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

نوع مقاله : مقاله پژوهشی

نویسندگان

• محمدحسین جلالیان سده
• سیداحسان سیدی حسینی نیا

گروه مهندسی عمران، دانشکده مهندسی، دانشگاه فردوسی مشهد،

10.22067/jfcei.2023.85350.1270

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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عنوان مقاله [English]

Numerical Simulation of Mechanical Behavior of Unsaturated Granular Soil with Polygonal Particles Using Discrete Element Method

نویسندگان [English]

• Moha,mmad Hossein Jalalian
• Ehsan Seyedi Hosseininia

Department of Civil Engineering, Engineering Faculty, Ferdowsi University of Mashhad, Mashhad, Iran.

چکیده [English]

Numerical modeling of unsaturated soils has become increasingly popular in recent years. The Discrete Element Method (DEM) is a powerful tool for modeling granular materials by focusing on particle interactions. In this study, the behavior of unsaturated granular soil was investigated using two-dimensional DEM by considering meniscus formation among particles. Unlike previous studies that simply considered particle shapes as circular or spherical, this study used more realistic polygonal particles shape that forming meniscus can be examined in different pores with respect to the geometry and arrangement of the particles. However, because of symmetry in circular and spherical particles, the shape of the meniscus among these particles depends only to the size of the particles. To this end, using a program based on the DEM was developed and a soil sample were simulated under different suction values and confining pressures. The results showed that the shear strength of the sample augments by increasing suction until a specific value and then, decreased with further suction increases. It was also observed that the effect of meniscus force on increasing shear strength decreased with increasing confining pressures. Modeling particles of different sizes also showed that the effect of meniscus force is greater for smaller particles and decreases with particle size.

کلیدواژه‌ها [English]

• Unsaturated Soil
• Discrete Element Method
• Polygonal Particles
• Liquid Bridge
• Effect of Particles Shape

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