Analysis method for pile groups subjected to lateral and torsional loads
CHEN Ren-peng1, 2, ZHENG Zhong1, 2, KONG Ling-gang1, 2, LIN Dao-sheng1, 2
1. Key Laboratory of Soft Soils and Geoenvironmental Engineering, Ministry of Education, Zhejiang University, Hangzhou 310058, China; 2. Institute of Geotechnical Engineering, Zhejiang University, Hangzhou 310058, China
Abstract:Pile group foundations of large structures on the water are usually subjected to lateral and torsional loads induced by ship impact or waves, which can even cause their collapse. A hybrid model for pile groups including a rigid cap, elastic beams and nonlinear springs of soils is proposed. The nonlinear stiffness of each pile is computed by using the p-ycurve method in horizontal direction, the load transfer method and the τ-θcurve method in vertical direction, respectively. Pile group effect and load coupling effect among the degrees of freedom in pile head are considered by means of the pmultiplier and the analysis method for a single pile under torque coupled with lateral load and bending moment. The pile group model is solved by use of the Newton’s iterative method, and the results are verified through large-scale model tests. Additionally, parametric analysis is carried out as well. It is found that the distribution of shear force in each pile head is observably nonuniform. The variation of axial force of each individual pile in the group with different free lengths is presented. The study may support the design of pile groups subjected to complicated loads.
陈仁朋, 郑中, 孔令刚, 凌道盛. 水平及扭转荷载作用下群桩基础受力分析方法[J]. 岩土工程学报, 2013, 35(8): 1463-1469.
CHEN Ren-peng, ZHENG Zhong, KONG Ling-gang, LIN Dao-sheng. Analysis method for pile groups subjected to lateral and torsional loads. Chinese J. Geot. Eng., 2013, 35(8): 1463-1469.
VICKERY B J. Wind effects on building and structure-critical unsolved problems[C]// Proc IAHR/IUTAM Practical Experiences With Flow-induced Vibrations Symp. Karlsruhe, 1979: 823-828. FEAGIN L B. Lateral load tests on groups of battered and vertical piles[C]// Symposium on Lateral Load Tests on Piles. ASTM Special Publication. Philadelphia, 1953(154): 2-29. HOLLOWAY D M, MORIWAKI Y, STEVENS J B,et al. Response of a pile group to combined axial and lateral loading[C]// Proc 10th Int Conf on Soil Mech and Found Engrg. Stockholm: Boulimia Publishers, 1981, 2: 731-734. BROWN D A, MORRISON C, REESE L C. Lateral load behavior of a pile group in sand[J]. Journal of Geotechnical Engineering, ASCE, 1988, 114(11): 1261-1276. O’NEILL M W, GHAZZALY O I, HA H B. Analysis of three-dimensional pile groups with nonlinear soil response and pile-soil-pile interaction[C]// Proceedings of the 9th Offshore Technology Conference.’NEILL M W, GHAZZALY O I, HA H B. Analysis of three-dimensional pile groups with nonlinear soil response and pile-soil-pile interaction[C]// Proceedings of the 9th Offshore Technology Conference. 1977, 2: 245-256. CHOW Y K. Three-dimensional analysis of pile groups[J]. Journal of Geotechnical Engineering ASCE 1987, 113(6): 637-651. HU Z H, MCVAY M, BLOOMQUIST D,et al. Influence of torque on lateral capacity of drilled shafts in sands[J]. Journal of Geotechnical and Geoenvironment Engineering, 2006, 132(4): 456-464. KONG L G, ZHANG L M. Centrifuge modeling of torsionally loaded pile groups[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2007, 133(11): 1374-1384. KONG L G, ZHANG L M. Experimental study of interaction and coupling effects in pile groups subjected to torsion[J]. Canadian Geotechnical Journal, 2008, 45(7): 1006-1017. 贺 炜, 陈仁朋, 孔令刚, 等. 群桩受扭工作性状及非线性计算理论研究[J]. (岩土工程学报), 2010, 32(5): 751-756.(HE Wei, CHEN Ren-peng, KONG Ling-gang,et al. Bearing behaviors and nonlinear theory of pile groups subjected to torque[J]. Chinese Journal of Geotechnical Engineering, 2010, 32(5): 751-756. (in Chinese)) 陈仁朋, 王书行, 孔令刚, 等. 不同水平偏心距下群桩内力变化规律试验研究[J]. (岩石力学与工程学报), 2011, 30(3): 603-609.(CHEN Ren-peng, WANG Shu-hang, KONG Ling-gang,et al. Test investigation on distribution of internal forces in pile groups under different lateral eccentricities[J]. Chinese Journal of Rock Mechanics and Engineering, 2011, 30(3): 603-609. (in Chinese)) GEORGIADS M. Interaction between torsional and axial pile response[J]. International Journal for Numerical and Analytical Methods in Geomechanics, 1987, 11(6): 646-650. GORYUNOV B F. Discussion on analysis of piles subjected to the combined action of vertical and horizontal loads[J]. J Soil Mech Found Eng, 1975, 10(1): 10. REESE L C, COX W R, KOOP F D. Analysis of laterally loaded piles in sand[C]// Proceeding, Fifth Annual Offshore Technology Conference, Houston, 1974. COYLE H M, SULAIMAN I H. Skin friction for steel piles in sand[J]. Journal of Soil Mechanics & Foundations Div., ASCE, 1967, 93(SM6): 261-278. VIJAYVERGIYA V N. Load-movement characteristics of piles[C]// Ports 77, 4th Annual Symposium of the American. Long Beach, 1977. KONG L G. Behavior of pile groups subjected to torsion[D]. Hong Kong: The Hong Kong University of Science and Technology, 2006.