Article
Engineering, Geological
Xiao-Qian Zhang, Ming-Guang Li, Jin-Jian Chen
Summary: The study shows that excessive deformation of the foundation pit is closely related to the combined effect of rainfall and excavation. This response can be attributed to the variation in pore-water pressure and the effective stress induced by rainfall and excavation. Post-rainfall excavation is a key factor in further aggravating deformation in the foundation pit.
Article
Construction & Building Technology
Taishan Lu, Kai Wu, Songyu Liu, Guojun Cai
Summary: This paper proposes a method to quantify the three-dimensional effects of rectangular excavation in clay and carries out a comprehensive parametric study and experimental verification, offering a more reliable way to evaluate the mechanical behavior of excavation.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2023)
Article
Geosciences, Multidisciplinary
Chongzhi Wu, Li Hong, Lin Wang, Runhong Zhang, Samui Pijush, Wengang Zhang
Summary: This study proposes a convolutional neural network (CNN) surrogate model based on the classical architecture VGG6 for random field finite element analysis (RF-FEM). The model effectively reduces the computational burden and shows great potential in reliability analysis of spatially variable soils.
Article
Engineering, Geological
Yongqin Li, Wengang Zhang, Runhong Zhang
Summary: This study reviewed a complex braced excavation case history using finite element analysis to explore the impact of stress-induced soil anisotropy on excavation safety and the built environment. By simulating stress-induced anisotropy under different soil conditions, it revealed the characteristics of soil displacement and retaining structure deformation, emphasizing the significant influence of soil anisotropy on excavation responses.
Article
Engineering, Civil
Rakshanda Showkat, G. L. Sivakumar Babu
Summary: This paper proposes an equation based on Terzaghi theory to evaluate the variation of bearing capacity due to suction variations in unsaturated soils. The proposed equation yields higher bearing capacity values compared to conventional theories. The impact of soil properties and uncertainty factors is analyzed using a surrogate model, which predicts the surface displacements of the footing with enhanced accuracy and computational efficiency.
TRANSPORTATION GEOTECHNICS
(2023)
Article
Engineering, Environmental
A. Johari, A. R. Kalantari
Summary: This study establishes a stochastic framework to evaluate the reliability indices of individual failure modes in unsaturated soil excavation, considering the uncertainty of soil properties and unsaturated state. The system reliability index is obtained using the sequential compounding method, with non-saturated state affecting the mean and standard deviation of the safety factor.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2021)
Article
Computer Science, Interdisciplinary Applications
Meng Han, Xiangsheng Chen, Zhe Li, Jinqing Jia
Summary: This paper proposes an improved inverse analysis method and a modified apparent earth pressure model for braced excavations in soft clay. A new procedure for inverse analysis of excavation is suggested based on quintic spline interpolation function, and a trial algorithm is used to eliminate errors generated in the inverse process. The proposed inverse solutions are validated by numerical simulations and reported engineering examples and show good agreements. Based on the inverse data and empirical apparent pressure diagram (APD), a modified apparent earth pressure method for braced excavations in soft clay is further suggested, and the relationship between the degree of anisotropy of soft clay and apparent earth pressure coefficients is discussed.
COMPUTERS AND GEOTECHNICS
(2023)
Article
Construction & Building Technology
Jinyan Zhao, Stefan Ritter, Matthew J. DeJong
Summary: The current early stage assessment methods for deep excavation induced structural damage have large uncertainties due to modeling simplifications and incomplete information. This paper proposes an elastoplastic soil-structure-interaction solution to predict building response to adjacent deep excavations with braced supports, and explores the uncertainties in two case studies. The results suggest that prediction of ground movement profiles is the main source of uncertainty in early stage building damage assessment.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2022)
Article
Computer Science, Interdisciplinary Applications
Zixian Jin, Chengping Zhang, Wei Li, Shiqin Tu, Libin Wang, Saixu Wang
Summary: This paper investigates the impact of excavation stability on base heave failure using both numerical and analytical methods. It proposes a rigid block rotational failure mechanism based on the analysis of numerical results, and develops an analytical formula for the safety factor of excavation stability. The influences of soil and excavation conditions on stability are analyzed, and a rigid block rotational failure mechanism is proposed for stratified stratum. The results demonstrate the effectiveness of the proposed mechanism in calculating safety factor and providing a continuous and smooth failure surface.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Zheng Zhou, Dian-Qing Li, Te Xiao, Zi-Jun Cao, Wenqi Du
Summary: This study proposes a response surface-guided adaptive slope reliability analysis method which corrects the preliminary slope stability analysis based on response surface, and explores the failure mechanisms of slope stability in spatially varying soils.
COMPUTERS AND GEOTECHNICS
(2021)
Article
Computer Science, Interdisciplinary Applications
Chuantan Hou, Shihe Zhao, Junhao Zhong, Kezhi Song, Yongxin Li
Summary: This paper develops a framework using the kinematic approach to assess the face stability of tunnels in unsaturated soils under seismic conditions. Three methods are employed to represent the earthquake acceleration for the seismic analysis. The framework is validated and analyzed through comparison with prior research, and parameter analyses are performed to discuss the effects of various factors.
COMPUTERS AND GEOTECHNICS
(2023)
Article
Engineering, Geological
Mahmoud Ghazavi, Elmira Mahmoodi, Hesham El Naggar
Summary: An analytical solution is proposed to simulate the load-displacement variations of laterally loaded piles in unsaturated soils. The study develops analytical formulations for stiffness and p-y relations considering soil suction. The developed solutions are validated with pile tests and parametric studies evaluate the effects of pile length, cross-section configuration, and applied vertical load on the pile lateral response.
Article
Engineering, Civil
Guangyu Dai, Fei Zhang, Yuke Wang
Summary: This study presents stability analyses of layered soil slopes in unsaturated conditions and determines the factor of safety involving suction stress of unsaturated soil using a limit equilibrium method. The obtained results show that larger suction stress provided in unsaturated clay dominates the stability of the layered slopes, while the location and thickness of the clay layer have significant influences on slope stability.
FRONTIERS OF STRUCTURAL AND CIVIL ENGINEERING
(2022)
Article
Engineering, Environmental
Xin Gu, Qiang Ou, Wengang Zhang, Jie Fu, Shuli Hao
Summary: This study aims to estimate the stability of unsaturated slopes under water fluctuation. Both deterministic and probabilistic analyses were conducted using a user-defined ABAQUS Subroutine to simulate various dynamic water fluctuation conditions. The results showed that neglecting the spatial variability of soil strength parameters can lead to overestimated safety factors during water rising and rising-constant-falling, and underestimated stability during water falling, except at low falling velocities. Therefore, it is recommended to consider the inherent spatial variability of soil strength parameters when estimating reservoir slope stability.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2023)
Article
Engineering, Geological
Ari Surya Abdi, Chang-Yu Ou
Summary: This study investigates the failure mechanism of structural support systems in braced excavations using the three-dimensional finite-element method. By considering a new model of a strut-wall connection, the stability analysis yielded good results. The yielding of the strut-wall connection initiated the collapse of the bracing system, followed by the yield of struts and failure of soils. A robust failure mechanism was observed, where the yielding initially developed at the middle section towards the corner of excavation geometry.
INTERNATIONAL JOURNAL OF GEOMECHANICS
(2022)
Article
Engineering, Environmental
A. Johari, A. R. Kalantari
Summary: This study establishes a stochastic framework to evaluate the reliability indices of individual failure modes in unsaturated soil excavation, considering the uncertainty of soil properties and unsaturated state. The system reliability index is obtained using the sequential compounding method, with non-saturated state affecting the mean and standard deviation of the safety factor.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2021)
Article
Engineering, Geological
A. Johari, B. Vali, H. Golkarfard
Summary: Ground response analysis is greatly affected by uncertainties in soil parameters, and determining reliability indices for Peak Ground Acceleration (PGA) with consideration of soil layers cross-correlation is time-consuming. This study uses frequency domain analysis to treat layered-soil sites as serial components, and proposes a method to determine reliability indices and combine them using Sequential Compounding Method (SCM) for efficient computation. Comparisons with Monte Carlo Simulation (MCS) and Subset Simulation (SS) show high accuracy and reduced computational time with the proposed methods.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2021)
Article
Engineering, Geological
A. Johari, A. Talebi
Summary: This study applies a random finite-element method to model the behavior of a piled-raft foundation in complex soil-structure interaction, revealing that uncertainties in soil parameters have a greater impact on the foundation's differential settlement.
INTERNATIONAL JOURNAL OF GEOMECHANICS
(2021)
Article
Engineering, Environmental
A. Johari, H. Golkarfard, F. Davoudi, A. Fazeli
Summary: The study found that using only 5% nano-clay almost completely fixed the soil collapse behavior. It was concluded that reducing water content, dry density, and nano-clay contents increases the collapse potential of the soil, while increasing applied vertical stress also increases it.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2021)
Article
Engineering, Civil
A. Johari, H. Golkarfard, F. Davoudi, A. Fazeli
Summary: Collapsible soils, capable of withstanding relatively high pressure in an unsaturated state, pose challenges for infrastructures built in their regions, with nano-silica being studied as a potential stabilizer. Research findings indicate that the nano-silica content and saturation pressure have direct effects on the deformation of collapsible soils.
IRANIAN JOURNAL OF SCIENCE AND TECHNOLOGY-TRANSACTIONS OF CIVIL ENGINEERING
(2022)
Article
Engineering, Geological
A. H. Amjadi, A. Johari
Summary: The study combines nonlinear time-domain ground response analysis with variability of soil parameters by considering the boreholes' location using a geostatistical method. The results show that considering the boreholes' location significantly affects the seismic ground responses and their coefficient of variation. Among the surface responses in the studied site, peak ground displacement and peak ground acceleration exhibit the highest dispersion due to variability of soil properties.
BULLETIN OF EARTHQUAKE ENGINEERING
(2022)
Article
Engineering, Civil
A. Johari, H. Fooladi
Summary: This paper investigates the soil slope stability of a real site using geostatistical and finite element methods. Two procedures are used and compared, and the results show that the second method is more reliable and can provide better modeling of the soil properties in other parts of the site.
TRANSPORTATION GEOTECHNICS
(2022)
Article
Engineering, Geological
A. R. Kalantari, A. Johari
Summary: This study incorporates geostatistical conditional simulations and a pseudostatic approach into the Finite-Element Method (FEM) MATLAB code to improve the reliability of the retaining system under seismic conditions. The results show that utilizing the Conditional Random Finite-Element Method (CRFEM) can significantly improve the mean value of the Factor of Safety (FS) and reduce the related standard deviation. Moreover, the analysis reveals that bending moment and lateral displacement are the fundamental mechanisms in the static and seismic states.
INTERNATIONAL JOURNAL OF GEOMECHANICS
(2022)
Article
Construction & Building Technology
Abed Soleymani, Mohammad Amir Najafgholipour, Ali Johari
Summary: An experimental study was conducted to investigate the mechanical properties of clay brick masonry fabricated using traditional mortars. The compressive stress-strain behavior, compressive strength, elastic modulus, and rupture modulus of the mortars were determined. Tests on masonry prisms and wallettes were carried out to evaluate the compressive stress-strain behavior of masonry and the shear bond strength of the brick-mortar interface. The results showed that the highest compressive strength, elastic modulus, and diagonal shear strength were observed in the masonry fabricated with gypsum mortar.
JOURNAL OF BUILDING ENGINEERING
(2022)
Article
Construction & Building Technology
Abed Soleymani, Mohammad Amir Najafgholipour, Ali Johari, Sajad Jowkar
Summary: In this study, the effectiveness of the Near Surface Mounted (NSM) method for in-plane shear strengthening of traditional and historical Unreinforced Masonry (URM) walls was examined through a comprehensive experimental study. The study involved preparing square solid clay brick masonry wallettes with different types of traditional mortars and retrofitting them with NSM Glass Fiber Reinforced Polymer (GFRP) bars. Diagonal shear tests were then conducted to evaluate the in-plane shear behavior of the wallettes. The results show that the retrofitting method can enhance the in-plane shear strength and ultimate lateral drift capacity of the URM wallettes.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Engineering, Civil
A. R. Kalantari, A. Johari, M. Zandpour, M. Kalantari
Summary: Evaluation of stability and determination of the Critical Slip Surface (CSS) for soil slopes are important in geotechnical engineering. The stability and CSS are affected not only by soil heterogeneity, but also by borehole location and soil parameter prediction methods. This study combines Finite Element Method (FEM) and geostatistical method to evaluate reliability characteristics and CSS distribution with consideration of known data, borehole location, load uncertainty, and soil heterogeneity. Results show that conditional simulation improves the accuracy of Factor of Safety (FS) distribution by up to 14% compared to unconditional simulation, and reduces the related standard deviation by 4% to 40%. Conditional simulation also reduces uncertainty of the slip surface and unsafe distance from the slope edge. Soil heterogeneity has a major impact on CSS distribution and induces local CSS that cannot occur on homogeneous slopes.
TRANSPORTATION GEOTECHNICS
(2023)
Article
Engineering, Civil
A. Johari, H. Fooladi
Summary: This paper investigates the location of boreholes in slope stability projects by considering the conditional spatial variability of soil properties through geostatistical and finite element methods. A real site with fifteen boreholes is analyzed to determine the reliability indices of the global safety factor and maximum horizontal displacement safety factor of the slope. The study reveals that considering the conditional spatial variability of soil properties leads to different reliability indices for the global safety factor and the maximum horizontal displacement safety factor. Furthermore, the system reliability index without considering the location of the known data is higher than the real values, indicating a higher-confidence reliability index in analyses.
IRANIAN JOURNAL OF SCIENCE AND TECHNOLOGY-TRANSACTIONS OF CIVIL ENGINEERING
(2023)
Article
Engineering, Multidisciplinary
A. Johari, H. Golkarfard, M. Mesbahi
Summary: The expansion of urban areas and the resulting demand for residential spaces have led to the need for excavation in most construction projects. One of the significant challenges in geotechnical engineering is the impact of numerous factors on excavation methods. Therefore, selecting an appropriate stabilization method for excavation walls can effectively mitigate financial and life-threatening risks. Nano-materials, as stabilizing agents, play a central role in improving soil characteristics. This study investigates the use of nano-clay injection for stabilizing an actual excavation wall and examines the effects of modern procedures on soil slope resistance.
Article
Construction & Building Technology
Ali Khosravifardshirazi, Ali Johari, Akbar A. Javadi, Mohammad Hassan Khanjanpour, Behnaz Khosravifardshirazi, Mohammad Akrami
Summary: One key issue in structural and geotechnical engineering is that different parts of buildings are often analyzed separately and neglect some effects. This study evaluates the soil-structure interaction in the foundations of concrete buildings using the direct finite element method. The results show that the interaction can significantly affect foundation settlement, deformation, soil pressure, and reinforcement weight. An equation is provided to simplify considering these effects in foundation design.
Article
Engineering, Multidisciplinary
A. Johari, A. H. Amjadi, A. Heidari
Summary: In this study, the impact of uncertainties of dynamic soil property on ground response analysis was investigated by coupling nonlinear time-domain ground response analysis and uncertainties of soil parameters using MATLAB code. The maximum Coefficient Of Variation (COV) of peak ground motion parameters, including fundamental period, response spectrum, and amplification factor, was calculated in stochastic analysis. The results demonstrated that the heterogeneity of soil parameters had a significant effect on the variation of the surface Peak Ground Displacement (PGD), while the fundamental period was least affected among other stochastic responses.
Article
Computer Science, Interdisciplinary Applications
Yinghao Deng, Yang Xia, Di Wang, Yan Jin
Summary: This study investigates the mechanism of hydraulic fracture propagation in laminated shale, develops a numerical solver, and validates the effectiveness of the method through simulation experiments. The study also examines the influence of the interaction between hydraulic fractures and weak interfaces on the mechanical properties of shale.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Zhichao Zhang, Mingfei Feng, Guangshuo Zhou, Zhenglong Xu
Summary: A thermodynamic constitutive model for structured and destructured clays is proposed in this paper. The model includes state-dependent relations of hyperelasticity and plasticity without the concept of yielding surface. The proposed model captures the couplings between elasticity and plasticity and the effects of bonding structure.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Deze Yang, Xihua Chu
Summary: Creep and stress relaxation behaviors in granular materials are influenced by the time-dependent changes in their microstructure, with particle shape playing a significant role. However, the effects of particle shape on these behaviors are still not well understood. In this study, 3D DEM models incorporating the rate process theory and superellipsoids are used to simulate creep and stress relaxation in granular samples with different aspect ratios and blockiness. The results show that both aspect ratio and blockiness have a significant influence on creep and stress relaxation, with aspect ratio affecting creep through contact force ratio and blockiness affecting stress relaxation through variation in normal contact force anisotropy. These findings provide insights into the effects of particle shape on creep and stress relaxation in granular assemblies.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Shahab Amanat, Kourosh Gholami, Reza Rafiee-Dehkharghani, Dipanshu Bansal
Summary: This paper investigates the optimal design of wave barriers using the modified non-dominated sorting genetic algorithm-II (NSGA-II) and the Bloch-Floquet theory. The aim is to find the optimal design of plane wave barriers with a wide bandgap at a low-frequency range and low construction cost. The study develops a modified NSGA-II algorithm to determine the optimal arrangement of concrete in wave barrier unit cells. The performance of the optimal barriers is examined through finite element simulation and their efficacy in attenuating plane S-waves is verified.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Yanlin Su, Guoqing Cai, Fengjie Yin, Yepeng Shan, Annan Zhou
Summary: This paper presents a novel elastic-viscoplastic constitutive model that takes into account particle breakage to reproduce the time-dependent behavior of coarse-grained soil. The model integrates the Unified Hardening (UH) model, the elastic-viscoplastic (EVP) model, and the overstress theory. The relationship between particle breakage and loading rate is established, and state variables associated with the critical state of coarse-grained soil are derived to consider both time and particle breakage. A three-dimensional elastic-viscoplastic constitutive model is constructed by combining a one-dimensional viscoplastic hardening parameter with a secondary consolidation coefficient considering particle breakage. The proposed model requires 19 parameters and effectively describes the influence of time-dependency and particle breakage on the shear, dilatancy, and compression behaviors of coarse-grained soil with different confining pressures or initial void ratios. Experimental data comparisons validate the model's ability to replicate the time-dependent behavior of coarse-grained soil.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Shichao Zhang, Yaqiong Wang, Qidong Gao, Xiaobo Ma, Haixiao Zhou, Zhifeng Wang
Summary: Accurately evaluating and predicting ground settlement during tunnel excavation is essential for ensuring tunnel stability. This study conducted a probabilistic analysis of ground settlement under uncertain soil properties. The results demonstrate that spatially variable soils significantly influence the ground settlement in the vertical direction.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Xu Zhang, Bin Luo, Youjun Xu, Zhiwen Yang
Summary: This paper presents an analytical solution for horizontal displacements induced by small radius curve shield tunneling. The formula is derived based on the image method and Mindlin solution, considering additional thrust, frictional resistance, ground loss, and grouting pressure. The solution is validated with on-site data, demonstrating its reliability and providing a new approach for predicting and controlling stratum horizontal displacements in curve shield tunneling. The study finds that ground loss has the most significant influence on displacements, and soil closer to the tunnel exhibits larger horizontal displacements.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Jian-Hong Wan, Ali Zaoui
Summary: Ground vibrations during earthquakes can cause soil strength loss and structural damage. Rubber-soil mixtures (RSM) have shown promise in reducing residual ground deformation. This study used molecular dynamics simulations to investigate the friction behavior of the rubber-clay interface in RSM systems. The results revealed a direct correlation between normal stress and friction force, with denser soil systems exhibiting higher friction forces.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Hongying Wang, Qiang Zhang, Peinan Wu, Yanjing Li, Lijun Han, Guilei Han
Summary: In addition to the Mohr-Coulomb and Hoek-Brown criteria, other nonlinear functions are used to describe the plastic response of rock mass. This paper derived the equivalent cohesive strength, frictional angle, and dilatancy angle for nonlinear yield and plastic flow rock masses. The solution for a circular tunnel in any nonlinear yield and plastic flow rock masses was derived and verified using a numerical procedure. The analysis of strain-softening rock masses under two assumed nonlinear yield criteria was also studied.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Zhijun Wu, You Wu, Lei Weng, Mengyi Li, Zhiyang Wang, Zhaofei Chu
Summary: This study proposed a machine learning approach to predict the uniaxial compression strength (UCS) and elastic modulus (E) of rocks. By measuring meso-mechanical parameters and developing grain-based models, a database with 225 groups of data was established for prediction models. The optimized kernel ridge regression (KRR) and gaussian process regression (GPR) models achieved excellent performance in predicting UCS and E.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Mingjun Zhou, Zhenming Shi, Chong Peng, Ming Peng, Kahlil Fredrick E. Cui, Bo Li, Limin Zhang, Gordon G. D. Zhou
Summary: In this paper, the erosion and deposition processes during overtopping dam breaching are simulated using a novel method (ED-SPH). The proposed model is able to capture the complex behaviors of dam soil erosion, entrainment, and depositions. Soil deposition hinders particle movement and reduces water velocity at the water-soil interface.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
C. Chavez-Negrete, F. J. Dominguez-Mota, R. Roman-Gutierrez
Summary: To accurately simulate groundwater flow in porous layered media, it is important to consider all environmental factors and use a generalized finite differences scheme as a meshless method for spatial discretization. This approach ensures robustness and accuracy of the numerical solution.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Shuairun Zhu, Lulu Zhang, Lizhou Wu, Lin Tan, Haolong Chen
Summary: This paper investigates the effectiveness of the cascadic multigrid method applied to the improved Picard iteration method for solving nonlinear problems in deforming variably saturated porous media. Two improved Picard iteration methods are proposed, and their effectiveness is verified through numerical examples. The results show that the improved methods have faster convergence and higher computational efficiency compared to the classical method.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Yuan Cao, Yan-Guo Zhou, Kyohei Ueda, Yun-Min Chen
Summary: Investigated shear stress responses of enclosed soil in deep soil mixing (DSM) grid-improved ground, and revealed the characteristics of the waist effect and mathematical model for shear stress reduction ratio.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Jinfan Chen, Zhihong Zhao, Jintong Zhang
Summary: This study develops data-driven criteria to estimate the peak shear strength (PSS) of rock fractures, considering the effects of surface roughness features. A high-quality dataset is created using particle-based discrete element method and diamond-square algorithm. Tree-based models and convolutional neural network are trained to predict the PSS of rock fractures, and their reliability is verified using experimental data.
COMPUTERS AND GEOTECHNICS
(2024)
