Abstract
The current research aims to reinforce collapsible Sabkha soil by encased deep soil mixing columns (EDSMCs).
Full-scale three-dimensional numerical models are created to analyze the performance of footings on both untreated and treated
soil. Various parameters such as columns configuration, lime content, collapse index and geogrid stiffness are considered . The
results demonstrated that the conventional DSMCs significantly increase the bearing capacity of the collapsible soil under
immersion conditions, up to three times that of non-treated soil. However, the bearing capacity of the footing on the reinforced
soil still requires further enhancement. Utilizing geogrid encasement for DSMCs improves effectively the foundation bearing
capacity, and minimizes the foundation settlement and the columns lateral bulging compared to conventional DSMCs. The
minimum settlement and lateral bulging, and the greater loads carried by EDSMCs are achieved when utilizing higher geogrid
stiffness . In addition to the numerical analyses, multiple machine learning models including Logistic Regression (LR), Nonlinear
Regression (NLR), Support Vector Machine (SVM), Gaussian Process Regression (GPR), Random Forest (RF), Decision Tree
(DT), and Extreme Gradient Boosting (XGBoost) are developed. These models exhibited strong performance in predicting the
properties of treated Sabkha soil, with Coefficient of Determination (R2-Score) exceeding 0.95. The machine learning analyses
support the findings of the numerical analyses, emphasizing the significant role of geogrid encasement in enhancing footing
performance on the reinforced soil.
Key Words
collapsed settlement; deep soil mixing columns; geosynthetics; load transfer; machine learning
Address
Mohamed Elsawy: Department of Civil Engineering, Faculty of Engineering, Geotechnical and Foundations Engineering at University of Tabuk,
Tabuk 71491, Saudi Arabia;
Department of Civil Engineering, Faculty of Engineering, Geotechnical and Foundations Engineering at Aswan University,
Aswan 81542, Egypt
Abderrahim Lakhouit: Department of Civil Engineering, Faculty of Engineering, Environmental Engineering at University of Tabuk, Tabuk 71491, Saudi Arabia
Turki S. Alahmari: Department of Civil Engineering, Faculty of Engineering, University of Tabuk, Tabuk 71491, Saudi Arabia
Hossam AbdelMeguid: Department of Mechanical Engineering, Faculty of Engineering, University of Tabuk, 47913 Tabuk, Saudi Arabia;
Department of Mechanical Power Engineering, Faculty of Engineering, Mansoura University, El‑Mansoura 35516, Egypt
Mahmoud Shaban: Department of Electrical Engineering, College of Engineering, Qassim University, Saudi Arabia;
Department of Electrical Engineering, Faculty of Engineering, Aswan University, Aswan 81542, Egypt
Abstract
This article studies the flexural response of porous cross-ply laminated beams under sinusoidal mechanical and
thermal loads. The sinusoidal thermal load is linearly varying in the transverse direction. For the first time, this work takes into
consideration three porosity distribution models. Moreover, the analysis is performed via an improved Timoshenko beam theory
that eliminates the need for a shear correction factor and introduces a parabolic distribution for the transverse shear strain. The
beams are simply supported. The virtual work principle is utilized to derive the governing equations. The governing equations
are then solved analytically via Navier's rule for the simple support condition. The present work's validity is checked by
comparison with the results of Bernoulli Euler's classical, Timoshenko's first-order, Sayyad-Ghugal's trigonometric, Reddy's higher-order, and exact elasticity beam theories. The proposed theory is found to provide the closest results to those of the
elasticity theory in comparison with the other theories. Parametric studies are conducted to measure the influence of porosity
parameters on the response. Porosity distribution model 1 seems to have the greatest effect on the displacement results for both
the thermal and mechanical load cases, followed by porosity model 2. In the mechanical load case, the lateral and axial
displacements increase as the porosity volume fraction increases. However, the displacements for the thermal load case decrease
as the porosity volume fraction increases.
Key Words
cross-ply laminated beam; distribution models; flexural analysis; improved Timoshenko beam theory;
sinusoidal mechanical and thermal loads; thermal load; porosity; transverse linearly varying
Address
Muayad A. Rajeh: Department of Civil and Environmental Engineering, King Fahd University of Petroleum & Minerals, 31261 Dhahran,
Eastern Province, Saudi Arabia
Mohammed A. Al-Osta and Salah U. Al-Dulaijan: Department of Civil and Environmental Engineering, King Fahd University of Petroleum & Minerals, 31261 Dhahran,
Eastern Province, Saudi Arabia;
Interdisciplinary Research Center for Construction and Building Materials, KFUPM, 31261 Dhahran, Saudi Arabia
Fouad Bourada: Material and Hydrology Laboratory, University of Sidi Bel Abbes, Faculty of Technology, Civil Engineering Department, Algeria
Abdeldjebbar Tounsi: aterial and Hydrology Laboratory, University of Sidi Bel Abbes, Faculty of Technology, Civil Engineering Department, Algeria;
Mechanical Engineering Department, Faculty of Science and Technology, University of Rélizane, Algeria
Abdelouahed Tounsi: Department of Civil and Environmental Engineering, King Fahd University of Petroleum & Minerals, 31261 Dhahran,
Eastern Province, Saudi Arabia;
Interdisciplinary Research Center for Construction and Building Materials, KFUPM, 31261 Dhahran, Saudi Arabia;
Material and Hydrology Laboratory, University of Sidi Bel Abbes, Faculty of Technology, Civil Engineering Department, Algeria
Murat Yaylaci: Department of Civil Engineering, Recep Tayyip Erdogan University, 53100, Rize, Turkey;
Faculty of Turgut Kiran Maritime, Recep Tayyip Erdogan University, 53900, Rize, Turkey
Abstract
Bentonite serves as a buffer/backfill material in deep geological repositories for high-level nuclear waste. From
compaction to on-site installation, bentonite blocks undergo drying-induced shrinkage that can compromise the
engineering barrier's mechanical integrity and radionuclide containment. In this paper, initially unsaturated bentonite is
taken as the research object, and the indoor constant temperature drying test is carried out. The effects of initial dry
density and initial water content on water evaporation, shrinkage deformation, and fracture evolution of bentonite are
studied, respectively. The experimental results show that the initial dry density and initial water content have a significant
effect on the water evaporation, shrinkage deformation, and crack evolution of bentonite. The larger the initial dry density
or the smaller the initial water content, the less the water loss of bentonite in the evaporation process, the smaller the
shrinkage deformation, and the fewer the number of cracks on the surface of bentonite. The shrinkage geometric factor
can quantitatively describe the proportion of axial strain in the total volumetric strain. After drying, the shrinkage
geometric factors of all compacted bentonite samples are between 1 and 3, which indicates that the axial strain accounts
for a large proportion of the total volumetric strain, and the shrinkage deformation exhibits anisotropy. The effects of
initial dry density and initial water content on water evaporation, shrinkage deformation, and fracture evolution of
bentonite are closely related to their effects on inter-aggregate pores.
Key Words
bentonite; fracture evolution; initial dry density; initial water content; shrinkage deformation
Address
Chunyuan Zhou, Geng Niu, Xiao Han and Xinrui Wang: School of Science, Qingdao University of Technology, Qingdao 266520, China
Liang Kong: chool of Science, Qingdao University of Technology, Qingdao 266520, China;
School of Civil Engineering, Qingdao University of Technology, Qingdao 266520, China
Jiaqi Liu: School of Civil Engineering, Qingdao University of Technology, Qingdao 266520, China
Abstract
This study investigates the long-term response of granular materials subjected to repetitive mechanical loads through
integrated experimental and numerical approaches. Repetitive Ko-loading tests, triaxial tests, and simple shear tests reveal two
critical asymptotic states governing system behavior: (1) a terminal void ratio controlling volumetric stabilization, and (2) stressobliquity-
dependent shear modes transitioning between shakedown and ratcheting. Results demonstrate that repetitive loading
alters the coefficient of earth pressure through fabric evolution, quantified via shear wave velocity-stress relationships. Granular
degradation analyses show particle abrasion dominates at low-stress/high-cycle conditions, while fines content critically
influences deformation response through threshold fines fractions. A new dimensionless shear stress ratio successfully predicts
long-term shear response between shakedown and ratcheting. Hybrid numerical modeling combining conventional constitutive
model with empirical strain accumulation reduces computational errors and enhance convergency to conventional methods for
high-cycle simulations.
Key Words
energy geosystems; ratcheting; repetitive mechanical loads; shakedown; terminal void ratio
Address
Wonjun Cha: Department of Civil Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
Sang Yeob Kim: Department of Fire and Disaster Prevention, Konkuk University,
268, Chungwon-daero, Chungju, 27478, Republic of Korea
Chan Kim and Junghee Park: Department of Civil and Environmental Engineering, Incheon National University,
119 Academy-ro, Yeonsu-gu, Incheon 22012, Republic of Korea
Abstract
This study investigates the effect of loading frequency on the liquefaction resistance of reconstituted sandy soils with
different grain size distributions. Three sand samples (SAND1, SAND2, and SAND3) were tested under undrained cyclic
loading using the cyclic direct simple shear (CDSS) test. The experimental program was performed at multiple cyclic stress
ratios (CSRs) and loading frequencies ranging from 0.03 Hz to 0.5 Hz. The number of cycles to liquefaction (Ncyc-liq), excess pore
water pressure generation, and cyclic resistance ratio at 15 cycles (CRR15) were evaluated to assess the frequency-dependent
liquefaction behavior. The results reveal a consistent trend across all three sand types, characterized by two distinct behavioral
zones. In the low-frequency range (0.03–0.10 Hz), the influence of frequency on Ncyc-liq and CRR is minimal. However, when
the frequency exceeds 0.10 Hz, both parameters exhibit significant increases, indicating enhanced liquefaction resistance. This
transition at 0.10 Hz was observed consistently, regardless of CSR level or soil type, and is proposed as a threshold frequency
distinguishing a Stable/Minor-Effect Zone from an Increasing Resistance Zone. The findings underscore the importance of
incorporating loading frequency into liquefaction assessments. The threshold frequency offers a useful reference for engineering
calculations and seismic stability assessments of sandy soils, as it marks the boundary beyond which frequency effects must be
carefully considered in liquefaction evaluation and design.
Key Words
cyclic direct simple shear test; liquefaction resistance of sand; loading frequency
Address
Dong-Kiem-Lam Tran: Department of Civil Engineering, University of Architecture Ho Chi Minh City, Ho Chi Minh City, Viet Nam
Sung-Sik Park: Department of Civil Engineering, Kyungpook National University, 80, Daehak-ro Buk-gu, Daegu 41566, Republic of Korea
Abstract
This study investigates the dynamic behavior of nonlocal thermoelastic solid with diffusion subjected to Ramp type
thermal source, with a focus on the influence of nonlocal parameter on the material. To examine this we consider nonlocal
thermoelastic solid with diffusion. The governing equations are solved using Integral transforms to analyze the nonlocal
parameter response of the thermoelastic solids with diffusion. Our findings show that change in nonlocal parameter resulted in
the variations of normal stress, shear stress, mass concentration and temperature. The study highlights the importance of
nonlocality in determining the stress, temperature and concentration fields in nonlocal thermoelastic- diffusive solids due to
ramp type heat. The results provide valuable insights for applications in advanced materials science, micro- and nano-scale
engineering, and dynamic load analysis, where understanding the coupled effects of nonlocality, thermoelasticity, and diffusion
is essential.
Key Words
angular ferequency; fourier transformation; nonlocal; stress; thermoelastic; thermomechanical
Address
Belay Fikadu Gerba, Parveen Lata and Satya Bir Singh: Department of Mathematics, Punjabi University, Patiala, 147002, India
