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پژوهشکده مهندسی ژئوتکنیک، پژوهشگاه بین المللی زلزله شناسی و مهندسی زلزله
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گروه مهندسی عمران، دانشکده فنی و مهندسی، دانشگاه شهرکرد
چکیده
ارزیابی دقیق منحنیهای رفتار دینامیکی خاکها از مراحل مهم و اساسی در حل مسائل ژئوتکنیک لرزه‌ای از جمله تحلیل پاسخ زمین میباشند. مطالعات بسیاری جهت ارزیابی این منحنیها که شامل منحنیهای سختی برشی و نسبت میرایی هستند، صورت گرفته است. اکثر این مطالعات بر روی خاکهای سیلیکاتی انجام پذیرفته است. مطالعات زمینشناسی حاکی از آن است که بخش وسیعی از سطح زمین در نواحی گرمسیری از جمله نواحی جنوبی کشور ایران پوشیده از خاکهای کربناتی است. از این‌رو بررسی رفتار خاکهای کربناتی تحت بارهای دینامیکی از اهمیت بالایی برخوردار است. در این مقاله مطالعات تحلیلی، تجربی و آماری انجام شده بر روی منحنیهای رفتار دینامیکی خاکها بررسی و اثر پارامترهای مختلف بر این منحنیها شرح داده میشود. در ادامه مطالعات آزمایشگاهی چرخهای و دینامیکی انجام شده در فشارهای محدودکننده‌ی میانگین 40، 200 و 400 کیلو پاسکال و دانسیتهی نسبی 50 و 80 درصد بر روی ماسه کربناتی بوشهر گزارش میشوند. در نهایت پارامترهای دینامیکی حاصل از آزمون‌های آزمایشگاهی این تحقیق با مطالعات گذشته مقایسه شد که نتایج حاصل نشان از تفاوت رفتاری ماسهی کربناتی بوشهر با الگوهای مبتنی بر ماسههای سیلیکاتی داشته است.
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