Masoud Zare | University of Nevada, Reno (original) (raw)

Papers by Masoud Zare

Journal of Geology and Mining Research, Aug 31, 2009

In this paper, an analytical modeling has been carried out to realize the effect of appending a s... more In this paper, an analytical modeling has been carried out to realize the effect of appending a supplementary percussive load to the rotary energy of tunnel boring machine's disc cutters, as a novel technology. In this path, two models have been built by using the theory of plasticity for prediction of the amount of penetration of a disc cutter assumed in form of a V-shaped indenter in rock medium. Since the types of applied loads at two phases (rotary versus percussive) differ, it was obligatory to consider different analytical models for each phase. At first stage of the modeling process, a part of previously constructed model for determination of tool penetration into rock has been used. Then, at the next stage, the depth of penetration resulted from the impacts of a striker on the disc cutter has been modeled by using the kinematic method. The aggregative penetration of the disc by application of rotary-percussive load has been considered as non-algebraic summation of penetrations in two stages. Finally, an illustrative example has been presented to show the application of the models in a real situation. In both models, the friction between penetrating tool and the rock has been taken into account.

International Journal of Environmental Research and Public Health, 2022

Pillars are important structural elements that provide temporary or permanent support in undergro... more Pillars are important structural elements that provide temporary or permanent support in underground spaces. Unstable pillars can result in rock sloughing leading to roof collapse, and they can also cause rock burst. Hence, the prediction of underground pillar stability is important. This paper presents a novel application of Logistic Model Trees (LMT) to predict underground pillar stability. Seven parameters—pillar width, pillar height, ratio of pillar width to height, uniaxial compressive strength of rock, average pillar stress, underground depth, and Bord width—are employed to construct LMTs for rock and coal pillars. The LogitBoost algorithm is applied to train on two data sets of rock and coal pillar case histories. The two models are validated with (i) 10-fold cross-validation and with (ii) another set of new case histories. Results suggest that the accuracy of the proposed LMT is the highest among other common machine learning methods previously employed in the literature. Mo...

International Journal of Oil, Gas and Coal Technology, 2018

In this paper, the potential use of spiral separators in the circuit of the Alborz-Sharghi coal p... more In this paper, the potential use of spiral separators in the circuit of the Alborz-Sharghi coal processing plant in northeastern Iran is evaluated. The current circuit of the plant was carefully investigated. The necessary samples were collected from the overflow discharge of the hydro-cyclone and used to feed the pilot spiral circuit of the plant. The most important operating variables, including the feed size distribution, the feed pulp density and the feed rate, were considered at three levels (low, base and high) and analysed to determine the optimal spiral recovery. Twenty-seven experiments were designed according to the Taguchi method using an orthogonal array. The results revealed the optimal spiral recovery (68.8%) for specific levels of the considered parameters with an extensive sensitivity analysis. A new flow sheet of the circuit of the Alborz-Sharghi coal washing plant, which involves two spiral separators is presented. [

Proceedings of the Institution of Civil Engineers - Geotechnical Engineering, 2018

In this paper, the performance of an earth pressure balance tunnel-boring machine (EPB-TBM) durin... more In this paper, the performance of an earth pressure balance tunnel-boring machine (EPB-TBM) during tunnel construction is analysed. A case study with data from the east–west part of the Tehran metro line 7 is employed to develop a methodology. Several parameters of different types that influence TBM operations in soft ground are identified and analysed, and the probabilistic systems approach is utilised to interpret the interactions between pairs of parameters. For this purpose, the probabilistic expert semi-quantitative and Monte Carlo simulation techniques have been employed. An index is developed to calculate the utilisation along the studied tunnel path. The results have been compared with real utilisation factor values from the project, showing an excellent agreement between estimations and observations.

Periodica Polytechnica Civil Engineering, 2015

Natural rock joints infilled with soil materials may show a reduced shear strength, which influen... more Natural rock joints infilled with soil materials may show a reduced shear strength, which influences rock mass stability. The aim of this paper is to experimentally investigate the shear behaviour of infilled rock joints, taking into account joint surface characteristics and the properties of the joint and infill materials. A new model for predicting the shear strength of infilled joints is presented, on the basis of a series of tests carried out on natural rock joints with same surface roughness, with clay, sand and sandy-clay used as infill materials. All tests were carried out in a shear box apparatus under constant normal load (CNL) conditions. The empirical model was finally validated based on the experimental data from the literature. The results showed an acceptable confidence level for the model and reported that the new model successfully describes the observed shear behaviour of natural infilled rock joints.

Environmental Earth Sciences, 2011

Page 1. ORIGINAL ARTICLE The assessment of rock slope instability along the Khosh-Yeylagh Main Ro... more Page 1. ORIGINAL ARTICLE The assessment of rock slope instability along the Khosh-Yeylagh Main Road (Iran) using a systems approach Reza KhaloKakaie • Masoud Zare Naghadehi Received: 26 July 2009 / Accepted: 16 December 2011 Ó Springer-Verlag 2011 ...

This paper describes the improvements to rock engineering systems (RES) approach to be applied in... more This paper describes the improvements to rock engineering systems (RES) approach to be applied in slope stability assessment considering the total system containing almost all the factors influencing the problem. The first improvement uses introducing the probabilities to coding val-ues assignments and the other is an ongoing project which produces an objective framework to be used in the rock slopes instability hazard assessment.

Tunnelling and Underground Space Technology, 2013

This paper describes the design and implementation of a new laboratory apparatus to model the rec... more This paper describes the design and implementation of a new laboratory apparatus to model the recently proposed rotary-percussive penetration (RPP) technology to be applied in tunnel boring machines (TBMs). It also deals with the tests carried out to explore the pure effect of appending a percussive load to the other applied loads during excavation in the prepared specimens. Results of this study confirmed that the combined mode of cutting-impact is very effective in the cutting of the moulded specimens. A good agreement was also achieved between the results of the experiments and the previously developed analytical model. Therefore, this research generally shows that the percussive load can ultimately improve the rate of penetration (ROP) of disc cutters of a modelled tunnel boring machine.

International Journal of Rock Mechanics and Mining Sciences, 2013

A new Mine Slope Instability Index (MSII) to assess the (in)stability conditions of slopes in ope... more A new Mine Slope Instability Index (MSII) to assess the (in)stability conditions of slopes in open-pit mining is presented. Eighteen parameters that can be easily obtained and rated in the field, and that are important for open-pit slope stability, are employed for the MSII definition. Their corresponding ratings are also proposed, so that the MSII can be computed as a simple weighted sum of ratings for all parameters considered; to minimize subjectivity the weights are computed, in the context of the Rock Engineering Systems paradigm, using an optimized Back-Propagation Artificial Neural Network that has been trained with an extensive database of worldwide open-pit slope stability case histories. Results show that the ANN provides a highly reliable RES interaction matrix, and also that the selected parameters are important for open-pit slope stability. Slope (in)stability hazard levels are defined based on MSII values and the predictions of the newly proposed MSII are validated by comparing our predictions with the actual (i.e. observed) behaviour corresponding to 12 independent case histories that were not used for the ANN training. An excellent agreement between predictions and observations has been found, with only one (out of 12) cases providing an incorrect prediction.

Coal Operators' Conference, 2008

Today risk analysis is largely employed in studying the uncertainty of financial decisions in new... more Today risk analysis is largely employed in studying the uncertainty of financial decisions in new mining ventures. The methodology for examination and quantification of financial risks is investigated in this paper. A coal mining project is generally a long term process. Also, any increase in the project time, raises the probability of variation in effective financial parameters. Therefore, the forecasting and risk analysis for this kind of projects will be more important. For this reason, this work has been prepared for the purpose of ...

In study of the behaviour of roof strata in underground coal mines the strength of the roof rock,... more In study of the behaviour of roof strata in underground coal mines the strength of the roof rock, particularly, the unconfined compressive strength (UCS) plays a significant role. Application of simple tools in assessment of the rock strength has been practiced by many researchers one of which being Schmidt hammer. Due to its portability, easiness in use, rapidity, low cost and its non-destructive procedure of application, it is among the most popular tools in this respect. Application of this tool in prediction of the roof rock strength, ...

Engineering Geology, 2011

A probabilistic expert semi-quantitative (PESQ) coding methodology is employed to assess the impo... more A probabilistic expert semi-quantitative (PESQ) coding methodology is employed to assess the importance of factors that affect the stability of rock slopes within the rock engineering systems (RES) framework. With this newly proposed PESQ coding framework, uncertainties in the assignments of codes are expressed using probabilities that are assigned to each particular coding value. Rock slopes in the Khosh-Yeylagh region in Iran have been employed as an example case to illustrate the utilization of this method in rock slope engineering, and nine parameters are considered as the main factors modeling the stability of the slope system. In addition to the probabilistic coding, other typical RES procedures can also be performed non-deterministically, therefore allowing consideration of uncertainties in the RES analysis. The existence of "previous instabilities" has been found to be the most important parameter, therefore suggesting the importance of performing a site survey of similar slopes in the area; and "geology and lithology" and "mechanical properties of discontinuities" have also been found to be quite significant parameters. The degree of dominance or subordinance of parameters with respect to the slope system has also been interpreted probabilistically. The newly proposed approach could be a simple but efficient tool in evaluation of the parameters affecting the stability of rock slopes and hence be useful in decision making under uncertainties.

Measurement, 2018

Hard rock TBM performance prediction is of great interest to the tunneling community on account o... more Hard rock TBM performance prediction is of great interest to the tunneling community on account of its importance in time and cost risk management of underground projects. Continuous development of new empirical models in recent decades reveals the importance of accurate prediction of this factor in diverse ground and machine conditions. The great number of different parameters influencing TBM performance and the high variability linked to specific field conditions cause the problem to be very complex. Gene expression programming (GEP) models, a robust variant of genetic programming, are developed in this study to correlate hard rock TBM performance with routine ground properties for project design applications. The developed models are compared with those from statistical and soft computing-based models in the literature. Overall, GEP models show good performance and are proven to be much better than the previous models. The proposed models of this study can be remarked as an ultimate stage to one decade of researchers’ attempts to improve the accuracy of predictive equations developed through a well-known database of TBM performance in one of the most complex tunneling projects in the world.

EUROCK 2018: Geomechanics and Geodynamics of Rock Masses, 2018

Rock bursts induced by the superposition of static and dynamic loads could cause rock ejection, c... more Rock bursts induced by the superposition of static and dynamic loads could cause rock ejection, casualties, deformation of the supporting structures and damage of the equipment on site, hence making it crucial to study the topic in depth. A novel application of Rock Engineering Systems incorporating a probabilistic expert semi-quantitative (PESQ) coding methodology is proposed in this paper to analyze the importance of factors that could affect damage due to rock burst occurrence. To that end, six parameters —ratio of total maximum principal stress to UCS, type of support system, excavation span, geology condition, approximate peak particle velocity (PPV) and seismic event magnitude— are selected from reports of Australian and Canadian underground rock mines. The distribution of Cause and Effect for each parameter and their corresponding importance can be obtained from the probabilistic coding. Results show that high interactive probability parameters are excavation span (P3) and approximate peak particle velocity (PPV) (P5). And the geology factor (P4) has the highest probability to dominate the system. Therefore, the approach proposed could be an efficient tool to estimate the interaction of parameters related to rock burst damage.

Proceedings of the Institution of Civil Engineers: Geotechnical Engineering, 2018

In this paper, the performance of an earth-pressure balance tunnel boring machine (EPB-TBM) durin... more In this paper, the performance of an earth-pressure balance tunnel boring machine (EPB-TBM) during tunnel construction is analyzed. A case study with data from the East-West part of Tehran Metro Line 7 is employed to develop a methodology. Several parameters of different types that influence TBM operations in soft ground are identified and analyzed, and the probabilistic systems approach is utilized to interpret the interactions between pairs of parameters. For this purpose, the probabilistic expert semi-quantitative (PESQ) and Monte Carlo Simulation techniques have been employed. An index is developed to calculate the utilization along the studied tunnel path. The results have been compared with real utilization factor values of the project, showing an excellent agreement between estimations and observations.

This paper presents an extended multifactorial fuzzy evaluation of hard rock tunnel boring machin... more This paper presents an extended multifactorial fuzzy evaluation of hard rock tunnel boring machine performance. Several modifications have been applied to an earlier work of the authors team in 2009 to capture better prediction capabilities of TBM penetrability modeling.