مطالعه اثرات اندازه ذرات بر رفتار پیش لرزه ای مدل های فیزیکی متشکل از خاک های دانه ای خشک بد دانه بندی شده

نوع مقاله : مقاله کامل پژوهشی

نویسنده

گروه مهندسی عمران، دانشکده مهندسی، دانشگاه صنعتی کرمانشاه

چکیده

رفتار پیش ­لرزه ­ای دپوهای طبیعی و خاکریزهای مصنوعی متشکل از مصالح دانه ­ای به ­شدت تابع وضعیت دانه ­بندی آن­هاست. در این مقاله مدل­ های فیزیکی کوچک- مقیاس ساخته ­شده از مصالح دانه ­ای خشک، از نوع ماسه و شن بددانه­ بندی شده با چگالی نسبی کم تا متوسط مابین 20% تا 60% مورد ارزیابی قرار گرفته است. در این مطالعه، مدل ­های فیزیکی لایه خاکریز دانه ­ای به­ کمک ابزار دقیق، برای اندازه­ گیری فرکانس ­های طبیعی تجهیز شده ­اند. اثر اجتناب­ ناپذیر سختی بالای مرزهای مصنوعی در مدل­ سازی­ های فیزیکی، یعنی دیواره ­های جعبه صلب بر پاسخ ­های فرکانسی محاسبه شده است. حسگرهای شتاب برای کنترل اثرات دانه ­بندی و چگالی نسبی بر مقادیر فرکانس ­های طبیعی در ارتفاع مدل خاکریز نصب شده ­اند. از روش پالس ضربه و استخراج توابع تاریخچه زمانی و طیفی شتاب جهت برآورد پاسخ ­های فرکانس طبیعی خاکریز با مصالح دانه ­ای مختلف، استفاده شده است. نتایج این مطالعه نشان می ­دهد که با افزایش اندازه ذرات خاک دانه ­ای بددانه ­بندی شده و کاهش ناگزیر چگالی نسبی آن در یک انرژی تراکمی یکسان، مقادیر فرکانس طبیعی (تشدید) آن کاهش می ­یابد. همچنین در بین عوامل هندسی مدل، اثر ارتفاع مدل فیزیکی بر فرکانس طبیعی، بیشتر از اثرات طول و عرض مدل است. رابطه ریاضی وابستگی فرکانس طبیعی مدل به ­اندازه میانگین ذرات مصالح دانه ­ای به­ شکل سهموی واسنجی شده است.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Study of the Effects of Particle Size on the Pre-Seismic Behavior of Physical Models of Dry Granular Soils

نویسنده [English]

  • Yazdan Shams Maleki
Faculty of Engineering, Department of Civil Engineering, Kermanshah University of Technology (KUT), Kermanshah, Iran
چکیده [English]

To study the dynamics of embankment models, which is the basis for the construction of many engineering structures, physical modeling with different scales can be performed. The pre-seismic behavior of physical models has a great impact on the subsequent results of their seismic modeling. Appropriate experiments in this field can be used for pre-seismic examination of physical models. Free vibration and impact tests are among these tests (Dezi et al., 2012; Capatti et al., 2018; Kramer, 1996). Impact pulse tests (IPT) can be used to determine the natural frequency characteristics of physical models. Interpretation of frequency responses provides researchers with appropriate pre-seismic parameters. According to the evaluation of these findings in the first step, a suitable geometric scale can be selected for physical modeling. In addition, the relationship between soil conditions in terms of density and particle size and frequency response quantities of physical models is also determined. In this paper pre-seismic simulations of a small-scale physical model of a granular soil layer inside a rigid physical modeling box are developed.

کلیدواژه‌ها [English]

  • Granular embankment
  • Natural frequency
  • Physical model
  • Pre-seismic model
  • Particle size
بایبوردی ش، مجتهدی ع، "توسعه یک روش کارآمد عیب­ یابی سازه ای در سکوهای فراساحلی شابلونی با استفاده از الگوریتم فراابتکاری اجتماع ذرات"، نشریه مهندسی عمران و محیط زیست دانشگاه تبریز، 1395، 46 (4)، 37-49.
روشن­ روان آ، تاری ­نژاد ر، دامادی ­پور م، محجوب ح، "شناسایی مودال سد بتنی قوسی با استفاده از روش ترکیبی تجزیه دامنه فرکانس و تبدیل موجک"، نشریه مهندسی عمران و محیط زیست دانشگاه تبریز، 1395، 46 (3)، 17-29.
Al-Defae AH, Caucis K, Knappett JA, “Aftershocks and the whole-life seismic performance of granular slopes”, Geotechnique, 2013, 63 (14), 1230-1244. https://doi.org/10.1680/geot.12.P.149
Altunisik AC, Kalkan EFYFY, Ozgan K, Karahasan OS, Bostanci A, “Non-destructive modal parameter identification of historical timber bridges using ambient vibration tests after restoration”, Measurement, 2019, 146, 411-424. https://doi.org/10.1016/j.measurement.2019.06.051
American society for testing and materials, “Annual book of ASTM standards”, 1999, 4, 04.08, west Conshohoken Pa.
Bartilson DT Jang J, Smyth AW, “Symmetry properties of natural frequency and mode shape sensitivities in symmetric structures”, Mechanical Systems and Signal Processing, 2020, 143, 106797. https://doi.org/10.1016/j.ymssp.2020.106797
Brøns M, Thomsen JJ, “Experimental testing of Timoshenko predictions of supercritical natural frequencies and mode shapes for free-free beams”, Journal of Sound and Vibration, 2019, 459, 114856. https://doi.org/10.1016/j.jsv.2019.114856
Capatti MC, Dezi F, Carbonari S, Gara F, “Full-scale experimental assessment of the dynamic horizontal behavior of micropiles in alluvial silty soils”, Soil Dynamics and Earthquake Engineering, 2018, 113, 58-74. https://doi.org/10.1016/j.soildyn.2018.05.029
Capatti MC, Dezi F, Carbonari S, Gara F, “Dynamic performance of a full-scale micropile group: Relevance of nonlinear behaviour of the soil adjacent to micropiles”, Soil Dynamics and Earthquake Engineering, 2020, 128, 105858. https://doi.org/10.1016/j.soildyn.2019.105858
Chellapandi P, Chetal SC, Raj B, “Numerical simulation of fluid-structure interaction dynamics under seismic loadings between main and safety vessels in a sodium fast reactor”, Nuclear Engineering and Design, 2012, 253, 125-141.
Cubrinovski M, Ishihara K, “Maximum and Minimum Void Ratio Characteristics of Sands”, Soils and Foundations, 2002, 42 (6), 65-78.
Cubrinovski M, Ishihara K, “Empirical Correlation between SPT N-Value and Relative Density for Sandy Soils”, Soils and Foundations, 1999, 39 (5), 61-71. https://doi.org/10.3208/sandf.39.5_61
Dahak M, Touat N, Benseddiq N, “On the classification of normalized natural frequencies for damage detection in cantilever beam”, Journal of Sound and Vibration, 2017, 402, 70-84.
Dezi F, Gara F, Roi D, “Dynamic response of a near-shore pile to lateral impact load”, Soil Dynamics and Earthquake Engineering, 2012, 40,34-47. https://doi.org/10.1016/j.soildyn.2012.04.002
Dezi F, Gara F, Roi D, “Experimental study of near-shore pile-to-pile interaction”, Soil Dynamics and Earthquake Engineering, 2013, 48, 282-293. https://doi.org/10.1016/j.soildyn.2013.01.025
Ding H, Tan X, Dowell EH, “Natural frequencies of a super-critical transporting Timoshenko beam”, European Journal of Mechanics/A Solids, 2017. https://doi.org/10.1016/j.euromechsol.2017.06.007
Elshamy M, Crosby WA, Elhadary M, “Crack detection of cantilever beam by natural frequency tracking using experimental and finite element analysis”, Alexandria Engineering Journal, 2018. https://doi.org/10.1016/j.aej.2018.10.002
Fei H, Danhui D, Zichen D, “A dynamic stiffness-based modal analysis method for a double-beam system with elastic supports”, Mechanical Systems and Signal Processing, 2021, 146, 106978.
Hente C, Gebhardt CG, Pache D, Rolfes R, “On the modal analysis of nonlinear beam and shell structures with singular mass and stiffness matrices”, Thin-Walled Structures, 2019, 144, 106310. https://doi.org/10.1016/j.tws.2019.106310
Hu T, Ding X, Shen L, Zhang H, “Improved adaptive growth method of stiffeners for three-dimensional box structures with respect to natural frequencies”, Computers and Structures, 2020, 239, 106330. https://doi.org/10.1016/j.compstruc.2020.106330
Iai S, “Similitude for shaking table tests on soil-structure-fluid model in 1 g gravitational field”, Soil Found, 1989, 29 (1), 105-118.
Kramer SL, “Geotechnical earthquake engineering”, 1996, New Jersey: Prentice-Hall. ISBN-10:
0133749436
Lee JW, Lee JY, “Contribution rates of normal and shear strain energies to the natural frequencies of functionally graded shear deformation beams”, Composites Part B, 2018, 159, 86-104. https://doi.org/10.1016/j.compositesb.2018.09.050
Leng J, Peterman KD, Bian G, Buonopane SG, Schafer BW, “Modeling seismic response of a full-scale cold-formed steel-framed Building”, Engineering Structures, 2017, 153, 146-165.
NI, National Instruments Corp., USA. http://www.ni.com/.2022.
Nicoletti R, “On the natural frequencies of simply supported beams curved in mode shapes”, Journal of Sound and Vibration, 2020, 485, 115597. https://doi.org/10.1016/j.jsv.2020.115597
Niu Z, “Two-step structural damage detection method for shear frame structures using FRF and Neumann series expansion”, Mechanical Systems and Signal Processing, 2021, 149, 107185.
Noolvi B, Nagaraj S, “Modal analysis of smart composite cantilever beams”, Materials Today: Proceedings, 2020. https://doi.org/10.1016/j.matpr.2020.03.643
Payan M, Khoshghalb A, Senetakis K, Khalili N, “Effect of particle shape and validity of Gmax models for sand: A critical review and a new expression”, Computers and Geotechnics, 2016, 72, 28-41.
Sinha A, “Computing natural frequencies and mode shapes of a non-uniform circular membrane”, Mechanics Research Communications, 2020, 107, 103553. https://doi.org/10.1016/j.mechrescom.2020.103553
Sharifi A, Sharifipour M, Rizvandy A, “Laboratory investigation into the effect of particle sizes on shear wave parameters using bender elements test results”, Geotechnical Testing Journal, 202, 43 (5), 1216-1232. https://doi.org/10.1520/GTJ20180240
Shifrin EI, Lebedev IM, “Identification of multiple cracks in a beam by natural frequencies”, European Journal of Mechanics/A Solids, 2020, 84, 104076. https://doi.org/10.1016/j.euromechsol.2020.104076
Shravan HG, Rudesh RM, “Effect of Notch. Depth & Location on Modal Natural Frequency of Cantilever Beams”, 2016.
Sun W, Wang Z, Yan X, Zhu M, “Inverse identification of the frequency-dependent mechanical parameters of viscoelastic materials based on the measured FRFs”, Mechanical Systems and Signal Processing, 2018, 98, 816-833.
Tomasiello S, “A Simplified Quadrature Element Method to compute the natural frequencies of multispan beams and frame structures”, Mechanics Research Communications, 2011, 38, 300-304.
Ueno K, “Methods for preparation of sand samples”, Proceedings of 1998 international conference of centrifuge, 1998, 98, 1047-56.
Wood DM, “Geotechnical modeling. [Version 2.2]”, London: Taylor & Francis Group, 2004.
Zalka KA, “A simplified method for calculation of the natural frequencies of Wall-frame buildings”, Engineering Structures, 2001, 23, 1544-1555. https://doi.org/10.1016/S0141-0296(01)00053-0
Zhang K, Yan Y, “Multi-cracks identification method for cantilever beam structure with variable cross-sections based on measured natural frequency changes”, Journal of Sound and Vibration, 2017, 387, 53-65.