بررسی آزمایشگاهی تأثیر سختی مسلح کننده و اندازه‌ی ذرات خاک بر مقاومت بیرون کشیدگی مسلح کننده از خاک

نوع مقاله : مقاله پژوهشی

نویسندگان

دانشکده فنی و مهندسی، دانشگاه محقق اردبیلی، اردبیل، ایران

چکیده

یکی از مهمترین عوامل تاثیرگذار در رفتار مکانیکی سیستم‌های خاک مسلح، پارامترهای اندرکنش بین خاک و مسلح ‌کننده در فصل مشترک آنها می باشد. پارامترهای مکانیکی فصل مشترک خاک و مسلح‌کننده به مشخصات خاک و مسلح‌کننده وابسته است. در این تحقیق تأثیر اندازه دانه‌های خاک و نیز سختی مسلح‌کننده در مقاومت بیرون‌کشیدگی مسلح‌کننده از خاک بصورت آزمایشگاهی بررسی شده است. مقاومت بیرون‌کشیدگی سه نوع مسلح کننده با سختی‌های متفاوت در سه نوع خاک با دانه‌بندی‌‌های مختلف مورد بررسی قرار گرفته است. آزمایش‌های بیرون‌کشیدگی در سه سطح تنش 50، 100 و 150 کیلوپاسکال انجام شده است. برای بررسی این موضوع و تعیین شاخصی برای سختی مسلح‌کننده، دستگاهی ساخته شده است تا بتوان مقدار نفوذ دانه‌های جامد خاک در مسلح کننده اندازه‌گیری کرد. نتایج آزمایش‌ها نشان می‌دهد فرورفتگی دانه‌های خاک در مسلح‌کننده تأثیر زیادی در مقاومت بیرون‌کشیدگی مسلح‌کننده از خاک داشته است. مقدار نفوذ دانه‌های جامد خاک در مسلح‌کننده با کاهش سختی مسلح‌کننده و افزایش اندازه قطر دانه‌های خاک افزایش می‌یابد. برای هر سطح تنش قائم مشخص، هر چقدر میزان نفوذ دانه‌های جامد خاک در مسلح کننده بیشتر بوده، مقاومت بیرون کشیدگی آن مسلح کننده نیز بیشتر بوده است. نتایج نشان می‌دهد با افزایش قطر دانه‌های جامد خاک، مقاومت بیرون‌کشیدگی مسلح کننده نیز افزایش یافته است ولی این افزایش در مورد مسلح کننده‌ با سختی کمتر در مقایسه با مسلح‌کننده سختی بیشتر، چشم‌گیرتر بوده است و نیز اختلاف مقاومت بیرون کشیدگی سه مسلح‌کننده با سختی های مختلف در خاک ریزدانه  کمتر از اختلاف مقاومت بیرون‌کشیدگی سه مسلح کننده در خاک درشت دانه بوده است که نشان دهنده تأثیر همزمان سختی مسلح‌کننده و اندازه دانه‌های خاک در مقاومت بیرون‌کشیدگی می‌باشد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

A laboratory study of the influence of reinforcement stiffness and the size of soil particles on soil pull-out strength

نویسندگان [English]

  • Ahad Ouria
  • Eliar Heidarli
  • Saeed Karamzadegan
Civil Engineering Department, University of Mohaghegh Ardabili, Ardabil, Iran
چکیده [English]

The interaction parameters between soil and reinforcement at their interface play a critical role in influencing the mechanical behavior of reinforced soil systems. Interaction parameters between soil and reinforcement influence reinforced soil behavior mechanically. In this research, the effect of the size of soil grains and the stiffness of the reinforcement on the pull-out resistance of the reinforcement from the soil has been investigated in a laboratory. The pullout resistance of three types of reinforcements with different stiffness in three types of soil with different grain sizes has been investigated. Pull-out tests have been performed at three stress levels of 50, 100, and 150 kPa. To investigate this issue and determine an evaluation for the stiffness of the reinforcement, a device has been built to measure the penetration of solid soil grains in the reinforcement. The results of the tests show that the penetration of soil grains into the reinforcement has a significant impact on the resistance of the reinforcement to being pulled out of the soil. The amount of penetration of solid soil grains into reinforcement increases by reducing the stiffness of the reinforcement and increasing the size of the diameter of the soil grains. For each specific vertical stress level, the greater the penetration of solid soil grains into reinforcement, the higher the pull-out strength of that reinforcement. The results show that with the increase in the diameter of the solid grains of the soil, the pullout resistance of the reinforcement has also increased, but this increase has been more significant in the case of reinforcement with lower stiffness compared to reinforcement with higher stiffness. Also, the difference in the pullout resistance of three reinforcements with different stiffness in fine-grained soil was less than the difference in the pullout resistance of three reinforcements in coarse-grained soil, which indicates the simultaneous effect of reinforcement stiffness and soil grain size on pullout resistance.

کلیدواژه‌ها [English]

  • Pull out strength
  • reinforcement stiffness
  • soil and reinforcement interaction
  • soil grain size
  • reinforced soil
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