Evaluation of engineering characteristics of new and old soft soil foundation based on advanced CPTU data
WANG Meng1, CAI Guo-jun1, LIU Wen-liang1, WU Jia-ming2, LIU Song-yu1, LIN Jun1, DAI Ji-qun3
1. Institute of Geotechnical Engineering, Southeast University, Nanjing 210096, China; 2. China Design Group Co., Ltd., Nanjing 210096, China; 3. Nanjing Hydraulic Research Institute, Nanjing 210029, China
Abstract：The widening project of highways on soft soil foundation faces great challenges. It is necessary to evaluate the engineering characteristics of the new and old foundation soils comprehensively. The traditional methods in laboratory cause disturbance to the soils, which is long and costly. As a new in-situ testing technology, CPTU, can be used to obtain parameters precisely and continuously including cone tip resistance, sidewall friction and pore water pressure. The multi-functional CPTU technology is used to test the new and old foundation soils of the Beijing-Shanghai Expressway. Based on the bearing capacity theory and the cavity expansion theory, the parameters of the old and new foundation soils are interpreted, such as the stress history, deformation and consolidation. It’s found that the distribution, thickness and depth of soft soil layer can be more determined accurately. In addition, the above-mentioned important engineering parameters can be provided as the scientific evidences for the prediction of differential settlement of old roadbed and the design and construction of subgrade splicing.
王蒙, 蔡国军, 刘文亮, 吴家铭, 刘松玉, 林军, 戴济群. 基于CPTU测试的高速公路改扩建新老地基土工程特性评价研究[J]. 岩土工程学报, 2019, 41(S2): 81-84.
WANG Meng, CAI Guo-jun, LIU Wen-liang, WU Jia-ming, LIU Song-yu, LIN Jun, DAI Ji-qun. Evaluation of engineering characteristics of new and old soft soil foundation based on advanced CPTU data. Chinese J. Geot. Eng., 2019, 41(S2): 81-84.
[1] 高翔, 高速公路新老路基相互作用分析与处理技术研究[D]. 南京: 东南大学, 2006. (GAO Xiang.Research on the interaction between new and existing embankments and treatment techniques in highway widening engineering[D]. Nanjing: Southeast University, 2006. (in Chinese)) [2] 孙杰. 软土地基高速公路拼宽工程变形特性研究[D]. 南京: 河海大学, 2005. (SUN Jie.Study on the deformation features of widening of expressway on soft groundwork[D]. Nanjing: Hohai University, 2005. (in Chinese)) [3] JIANG Xin, JIANG Yi, LIANG Xue-jiao, et al.Numerical simulation on deformation behaviors for widened expressway embankment over soft ground[J]. Journal of Rail Way Science and Engineering, 2015, 12(5): 1039-1046. [4] WANG Hao, HUANG Xiao-ming.Stress and deformation due to embankment widening with different treatment techniques[J]. Journal of Central South University of Technology, 2011, 18(4): 1304-1310. [5] 蔡国军, 现代数字式多功能CPTU技术理论与工程应用研究[D]. 南京: 东南大学, 2010. (CAI Guo-jun.Study on theory and engineering application of digital multifunctional piezocone penetration test (CPTU)[D]. Nanjing: Southeast University, 2006. (in Chinese)) [6] 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)) [7] MAYNE P W.Determination of OCR in clays by piezocone tests using cavity expansion and critical state concepts[J]. Soils and Foundations, 1991, 31(2): 65-76. [8] SENNESET K, SANDVEN R, JANBU N.Evaluation of soil parameters from piezocone tests[J]. Transportation Research Record, 1989: 1235. [9] 蔡国军, 刘松玉, 童立元, 等. 基于孔压静力触探的连云港海相黏土的固结和渗透特性研究[J]. 岩石力学与工程学报, 2007, 26(4): 846-852. (CAI Guo-jun, LIU Song-yu, TONG Li-yuan, et al.Study on consolidation and permeability properties of Lianyungang marine clay based on piezocone penetration test[J]. Chinese Journal of Rock Mechanics and Engineering, 2007, 26(4): 846-852. (in Chinese)) [10] TEH C I, HOULSBY G T.Analytical study of the cone penetration test in clay[J]. Géotechnique, 1991, 41(1): 17-34.
