaction levels was analyzed. The sensitivity of each factor to the peak volume strain was explored, and the energy evolution mechanism of frozen calcareous clay during the triaxial compression process was analyzed. The findings are summarized as follows: (1) The deviatoric stress-axial strain curves demonstrate the strain-hardening characteristics of frozen calcareous clay specimens. Furthermore, as temperature decreases, the hardening degree increases. (2) Sensitivity analysis indicates that the factors’ influence on peak volumetric strain ranks as follows: dry density > confining pressure > temperature > water content. Under the various interactions, specimens exhibit significant volumetric shrinkage. When the temperature remains constant, peak volumetric strain is negatively correlated with dry density but positively correlated with confining pressure. (3) Input energy density, elastic strain energy density, and dissipated energy density of frozen calcareous clay all increase with axial strain. (4) When temperature is held constant, both peak input energy density and peak dissipated energy density rise with increasing confining pressure. Meanwhile, peak elastic strain energy density shows a linear increase with higher confining pressure and lower temperatures.

Experimental investigation on mechanical properties and strength criteria of frozen soft rock.

Excavation of underground engineering structures involving deeply buried water-rich soft rocks is generally carried out using the artificial freezing method. A series of undrained uniaxial and triaxial shear and creep tests were conducted on soft rocks under different confining pressures (0, 0.2, 0.5, and 1.0 MPa) at different freezing temperatures (room temperature, -5°C, -10°C, and -15°C). Test results indicate that the frozen soft rocks show strain softening characteristics. The stress-strain curve changes from a straight line to a curve as deviatoric stress constantly increases, while it decreases abruptly after the deviatoric stress reaches the peak and is slightly affected by the freezing temperature. At the same temperature, shear strength increases at a rate of 5.6 MPa/°C with increasing confining pressure; as freezing temperature decreases, the shear strength increases at 0.34 MPa/°C, and cohesion increases at 0.6 MPa/°C. Under the same confining pressure, the failure strain of soft rock decreases with the decrease of temperature. The Mohr-Coulomb (M-C) criterion can accurately describe the failure process of frozen soft rocks in the pre-peak stage, with a correlation coefficient greater than 0.98. Within the test stress range, soft rocks display attenuated stable creep deformation. Acoustic emission (AE) tests were conducted to further verify that the soft rocks show shear failure under load, with a shear plane showing an angle of 45° with the horizontal. The research findings provide technical support and theoretical reference for studying rock mechanical properties as well as for designing and carrying out underground freezing of rocks in a low-temperature environment.

Anisotropic distortional hardening based on deviatoric stress invariants under non-associated flow rule. Part-II: Generalization combined with non-quadratic yield function under associated flow rule

Anisotropic distortional hardening based on deviatoric stress invariants under non-associated flow rule. Part-II: Generalization combined with non-quadratic yield function under associated flow rule

Model representations of the theory of thermal shock of viscoelastic bodies

Model representations of the theory of thermal shock of viscoelastic bodies based on two different approaches are considered. In the first approach, based on the introduction of stress and strain deviators using linear rheological models of Maxwell and Kelvin, new integral and differential relations are proposed, including simultaneously dynamic and quasi-static models for viscoelastic and elastic media, generalizing the results of previous studies. The proposed constitutive relations of the new form are applicable to describe the thermal response of bodies of canonical shape, limited by the boundaries of a rectilinear shape in Cartesian coordinates and are extended to the case of curvilinear boundaries in cylindrical and spherical coordinates. The second approach describes an elastic-viscoelastic analogy, which consists in the fact that the original problem of temperature stresses of a viscoelastic body can be reduced to the equivalent problem of thermoelasticity by replacing the shear modulus and Poisson’s ratio in the operational (according to Laplace) solution of the thermoelastic problem with their images as in the model Maxwell and in the Kelvin model. It is shown that after performing the inverse transformation, an analytical solution to the problem for a thermoviscoelastic medium is found. An illustrative example is given and the differences in the thermal response to sudden heating of an elastic and viscoelastic medium are analyzed.

Quantitative kinetic rules for plastic strain-induced α - ω phase transformation in Zr under high pressure

Plastic strain-induced phase transformations (PTs) and chemical reactions under high pressure are broadly spread in modern technologies, friction and wear, geophysics, and astrogeology. However, because of very heterogeneous fields of plastic strain Ep and stress σ tensors and volume fraction c of phases in a sample compressed in a diamond anvil cell (DAC) and impossibility of measurements of σ and Ep, there are no strict kinetic equations for them. Here, we develop a kinetic model, finite element method (FEM) approach, and combined FEM-experimental approaches to determine all fields in strongly plastically predeformed Zr compressed in DAC, and specific kinetic equation for α-ω PT consistent with experimental data for the entire sample. Since all fields in the sample are very heterogeneous, data are obtained for numerous complex 7D paths in the space of 3 components of the plastic strain tensor and 4 components of the stress tensor. Kinetic equation depends on accumulated plastic strain (instead of time) and pressure and is independent of plastic strain and deviatoric stress tensors, i.e., it can be applied for various above processes. Our results initiate kinetic studies of strain-induced PTs and provide efforts toward more comprehensive understanding of material behavior in extreme conditions.

Effect of silt fines on the undrained monotonic behavior of compacted tuff soil

The present study explores the influence of silt content on the undrained monotonic behavior of compacted tuff. All undrained triaxial tests were performed at both relative densities Dr = 50 and 90% and compacted with the optimum water content on tuff soil mixed with silt in the range of 0 to 50%. Experimental results show that adding fines content (FC) up to 20% increases the resistance of dense compacted tuff (Dr = 90%) by about 35% for 100 kPa of confining pressure, and the addition of 10% silt fines results in a maximum increase of 15.71% in the medium dense state specimen (Dr = 50%). The deviator stress reveals a decrease by adding more than 20% of silt. Moreover, the soil cohesion was found to attain maximum values with the optimum silt percentage of FC = 10% for medium-density samples (Dr = 50%) and FC = 20% for dense samples (Dr = 90%), respectively. Finally, the study showed a direct correlation between the cohesion of the soil prepared in a dense state (Dr = 90%) and the soil’s maximum dry density (MDD). In particular, the maximum dry density corresponds to a higher cohesion.

Design Analysis of the Welding Fume Blower Bracket in the Welding Laboratory at Politeknik Sinar Mas Berau Coal

Sinar Mas Berau Coal Polytechnic has equipped a welding laboratory with blower installation according to welding standards. Installing the blower requires a bracket as a holder. For the design, the type of material used is ASTM A36 material and analyzes the simulation of fume blow welding brackets with angle iron measuring 5x5 cm. In implementing the working steps for a sturdy and strong bracket within the tolerance limits explained as follows, namely planning and modeling the frame, simulating and calculating theoretically. Based on the design and testing of the welding fume blower bracket using the Autodesk Inventor 2018 application with a given load of 186,778 N. This test tests the maximum and minimum von Mises stress, displacement, safety factor, which is calculated using the Autodesk Inventor 2018 simulation. The results compare the theory and simulation. ASTM A36 material has a yield stress value of 248.225 Mpa, obtained by von Misese stress simulation calculations of 51.64 Mpa and theoretical calculations of 45.88 Mpa. The results of the von Mises stress deviation between simulation and theory are 11.29%. For displacement, theoretical calculations get a figure of 0.02247 and simulation results get a value of 0.09468. The results of the displacement deviation between simulation and theory are 3.21%. For the safety factor obtained in the analysis using software and theoretical calculations, the welding fume blower bracket obtained a safety factor value of 4.80 with theoretical calculations and 5.41. The results of the safety factor deviation between simulation and theory are 12.56%.

Modeling of Creep Closure of Salt Rocks Drilled by Directional Wells

This paper presents a strategy for three-dimensional modelling of directional wells penetrating salt rocks, aiming at predicting the closure of these rocks due to creep. One of the major challenges in oil production in the pre-salt region is drilling through thick layers of salt rocks. During drilling, these rocks deform in the direction of the wellbore closure due to creep. The accumulated deformation of the wellbore wall over a given time interval can lead to the restriction of the drilling string's passage and even its irretrievably trapped. Directional wells in salt regions present an even greater complexity, as changes in inclination alter the stress distribution around the well, changing the configuration of the deviatoric stress, with no symmetry around the well's central axis (as in vertical wells). This paper discusses a strategy for modelling directional wells in salt regions using the commercial software Abaqus. This software implements the Finite Element Method, including its three-dimensional formulation, and allows modeling of creep deformation of materials, enabling the implementation of constitutive models different from traditional ones through subroutines. The adopted constitutive equation is the most recurrent in the literature to describe the creep phenomenon in wells through Brazilian salt rock. To verify the developed strategy, a vertical well is modelled, and the obtained results are compared with those presented by axisymmetric modeling, already consolidated in other works developed by the group. After verification, directional wells are modelled and studied, and their behavior is discussed regarding the observed displacement and stress fields, mainly along the region near the wellbore wall. This work contributes to the understanding of the creep behavior in salt rocks when drilled by directional wells, and discusses some strategies that can contribute to the stability of the rock formation, aiming at the safe and efficient construction of wells in salt regions.

Mechanical Properties and Damage Constitutive Model of Saturated Sandstone Under Freeze-Thaw Action.

In order to investigate the impact of freeze-thaw damage on sandstone under the coupling of ground stress and pore water pressure, three types of porous sandstone were subjected to freezing at different negative temperatures (-5 °C, -10 °C, -15 °C, and -20 °C). Subsequently, hydraulic coupling triaxial compression tests were conducted on the frozen and thawed sandstone. We analyzed the effects of porosity and freezing temperature on the mechanical properties of sandstone under hydraulic coupling and performed nuclear magnetic resonance tests on sandstone samples before and after freezing and thawing. The evolution of the pore structure in sandstone at various freezing and thawing stages was studied, and a statistical damage constitutive model was established to validate the test results. The results indicate that the stress-strain curves of sandstone samples under triaxial compression after a freeze-thaw cycle exhibit minimal changes compared to those without freezing at normal temperature. The peak deviator stress shows a decreasing trend with decreasing freezing temperature, particularly between -5 °C and -10 °C, and then gradually stabilizes. The elastic modulus of sandstone with different porosity decreases with the decrease in freezing temperature, and the decrease is more obvious in the range of -5 °C~-10 °C, decreasing by 2.33%, 6.11%, and 10.5%, respectively. Below -10 °C, the elastic modulus becomes similar to that at -10 °C, and the change tends to stabilize. The nuclear magnetic porosity of sandstone samples significantly increases after freezing and thawing. The smaller the initial porosity, the greater the rate of change in nuclear magnetic porosity after a freeze-thaw cycle. The effects of freeze-thaw damage on the T2 distribution of sandstone with different porosity levels vary. We established a statistical damage constitutive model considering the combined effects of freeze-thaw damage, ground stress, and pore water pressure. The compaction coefficient K was introduced into the constitutive model for optimization. The change trend of the theoretical curve closely aligns with that of the test curve, better characterizing the stress-strain relationship of sandstone under complex pressure environments. The research findings can provide a scientific basis for wellbore wall design and subsequent maintenance in complex environments.

Isolating the effects of deviatoric and hydrostatic stress on damage evolution using cold extrusion experiments

Isolating the effects of deviatoric and hydrostatic stress on damage evolution using cold extrusion experiments

Three-dimensional elastoplastic constitutive model for cement stone based on fractional flow rule

The strain paths of cement stone in the deviatoric and meridian planes under the constant Lode angle loading path (true triaxial stress state) are analyzed. The amount of volumetric and shear strains first increases and then decreases with the intermediate principal stress coefficient. Owing to the generation of plastic volumetric strain and plastic shear strain in the direction of deviatoric stress, the strain path exhibits nonlinearity in the meridian planes. The deviation of the strain path from the constant Lode angle arises from the accumulation of plastic shear strain along the Lode angle direction. In the framework of fractional plasticity, a three-dimensional elastoplastic constitutive model incorporating Lode angle is proposed, including yield function, potential function, and fractional flow rule. The yield surface evolves in both meridian and deviatoric planes, allowing the yield function to precisely characterize the stress state. Since the plus-minus sign in the flow direction of the yield surface is opposite to that in the flow direction of cement stone, a simple elliptic function incorporating Lode angle serves as the potential function. The procedure for the determination of fractional order based on the entirety of the deformation process is proposed, including variable and constant fractional order. The comparison between the experimental result and the analytical solution of constitutive model confirms its accuracy and validity. Furthermore, the difference between variable and constant fractional order on deformation is analyzed. The comparison results indicate that the variable fractional order can provide a more accurate description of deformation than the constant fractional order.

Relationship between void characteristics and re-liquefaction resistance: An image analysis study

To scrutinize the impact of void characteristics on re-liquefaction resistance, a series of constant-volume cyclic bi-axial tests was conducted on an assembly of plastic rods. The first and second liquefaction stages involved the application of isotropic compression at 100 kPa followed by constant-volume cyclic loading with the deviator stress set at 30 or 60 kPa. This study introduced an innovative image analysis method to quantify four void characteristics: anisotropy index (Ie) and average void element size (Ae) for the element-based analysis, and local anisotropy index (Ie,ij) and local void ratio (eij) for the grid-based analysis. The newly developed anisotropy index was seen to facilitate the assessment of the primary alignment and degree of anisotropy in void elements. The results confirmed that an increase in re-liquefaction resistance is evident in specimens with lower average eij, coefficient of variation (CV) of eij, and Ie, indicating denser, more homogeneous, and isotropic conditions. Nevertheless, specimens with a greater degree of anisotropy were found to be more susceptible to re-liquefaction. The development of strain in the early stages of cyclic loading was found to be predominantly influenced by the anisotropy index, underscoring the imperative need for an enhanced method that can predict liquefaction resistance, as well as re-liquefaction resistance, and incorporates the anisotropy index.