پیوندهای مفید
آمار
| تعداد نشریات | 8 |
| تعداد شمارهها | 437 |
| تعداد مقالات | 5,648 |
| تعداد مشاهده مقاله | 7,656,941 |
| تعداد دریافت فایل اصل مقاله | 6,327,054 |
مطالعه آزمایشگاهی ظرفیت باربری شالوده دایرهای واقع بر سطح خاک دانهای مسلح به ژئوگرید | ||
| نشریه مهندسی عمران امیرکبیر | ||
| مقاله 15، دوره 50، شماره 5، آذر و دی 1397، صفحه 973-986 اصل مقاله (1.25 M) | ||
| نوع مقاله: مقاله پژوهشی | ||
| شناسه دیجیتال (DOI): 10.22060/ceej.2017.13150.5339 | ||
| نویسندگان | ||
| عبداله تبرئی1؛ سعید ابریشمی* 2؛ سید احسان سیدی حسینی نیا2؛ نوید گنجیان1 | ||
| 1دانشگاه آزاد اسلامی، واحد علوم و تحقیقات تهران، گروه مهندسی عمران، تهران، ایران | ||
| 2گروه مهندسی عمران، دانشکده مهندسی، دانشگاه فردوسی مشهد، ایران | ||
| چکیده | ||
| پژوهش حاضر به منظور بررسی اثر مسلح سازی بر ظرفیت باربری شالوده دایرهای واقع بر خاک دانهای صورت گرفته ً است. بدین منظور، جمعا 7آزمایش بارگذاری صفحه بزرگ مقیاس بر روی صفحه دایرهای به قطر 300میلیمتر انجام گرفته و جهت آماده سازی نمونهها از سیستم بارش پردهای متحرک که توسط 60آزمایش بارش کالیبره گردیده، استفاده شده است. در سیستم آزمایشگاهی طراحی و ساخته شده، جهت اندازه گیری فشار زیر شالوده از روش جدیدی استفاده شده است. در کلیه آزمایشهای بارگذاری روی خاک مسلح به ژئوگرید، فقط از یک لایه مسلح کننده استفاده شده و اثر عمق این لایه از کف شالوده مورد بررسی قرار گرفته است. نتایج آزمایشها نشان دادند که استفاده از ژئوگرید، سبب افزایش ظرفیت باربری شالوده دایرهای تا حدود 1/56برابر حالت غیرمسلح میگردد. به علاوه، با افزایش عمق لایه ژئوگرید (نسبت ،)u/DFشیب نمودار بار- نشست (سختی پی) کاهش مییابد. به ازای مقادیر ،u/DF< 0/67اثر این پارامتر (عمق بیبعد) بر ظرفیت باربری شالوده ثابت میگردد که این امر بیانگر تغییر مکانیزم عملکرد مسلح کننده و وقوع گسیختگی در توده خاک بالای لایه ژئوگرید است. همچنین، نتایج نشان میدهد که با افزایش فاصله از مرکز شالوده، مقادیر فشار نرمال وارد بر کف شالوده کاهش مییابد. | ||
| کلیدواژهها | ||
| آزمایش بارگذاری صفحه؛ شالوده دایرهای؛ ژئوگرید؛ ظرفیت باربری؛ نشست | ||
| موضوعات | ||
| خاک مسلح | ||
| عنوان مقاله [English] | ||
| A Study on Bearing Capacity of Circular Footing Resting on Geogrid Reinforced Granular Soil | ||
| نویسندگان [English] | ||
| A. Tabaroei1؛ S. Abrishami2؛ E. Seyedi Hosseininia2؛ N. Ganjian1 | ||
| 1Department of Civil Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran | ||
| 2Department of Civil Engineering, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran | ||
| چکیده [English] | ||
| This study has been conducted to investigate the effect of reinforcing on the bearing capacity of circular footing resting on granular soil. For this purpose, a total number of seven large-scale plate load tests were carried out on a circular plate with a diameter of 300 mm. In order to prepare specimens, a portable curtain rain system is used which is calibrated by 60 raining tests. In the current designed and developed experimental system, a new method is used to measure the normal pressure at footing base. In all loading experiments on soil reinforced with geogrid, only one geogrid layer is used and the effect of depth of this layer from footing base is investigated. The results showed that with provision of geogrid, the bearing capacity of circular footing increases up to 1.56 times of unreinforced mode. In addition, it is shown that by increasing the ratio of u/DF, the slope of load-settlement curve (stiffness) decreases. For values of u/DF>0.67, the effect of this parameter (dimensionless depth of geogrid) on bearing capacity of the footing is constant, which indicates that the reinforcing mechanism has been changed and the failure occurs at the upper soil mass (above the geogrid). Also, the results showed that with increasing of the distance from center of the footing, the value of normal pressure applied at footing base reduces. | ||
| کلیدواژهها [English] | ||
| Plate Loading Test, Circular Footing, Geogrid, Bearing Capacity, Settlement | ||
|
سایر فایل های مرتبط با مقاله
|
||
| مراجع | ||
|
[1] R.J. Fragaszy, E. Lawton, Bearing Capacity of Reinforced Sand Subgrades, Journal of Geotechnical Engineering, 110(10) (1984) 1500-1507. [2] M.T. Omar, B.M. Das, V.K. Puri, S.C. Yen, Ultimate Bearing Capacity of Shallow Foundations on Sand with Geogrid Reinforcement, Canadian Geotechnical Journal, 30(3) (1993) 545-549. [3] M.T. Omar, B.M. Das, V.K. Puri, S.C. Yen, E.E. Cook, Shallow Foundations on Geogrid-Reinforced Sand, Transportation Research Record, (1414) (1992) 59-64. [4] E.C. Shin, B.M. Das, E.S. Lee, C. Atalar, Bearing Capacity of Strip Foundation on Geogrid-Reinforced Sand, Geotechnical & Geological Engineering, 20(2) (2002) 169-180. [5] S.K. Dash, K. Rajagopal, N.R. Krishnaswamy, Performance of Different Geosynthetic Reinforcement Materials in Sand Foundations, Geosynthetics International, 11(1) (2004) 35-42. [6] C.R. Patra, B.M. Das, C. Atalar, Bearing Capacity of Embedded Strip Foundation on Geogrid-Reinforced Sand, Geotextiles and Geomembranes, 23(5) (2005) 454-462. [7] C.R. Patra, B.M. Das, M. Bhoi, E.C. Shin, Eccentrically Loaded Strip Foundation on Geogrid-Reinforced Sand, Geotextiles and Geomembranes, 24(4) (2006) 254-259. [8] M. El Sawwaf, Experimental and Numerical Study of Eccentrically Loaded Strip Footings Resting on Reinforced Sand, Journal of Geotechnical and Geoenvironmental Engineering, 135(10) (2009) 1509-1518. [9] S.N. Moghaddas Tafreshi, A.R. Dawson, Comparison of Bearing Capacity of a Strip Footing on Sand with Geocell and with Planar Forms of Geotextile Reinforcement, Geotextiles and Geomembranes, 28(1) (2010) 72-84. [10] S.N. Moghaddas Tafreshi, A.R. Dawson, Behaviour of Footings on Reinforced Sand Subjected to Repeated Loading - Comparing Use of 3D and Planar Geotextile, Geotextiles and Geomembranes, 28(5) (2010) 434-447. [11] M.T. Adams, J.G. Collin, Large Model Spread Footing Load Tests on Geosynthetic Reinforced Soil Foundations, Journal of Geotechnical and Geoenvironmental Engineering, 123(1) (1997) 66-72. [12] A. Ghosh, A. Ghosh, A.K. Bera, Bearing Capacity of Square Footing on Pond Ash Reinforced with Jute-Geotextile, Geotextiles and Geomembranes, 23(2) (2005) 144-173. [13] W. Chung, G. Cascante, Experimental and Numerical Study of Soil-Reinforcement Effects on the Low-Strain Stiffness and Bearing Capacity of Shallow Foundations, Geotechnical & Geological Engineering, 25(3) (2007) 265-281. [14] G.M. Latha, A. Somwanshi, Bearing Capacity of Square Footings on Geosynthetic Reinforced Sand, Geotextiles and Geomembranes, 27(4) (2009) 281-294. [15] G.M. Latha, A. Somwanshi, Effect of Reinforcement Form on the Bearing Capacity of Square Footings on Sand, Geotextiles and Geomembranes, 27(6) (2009) 409-422. [16] N.F. Ismael, Loading Tests on Circular and Ring Plates in Very Dense Cemented Sands, Journal of Geotechnical Engineering, 122(4) (1996) 281-287. [17] J.H. Boushehrian, N. Hataf, Experimental and Numerical Investigation of the Bearing Capacity of Model Circular and Ring Footings on Reinforced Sand, Geotextiles and Geomembranes, 21(4) (2003) 241-256. [18] M. Laman, A. Yildiz, Numerical Studies of Ring Foundations on Geogrid-Reinforced Sand, Geosynthetics International, 14(2) (2007) 52-64. [19] M. El Sawwaf, A. Nazir, Behavior of Eccentrically Loaded Small-Scale Ring Footings Resting on Reinforced Layered Soil, Journal of Geotechnical and Geoenvironmental Engineering, 138(3) (2011) 376-384. [20] J. Binquet, K.L. Lee, Bearing Capacity Tests on Reinforced Earth Slabs, Journal of the Geotechnical Engineering Division, 101(12) (1975a) 1241-1255. [21] J. Binquet, K.L. Lee, Bearing Capacity Analysis of Reinforced Earth Slabs, Journal of the Geotechnical Engineering Division, 101(12) (1975b) 1257-1276. [22] V.A. Guido, D.K. Chang, M.A. Sweeney, Comparison of Geogrid and Geotextile Reinforced Earth Slabs, Canadian Geotechnical Journal, 23(4) (1986) 435-440. [23] V.A. Guido, J.D. Knueppel, M.A. Sweeney, Plate Loading Tests on Geogrid-Reinforced Earth Slab, in: Geosynthetics' 87 Conf., New Orleans, 1987, pp. 216-225. [24] E.C. Shin, B.M. Das, C. Atalar, Cyclic Plate Load Test on Geogrid-Reinforced Granular Pad, in: Proceedings of the VII International Conference on Geosynthetics, Nice, France, 2002, pp. 423-426. [25] S.K. Dash, S. Sireesh, T.G. Sitharam, Model Studies on Circular Footing Supported on Geocell Reinforced Sand underlain by Soft Clay, Geotextiles and Geomembranes, 21(4) (2003) 197-219. [26] T.G. Sitharam, S. Sireesh, Model Studies of Embedded Circular Footing on Geogrid-Reinforced Sand Beds, Proceedings of the Institution of Civil Engineers-Ground Improvement, 8(2) (2004) 69-75. [27] T.G. Sitharam, S. Sireesh, Behavior of Embedded Footings Supported on Geogrid Cell Reinforced Foundation Beds, Geotechnical Testing Journal, 28(5) (2005) 452-463. [28] P. Basudhar, S. Saha, K. Deb, Circular Footings Resting on Geotextile-Reinforced Sand Bed, Geotextiles and Geomembranes, 25(6) (2007) 377-384. [29] S. Sireesh, T.G. Sitharam, S.K. Dash, Bearing Capacity of Circular Footing on Geocell–Sand Mattress overlying Clay Bed with Void, Geotextiles and Geomembranes, 27(2) (2009) 89-98. [30] A.A. Lavasan, M. Ghazavi, Behavior of Closely Spaced Square and Circular Footings on Reinforced Sand, Soils and Foundations, 52(1) (2012) 160-167. [31] A. Demir, A. Yildiz, M. Laman, M. Ornek, Experimental and Numerical Analyses of Circular Footing on Geogrid-Reinforced Granular Fill underlain by Soft Clay, Acta Geotechnica, 9(4) (2014) 711-723. [32] ASTM D1194-94, Standard Test Method for Bearing Capacity of Soil for Static Load and Spread Footings (Withdrawn 2003), ASTM International, West Conshohocken, PA, 2003. [33] M. Naseri, E.S. Hosseininia, Elastic Settlement of Ring Foundations, Soils and Foundations, 55(2) (2015) 284-295. [34] M. Movahedifar, J. Bolouri-Bazaz, An Investigation on the Effect of Cyclic Displacement on the Integral Bridge Abutment, Journal of Civil Engineering Management, 20(2) (2014) 256-269. [35] P.T. Brown, Numerical Analyses of Uniformly Loaded Circular Rafts on Deep Elastic Foundations, Geotechnique, 19(3) (1969) 399-404. [36] M. Aryafar, S. Abrishami, M. Azadi, Modeling of Dynamic Behavior of Circular Foundations Resting on Sand Reinforced with Geogrid Using Finite Element Methods, in: 4th Int. Conf. Geot. Eng. Soil Mech., Tehran, Iran, 2010. [37] T.W. Pfeifle, B.M. Das, Model Tests for Bearing Capacity in Sand, Journal of the Geotechnical Engineering Division, 105(9) (1979) 1112-1116. [38] S. Abrishami, The Study of Cyclic Bearing Capacity of Dry Geogrid Reinforced Sand by Physical Modeling, Amirkabir University of Technology, Tehran, Iran, 2010. [39] A. Tabaroei, S. Abrishami, E.S. Hosseininia, Comparison between Two Different Pluviation Setups of Sand Specimens, Journal of Materials in Civil Engineering, 29(10) (2017) 04017157. [40] B.M. Das, Principles of Foundation Engineering, Cengage learning, 2015. [41] ASTM D422-63(2007)e2, Standard Test Method for Particle-Size Analysis of Soils (Withdrawn 2016), ASTM International, West Conshohocken, PA, 2007. [42] ASTM D2216-10, Standard Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass, ASTM International, West Conshohocken, PA, 2010. [43] ASTM D854-14, Standard Test Methods for Specific Gravity of Soil Solids by Water Pycnometer, ASTM International, West Conshohocken, PA, 2014. [44] ASTM D4254-16, Standard Test Methods for Minimum Index Density and Unit Weight of Soils and Calculation of Relative Density, ASTM International, West Conshohocken, PA, 2016. [45] ASTM D2487-17, Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System), ASTM International, West Conshohocken, PA, 2017. [46] ASTM D3080 / D3080M-11, Standard Test Method for Direct Shear Test of Soils Under Consolidated Drained Conditions, ASTM International, West Conshohocken, PA, 2011. [47] B.M. Das, E.C. Shin, M.T. Omar, The Bearing Capacity of Surface Strip Foundations on Geogrid-Reinforced Sand and Clay - A Comparative Study, Geotechnical & Geological Engineering, 12(1) (1994) 1-14 . [48] T. Yetimoglu, J.T.H. Wu, A. Saglamer, Bearing Capacity of Rectangular Footings on Geogrid-Reinforced Sand, Journal of Geotechnical Engineering, 120(12) (1994) 2083-2099. [49] B.V.S. Viswanadham, D. König, Studies on Scaling and Instrumentation of a Geogrid, Geotextiles and Geomembranes, 22(5) (2004) 307-328. | ||
|
آمار تعداد مشاهده مقاله: 1,736 تعداد دریافت فایل اصل مقاله: 1,721 |
||
