شبیه سازی عددی رفتار مکانیکی خاک دانه‌ای غیراشباع با ذرات چند گوشه با استفاده از روش اجزای مجزا

مهندسی عمران فردوسی

مقاله 5، دوره 36، شماره 4 - شماره پیاپی 44، دی 1402، صفحه 77-94   

نوع مقاله: مقاله پژوهشی

شناسه دیجیتال (DOI): 10.22067/jfcei.2023.85350.1270

نویسندگان

محمدحسین جلالیان سده؛ سیداحسان سیدی حسینی نیا^*

گروه مهندسی عمران، دانشکده مهندسی، دانشگاه فردوسی مشهد،

چکیده

مدلسازی عددی خاک‌های غیراشباع، امروزه مورد توجه قرار گرفته است. روش اجزای مجزا توانایی مناسبی در مدلسازی منیسک بین ذرات دارد. در این پژوهش رفتار خاک دانه‌ای غیر اشباع با استفاده از مدلسازی دو محوری به شیوه اجزای مجزا مورد بررسی قرار گرفته است. بر خلاف پژوهش‌های گذشته که شکل ذرات به صورت ساده دایروی یا کروی در نظر گرفته می‌شدند، در این مدلسازی از ذرات چند گوشه استفاده شده است که تطابق بیشتری با شکل واقعی ذرات دارد و می‌توان امکان تشکیل منیسک در حفرات مختلف را با توجه به هندسه و آرایش ذرات در کنار هم بررسی کرد. در حالی‌که به دلیل تقارن در ذرات دایروی و کروی، شکل منیسک در بین این ذرات فقط به اندازه ذرات بستگی دارد. با توسعه یک برنامه موجود بر پایه روش اجزای مجزا، ذرات در مکش‌ها و تنش‌های همه جانبه مختلف تحت بارگذاری دو محوری قرار گرفتند. نتایج نشان داد که با افزایش مکش تا حد مشخصی، مقاومت برشی نمونه افزایش می‌یابد و پس از آن با افزایش مکش، مقاومت برشی کاهش ‌می‌یابد. همچنین مشاهده شد که با افزایش تنش همه جانبه، اثر نیروی منیسک بر مقاومت برشی کاهش می‌یابد. مدلسازی ذرات با اندازه‌های مختلف همچنین نشان داد که تاثیر نیروی منیسک بر ذرات کوچک‌تر، بیشتر است و با افزایش اندازه ذرات اثر نیروی منیسک بر مقاومت برشی کمتر می‌شود.

کلیدواژه‌ها

خاک غیر اشباع؛ روش اجزای مجزا؛ ذرات چند گوشه؛ پل مایع؛ تاثیر شکل ذرات

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