بررسی وابستگی سرعت موج برشی به اندازه دانه‌های خاک ماسه‌ای

نوع مقاله : Articles

نویسندگان

دانشگاه رازی، کرمانشاه

چکیده

در محدوده کرنش‌های کوچک (ε≤〖10〗^(-3)%)، سرعت موج برشی (Vs) و متعاقب آن مدول برشی حداکثر (Gmax) یکی از مؤلفه‌های اساسی برای انجام محاسبات ژئوتکنیکی و تحلیل‌ دینامیکی خاک‌ها می باشد. تأثیر اندازه دانه ها در هنگام انتشار امواج بر رفتار دینامیکی خاک، یکی از مسائل مهم و مورد بحث محققین است. در گذشته تأثیر اندازه دانه های خاک بر سرعت موج برشی، معمولاً در دامنه محدودی از اندازه دانه‌های خاک مورد برسی قرارگرفته است. اگرچه نتایج این تحقیقات، تأثیرهای متفاوت اندازه دانه های خاک بر سرعت موج برشی را نشان می دهد، اما نتیجه ای قطعی از تأثیر اندازه دانه های خاک بر سرعت موج برشی ارائه نگردیده است. در این تحقیق به روش آزمایشگاهی و با استفاده از دستگاه المان خمشی، تأثیر اندازه دانه های خاک بر سرعت موج برشی در دامنه وسیعی از اندازه دانه های خاک ماسه ای خشک، تحت فشارهای همه جانبه از 50 تا 500 کیلو پاسکال در دستگاه سه‌محوری بررسی شد. به کمک الک‌های استاندارد ASTM خاک ماسه ای در 10 گروه تفکیک شد. از هر گروه، نمونه های سه‌محوری به روش تراکم کاهش یافته و با رعایت نسبت تخلخل یکسان تهیه و مورد آزمایش قرار گرفت. نتایج بررسی ها نشان می-دهد که سرعت موج برشی به‌اندازه‌ی دانه ها وابسته است، به‌طوری‌که در قطر متوسط دانه ها از 225/0 تا 29/1 میلی‌متر با افزایش قطر، سرعت موج برشی افزایش و برای قطر متوسط دانه ها از 29/1 تا 14/7 میلی‌متر با افزایش قطر سرعت موج برشی کاهش می یابد.Investigating the Interrelationships Between Shear-Wave Velocity and Particle Size of a Sandy SoilAbolhasan Sharifi1 and Mohammad Sharifipour2*1. Ph.D. Candidate, Department of Civil Engineering, Razi University, Kermanshah, Iran2. Assistant Professor, Department of Civil Engineering, Razi University, Kermanshah, Iran,*Corresponding Author, email: sharifipour@razi.ac.irKeywords: Shear-Wave Velocity, Soil Particle Size, Bender Elements Test, Shear Modulus, Small-Strain Behaviour.--English abstract is in the final page of the pdf file--

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