Mahdi Shadab FarSharif University of Technology | SHARIF · Department of Civil Engineering
Mahdi Shadab Far
Ph.D.
I am currently employed as a senior researcher. I welcome offers to join the faculties of Geotechnical Engineering.
About
59
Publications
15,459
Reads
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441
Citations
Citations since 2017
Introduction
In recent years, I have focused mostly on the analysis of geohazards using probabilistic approaches and stochastic analysis, as well as the computation of risk and resilience of downstream infrastructure. In this regard, I have also utilized artificial intelligence approaches, particularly deep learning methods. Currently, I am increasing the scope of my study to include landslide analyses for coal tips and tailing dams, in addition to tunnel and underground engineering.
Education
August 2012
Publications
Publications (59)
This paper presents a framework for time-variant system reliability analysis of concrete sewer pipes considering multiple modes of failure. Sewer pipelines are among critical infrastructure systems, designed to collect and transport wastewater away from communities. Such pipes are typically subjected to corrosion and subsequent damage because of co...
Prediction of thermal crack propagation in desiccated soils is imperfect due to the obscure field measurements, modeling approximations, and the underlying soil uncertainties. To address these issues, a probabilistic framework is developed to quantify the uncertainties and enhance the crack estimation reliability. Hence, the uncertainties associate...
Periodic cycles of flood and drought are aggravated by global warming, thereby inducing critical desiccation cracks in soils. However, the estimation and prevention of crack propagation is imperfect due to the imprecise field measurements and the underlying soil uncertainties. To address these issues, this study presents an alternative framework to...
People use trains as a means of transportation to travel to various nearby and distant destinations, resulting in an increasing amount of time spent inside such vehicles. Consequently, railway transportation sectors are focusing significantly more on enhancing passengers’ demand and level of satisfaction, including but not limited to high-speed tra...
Natural gas hydrate, a crystalline solid existing under high-pressure and low-temperature conditions, has been regarded as a potential alternative energy resource. It is globally widespread and occurs mainly inside the pores of deepwater sediments and sediments under permafrost area. Hydrate production via well depressurization is deemed well-suite...
The reinforcement of concrete columns with fabric reinforced cementitious matrix (FRCM) is one of the most challenging issues in the construction of concrete structures, as there is still an absence of a promising model to assess their performance. This is because the behavior of such elements is complex and accompanied by a high margin of uncertai...
Rockfall is a significant hazard to sites that are located at the foot of rock slopes. In such sites, there is a notable need to evaluate the potential for rockfall, estimate the extent of areas at risk, and design retaining structures to reduce the risk of rockfall-induced. This paper presents a probabilistic framework for predicting the formation...
This paper combines transient groundwater analysis with a Random Limit Equilibrium Method (RLEM) to assess the safety of an embankment dam under water level variations. To this end, shear strength parameters, i.e., cohesion and friction angle, are modeled as random variables. The prevailing uncertainties of soil hydraulic characteristics are taken...
This paper combines transient groundwater analysis with a Random Limit Equilibrium Method (RLEM) to assess the safety of an embankment dam under water level variations. To this end, shear strength parameters, i.e., cohesion and friction angle, are modeled as random variables. The prevailing uncertainties of soil hydraulic characteristics are taken...
Fabric-reinforced cementitious matrix (FRCM) is considered a unique technology for strengthening structural elements, in particular, concrete columns. The present study investigated the axial load-carrying capacity of the FRCM-strengthened concrete columns using a probabilistic approach. For this purpose, a total of 10 columns were numerically simu...
Much research has been conducted and published on the examination of the behavior of reinforced steel and concrete structures with a FRP system. Nevertheless, the performance of FRP differs from that of FRCM, particularly at high temperature and ultimate strength. The present study provides a review of previous research on structural elements (viz....
The quest to answer the longstanding question of how safe is safe enough has led to an evolution of design philosophies. The traditional philosophy has been based on ensuring that system capacity exceeds demand. This philosophy has been manifested in such design methods as allowable stress design (ASD) and load and resistance factor design (LRFD)....
This paper presents a dynamic system for estimating the spreading profile of COVID-19 in Thailand, taking into account the effects of vaccination and social distancing. For this purpose, a compartmental network is built in which the population is divided into nine mutually exclusive nodes, including susceptible, insusceptible, exposed, infected, va...
Predicting the way diseases spread in different societies has been thus far documented as one of the most important tools for control strategies and policy-making during a pandemic. This study is to propose a network autoregressive (NAR) model to forecast the number of total currently infected cases with coronavirus disease 2019 (COVID-19) in Iran...
Current assessments of rock mass quality of a NATM tunnel face are important in the practice of tunnel excavation. This study establishes a multi-source database and proposes a data driven method for the assessment. Thirteen multi-source variables describing the tunnel faces are considered as inputs, and the rock mass rating (RMR) values computed b...
Tunnel roof deflection is an important measure to control the safety of excavation activity, especially for large-section tunnels using the sequential construction method. A three-dimensional (3D) model of a sequential excavation project in the Lijiaping metro tunnel, Chongqing, China, was developed and the maximum tunnel roof deflection was calcul...
A probabilistic method is proposed in this study to predict the spreading profile of the coronavirus disease 2019 (COVID-19) in the United State (US) via time-variant reliability analysis. To this end, an extended susceptible-exposed-infected-vaccinated-recovered (SEIVR) epidemic model is first established deterministically, considering the quarant...
Due to the interference problems of complex on-site installations attached to shield tunnel lining surface, deep learning models, developed for leakage datasets of shield tunnels, are not prepared to meet engineering requirements. Therefore, it is of utmost importance to optimize the original model based on the characteristics of leakage datasets....
The study of rock fragmentation mechanism significantly contributes to the advancing speed of tunnel boring machines (TBMs). In this sense, numerous factors are shaping the rock fragmentation mechanism of their disc-cutters. Among them, rock structural parameters, such as joint inclination, orientation, spacing, etc., considerably impact cutting fo...
This paper develops a trend line‐based algorithm for signal decomposition in which the adjusted Savitzky–Golay filter is utilized to initiate the decomposition process. In this line, the proposed algorithm determines some special trend lines, mainly composed of the natural frequency of a bridge. An easy‐to‐implement algorithm is then provided to fo...
This paper presents an approach for the integrated process of classification and instance segmentation of leakage‐area and scaling images from shield tunnel linings. For this purpose, the previously established dataset of leakage‐area images by the authors is enlarged by means of adding scaling ones. Afterwards, data augmentation is implemented to...
This study introduces a simple and efficient method to determine the peak floor acceleration (PFA) at different performance levels for three types of plane reinforced concrete (RC) structures: moment-resisting frames (MRFs), infilled–moment-resisting frames (I-MRFs), and wall-frame dual systems (WFDSs). By associating the structural maximum PFA res...
This paper presents a review of the existing models for the estimation of explosion-induced crushed and cracked zones. The control of these zones is of utmost importance in the rock explosion design, since it aims at optimizing the fragmentation and, as a result, minimizing the fine grain production and recovery cycle. Moreover, this optimization c...
The responses of hydrate reservoir during gas production are complex due to the spatially and temporally evolving thermo-hydro-mechanical properties. Accurate modeling of the behavior, therefore, requires a coupled multiphysics simulator with a large number of parameters, leading to substantial computational demands. This makes it challenging to ef...
Difficulties in visual inspection of metro shield tunnels induced by various on-site installations (e.g., lighting instruments and pipelines) have been resolved by two-stage structural damage detection techniques based on deep learning known as the state-of-the-art on surface defects recognition. However, thresholds of the Intersection over Union (...
Geotechnical analysis and design are usually based on traditional methods and empirical relationships. However, various challenges , such as the inability to model all parameters involved and the uncertainty of model input, make these methods ineffective. Therefore, probabilistic methods recently began to be used to estimate the probability of slop...
Estimating the damage induced by an explosion around a blast hole has always been a challenging issue in geotechnical engineering. It is difficult to determine an exact dimension for damage zone since many parameters are involved in the formation of failures, and there are some uncertainties lying in these parameters. Thus, the present study adopte...
These data were used to develop the SGF-based bridge damage detection methods.
The published papers are linked to this data.
In this paper, a two-stage time-domain output-only damage detection method is proposed with a new energy-based damage index. In the first stage, the random decrement technique (RDT) is employed to calculate the random decrement signatures (RDSs) from the acceleration responses of a simply supported beam subjected to a moving load. The RDSs are then...
It is well‐known that a bridge may end up with severe damage under aftershocks, even if it resisted the main shock. As such, a quick assessment seems necessary when a bridge experiences an earthquake event. In this paper, an output‐only energy‐based method was developed to locate damaged cables in an tied‐arch bridge under seismic excitation. For t...
The cracked zones caused by tunnel excavations are among the major reasons for structural instability in mechanized tunnel projects. Thus, various methods have been proposed to evaluate such cracks in terms of size and depth. However, deterministic estimations have been associated with a margin of error due to the inherent uncertainties of the resp...
Slope stability analysis is one of the most challenging problems in geotechnical engineering. Due to the uncertainty involved in the problem, probabilistic methods are recently utilized to estimate the probability of slope failure. In this study, the slope stability is presented as an optimization problem and the Simulated Annealing (SA) method is...
In this short paper, the semi-empirical model introduced by Zheng et al. (2018) for evaluating the tunnel displacements induced by adjacent excavation was extended to a probabilistic model. To this end, the input parameters of the problem were defined as random variables with certain means and standard deviations. A reliability model was then estab...
An important segment of the reliability-based optimization problems is to get access to the sensitivity derivatives. However, since the failure probability is not a closed-form function of the input variables, the derivatives are not explicitly computable and rather require a full reliability analysis which is computationally expensive. In this pap...
Microsoft Excel document and macros for reliability sensitivity analysis (RSA).
(XLSM)
Empirical expressions for estimating the maximum induced strain on buried steel pipelines crossing strike-slip faults are proposed. These expressions have been obtained through parametric studies involving finite element analyses of 18 different case loads of buried pipelines. The pipe and its soil surrounding were modeled in Abaqus software with s...
Rock explosion has always been a complex problem because neither rock characteristics nor explosion waves could be accurately estimated. As such, this imposes a high uncertainty on deterministic methodologies available for damage prediction. In this paper, by defining two damage zones around the blast hole, including crushed and cracked zones, a fi...
In the paper presented by Liu et al. (2016), herein referred to as the original paper, a regression model was developed to estimate the compressive strain induced in X80 steel pipes crossing strike-slip faults. Later, a corrigendum (2018) was written by the original authors to correct the problems with the proposed equation and Fig. 14 of the origi...
Transmission of explosion waves through a rock medium causes a severe vibration that stimulates the mechanical behavior of rock mass. This stimulation imposes highly concentrated stresses on the ends of existing fine joints and depending on the toughness of the rock, causes them to propagate rapidly. Consequently, the propagation and joining of cra...
Structural load types, on the one hand, and structural capacity to withstand these loads, on the other hand, are of a probabilistic nature as they cannot be calculated and presented in a fully deterministic way. As such, the past few decades have witnessed the development of numerous probabilistic approaches towards the analysis and design of struc...
The dominant vibration period is one of the most important behavioral parameters of the structures that are widely used in most of the seismic design codes of structures. The proposed methods by the Codes and Standards for calculation of the dominant vibration period are only dependent to structure's height, and are obtained based on the first vibr...
By a quick look at the states, it can be realized that many cities in the world with rapid and considerable growth suffer from three key problems including road safety, air pollution and urban traffic management [6]. Due to the reasoning ability, humans have always looked forward the best environment and comfort and therefore tried to find operatio...
Today, most people have settled in a habitat named city, a place with a distinct structure and function from its surroundings, which has created a new mean of civilization and human identity. Undoubtedly one of the most vital lifelines in modern societies is the water pipelines and its governing system. In this regard, there should be a policy for...
One of the significant issues in the urban systems is the understanding and mastering the surroundings and how to deal and cope with potential problems. Confined and buried spaces such as underground tunnels that are created to conduct the urban traffic seem to be very important because its slightest mistake means a painful tragedy. Therefore it is...
One of the most important factors that may cause a buried steel pipeline to reach the failure limit is the permanent ground displacement. In this paper, assuming SHELL element for pipeline and SOLID element for soil and also considering the interaction of pipe-soil, analysis of buried pipelines crossing fault and parametric study of pipeline behavi...
Using Fiber Reinforced Products have a special position in strengthening of R-C structures. In this article by an approach based on equilibrium equation, a recommended method for designing FRP sheets has been developed. Facilitating this approach, the equations have been described as some curves. Finally a problem has been solved by both proposed m...
Questions
Questions (11)
Hello everyone,
I need to know if there is any software available to model the rainfall-induced slope failure? For instance, having the rainfall intensity and duration, can determine the infiltration of water in the soil and further calculate the slope stability condition?
I'm working on a civil engineering project. There are a few variables involved in the model. We need to use Copula to capture the correlation between variables. To this end, I am looking for an easy-to-use software that can fit different Copula Functions to available data. If you have any suggestion, please let me know. Thank you in advance!
I am looking for a source to teach stochastic differential equations, preferably a source without theorems/proofs, containing clear examples and source codes so that an undergraduate engineering student can use it. If you have any suggestion, please let me know.
I would like to know if there is any software for epidemic simulation using different SIR models (e.g., SIRD, MSIR, or MSEIR). I prefer to use commercial software without programming.
I am trying to simulate the time-dependent corrosion of underground concrete structures. I'm looking for easy-to-use software that can handle such models. I know that common numerical simulation software (such as ANSYS and ABAQUS) can be used for this purpose. However, I am looking for a more straightforward and simple simulation tool specifically developed for such models.
I'm working on a geotechnical project related to the reliability analysis of liquefied soil. What software can be used for probabilistic liquefaction analysis?
Does anyone know a geotechnical engineering software which can support subset simulation? I need to do some probabilistic analysis of a geotechnical project. However, due to the small probability, I need to use subset simulation instead of the crude Monte Carlo analysis.
When using SIR model to predict the spread of COVID 19, what should be set in the total population? Is it the total population of the target region or just a portion of the total population exposed to the disease?
Does anyone know a practical source that can be used to learn multivariate Copula, with clear explanations and practical examples, without theorems/proofs? I need it for an engineering undergraduate class.
I am trying to use random fields to simulate the uncertainty of soil profiles (in 2D and 3D) in FLAC. I want to ask everyone, is there any example that can clearly explain how to do this simulation, either in FLAC or other software packages?
Dear all,
I am trying to simulate soil liquefaction under full dynamic analysis. I would like to know if there are any software packages (except FLAC) with clear manual examples of how to simulate soil liquefaction?
Projects
Projects (5)
In practice, the productivity of a typical gas hydrate site is heavily influenced by the spatially variable reservoir conditions as well as the complex gas-liquid migration mechanisms. Therefore, scientific prediction of production efficiency based on limited site information poses major challenges. This project shall present a practical approach for reasonably predicting the production responses of offshore gas hydrate reservoirs based on limited site data.
The health-care system is one of the most crucial infrastructure in any society, facing various types of hazards, including the spread of diseases. Planning appropriate strategies to control the disease requires an in-depth understanding of its transmission profile and future predictions. In this project, different numerical and statistical techniques are developed to provide reliable estimates of disease growth and further assist decision-making authorities in taking informed measures.
I proved that some special trend lines can be used for structural health monitoring and damage detection. Trend lines are simple to calculate and easy to use. Lets work together if you are also interested in this topic.
