Case study and practical analysis of lateral bearing characteristics of a single pile in Taihu soft soils using CPTU data
LI Hong-jiang1,2, LIU Song-yu1,2, TONG Li-yuan1,2, HA Si1,2, YANG Wan-yong3
1.Institute of Geotechnical Engineering, Southeast University, Nanjing 210096, China 2.Jiangsu Key Laboratory of Urban Underground Engineering & Environmental Safety, Southeast University, Nanjing 210096, China 3.Jiangsu Provincial Construction Drawing Examination & Verification Center, Nanjing 210036, China
Abstract：The muddy silty clay is rich in organic matter and widely distributed in Taihu soft soil foundation. It has a large water content and compressibility and is in a state of flow plasticity. All of these make it have bad engineering properties. Based on a pile foundation project which is adjacent to Taihu Lake, through the field pile tests and the p-y curve method of CPTU tests, the lateral bearing characteristics of super-long bored piles in Taihu soft soils and the response laws to the thickness change of muddy soft interlayer are studied. The case study show that the results of numerical calculation from CPTU data agree well with those of the field pile tests, and the load transfer depth is more than 20 m of laterally loaded piles in Taihu soft soils as a result of the influence of muddy soft interlayer. The values and positions of the maximum bending moment and zero point are changed in view of different muddy soft interlayer thicknesses. Within the scope of 0.5~6.0 m, the increment of pile top displacements and the bending moments due to the increasing interlayer thickness decrease. The above research achievements may provide technical supports for the design of laterally loaded piles in Taihu soft soils.
李洪江, 刘松玉, 童立元, 哈斯, 杨万勇. 基于CPTU测试太湖软土地层单桩水平承载实用分析及案例研究[J]. 岩土工程学报, 2018, 40(2): 378-383.
LI Hong-jiang, LIU Song-yu, TONG Li-yuan, HA Si, YANG Wan-yong. Case study and practical analysis of lateral bearing characteristics of a single pile in Taihu soft soils using CPTU data. Chinese J. Geot. Eng., 2018, 40(2): 378-383.
[1] 缪林昌. 软土力学特性与工程实践[M]. 北京: 科学出版社, 2012. (MIAO Lin-chang.Soft soil mechanics characteristic and engineering practice[M]. Beijing: Science Press, 2012. (in Chinese)) [2] POTTS D M, DAY R A.Use of sheet pile retaining walls for deep excavations in stiff clay[J]. Proceedings of the Institution of Civil Engineers, 1990, 88(6): 899-927. [3] WHITTLE A J, HASHASH Y M A, WHITMAN R V. Analysis of deep excavation in Boston[J]. Journal of Geotechnical Engineering, 1993, 119(1): 69-90. [4] HONG Z, LIU S, SHEN S, et al.Comparison in undrained shear strength between undisturbed and remolded Ariake clays[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2006, 132(2): 272-275. [5] LO K Y, HO K S, INCULET I I.Field test of electroosmotic strengthening of soft sensitive clay[J]. Canadian Geotechnical Journal, 1991,28(1): 74-83. [6] 龚晓南. 21世纪岩土工程发展展望[J]. 岩土工程学报, 2000, 22(2): 238-242. (GONG Xiao-nan.Prospects for the development of geotechnical engineering in the 21th century[J]. Chinese Journal of Geotechnical Engineering, 2000, 22(2): 238-242. (in Chinese)) [7] 刘松玉, 蔡国军, 童立元, 等. 现代多功能CPTU技术理论与工程应用[M]. 北京: 科学出版社, 2013. (LIU Song-yu, CAI Guo-jun, TONG Li-yuan, et al.Research and engineering application of the digital multifunctional piezocone penetration test system (CPTU)[M]. Beijing: Science Press, 2013. (in Chinese)) [8] 刘松玉, 蔡国军, 邹海峰. 基于CPTU 的中国实用土分类方法研究[J]. 岩土工程学报, 2013, 35(10): 1765-1776. (LIU Song-yu, CAI Guo-jun, ZOU Hai-feng.Practical soil classification methods in China based on piezocone penetration tests[J]. Chinese Journal of Geotechnical Engineering, 2013, 35(10): 1765-1776. (in Chinese)) [9] 李洪江, 刘松玉, 童立元. 基于CPTU测试p-y曲线法及其在桩基水平承载中的应用[J]. 岩石力学与工程学报, 2017, 36(2): 513-520. (LI Hong-jiang, LIU Song-yu, TONG Li-yuan.A p-y curve method for determining the horizontal bearing capacity of single pile based on CPTU test and its application[J]. Chinese Journal of Rock Mechanics and Engineering, 2017, 36(2): 513-520. (in Chinese)) [10] REESE L C.Computer program LPILE plus version 4.0 technical manual[M]. Austin: Ensoft, Inc, 2000. [11] JGJ 106—2014 建筑基桩检测技术规范[S]. 2014. (JGJ106—2014 Technical code for testing of building foundation piles[S]. 2014. (in Chinese))
