IJE TRANSACTIONS B: Applications Vol. 32, No. 5 (May 2019) 667-672   

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D. Azan and A. Haddad
( Received: November 10, 2018 – Accepted in Revised Form: May 02, 2019 )

Abstract    In this study, fuzzy logic was implemented to formulate the fuzziness of layer boundaries for a two-layered clay soil. A field of two-layered clay with fuzzy boundaries between layers was generated, and then the bearing capacity of strip footing on this field was calculated by the assumption of plane-strain conditions. The Mohr-Coulomb failure criterion was used and bearing capacity calculations were based on finite difference method. The effect of fuzziness in layer boundaries was investigated for the case of strong-over-weak clay. It is concluded that the analyses by applying fuzzy boundaries yielded more conservative results than classical two-layered bearing capacity calculations when the ratio of thickness of upper layer to the width of footing exceeds 1. When the ratio of thickness of upper layer to the width of footing is lower than 1, the bearing capacity of footing on two-layered clay is higher by considering fuzzy boundaries.


Keywords    Bearing Capacity; Difference Method; Fuzzy Boundary; Fuzzy Logic; Uncertainty; Two-layered Clay; Finite



در این تحقیق منطق فازی جهت فرموله کردن ابهام در مرز لایه بندی برای خاک رسی دو لایه استفاده شده است. میدان خاکی با لحاظ مرزبندی فازی میان لایه¬ها ایجاد شده و سپس ظرفیت باربری پی نواری واقع بر این میدان توسط فرضیه کرنش صفحه¬ای محاسبه شده است. جهت محاسبه ظرفیت باربری مدل مور-کلمب با بهره گیری از روش تفاضل محدود استفاده شده است. اثر ابهام در مرز لایه¬بندی برای خاک دولایه رسی لایه سخت بر لایه ضعیف¬تر مورد بررسی قرار گرفته است. نتایج نشان¬دهنده این مطلب است که با اعمال لایه¬بندی فازی کاهش در ظرفیت باربری هنگامی که عمق لایه اول از عرض پی بیشتر است رخ می¬دهد. در حالتی که عمق لایه¬ی اول کمتر از عرض پی است ظرفیت باربری خاک دو لایه رسی با لحاظ مرزبندی فازی افزایش می¬یابد.


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