Abstract
The paper examines the nonlinear post buckling responses of layered nano-materials reinforced soil and
rocks of multiscale interactions that affect geomechanical stability. It proposes a modeling framework to model
spatial variation of material properties via soil and rocks layers (and also through nanomechanics reinforcing effects
including increases in the stiffness and shear resistance). A set of equations governing the energy principles as the
governing equations are formulated and their solution is traced in conjunction between Rayleigh-Ritz approach and
iterative numerical methods to trace the post-buckling behavior. Important parameters investigated are the
concentration of reinforcement, the thickness of the layers, mechanical characteristics of the soil and rocks and the
geometry of the weak planes or cut-outs in the system. Findings indicate that nanocomposites reinforcement adds
significant value to the load-bearing capacity, suppressing the post-buckling initiation, and structural integrity as a
whole. It is a study as it gives feedback in the optimization of nano-reinforced geomechanical structures to ensure
better performance of such structures in foundations, slopes, and underground construction under complicated
loading conditions.
Key Words
geomechanical structures; nanomechanical; nonlinear post-buckling analysis; soil–rock
systems
Address
Yurun Wang: Faculty of Public Security and Emergency Management,
Kunming University of Science and Technology, Yunnan 650093, China
Mohsen Nasihatgozar: Department of Mechanical engineering, Kas.C., Islamic Azad university, Kashan, Iran
Seyyed Rohollah Taghaodi: Department of Industrial engineering, Kas.C., Islamic Azad university, Kashan, Iran
M. Ghaytani: Department of Mechanical Engineering, National Iranian Oil Engineering and Construction Company
(NIOEC), Iran
Abstract
The production of geogrids for use in geotechnical engineering applications could benefit from 3D
printers providing the opportunity for rapid design development and application of economical, easily accessible, and
environmentally friendly raw materials. This study looks at how the design parameters, like aperture shape, rib
thickness, and rib width, affect the tensile strength and strain behavior of geogrids designed with open-access
software and printed with a large-scale 3D printer working based on fused deposition modeling techniques. Besides,
a comparison of the performance of 3D-printed and factory-made geogrids has also been conducted on triaxial
geogrids. The tensile strength and thermo-mechanical properties of geogrid samples have been characterized using
uniaxial tensile tests and differential scanning calorimetry (DSC) analysis. The results revealed that the tensile
strength and tensile moduli of geogrids increase with increasing junction thickness, rib thickness, and rib width.
Findings also showed that the single rib of geogrids with biaxial (BX) architecture had a larger cross-section than that
in triaxial (TX) grid structure by about 40% to satisfy the same mass of fabricated geogrids, and resultantly, the
maximum load capacity of BX-grids overpass that of TX-grids by about 6%. However, the TX-grids showed better
performance for unit strain at failure by over 6% as compared with BX-grids. Therefore, the experiments and
analysis have been mainly focused on the 3D-TX grids, their stress and strain analyses at different rib thickness, the
correlation with thermal properties of fabricated specimens and a comparison between the performance metrics
between the 3D-printed and counterpart factory-made geogrids.
Key Words
3D-printing; geogrids; soil reinforcement; tensile modulus; tensile tests
Address
Bahadir Ok and Bestami Mirac Sert: Department of Civil Engineering, Adana Alparslan Turkes Science and Technology University,
Balcali Neighborhood, Catalan Street No:201/1 01250, Saricam, Adana, Turkey
Mirsadegh Seyedzavvar and Cem Boga: Department of Mechanical Engineering, Adana Alparslan Turkes Science and Technology University,
Balcali Neighborhood, Catalan Street No:201/1 01250, Saricam, Adana, Turkey
Kadir Aydin: Department of Mechanical Engineering, Ostim Technical University,
100. Yil Blv. 06374, Yenimahalle, Ankara, Turkey
Abstract
This paper revisits a classical topic in the geotechnical profession, i.e., how to select an appropriate
method for slope stability analysis. This study focuses on slopes with weak soil layers, and the methods investigated
are the typical approaches based on the frameworks of limit equilibrium method (LEM), finite element method
(FEM) and limit analysis (LA). This study includes the LEMs, finite element stress method (FESM), strength
reduction method (SRM) and discontinuity layout optimization (DLO). It is found that when dealing with slopes
with weak soil layers using LEM, there are higher requirements for the factor of safety (FS) iteration algorithm. The
difficulty in convergence of FS during iterative solution may occur due to the assumption regarding the inter-slice
force, which may cause overestimated FS with relative error exceeding 45% for a slope with a weak foundation
layer. Meanwhile, the inherent transition of failure mechanisms of slopes with weak layers increases the difficulty in
determining the critical slip surface by LEMs. The non-convergence issue is avoided in FESM, but its FS results are
sensitive to the model domain and element size for a slope with a thin soft band (FS results ranging from 0.439 to
1.238 under different element sizes and model domains), exhibiting unsatisfactory performance under complex
conditions. In general, DLO has better performance in analyzing the stability of slopes with weak soil layers,
especially in capturing the failure mechanism.
Key Words
discontinuity layout optimization (DLO); failure mechanism; finite element method (FEM);
limit equilibrium method (LEM); slope stability analysis
Address
Lei Huang: College of Architecture and Civil Engineering, Sanming University, Sanming 365004, China;
Department of Civil and Environmental Engineering,
The Hong Kong Polytechnic University, Hong Kong, China;
Key Laboratory of Intelligent Construction and Monitoring of Engineering Structures in Fujian Province
College, China
Leilei Liu: Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring,
Ministry of Education, School of Geosciences and Info-Physics, Central South University,
Changsha 410083, China
Abstract
This study investigates the hygrothermal–thermodynamic free-vibration response of bio-inspired
helicoidal laminated composite plates. A simplified integral Higher-Order Shear Deformation Theory (HSDT) is
used to model a range of nonlinear rotation-angle layups, including Helicoidal-Recursive (HR), Helicoidal-
Exponential (HE), Helicoidal-Semicircular (HS), Fibonacci Helicoidal (FH), and Linear Helicoid (LH)
configurations. An analytical 2D formulation with four unknowns was developed using integral expressions. The
motion equations were derived using Hamilton' principle and solved using the Navier method. Our findings clarify
how hygrothermal environments affect laminated composite structures, revealing distinct performance differences
between conventional and bio-inspired helicoidal designs under these conditions. Both temperature and moisture,
individually and in combination, consistently lowered the fundamental vibration frequencies, indicating reduced
structural stiffness under environmental loading. We examined the effects of key factors, including layer count (up to
50), helicoidal layup schemes, and geometric properties, on the free-vibration behaviour. This comprehensive
analysis advances the understanding of vibrational performance under varying conditions and offers valuable
guidance for designing composites with improved environmental resilience, particularly in aerospace and marine
applications. The novelty of this study lies in its detailed examination of the hygrothermodynamic behaviour of bioinspired
helicoidal composites, offering valuable insights for optimising structural integrity in fluctuating environmental settings.
Key Words
bio-inspired helicoidal; hamilton; hygro-thermo-dynamic; laminated plates; vibration
Address
Ghani Gourdache: Materials and Hydrology Laboratory, University of Sidi Bel Abbes, Faculty of Technology,
Department of Civil Engineering, BP 89, Sidi Bel Abbes 22000, Algeria;
Department of Civil Engineering, Faculty of Civil Engineering and Architecture Engineering,
Amar Telidji University, Laghouat, Algeria
Mohammed El Amin Bourouis: Department of Civil Engineering, Faculty of Civil Engineering and Architecture Engineering,
Amar Telidji University, Laghouat, Algeria;
Laboratory of Structures, Geotechnics and Risks, Department of Civil Engineering,
Hassiba Benbouali University of Chlef, Ouled Fares, Algeria
Abderrahmane Menasria and Abdelhakim Bouhadra: Materials and Hydrology Laboratory, University of Sidi Bel Abbes, Faculty of Technology,
Department of Civil Engineering, BP 89, Sidi Bel Abbes 22000, Algeria;
University of Khenchela, Faculty of Sciences and Technology, Department of Civil Engineering,
BP 1252 Road of Batna, Khenchela 40000, Algeria
Mohamed Bourada: Materials and Hydrology Laboratory, University of Sidi Bel Abbes, Faculty of Technology,
Department of Civil Engineering, BP 89, Sidi Bel Abbes 22000, Algeria
Abdelmoumen Anis Bousahla: Laboratoire de Modélisation et Simulation Multi-échelle, Université de Sidi Bel Abbés, Algeria
Abdelouahed Tounsi: Materials and Hydrology Laboratory, University of Sidi Bel Abbes, Faculty of Technology,
Department of Civil Engineering, BP 89, Sidi Bel Abbes 22000, Algeria;
Department of Civil and Environmental Engineering, King Fahd University of Petroleum & Minerals, 31261
Dhahran, Eastern Province, Saudi Arabia
Mohammed A. Balubaid: Department of Industrial Engineering, Faculty of Engineering, King Abdulaziz University,
Jeddah, Saudi Arabia
A.A. Alsolami: Department of Mathematics, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
S.R. Mahmoud: Department of GRC, Applied College, King Abdulaziz University, Jeddah, Saudi Arabia
Abstract
Ground improvement techniques are essential for addressing settlement and deformation issues in soft
soil construction sites, preventing delays and structural failures. Stone column reinforced embankment systems have
emerged as efficient options among these techniques. The present investigation used numerical analysis to assess the
efficacy of stone column-reinforced embankments on soft soil, with a specific emphasis on a rectangular 3D strip
located beneath the centre of the embankment. An investigation is conducted to analyse the impact of several
parameters, including encasement length, encasement stiffness, column spacing, length, and pattern of stone column,
on settlement, lateral deformation, excess pore water pressure (PWP), and vertical stress. The findings indicate that
increasing the length of stone columns has a considerable effect on reducing the maximum settlement, with
reductions of up to 76% observed for end bearing stone columns. Stone columns with a closer spacing and a
triangular pattern are effective in minimizing settlement. When stone columns are end bearing and fully encased,
settlement is reduced by around 87% compared to untreated soil. The greatest enhancement is achieved when the
encasement stiffness is increased to 4000 kN/m, resulting in a measured value of 8.33. Overall, it offers useful
insights into the efficiency of stone column-reinforced embankments in reducing settlement and lateral deformation
problems in construction projects. These findings make a valuable contribution to the advancement of knowledge in
ground improvement techniques and have important implications for improving construction efficiency and
mitigating project hazards in soft soils
Abstract
In the current study, rectangular shape specimens containing holes and two-edge open flaws were
prepared using gypsum to investigate the effect of defects on the shear failure behavior of rock-like material under
different normal stresses. Firstly, three rock bridge angles were prepared. In each sample, the hole number was
different, i.e., one hole, two holes, and three holes. To investigate the fracture processes of the samples, direct shear
tests were carried out on them without the presence of the normal load. Concurrent with the experimental test,
numerical simulation was performed on similar samples using a two-dimensional particle flow code, PFC2D.
Secondly, numerical models containing closed notches and open holes were tested under three different normal
stresses in a direct shear test. The material simulation was carried out using the Flat-Joint model and pre-joints are
created as the Smooth Joints model. The results show that, in samples containing open notches, two tensile wing
cracks started from joint tips while propagating in the direction of shear loading till joined with the hole boundaries.
The rock bridge angles and the number of holes affect the failure pattern. The shear strength of models increased with
the increase of both the rock bridge angle and the number of holes. In samples containing the closed notches, the
failure pattern and shear strength were affected by the rock bridge angle, number of holes, and normal stresses. Also,
the results show that there is an acceptable agreement between physical models and numerical models.
Key Words
crack; direct shear test; hole; notch; PFC2D; rock bridge
Address
Mohamad Javad Azinfar and Seyed Amirasad Fatemi: 1Mining Group, Faculty of Engineering, University of Sistan and Baluchestan, Zahedan, Iran
Vahab Sarfarazi and Saeid Aghighi Ghafoor: Department of Mining Engineering, Hamedan University of Technology, Hamedan, Iran
