بهینه‌سازی ظرفیت باربری و نشست تفاضلی گروه شمع قائم با استفاده از الگوریتم ژنتیک

نوع مقاله: علمی - پژوهشی

نویسندگان

1 استادیار، دانشکده مهندسی عمران، دانشگاه تربیت دبیر شهید رجایی، تهران، ایران

2 کارشناس ارشد مهندسی ژئوتکنیک، دانشکده مهندسی عمران، دانشگاه تربیت دبیر شهید رجایی، تهران، ایران

چکیده

طول شمع‌ها در اغلب گروه‌های شمع‌، بصورت مساوی انتخاب و اجرا می‌شوند در حالیکه اندرکنش بین شمع‌ها نشان می‌دهد که این روش و شکل اجرا، همواره بهینه‌ترین و بهترین گزینه ممکن جهت دستیابی به ظرفیت باربری مناسب با کمترین نشست و جابجایی نمی‌باشد. در این مقاله بهینه‌سازی ظرفیت باربری، سختی محوری و نشست تفاضلی کلاهک در یک گروه شمع، با هندسه و طول متفاوت مورد ارزیابی قرار می‌گیرد. روش بهینه‌سازی مورد استفاده در این تحقیق برای یک گروه شمع با ظرفیت باربری اصطکاکی قابل کاربرد است. معیار بهینه‌سازی در این پژوهش، کاهش حجم بتن مصرفی در اجرای کلاهک و گروه شمع است که برای مقاصد اقتصادی و زیست محیطی می‌تواند بسیار مفید باشد چرا که با مصرف مصالح کمتر و به دنبال آن هزینه کمتر، گروه شمع می‌تواند عملکرد مورد انتظار را از نظر ظرفیت باربری و نشست نشان ‌دهد. در این مقاله گروه شمع 5×5 با آرایش مربعی و سطری مورد بررسی قرار می‌گیرند و بهینه‌سازی با بهره‌گیری از الگوریتم تکاملی ژنتیک انجام شده و برای تحلیل ظرفیت باربری شمع‌ها از نرم‌افزار اجزاء محدود Fb-Pier استفاده شده است.

کلیدواژه‌ها


عنوان مقاله [English]

Optimization of bearing capacity and unsymmetrical settlement of vertical pile group using genetic algorithm

نویسندگان [English]

  • Saeed Ghaffarpour Jahromi 1
  • Abdollah Hoseini 2
1 Assistant Professor, Department of Civil Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran
2 MSc of Geotechnical Engineering, Department of Civil Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran
چکیده [English]

Capacity of pile group is the summation of the individual piles capacity with influence of spacing between the piles. Pile groups usually have the same length, so if the spacing between piles is too close, the zones of stress around the pile will overlap and the ultimate load of the group is less than the sum of the individual pile capacities especially in the case of friction piles, where the efficiency of pile group is much less. In this research the optimization of bearing capacity and unsymmetrical settlement of cap in the vertical pile group using genetic algorithm were studied. Friction pile in granular soil, with different length and arrangement were investigated to find the best performance of the group for the axial stiffness, bearing capacity and unsymmetrical settlement. The criterion of optimization is the volume of concrete needs for piles and cap. Two patterns of 5×5 pile groups (row variation and squared variation) are studied in this research. The analysis of pile group to find bearing capacity was conducted using the finite element software (Fb-pier) and for optimization used evolutionary genetic algorithm method.

کلیدواژه‌ها [English]

  • Pile group
  • optimization
  • Efficiency of pile group
  • Overall stiffness
  • Unsymmetrical settlement
  • Evolutionary genetic algorithm

[1]Prakoso, W. A. and Kulhawy, F. H.. "Contribution to piled raft foundation design." J. Geotech. Engng, ASCE, 127No.1 (2001) 17-24.

[2]Eslami, A., Veiskarami, M. and Eslami, M. M.. "Piled- Raft Foundation (PRF) Optimization Design with Connected and Disconnected Piles", Proceedings of the 33rd Annual and 11th Int'l Conference on Deep Foundations, (October 2008), Deep Foundations Institute (DFI), New York, NY, U.S.A., 201-211.

[3]Veiskarami, M., Eslami, A., Ranjbar, M. M. and Riyazi, T.. "Geotechnical Interaction of Mat Foundation and Pile Group, Two Case Studies", Esteghlal Journal of Engineering, Isfahan University of Technology, 36, No. 1 (2007)93-107.

[4]Reul, O., Randolph, M. F.. "Design strategies for piled rafts subjected to nonuniform vertical loading." J. of Geotechical and Geoenvironmental Engineering, ASCE, 130No.1 (2004) 1-13.

[5]Randolph, M. F.. "Design methods for pile groups and piled rafts." State-of-the-Art Report, 13th Int. Conf. Soil Mech. Foundn Engng, New Delhi, No. 5 (1994) 61-82.

[6]Horikoshi, K., and Randolph, M. F.. "A contribution to optimum design of piled rafts." Geotechnique, 48 No.3 (1998) 301- 317.

[7]Horikoshi, K., and Randolph, M. F.. "On the definition of raft-soil stiffness ratio for rectangular rafts." Geotechnique, , 47 No.5, (1997) 1055- 1061.

[8]Coyle, H. M., and Reese, L. C.. "Load transfer for axially loaded pile in clay." J. Soil Mech. and Found. Div., 89 No. 2 (1966) 1-25.

[9]Lee, K. M. and Xiao, Z. R.. "A simplified nonlinear approach for pile group settlement analysis in multilayered soils." Can. Geotech. J., 38 No. 5 (2001)1063-1080.

[10]Kim, H. T., Yoo, H. K., and Kang, I. K.. "Genetic algorithm-based optimum design of piled raft foundations with model tests." Geotech. Eng. No. 33 (2001) 1-11.  

[11]Belevičius, B., Ivanikovas, S., Šešok, D.,  Valentinavičius, S., Žilinskas, J.. “Optimal Placement Of Piles In Real Grillages Experimental Comparison Of Optimization Algorithms". 124X Information Technology and Control, 40 No.2 (2011)

[12]Momeni, E., Nazir, R., Jahed Armaghani, D., Maizir, H. “Prediction of pile bearing capacity using a hybrid genetic algorithm-based ANN ". Measurement, No. 57 (2014) 122–131.

[13]Yasrebi, SH. and Golshani A., “Determination of Bearing Capacity for Driven Piles in Sandy Soils by Using Artificial Neural Network Method” Moddares Journal, No.14 (2013) 27-36.

[14]Padfield, C. J., and Sharrock, M. J. "Settlement of structures on clay soils, Construction Industry Research and Information Association (CIRIA), (1983) U.K.

[15]Chow, Y. K., and Thevendran , V." Optimization of pile group." Comput. Geotech.  No.4 (1987) 43-58.

[16]Reul, O., and Randolph, M. F. "Piled rafts in overconsolidated clay: Comparison of in situ measurements and numerical analyses." Geotechnique, 53 No. 3 (2003) 301- 315.

[17]Bridge Software Institute (BSI). FB-Pier v3 program, Bridge Software Institute, Uni. of Florida, Gainesville, (2003).

[18]O,Neill, M. W., and Reese, L. C.." Drilled shafts: Construction procedures and design methods." U.S. Dept. of Transportation, FederalHighway Administration, Office of Implementation, McLean, Va. (1999).

[19]Poulos, H. G., Carter, J. P., and Small, J. C. "Foundations and retaining structures-Research and practice." Proc., 15th Int. Conf. on Soil Mechanics and Foundation Engineering, (2001) 2527–2606.

[20]Goldberg, D. E. "Genetic algorithms in search, optimization, and machine learning." Addison-Wesley, New York (1989).

[21]Bavi O. and Saleho M. “Genetic algorithms & optimization of composite structures” Abed Publications, Tehran, 2011.

[22]Coello, C. A. C. "Theoretical and numerical constraint-handling techniques used with evolutionary algorithms-A survey of the state of the art." Comput. Methods Appl. Mech. Eng. No. 191 (2002) 1245–1287.

[23]Horikoshi, K., and Randolph, M. F." On the definition of raft-soil stiffness ratio for rectangular rafts."  Geotechnique, 47 No. 5 (1997) 1055- 1061.

[24]Guo, W. D., and Randolph, M. F. “Vertically loaded piles in non-homogeneous media." Int. J. Number. Analyt. Meth. Geomech. No. 21 (1997) 507-532.

[25]Cao, X. D., Wong, M. F. and Chang, M. F. "Behavior of model rafts resting on pile-reinforced sand." J. Geotech. Engng, ASCE, 130 No. 2 (2004) 129-138.

[26]Eslami, A., Veiskarami, M. and Eslami, M. M. "Study on optimized piled-raft foundations (PRF) performance with connected and non-connected piles- three case histories ". International Journal of Civil Engineering, March (2011).

[27]Franke, E. "Calculation methods for raft foundations in Germany." Design application of raft foundations, Edited by J. A. Hemseley, Thomas Telford Ltd, London, (2000) 283-322.

[28]Horikoshi, K. and Randolph, M. F. "A contribution to optimum design of piled rafts." Geotechnique, 48 No.3 (1998) 301-317.