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shear-wave-velocity
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The Effect of Fines Content and its Type on Shear Wave Velocity and Liquefaction Resistance of Sandy Soils
, Ph.D. Dissertation Sharif University of Technology ; Ahmadi, Mohammad Mehdi (Supervisor)
Abstract
Liquefaction is one of the most destructive geotechnical phenomena, and so the determination of soil liquefaction is very important. Shear wave velocity measurement is one of the methods of the soil liquefaction potential evaluation. The use of this method has increased substantially in recent years, due to its advantages compared to other methods, especially for microzonation of liquefaction potential. However, proposed curves for liquefaction evaluation which are based on the shear wave velocity measurement are more conservative than curves based on SPT and CPT, especially for sands containing fines. Local information from sites that have been liquefied previously and the shear wave...
Effect of fines type and content of sand on correlation between shear wave velocity and liquefaction resistance
, Article Geotechnical and Geological Engineering ; 2016 , Pages 1-20 ; 09603182 (ISSN) ; Ahmadi, M. M ; Sharif University of Technology
Springer International Publishing
Abstract
The use of shear wave velocity (Vs) measurements as an in situ test for evaluation of liquefaction potential has increased substantially due to its advantages. Relatively large numbers of studies have been performed to establish the correlation between Vs and liquefaction resistance (CRR) of clean sands. Usually, natural sands contain silt and/or clay, and previous studies have shown that both the amount of fines and their nature influence the values of CRR as well as Vs. Therefore, the CRR–Vs correlations may also be affected by fines content and type of sandy soils. However, effect of fines content and especially fines type of sandy soils on the correlation between Vs and CRR is...
Comparison of Slopes' Pgds Derived From Newmark Rigid Block Theory With 1g Shaking Table Model Tests
, M.Sc. Thesis Sharif University of Technology ; Jafarzadeh, Fardin (Supervisor)
Abstract
Moderate to large magnitude earthquakes trigger hundreds to thousands of slope stability failures and landslides in coherent masses. In many earthquakes, landslides have been responsible for as much or more damage than all other seismic hazards combined. Earthquake-induced landslides have a detrimental impact on the serviceability of slopes by damaging nearby structures, roadways, utilities, power lines and communication networks. In this research large-scale shaking table model tests were conducted to study slope behavior under earthquake conditions on Sharif University shaking table. The model slopes were installed into a model box with a length of 3 m, width of 1 m, and height of 1.5 m. A...
Dynamic parameters of dry sand using one dimensional shaking table tests
, Article 6th International Conference on Physical Modelling in Geotechnics, ICPMG'06, Hong Kong, 4 August 2006 through 6 August 2006 ; Volume 1-2 , 2006 , Pages 279-283 ; 041541587X (ISBN); 9780415415873 (ISBN) ; Torghabeh, E. A ; Farahi Jahromi, H ; Sharif University of Technology
2006
Abstract
In this paper the dynamic properties of Babolsar dry sand was investigated through one dimensional shaking table tests. 8 models of Babolsar loose dry sand under low confining pressures, were subjected to different harmonic and irregular dynamic loadings. The container was a laminar shear box having 24 layers each moving on the lower one. The dynamic properties including shear wave velocity, maximum shear modulus and damping ratio of the samples were addressed in this project. © 2006 Taylor & Francis Group, London
Requirements for soil-specific correlation between shear wave velocity and liquefaction resistance of sands
, Article Soil Dynamics and Earthquake Engineering ; Vol. 57, issue , 2014 , pp. 152-163 ; ISSN: 02677261 ; Akbari Paydar, N ; Sharif University of Technology
Abstract
The application of the simplified method for evaluating the liquefaction potential based on shear wave velocity measurements has increased substantially due to its advantages, especially for microzonation of liquefaction potential. In the simplified method, a curve is proposed to correlate the cyclic resistance ratio (CRR) with overburden stress-corrected shear wave velocity (Vs1). However, the uniqueness of this curve for all types of soils is questionable. The objective of this research is to study whether the correlation between CRR and Vs1 is unique or not. Besides, the necessity of developing the soil-specific correlations is also investigated. Based on laboratory test data, a new...
A Carbonate Reservoir Characterization Using AVO Analysis on 3D Seismic Data
, Ph.D. Dissertation Sharif University of Technology ; Pishvaie, Mahmoud Reza (Supervisor) ; Javaherian, Abdolrahim (Supervisor) ; Nabi Bidhendi, Majid (Co-Advisor)
Abstract
In this project, some issues facing the application of AVO in carbonate reservoirs were studied,reviewed and discussed: physical relationships between elastic and reservoir rock properties to estimate compressional and shear wave velocities both on core measurements and well logging data, sensitivity analysis for Gassmann‐Biot and Kuster‐Toksoz rock physics models on the representative carbonate samples, lithology discrimination and reservoir characterization in carbonate intervals using AVO seismic attributes and specifically LambdaRho‐MuRho approach.The studied area (Azadegan Oil Field) is an area about 1174 km2 of 3D seismic data and was containing of six wells in the time of study. In...
Influence of fines content and type on the small-strain shear modulus of sand
, Article Scientia Iranica ; Vol. 21, issue. 4 , 2014 , p. 1281-1296 ; Ahmadi, M. M ; Sharif University of Technology
Abstract
The small-strain shear modulus, Go, is an important fundamental soil property. Although many studies have been conducted on this property for clean sands and pure clays, small-strain behavior for mixtures of sand and fines has been less addressed. This paper presents the results of a comprehensive laboratory study on G0 value of sand containing various amounts of different fines. To this aim, bender elements were integrated into a conventional triaxial apparatus, and shear wave velocity was measured on samples of sand with different amounts of highly-plastic, medium-plastic, low-plastic, or non-plastic fines at different void ratios. Measuring the shear wave velocity and thus...
Correlation of shear wave velocity with liquefaction resistance for silty sand based on laboratory study
, Article 15th Asian Regional Conference on Soil Mechanics and Geotechnical Engineering, ARC 2015: New Innovations and Sustainability, 9 November 2015 through 13 November 2015 ; 2015 , Pages 794-799 ; Ahmadi, M. M ; Sharif University of Technology
Asian Regional Conference on Soil Mechanics and Geotechnical Engineering
2015
Abstract
Several methods have been used for the evaluation of liquefaction potential, among which the simplified method is mostly used. In this method, which is mainly based on standard penetration test (SPT), cone penetration test (CPT) and shear wave velocity (Vs) measurement, a boundary curve is provided to separate the liquefiable and non-liquefiable soil zones. Vs measurement is a good alternative method of penetration-based methods (SPT and CPT). This is especially true in micro-zonation of liquefaction potential. Although relatively large studies have been carried out to establish the correlation between Vs and liquefaction resistance for sands; there are uncertainties about the effects of...
Soil-Structure interaction effect on fragility curve of 3D models of concrete moment-resisting buildings
, Article Shock and Vibration ; Volume 2018 , 2018 ; 10709622 (ISSN) ; Rahimzadeh Rofooei, F ; Nekooei, M ; Sharif University of Technology
Hindawi Limited
2018
Abstract
This paper presents the probabilistic generation of collapse fragility curves for evaluating the performance of 3D, reinforced concrete (RC) moment-resisting building models, considering soil-structure interaction (SSI) by concentration on seismic uncertainties. It considers collapse as the loss of lateral load-resisting capacity of the building structures due to severe ground shaking and consequent large interstory drifts intensified by P-Δ effects as well as the strength and stiffness deterioration of their lateral load carrying systems. The estimation of the collapse performance of structures requires the relation between the intensity measure (IM) and the probability of collapse...
Introducing a method for calculating water saturation in a carbonate gas reservoir
, Article Journal of Natural Gas Science and Engineering ; Volume 70 , 2019 ; 18755100 (ISSN) ; Nabi Bidhendi, M ; Masihi, M ; Emamzadeh, A ; Sharif University of Technology
Elsevier B.V
2019
Abstract
Cementation factor greatly affects water saturation estimation. Factors such as depositional environment, diagenesis and depositional architecture make the estimation of water saturation a big challenge in carbonate reservoirs. The current study is introduced a method for calculating cementation factor in Archie formula. First, (MRGC) technique was applied on the (NMR) logging parameters along with (NDS) data to obtain the optimum number of clustering. After that, fuzzy logic method was applied on conventional log parameters obtained from the wells without any NMR log data. In the third part of the study, a novel crossplot introduced including compressional to shear-wave velocity ratio...
Characterizing the effect of fines content on the small strain shear modulus of sand-silt mixtures during hydraulic hysteresis
, Article 4th International Conference on Transportation Geotechnics, ICTG 2021, 23 May 2021 through 26 May 2021 ; Volume 165 , 2022 , Pages 837-849 ; 23662557 (ISSN); 9783030772338 (ISBN) ; Mohsen Haeri, S ; Khosravi, A ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2022
Abstract
Small strain shear modulus, Gmax, is one of the most important parameters for the characterization of the behavior of earth structures subjected to static or dynamic loading conditions. This research presents an experimental laboratory study on the effect of non-plastic fines content and hydraulic hysteresis on the Gmax of unsaturated sandy soils. In this regard, clean Firoozkuh No. 161 silica sand which is classified as poorly graded sand was mixed with different percentages of non-plastic Firoozkuh silt. A set of bender element tests were carried out using two modified triaxial devices. The modifications on these two apparatus were to add HAV ceramic discs for air–water control of...