ارزیابی اثرات توپوگرافی بر تفرق امواج لرزه‌ای با‌استفاده از روش المان مرزی

نوع مقاله : یادداشت پژوهشی

نویسندگان

• محسن ایثاری
• رضا تاری نژاد

دانشگاه تبریز

10.22067/civil.v30i2.33582

چکیده

در این تحقیق برای ارزیابی اثرات توپوگرافی از روش المان مرزی سه‌بعدی که یکی از فنون عددی بسیار قدرتمند برای تحلیل مسائل به‌ویژه موضوعات مربوط به انتشار امواج است، استفاده می‌شود. نتایج به‌دست‌آمده از تحلیل توپوگرافی‌های مختلف به شکل‌های مثلثی، ذوزنقه‌ای، نیم‌دایره‌ای و نیم‌بیضوی تحت اثر امواج لرزه‌ای SH نشان می‌دهد که یکی از مهم‌ترین عوامل تأثیرگذار بر الگوی رفتار دینامیکی دره، پارامتر هندسی (شکل و عمق) می‌باشد، که این عوامل در فرکانس‌های مختلف اثرات متفاوتی از خود نشان می‌دهند. علاوه‌براین، اثر پارامترهای دیگر مانند زاویۀ برخورد و همچنین خواص مصالح دره (مدول الاستیسیته، میرایی و ضریب پواسون) نیز مورد ارزیابی قرار گرفتند.

کلیدواژه‌ها

• توپوگرافی
• المان مرزی
• تفرق امواج
• اثرات ساختگاه
• هندسۀ دره

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عنوان مقاله [English]

Investigation Effects of Canyon Topography on the Seismic Wave Scattering by 3D-BEM

نویسندگان [English]

• mohsen isari
• Reza Tarinejad

University of Tabriz

چکیده [English]

A Boundary Element Code has been developed and verified by numerous study .The results of the analysis of topographic forms triangular, trapezoidal, semi-circular and semi-elliptical under seismic SH waves show that one of the important factors that influence on the dynamic behavior canyons are geometric parameters (shape and depth). These factors with different frequency have various effect. The results indicated that several parameters such as wave parameters (frequency and direction) are factors that affecting the pattern of displacement on the canyon. It was demonstrated that the effects of this parameters are highly dependent with incoming frequency. That is demonstrated with increasing frequency, Effects of depth is increases. It is clear that, the graph of materials effects (damping and Poisson) on the dynamic behavior and displacement pattern are undeniable and increase the accuracy of result that need to be considered.

کلیدواژه‌ها [English]

• Topography
• Three-Dimensional Boundary Element method
• Wave Scattering, Site Effect
• Canyon Geometry

مراجع

1. Alves, W.S., "Nonlinear Analysis of Pacoima Dam with Spatially Non-uniform Ground Motion", PhD Dissertation, California Institute of Technology, (2005).

2. Kojic,S.B., "Earthquake Response of Arch Dams to Non-uniform Canyon Motion, PhD Dissertation", Southern California University, (1988).

3. Mossessian, T.K. and Dravinski, M., "Amplification of Elastic Waves by a Three Dimensional Valley. part2: Transient Response", Earth Eng and StrucDyn, Vo1. 19, (1990).

4. Mossessian, Tomi, K. and Dravinski, M., "Amplification of Elastic Waves by a Three Dimensional Valley. partl: Steady-state Response", Earth Eng and StrucDyn, Vo1.19, (1990).

5. Yuan, C. Z., Xiong, Z. J. and Cheung, Y. K., "A Semi-Analytical Boundary Element Method for Scattering of Waves in a Half Space", Earth Eng and Struc Dyn,Vo1. 19, (1990).

6. Eshraghi, H &Dravinski, M., "Scattering of Plane Harmonic SH, SV, P and Rayleigh Waves by Non-axisymmetric Three dDimensional Canyons: A Wave Function Expansion Approach", Earth Eng and Struc.Dyn, Vo1. 18, (1989).

7. تاری‌نژاد، رضا، «بارگذاری زلزله برای سازه‌های واقع در ساختگاه‌های دره‌ای»، رسالۀ دکتری با راهنمایی دکتر محمدتقی احمدی، دانشکدۀ فنی مهندسی، دانشگاه تربیت مدرس، (1386).

8. Kamalian, M., Jafari, M.K., Sohrabi-Bidar, A. Razmkhah, A.,"Shape Effects on Amplification Potential of Two Dimensional Hills", JSEE, Vol. 8, No.2, PP. 58-70 (In Farsi), (2003).

9. Kamalian, M., Jafari, M.K., Sohrabi, A., "On Time-domain Two-dimensional Site Response Analysis of Topographic Structures by BEM", J. Seismological Earthquake Engineering, 5(2), PP. 35-45, (2003).

10. Kamalian, M., Gatmiri, B., Sohrabi, A., "Amplification Pattern of 2D Semi-sine-shaped Valleys Subjected to Vertically Propagating Incident Waves", Commun. Numer. Meth. Engng, 23, PP. 871–887, (2007).

11. Omidvar, B., Rahimian, "M.3D Topography Effects on Amplification of Plane Harmonic Body and Surface Waves", JSEE, (2010).

12. Omidvar, B.,Rahimian, M. "Three-Dimensional Scattering of Plane Harmonic SH", SV, and P Waves in Multilayered Alluvial Valleys. ASIAN JOURNAL OF CIVIL ENGINEERING (BUILDING AND HOUSING) Vol. 11, No. 5, PP. 605-626, (2010).

13. Gatmiri, B. and Arson, C. "Seismic Site Effects by an Optimized 2D BE/FE Method II. Quantification of Site Effects in Two-Dimensional Sedimentary Valleys", Soil Dynamics and Earthquake Engineering, 28, PP. 646-661, (2008).

14. Gatmiri., B, Nguyen, K-V, Dehghan, K., "Seismic Response of Slopes Subjected to Incident SV Wave by an Improved Boundary Element Approach", Int. J. Numer. Anal. Meth. Geomech, (2007).

15. Sohrabi-Bidar, A., Kamalian, M., Jafari, M.K, "Time-domain BEM for Three-dimensional Site Response Analysis of Topographic Structures", Int. J. Numer. Meth. Engng, 79, PP. 1467–1492, (2009).

16. Sohrabi-Bidar, A., Kamalian, M. and Mohammad Kazem Jafari, "Seismic Response of 3-D Gaussian-Shaped Valleys to Vertically Propagating Incident Waves", Geophys. J. Int. 183, PP. 1429–1442, (2010).

17. Dominguez, J., "Boundary Elements in Dynamics", Elsevier, (1993).

18. Manolis, G.D., Beskos, D.E., "Boundary Element Methods in Elastodynamics", Unwin Hyman Ltd, ISBN: 004-620019-3, (1988).

19. Zhang, L. and Chopra, A. K., "Three-Dimensional Analysis of Spatially Varying Ground Motions around a Uniform Canyon in a Homogeneous Half-space", Earthquake Engineering and Structural Dynamics; 20, PP. 911-926, (1991).