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    Assessing the shear behavior of oriented rock joints under constant normal loading conditions

    , Article Geotechnical Special Publication ; February , 2014 , p. 553-562 Khosravi, A ; Khosravi, M ; Sadaghiani, M. H ; Meehan, C. L ; Amini, E ; Sharif University of Technology
    Abstract
    This paper presents results from a series of constant normal load direct shear tests on artificially created rock joints, in an attempt to quantify the effects of different factors that contribute to the shear strength along "ideal" rock joints. Particular focus is given to the effect of asperity orientation with respect to the direction of shearing. In many historical rock joint shear strength criteria, the effect of a joint's roughness on the joint shear strength is described based on analysis of only a single profile in the direction of shearing. More recent studies have observed that the distribution of sheared area on a joint surface during shear is significantly affected by the... 

    Ranking of hazardous road locations in two-lane two-way Rural roads with no crash record

    , Article ATRF 2011 - 34th Australasian Transport Research Forum ; 2014 Habibian, M ; Mesbah, M ; Sobhani, A ; Sharif University of Technology
    Abstract
    Crash data availability is a significant requirement for identifying hazardous roads. However, for roads with poor data sets or no crash record, a method is needed to find and rank road segments independent of the crash records. In this paper, an auditing based methodology is proposed to determine the hazardous locations. A Rural road is investigated by decomposing it first into six elements, and then into safety factors corresponding to each element. The elements are: straight segments, horizontal and vertical curves, bridges, tunnels, merges and intersections, and side road land use. The relative contribution of the elements to the safety of a road segment is determined using the... 

    Effect of polymer content and temperature on mechanical properties of lightweight polymer concrete

    , Article Construction and Building Materials ; Volume 260 , 2020 Heidarnezhad, F ; Jafari, K ; Ozbakkaloglu, T ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    This study investigates the mechanical properties of lightweight polymer concrete (LWPC) containing four different polymer ratios (10%, 12%, 14%, and 16%) tested at three different temperatures (−15 °C, +5 °C, and +25 °C) using destructive and non-destructive tests. In addition, a series of expressions are suggested to predict the splitting-tensile, flexural and impact strength of LWPC based on the main parameters and compressive strength. The analysis of variance (ANOVA) method was also used to determine relative contributions of the experimental parameters. The results of the destructive tests show that increasing the polymer ratio caused an increase in the compressive, splitting-tensile,... 

    Atomistic insight into the behavior of ions at an oil-bearing hydrated calcite surface: implication to ion-engineered waterflooding

    , Article Energy and Fuels ; Volume 35, Issue 16 , 2021 , Pages 13039-13054 ; 08870624 (ISSN) Badizad, M. H ; Koleini, M. M ; Greenwell, H. C ; Ayatollahi, S ; Ghazanfari, M. H ; Sharif University of Technology
    American Chemical Society  2021
    Abstract
    This research provides an atomistic picture of the role of ions in modulating the microstructural features of an oil-contaminated calcite surface. This is of crucial importance for the rational design of ion-engineered waterflooding, a promising technique for enhancing oil recovery from carbonate reservoirs. Inspired by a conventional lab-scale procedure, an integrated series of molecular dynamics (MD) simulations were carried out to resolve the relative contribution of the major ionic constituent of natural brines (i.e., Na+, Cl-, Mg2+, Ca2+, and SO42-) when soaking an oil-bearing calcite surface in different electrolyte solutions of same salinity, namely, CaCl2, MgCl2, Na2SO4, MgSO4, and...