مطالعه عددی افزایش ظرفیت باربری پی‌های حلقوی و دایره ای مستقر بر خاک های دانه ای مسلح شده توسط سامانه مهارشبکه

نویسندگان
1 هیات علمی دانشگاه شیراز
2 هیات علمی دانشگاه یاسوج
3 دانش آموخته دانشگاه یاسوج
چکیده
تسلیح خاک یکی از روش‌های بهبود خواص مکانیکی خاک است. پژوهش‌های زیادی طی چهار دهه اخیر به منظور تعیین نوع مسلح کننده و همچنین میزان افزایش ظرفیت باربری خاک مسلح شده با مسلح کننده‌ها انجام شده است. به تازه‌گی نوع جدیدی از مسلح کننده‌های پلیمری برای افزایش ظرفیت باربری خاک‌های دانه‌ای ابداع شده است. این سامانه جدید که مهارشبکه (G-A)نام‌گذاری شده است]1[، با تغییر ساختار ژئوگرید معمولی و اضافه کردن قلاب­های پلیمری به آن، ساخته می­شود. در این مقاله سعی شده است که با کمک تحلیل­های عددی، توان این نوع مسلح­کننده در افزایش ظرفیت باربری پی­های حلقوی و دایره­ای بررسی شد. عمق اولین لایه مسلح کننده، فاصله بین لایه‌ها، تعداد لایه‌ها، پهنای مسلح کننده و پهنای موثر قلاب‌گذاری در دو حالت پی حلقوی و دایره‌ای به گونه‌ای تعیین شده‌اند که شاهد بیشترین ظرفیت باربری باشیم. تاثیر سختی مسلح کننده در افزایش ظرفیت باربری در پی‌ها نیز مورد بررسی قرار گرفته‌اند. در پایان نتایج بدست آمده، با نتایج ظرفیت باربری پی واقع بر خاک ماسه­ای غیرمسلح و ماسه مسلح­شده با ژئوگرید معمولی مقایسه می­شوند.

کلیدواژه‌ها


عنوان مقاله English

A Numerical Study on Bearing Capacity of Ring and Circular Foundations on Granular Soils Reinforced by Grid-Anchor System

نویسنده English

Mansour Mosallanezhad 1
1 هیات علمی
چکیده English

Abstract: Soil reinforcement is one of the soil improvement techniques. Over the last four decades, a large number of researches have been carried out in order to obtain the reinforcement type and the bearing capacity improvement of the reinforced soil. A new reinforcement type called Grid-Anchor (G-A) has been recently invented which is made of geogrids by adding polymer anchors to it. In this study the bearing capacity of ring and circular footings located on granular soils reinforced with the G-A is investigated using numerical analyses. Commercial finite-element software PLAXIS is employed to perform the simulations. The effect of depth of the first reinforcement layer, the vertical spacing, the number and width of reinforcement layers, the distance that anchors are effective, for each foundation were investigated. The effect of reinforcement stiffness for two types of footing has been investigated. A comparison between the results obtained for the G-A and geogrid reinforcement systems and unreinforced soils is demonstrated as well. Abstract: Soil reinforcement is one of the soil improvement techniques. Over the last four decades, a large number of researches have been carried out in order to obtain the reinforcement type and the bearing capacity improvement of the reinforced soil. A new reinforcement type called Grid-Anchor (G-A) has been recently invented which is made of geogrids by adding polymer anchors to it. In this study the bearing capacity of ring and circular footings located on granular soils reinforced with the G-A is investigated using numerical analyses. Commercial finite-element software PLAXIS is employed to perform the simulations. The effect of depth of the first reinforcement layer, the vertical spacing, the number and width of reinforcement layers, the distance that anchors are effective, for each foundation were investigated. The effect of reinforcement stiffness for two types of footing has been investigated. A comparison between the results obtained for the G-A and geogrid reinforcement systems and unreinforced soils is demonstrated as well. Abstract: Soil reinforcement is one of the soil improvement techniques. Over the last four decades, a large number of researches have been carried out in order to obtain the reinforcement type and the bearing capacity improvement of the reinforced soil. A new reinforcement type called Grid-Anchor (G-A) has been recently invented which is made of geogrids by adding polymer anchors to it. In this study the bearing capacity of ring and circular footings located on granular soils reinforced with the G-A is investigated using numerical analyses. Commercial finite-element software PLAXIS is employed to perform the simulations. The effect of depth of the first reinforcement layer, the vertical spacing, the number and width of reinforcement layers, the distance that anchors are effective, for each foundation were investigated. The effect of reinforcement stiffness for two types of footing has been investigated. A comparison between the results obtained for the G-A and geogrid reinforcement systems and unreinforced soils is demonstrated as well

کلیدواژه‌ها English

Ring Foundation
Circular Foundation
bearing capacity
Grid-Anchor (G-A)
Reinforced soil
[1] Mosallanezhad ,M., Hataf,N., Ghahramani, A. " Experimental study of bearing capacity ofgranular soils, reinforced with innovative Gride-Anchor system."Geotechnical GeologicalEngineering 26, pp. 299-312, 2008.
 
[2] Vidal, K. (1966). "La terre Armee". Anales de I'Institute Technique du Batiment et des Travaux Publiques, Jully- Augest, 888-938.
[3] Ohri, M.L., Purhit, D. G. M., and Dubey, M.L. (1997). "Behavior of Ring Footings on Dune Sand Overlaying Dense Sand".  Pres. Int. Conf. Civil Eng, Tehran Iran.
[4]Razavi, M.R., Hataf, N." Behavior of ring foundation on sand."Iranian Journal ofScience  and Technology, Transaction B, Vol.27, pp. 47-56, 2003.
 [5] Boushehrian, J. H., Hataf, N." Experimental and numerical investigation of the bearing‌‌‌‌­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­capacity of model circular and ring footings on reinforced sand."Journal of Geotextiles andGeomembranes (21), pp. 241-256, 2003.
[6] Karaulov, A. M. "Experimental and Theoretical research on the bearing capacity of ringfoundation beds."Soil Mechanics and Foundation Engineering, Vol. 43, No. 2. pp. 37-40, 2006.
[7] Boushehrian, A. H., Hataf, N. "Bearing capacity of foundation on reinforced clay."The12th international conference IACMAG, pp. 3546-3551, 2008.
[8] امینی، فاروق؛ بازیار، محمدحسین؛ مصلی نژاد، منصور؛ "بررسی افزایش ظرفیت باربری پی حلقوی واقع برخاک‌های ماسه‌ای مسلح شده با مهارشبکه (G-A)"، پایان نامه کارشناسی ارشد، دانشگاه یاسوج (1389)