تأثیر تعداد و جنس لایه های خاک بر پاسخ سازه های مدفون در برابر انفجار

نوع مقاله : مقاله پژوهشی

نویسندگان

دانشکده مهندسی عمران، واحد بوشهر، دانشگاه آزاد اسلامی، بوشهر، ایران

چکیده

در حوزۀ سازه‌های مدفون یا زیرزمینی، پدافند غیرعامل در واقع همان تلاش برای طراحی، بهسازی و جانمایی مناسب این نوع سازه ­ها است. مدل‌سازی عددی و کامپیوتری یکی از بهترین روش­ هایی است که می­توان از آن برای تحلیل مسائل استفاده نمود. در این تحقیق با استفاده از نتایج گذشته صحت نتایج مدل‌سازی بارگذاری انفجار سطحی مورد ارزیابی قرار گرفته و پس از اطمینان از این مدل‌سازی، به بررسی سازه مدفون در خاک ­های متفاوت و سیستم لایه ­ای پرداخته شده است. در مدل‌سازی اثر اندرکنش خاک و سازه لحاظ شده و تحلیل به صورت غیرخطی با استفاده از نرم‌افزار آباکوس انجام گرفته است، سازه در خاک به صورت تک لایه، دو لایه و سه لایه با عمق دفن 8 متر از سطح زمین مدفون شده و به بررسی و مقایسه تغییر مکان و تنش پرداخته شده است. خاک­ های مورد استفاده در این تحقیق ماسه نرم، ماسه سخت و خاک رس می­ باشد. نتایج به دست آمده نشان می ­دهد که، بیشترین جابجایی مربوط به شرایط قرارگیری لایه اول ماسه نرم، لایه دوم ماسه سخت و لایه سوم خاک رس، و کمترین مقدار جابجایی در شرایط خاک تک لایه، حالت ماسه نرم می‌باشد. همچنین تغییر در جنس و تعداد لایه ­ها گاهی تا 100 درصد کاهش برای تنش ­های حاصل و تا 19 درصد برای جابجایی در سازۀ مدفون را به همراه دارد. این مسأله ضرورت تأثیر لایه­ بندی خاک را در طراحی سازه ­های مدفون نشان می­ دهد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Effect of Number and Type of Soil Layers on the Response of Buried Structures to Explosion

نویسندگان [English]

  • Mobin Hematyan
  • Hadi Dashti
Department of Civil Engineering, Bushehr Branch, Islamic Azad University, Bushehr, Iran
چکیده [English]

In the field of buried or underground structures, the objective of passive defense is to properly design, improve and place such structures. Among the best methods to analyze the problems are numerical and computer models. In the present research, using the previous results, the accuracy of surface explosion loading modeling results was evaluated. Moreover, the structures buried in different soils and the layered system were investigated after ensuring these models. To model the effect of soil-structure interaction, the analysis is performed non-linearly using Abaqus software. The structure is buried in the soil as a single layer, double layers, and triple layers with a burial depth of 8 m above the ground while comparing the displacement and stress. The soils used in this research are soft sand, hard sand, and clay. The results show that the highest displacement is related to the placement of the first layer of soft sand, the second layer of hard sand, and the third layer of clay. However, the lowest amount of displacement is associated with a single layer of soft sandy soil. Also, changes in the material and the number of layers sometimes lead to a reduction of more than 100% and 19% respectively in the resulting stresses and the displacement in the buried structure. This issue shows the necessity of the effect of soil layering in the design of buried structures.

کلیدواژه‌ها [English]

  • Soil layering
  • Explosion
  • Buried structure
  • Numerical modeling
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