Amin Keshavarz

Verified

Amin verified their affiliation via an institutional email.

Learn more

Verified

Amin verified their affiliation via an institutional email.

Learn more

• PhD
• Professor (Associate) at Persian Gulf University

This paper investigated the seismic bearing capacity of strip footings on cohesive-frictional slopes using Finite Element Limit Analysis (FELA). The Modified pseudo-dynamic (MPD) approach was used for modelling seismic conditions due to its capability to consider the changes in the amplitude and the phase of acceleration. The OptumG2, a FELA-based...

A series of lower-bound adaptive finite element limit analyses (LB-AFELA) was performed to compute the ultimate bearing capacity of a rigid rough strip footing situated on the crest of a rock slope with an underground circular void. The generalized Hoek–Brown criterion was utilized. The results were presented using a dimensionless bearing capacity...

This paper provides a comprehensive examination of the dynamic behavior of buried pipelines under blast loadings to improve the literature in this field. The study presents both analytical and numerical solutions based on the Euler–Bernoulli beam theory to evaluate the response of pipelines surrounded by soil. The soil is simulated as a viscoelasti...

Optimisation-based backcalculation problem in order to extract pavement moduli and thickness have been drastically developed nowadays. It not only serves a feasible cost-effective technique but also shapes a special class of non-destructive tests. The historical course of evolution in this field has caused the emergence of a variety of detector cri...

Although considerable research has explored the static and seismic bearing capacity of strip footings on slopes or excavations, the influence of clay strength anisotropy on the bearing capacity of strip footing near excavations, specifically considering pseudo‐dynamic conditions, remains unexplored. This study used the finite element limit analysis...

The ultimate bearing capacity of a strip footing placed horizontally over the edge of a sloping rock mass has been determined on the basis of the stress characteristics method (SCM) using the generalized Hoek–Brown yield criterion. The effect of footing–rock interface roughness on the results has also been analyzed. The problem has been solved, in...

A true understanding of interaction between soil and reinforcements is of great help in safe designing of mechanically stabilized earth (MSE) walls. In this paper, in order to study the interaction between the soil and Polymeric Strap (PS), large-scale laboratory pullout tests were carried out on the straps buried in the dry compacted granular soil...

This study investigated active and passive lateral earth pressure in the presence of anisotropic seepage conditions. The soil was assumed to be granular and fully saturated. Three methods were used to solve the problem: (1) the upper bound limit analysis method (UBM); (2) upper and lower bound solutions of finite-element limit analysis (FELA); and...

Soil-reinforcement interaction consists of three factors including frictional resistance, shear strength of the soil and passive resistance. In the ordinary polymeric strap (PS) reinforcement, only frictional resistance contributes to pullout resistance. In this study, in order to develop passive resistance in the soil, a number of angles as transv...

The limit equilibrium analysis through the horizontal slice method is used to study the seismic stability of reinforced soil slopes by satisfying the equilibrium of the horizontal and vertical forces as well as moments. Unlike the pseudo-static (PS) method, the pseudo-dynamic method consideres the effects of time and phase difference of the P and S...

The present study investigated the bearing capacity of strip footings on a bed of granular fiber-reinforced soils. Analyses were performed by the stress characteristics method (SCM). The failure criterion considers anisotropic distribution of fiber orientation and ignores the rupture of reinforcements. Seismic effects were included in the stress eq...

Many construction projects such as bridges, barriers, road construction, etc. use rigid or flexible retaining walls. Seismic behaviour analysis of such structures is difficult and complex due to the complexity of the relationships governing wall behaviour. Three methods of field observation, laboratory simulation and numerical modelling can be used...

Using vertical skirts as soil reinforcement in conjunction with strip footing can increase the bearing capacity of a footing located near a cohesionless slope. This paper adopted lower and upper bounds of finite element limit analysis (FELA) to compute the bearing capacity of a strip footing with vertical skirts resting on the cohesionless slope un...

This study presents the yield acceleration of reinforced soil slopes using the horizontal slice approach. Yield acceleration plays a key role in calculating the permanent seismic displacement of slopes. The modified pseudo-dynamic method, in conjunction with the equivalent linear site response analysis, is used. Unlike the pseudo-static analysis, t...

In this paper, the horizontal slice method (HSM) is employed to examine the stability of reinforced soil slopes. In this method, the soil mass is divided into a series of horizontal slices, and then the stability of each slice is examined. Unlike the previous studies, the formulation presented in this paper is able to analyse any type of the slidin...

In this study, several effective parameters and geometrical features were considered to present the design charts and the reduction coefficients tables to obtain the bearing capacity of a strip footing placed near a c-ϕ excavation under static and seismic conditions by using Finite Element Limit Analysis (FELA). The effects of setback distance to f...

The Piled raft foundations are one of the most useful structures to control the total and differential settlements. In the present study, a three-dimensional analysis is performed using the finite element method (FEM) to evaluate the behaviour of the piled raft foundations due to the groundwater level changes. The results show that the groundwater...

In this paper, undrained seismic bearing capacity of a strip footing placed on a slope in both homogeneous and heterogeneous soils is investigated using the lower and upper bounds of finite element limit analysis. Effective parameters on the bearing capacity and failure patterns are examined. Design charts and tables are provided to evaluate undrai...

In this paper, U-shape polymeric strap (UPS) reinforcement, which can develop passive resistance in the soil, is investigated. The curved (looped) part of the strap at the free end of the reinforcement generates a passive resistance in the soil and increases the pullout resistance beyond what is available due to friction of the horizontal portions...

Lateral spreading is one of the most significant destructive and catastrophic phenomena associated with liquefaction caused by earthquake and can impose very serious damages to structures and engineering facilities. The aim of this study is to evaluate liquefaction induced lateral spreading and finding new relations using gene expression programmin...

In the present study the numerical Incremental Differential Quadrature Method (IDQM) was utilized in order to produce a general solution for one-dimensional consolidation of layered unsaturated soil under two different states: (i) constant loading and exponentially time growing drainage, and (ii) time-dependent loading and semi-permeable boundary c...

The connection point between the wall stem and the foundation is often considered as a rigid point. However, this connection may not be fully rigid. This paper evaluates the effect of variation in the rotational stiffness (Sr) and wall height on the behaviour of a retaining wall using finite-element method (FEM). The results of the numerical analys...

It is crucial to estimate the behavior of layered unsaturated soils with time-dependent loading for several reasons, including (1) construction of a building is a time-consuming process and loading on the soil can be altered over time, and (2) the soils found in nature are often unsaturated and layered. There are two different approaches for analyz...

Assessment of the reinforcement behavior of soil under cyclic and monotonic loads is of great importance in the safe design of mechanically stabilized earth walls. In this article, the method of conducting a multistage pullout (MSP) test on the polymeric strip (PS) is presented. The post-cyclic behavior of the reinforcement can be evaluated using a...

The method of stress characteristics has been used for computing the ultimate bearing capacity of strip and circular footings placed on rock mass. The modified Hoek-and-Brown failure criterion has been used. Both smooth and rough footing-rock interfaces have been modeled. The bearing capacity has been expressed in terms of nondimensional factors Nσ...

Calculation of permanent seismic displacement of reinforced soil slopes plays a very important role in proper and optimal design of these structures in earthquake-prone regions. In the Newmark’s sliding block method, yield acceleration is required to calculate the permanent displacement. Pseudo-Static (PS) is an approximation method to compute yiel...

In this research, the reliability analysis of seismic ultimate bearing capacity of strip footing is assessed with implementing slip lines method coupled with random field theory. The probability density functions of seismic and static bearing capacities which are log-normal and nearly normal distribution respectively are compared to each other. The...

The Stress Characteristics Method (SCM) or slip line method is a rigorous method to solve geotechnical engineering problems. This method has been used in many geotechnical engineering problems. Although SCM has been used in previous researches to evaluate the seismic passive lateral earth pressure, however, previous researchers have not considered...

The stress characteristics method (SCM) has been used to compute the bearing capacity of smooth and rough ring foundations. Two different failure mechanisms for a smooth footing, and four different mechanisms for a rough footing have been considered. For a rough base, a curvilinear non-plastic wedge has been employed below the footing. The analysis...

The slip line or Stress Characteristics Method (SCM) is used to analyze the active lateral earth pressure in the axisymmetric case. In this paper, in addition to the retaining walls in the axisymmetric and plane strain conditions that studied in the past, a new model of the retaining wall in the axial symmetry is considered, which widely used in th...

This paper attempted to examine the passive lateral earth pressure of axisymmetric retaining walls. The Stress Characteristics Method (SCM) was employed for analysis. The stress equilibrium equations were obtained through the finite difference method along the characteristic lines. Effects of backfill slope, wall angle, and radius of retaining wall...

In this study, the differential quadrature method (DQM), a mathematically simple, accurate, and computationally efficient numerical tool, was employed to analyze the response of single piles under dynamic axial loading. The dynamic behavior of the piles and surrounding soil were modeled using the one-dimensional (1D) or three-dimensional (3D) axisy...

در این مقاله، ظرفیت باربری پی های نواری، روی بستری از خاک های دانه ای مسلح شده با فیبر، بررسی شده است. برای تحلیل از روش مشخصه‌های تنش استفاده گردیده است. معیار گسیختگی در نظر گرفته شده، توزیع جهت گیری مسلح کننده‌ها را به صورت ایزوتروپ در نظر می‌گیرد و از پارگی مسلح‌کننده‌ها صرف‌نظر می‌کند. اثرات لرزه‌ای به صورت ضرایب شبه‌استاتیکی افقی و عمودی در م...

The plastic critical depth or the conventional tension crack depth has a considerable effect on the active lateral earth pressure in cohesive soils. In this paper the depth for c-ϕ soils has been evaluated in the seismic case using the stress-characteristics or slip-line method. The plastic critical depth was calculated on the basis of the theory o...

Lateral earth pressure on retaining walls is a widely researched classical problem in geotechnical engineering. This study investigates the active lateral earth pressure on a circular retaining wall using the stress characteristics method in the presence of soil-wall adhesion and friction. A computer code was developed for determining the lateral p...

In this paper, the active lateral earth pressure is evaluated using the stress characteristics or slip line method. The lateral earth pressure is expressed as the lateral earth pressure coefficients due to the surcharge, the unit weight and cohesion of the backfill soil. Seismic horizontal and vertical pseudo-static coefficients are used to conside...

In this paper, the bearing capacity of strip footings on rock masses has been studied in the seismic case. The stress characteristics or slip line method was used for analysis. The problem was analyzed in the plane strain condition using the Hoek-Brown failure criterion. First, the equilibrium equations along the stress characteristics were obtaine...

The method of Zero Extension Lines (ZEL) has been used to evaluate the static and seismic active lateral earth pressure on an inclined wall retaining inclined c-phi backfill. The equilibrium equations along the Zero Extension Lines have been solved using the finite difference method. A computer code is prepared to analyze the retaining wall, calcul...

As the most important dynamic properties of soils, shear modulus and damping ratio are two parameters employed to solve problems including seismic site response evaluation, dynamic analyses and equivalent-linear models. The work presented in this paper proposes two models for evaluation of the normalized shear modulus and two additional models for...

Several theories exist regarding the displacement of slopes and earth walls such as Newmark. The used of reinforced soil to design of earth walls and slopes is a method that has become popular in recent years. In some places, structures such as retaining walls and soil slopes have been in seismic active regions and when earthquake occurs, the struc...

Truss weight is one of the most important factors in the cost of construction that should be reduced. Different methods have been proposed to optimize the weight of trusses. The artificial bee colony algorithm has been proposed recently. This algorithm selects the lightest section from a list of available profiles that satisfy the existing provisio...

تعیین ظرفیت باربری پی‌های نواری یکی از مسائل کلاسیک مهندسی ژئوتکنیک می‌باشد. در این مقاله، ظرفیت باربری پی‌های سطحی نواری با روش مشخصه‌های تنش ارزیابی شده است. برای این منظور معادلات تعادل تنش روی خطوط مشخصه‌ با استفاده از روش تفاضل حدی حل شدند. اثرات زلزله به صورت ضرایب شبه‌استاتیکی افقی و قائم به مسئله اعمال شده است. برای تعیین ظرفیت باربری بر اس...

Pipelines are often referred as "lifelines" and this demonstrates that pipelines play an important role in human's life. Due to huge length and wide geographical distribution of pipelines, they are subjected to more seismic hazards. Seismic wave propagations affect the operation of buried pipelines which influence safety of these systems during and...

The ultimate bearing capacity of strip foundations situated on reinforced soils has been analyzed in this paper using the stress characteristics method. A computer code has been written to analyze the slip line net and to calculate the ultimate load distribution beneath the foundation. The ultimate bearing capacity is expressed in terms of bearing...

Stability of soil slopes is a big concern for civil engineers which are commonly analyzed using limit equilibrium methods. Most available software is based on finding the critical circular slip surface that is not suitable for layered soils. Therefore many works have been presented for finding this noncircular slip surface using optimization method...

A simple displacement-type block model is proposed to compute the compression–load–time response of an idealized seismic buffer placed against a rigid wall and used to attenuate earthquake-induced dynamic loads. The seismic buffer is modelled as a linear elastic material and the soil wedge shear surface by a stress-dependent linear spring. The mode...

Different methods have been proposed for the analysis of the stability of reinforced soil. One of them is the method of characteristics, which treats the reinforced soil as a homogeneous but an-isotropic material. Soil masses are weak under the application of reversible/dynamic forces and reinforcing would be much helpful in these cases. In this pa...