Experimental studies on vacuum preloading incorporated with electro-osmosis consolidation for dredger fill
SUN Zhao-hua1, 2, YU Xiang-juan2, GAO Ming-jun2, WU Kun1
1. School of Architecture Engineering, Nantong University, Nantong 226019, China; 2. Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing 210098, China
Abstract:The dewatering effect of dredger fill using the vacuum preloading incorporated with electro-osmosis in different ways is evaluated by implementing six laboratory tests. The test results show that the asynchronous consolidation effect of the vacuum preloading incorporated with electro-osmosis is better than that of the other tests. However, the vacuum preloading and electro-osmosis will not be able to give full play to the drainage effect if the alternate time is too short. Alternatively, the energy provided by the vacuum preloading and electro-osmosis will not be able to make full use if the alternate time is too long. There are some advantages when using the vacuum preloading and electro-osmosis asynchronous reinforcement. The alternate time of vacuum preloading and electro-osmosis has to be constantly adjusted according to the water discharge or drainage rate in engineering application.
[1] 彭 涛, 武 威, 黄少康, 等. 吹填淤泥的工程地质特性研究[J]. 工程勘察, 1999(5): 3-7. (PENG Tao, WU Wei, HUANG Shao-kang, et al. Research on engineering geologic properties of blown filled muck[J]. Geotechnical Investigation and Surveying, 1999(5): 3-7. (in Chinese)) [2] 鲍树峰, 娄 炎, 董志良, 等. 新近吹填淤泥地基真空固结失效原因分析及对策[J]. 岩土工程学报, 2014, 36(7): 1350-1359. (BAO Shu-feng, LOU Yan, DONG Zhi-liang, et al. Causes and countermeasures for vacuum consolidation failure of newly-dredged mud foundation[J]. Chinese Journal of Geotechnical Engineering, 2014, 36(7): 1350-1359. (in Chinese)) [3] 朱群峰, 高长胜, 杨守华, 等. 超软淤泥地基处理中真空度传递特性研究[J]. 岩土工程学报, 2010, 32(9): 1429-1433. (ZHU Qun-feng, GAO Chang-sheng, YANG Shou-hua, et al. Transfer properties of vacuum degree in treatment of super-soft muck foundation[J]. Chinese Journal of Geotechnical Engineering, 2010, 32(9): 1429-1433. (in Chinese)) [4] 应 舒, 高长胜, 黄家青. 新吹填淤泥地基浅层处理试验研究[J]. 岩土工程学报, 2011, 32(12): 1956-1960. (YING Shu, GAO Chang-sheng, HUANG Jia-qing. Experimental study on surface-layer improvement of soft foundation filled by newly dredged silt[J]. Chinese Journal of Geotechnical Engineering, 2011, 32(12): 1956-1960. (in Chinese)) [5] CHAI J, MIURA N, BERGADO D T. Preloading clayey deposit by vacuum pressure with cap-drain: analyses versus performance[J]. Geotextiles and Geomembranes, 2008, 26(3): 220-230. [6] 金小荣, 俞建霖, 龚晓南, 等. 真空预压部分工艺的改进[J]. 岩土力学, 2007, 28(12): 2711-2714. (JIN Xiao-rong, YU Jian-lin, GONG Xiao-nan, et al. Improvement of partial technology for vacuum preloading[J]. Rock and Soil Mechanics, 2007, 28(12): 2711-2714. (in Chinese)) [7] 龚晓南, 岑仰润, 李昌宁. 真空排水预压加固软土地基的研究现状及展望[C]// 地基处理理论与实践—第七届全国地基处理学术讨论会论文集. 兰州: 中国水利水电出版社, 2002: 3-7. (GONG Xiao-nan, CHEN Yang-run, LI Chang-ning. Actuality and expectation in the research of vacuum preloading reinforcement of soft foundation[C]// Theory and Practice of Foundation Treatment——The 7th National Academic Conference on Foundation Treatment. Lanzhou: China Water and Power Press, 2002: 3-7. (in Chinese)) [8] CASAGRANDE L. Electro-Osmosis in soils[J]. Géotechnique, 1949, 1(3): 159-177. [9] RITTIRONG A, SHANG J Q, MOHAMEDELHASSAN E, et al. Effects of electrode configuration on electrokinetic stabilization for caisson anchors in calcareous sand[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2008, 134(3): 352-365. [10] SU J Q, WANG Z. The two-dimensional consolidation theory of electro-osmosis[J]. Géotechnique, 2003, 53(8): 759-763. [11] JONES C, FAKHER A, HAMIR R, et al. Geosynthetic materials with improved reinforcement capabilities[C]// Proceedings of the International Symposium on Earth Reinforcement. Fukuoka: CRC Press, 1996, 2: 865-883. [12] 庄艳峰, 邹维列, 王 钊, 等. 一种可导电的塑料排水板:中国, 201210197981.4[P]. 2012-10-10. (ZHUANG Yan-feng, ZOU Wei-lie, WANG Zhao, et al. A conductive plastic drain board: China, 201210197981.4[P]. 2012-10-10. (in Chinese)) [13] 房营光, 徐 敏, 朱忠伟. 碱渣土的真空-电渗联合排水固结特性试验研究[J]. 华南理工大学学报(自然科学版), 2006, 34(11): 70-75. (FANG Ying-guang, XU Min, ZHU Zhong-wei. Experimental investigation into draining consolidation behavior of soda residue soil under vacuum preloading-electro-osmosis[J]. Journal of South China University of Technology (Natural Sciences), 2006, 34(11): 70-75. (in Chinese)) [14] 王柳江, 刘斯宏, 汪俊波, 等. 真空预压联合电渗法处理高含水率软土模型试验[J]. 河海大学学报(自然科学版), 2011, 39(6): 671-675. (WANG Liu-jiang, LIU Si-hong, WANG Jun-bo, et al. Model test for high-water-content soft soil treatment under vacuum preloading in combination with electroosmosis[J]. Journal of Hohai University (Natural Sciences), 2011, 39(6): 671-675. (in Chinese)) [15] 吴 辉, 胡黎明. 真空预压与电渗固结联合加固技术的理论模型[J]. 清华大学学报(自然科学版), 2012, 52(2): 182-185. (WU Hui, HU Li-ming. Analytical models of the coupling of vacuum preloading and electro-osmosis consolidation for ground stabilization[J]. Journal of Tsinghua University (Science and Technology), 2012, 52(2): 182-185. (in Chinese)) [16] PENG J, XIONG X, MAHFOUZ A H, et al. Vacuum preloading combined electroosmotic strengthening of ultra-soft soil[J]. Journal of Central South University, 2013, 20(11): 3282-3295. [17] SUN Z H, GAO M J, YU X J. Vacuum preloading combined with electro-osmotic dewatering of dredger fill using electric vertical drains[J]. Drying Technology, 2015, 33(7): 847-853. [18] 孙召花. 基于EVD的真空-电渗联合加固吹填土地基试验与理论研究[D]. 南京: 河海大学, 2015. (SUN Zhao-hua. Experimental and theoretical study of vacuum preloading combined with electro-osmotic consolidation on dredger fill foundation using EVD[D]. Nanjing: Hohai University, 2015. (in Chinese))