Abstract:Nine groups of model tests on the geocell-reinforced cushion, bag-sand well, gravel pile and flexible pile composite foundation are completed to analyze the consolidation effect of different types of composite foundations based on the similarity theory. Some conclusions are drawn as follows: (1) the inclusion of horizontal reinforcement can spread the upper load and raise the bearing capacity, and the reinforced effect of geocell is superior to that of geogrid; (2) the effect of pile groups cannot be neglected when analyzing composite foundation with piles and their bearing capacity is superior to that of horizontal reinforcement composite foundation obviously; (3) the volatility of bearing capacity of piles and soil changes under different loading ranges, and that under single-pile loading range is higher than that under three piles and seven piles. The pile-soil stress ratio of the pile head of gravel pile composite foundation is larger than that of gravel pile + geogrid composite foundation. The smallest is gravel pile + geocell composite foundation, but for the foundation of flexible pile types is flexible pile + geocell composite foundation larger than flexible pile + geogrid composite foundation, and the smallest is flexible pile composite foundation; (4) the pile-soil stress ratio of bottom pile of bag-sand well and gravel pile composite foundation is about 1 and for the flexible pile composite foundation it is much larger and the largest value is about 24; the pore-water pressure is larger and the velocity of dispersion is faster in shallow foundation than those in deep foundation of pile. The pore-water pressure, and that is bigger of piles composite foundation is larger than that of soft soil foundation and geocell-reinforced composite foundation, and the outflow velocity of bag-sand well and gravel pile composite foundation is faster than that of flexible pile composite foundation.
赵明华, 龙军, 张玲, 马缤辉, 何腊平. 不同型式复合地基试验对比分析[J]. 岩土工程学报, 2013, 35(4): 611-618.
ZHAO Ming-hua, LONG Jun, ZHANG Ling, MA Bing-hui, HE La-ping. Comparative analysis of model tests on different types of composite foundations. Chinese J. Geot. Eng., 2013, 35(4): 611-618.
[1] 邹新军,杨 眉,赵明华. 未打穿砂井复合地基承载机理模型试验研究[J]. 岩土工程学报, 2010,32增刊2:1-4. ZOU Xin-jun, YANG Mei, ZHAO Ming-hua. Bearing behavior of ground with partially penetrated sand wells by model testing[J]. Chinese Journal of Geotechnical Engineering, 2010, 32S2: 1-4. (in Chinese) [2] 段继伟,龚晓南,曾国熙. 水泥搅拌桩的荷载传递规律[J]. 岩土工程学报, 1994,164:1-8. DUAN Ji-wei, GONG Xiao-nan, ZENG Guo-xi. Load transfer behavior of cement treated soil column[J]. Chinese Journal of Geotechnical Engineering, 1994, 164: 1-8. (in Chinese) [3] 陈艳平,赵明华,陈昌富,等. 土工格室碎石垫层-碎石桩复合地基相似模型试验[J]. 中国公路学报, 2006,191:17-22. CHEN Yan-ping, ZHAO Ming-hua, CHEN Chang-fu, et al. Similarity model test of geocell reinforced gravel mattress and gravel pile composite foundation[J]. China Journal of Highway and Transport, 2006, 191 [4] 牛琪瑛,郭 英,吴永娟,等. 碎石桩加固不同密实度液化土的孔隙水压力变化规律探讨[J]. 工程力学, 2010,27增刊1:159-163. NIU Qi-ying, GUO Ying, WU Yong-juan, et al. Study on pore water pressre variation of different density liquefiable sand soil reinforced by gravel pile[J]. Engineering Mechanics, 2010, 27S1 [5] KOUSIK D, NARENDRA K S, JAGTAP B N. Laboratory model studies on unreinforced and geogrid-reinforced sand bed over stone column-improved soft clay[J]. Geotextiles and Geomembranes, 2011,292:190-196. [6] 陈艳平. 土工格室碎石垫层+碎石桩复合地基模型试验研究[D]. 长沙: 湖南大学, 2003:26-43. CHEN Yan-ping. Research in model test of composite foundation bidirectionally reinforced by stone columns and geocell[D]. Changsha: Hunan University, 2003: 26-43. (in Chinese) [7] BARROSO M, TOUZE-FOLTZ N, SAIDI F K. Validation of the use of filter paper suction measurements for the determination of GCL water retention curves[C]// Proc 8th Int Conf on Geosynthetics Int Geosynthetics Society. Yokohama, 2006:171-174. [8] 郑 刚,王长祥,顾晓鲁. 软土中超长水泥搅拌桩复合地基承载力研究[J]. 岩土工程学报, 2002,246:675-679. ZHENG Gang, WANG Chang-xiang, GU Xiao-lu. Bearing capacity of composite foundation with long cement treated column in soft soil[J]. Chinese Journal of Geotechnical Engineering, 2002, 246: 675-679. (in Chinese) [9] MCGRATH T J. Design method for flexible pipe[R]. Rep Prepared for ASSHTO Flexible Culvert Liaison Committee, Simpson Gumpertz & Heger Inc.,Arlington, Mass, 1998. [10] 赵明华,张 玲,邹新军,等. 土工格室-碎石桩双向增强复合地基研究进展[J]. 中国公路学报, 2009,221:1-10. ZHAO Ming-hua, ZHANG Ling, ZOU Xin-jun, et al. Research progress in two-direction reinforced composite foundation formed by geocell reinforced mattress and gravel piles[J]. China Journal of Highway and Transport, 2009, 221 [11] 徐 挺. 相似理论与模型试验[M]. 北京: 中国农业机械出版社, 1982.XU Ting. Similarity theory and model test[M]. Beijing [12] 北京燕山石油化工股份有限公司树脂应用研究所. 土工格室及其工程性能简介[R]. 2000: 8-14. Beijing Yanshan Petrochemical Industry Co Ltd Resin Application Research Institute. A brief introduction of the engineering features of the geocell[R]. 2000: 8-14. (in Chinese)