MODEL TEST STUDY OF AUGERED PILING OF SCREW DISPLACEMENT AUGER IN SAND
DENG Yibing1，ZHOU Jian2，3，LIU Zhong4，ZHANG Chao5
(1. College of Ocean Environment and Engineering，Shanghai Maritime University，Shanghai 200135，China；2. Department of Geotechnical Engineering，Tongji University，Shanghai 200092，China；3. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education，Tongji University，Shanghai 200092，China；4. China Jingye Engineering Co.，Ltd.，Beijing 100088，China；5. Huzhou Zhongxin Condtruction and Exploitation Corporation，Huzhou，Zhejiang 313000，China)
Abstract：Aiming at the impact of augered piling on ground soil，model tests on augered piling of screw displacement auger in homogeneous sand are conducted by self-designed visualization model device. The mechanism for development of borehole is discussed. The displacement behaviors and stress development of soil nearby the borehole are analyzed in macro-scale during augered piling. The mesomechanism of interaction between auger and soil is studied by evolution of sand micro-fabric parameters. The model test results show that impact of augered piling on ground soil depends on vertical stress. The higher the vertical stress is，further the radial displacement in the soil transfers. Radial displacement of soil is mainly within 2.5 times of the auger diameter，accompanying with the significant hoop shear displacement of soil nearby the borehole. The soil nearby the borehole experiences the process of loading-unloading-loading. The sand particles in the area that auger contact width is approximately 5 times of the average particle diameters occur significant rotation. The point contact between sand particles and auger develops gradually surface contact with the evolution of isotropy on micro structure. The study results have some significance to disclose the mechanism of augered piling and macro-meso mechanical properties of soil nearby the borehole for the soil displacement screw pile.
邓益兵1，周 健2，3，刘 钟4，张 超5. 砂土中螺旋挤扩钻具下旋成孔过程的模型试验研究[J]. 岩石力学与工程学报, 2011, 30(12): 2558-2566.
DENG Yibing1，ZHOU Jian2，3，LIU Zhong4，ZHANG Chao5. MODEL TEST STUDY OF AUGERED PILING OF SCREW DISPLACEMENT AUGER IN SAND. , 2011, 30(12): 2558-2566.
刘 钟，张 义，李志毅，等. 新型螺旋挤土桩(SDSP)技术[C]// 第十届全国地基处理学术讨论会议论文集. 南京：东南大学出版社，2008：131-136.(LIU Zhong，ZHANG Yi，LI Zhiyi，et al. New soil displacement screw pile(SDSP) technique[C]// Proceedings of the 10th National Symposium on Ground Treatment. Nanjing：Southeast University Press，2008：131-136.(in Chinese))
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2011, Vol. 30 
