Experimental study on effects of vacuum loading modes on clogging of drainage board filtration membranes
XU Kai1, LIN Sheng-fa1, 2, GENG Zhi-zhou1, HAN Ran-ran3
1. Geotechnical Engineering Department, Nanjing Hydraulic Research Institute, Nanjing 210024, China; 2. Fujian Provincial Institute of Architectural Design and Research, Fuzhou 350000, China; 3. Tianjin Research Institute for Water Transport Engineering, Tianjin 300456, China
Abstract:The clogging of drainage board filtration membranes directly affects the effects of newly-dredged mud reinforced by the vacuum preloading drainage consolidation method, and the vacuum loading mode is one of the main reasons that cause clogging of drainage board filtration membranes. The drainage board filtration membranes with 5 kinds of different equivalent diameters are used to reinforce newly-dredged mud by controlling vacuum loading modes in laboratory. The surface settlement and vacuum degree at different depths of drainage board and soil are monitored during the tests, and the permeability of drainage board filtration membranes are tested after tests. The results show that for the vacuum load without gradient or with large gradient, the effects of vacuum preloading drainage consolidation method to reinforce newly-dredged mud are poor, and drainage board filtration membranes are easily clogged. The smaller the equivalent diameter of drainage board filtration membrane the more severe the clogging. The permeability of drainage board filtration membranes decreases after clogging that causes unfavorable effects on soil drainage consolidation. It is suggested that the equivalent diameter of drainage board filtration membranes should be larger, the vacuum load should be graded, and each vacuum load gradient shouldn’t be too large in engineering practice by using the vacuum preloading method to treat newly-dredged mud.
徐锴, 林生法, 耿之周, 韩冉冉. 真空加载方式对排水板滤膜淤堵影响试验研究[J]. 岩土工程学报, 2016, 38(z2): 123-129.
XU Kai, LIN Sheng-fa, GENG Zhi-zhou, HAN Ran-ran. Experimental study on effects of vacuum loading modes on clogging of drainage board filtration membranes. Chinese J. Geot. Eng., 2016, 38(z2): 123-129.
[1] 董志良, 张功新, 周 琦, 等. 天津滨海新区吹填造陆浅层超软土加固技术研发及应用[J]. 岩石力学与工程学报, 2011, 30(5): 1073-1080. (DONG Zhi-liang, ZHANG Gong-xin, ZHOU Qi, et al. Research and application of improvement technology of shallow ultra-soft soil formed by dredged in tianjin binhai new area[J]. Chinese Journal of Rock Mechanics and Engineering, 2011, 30(5): 1073-1080. (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] PALMEIRA E M, FANNIN R J, VAID Y P. A study on the behaviour of soil geotextile systems in filtration tests[J]. Canadian Geotechnical Journal, 1997, 33(6): 899-912. [4] FAURE Y H, BAUDOIN A, PIERSON P, et al. A contribution for predicting geotextile clogging during filtration of suspended solids[J]. Geotextiles and Geomembranes, 2006, 24(1): 11-20. [5] WU Cho-sen. Soil-nonwoven geotextile filtration behavior under contact with drainage materials[C]// Geotextiles and Geomembranes 24. 2006: 1-10. [6] Haegeman, Wim, William Van Impe. Filtration performance testing of geotextiles for vacuum consolidation drains[J]. Geosynthetics International, 1999, 6(1): 41-51. [7] 易华强. 土工织物反滤系统土体结构稳定性试验研究[D].北京: 清华大学, 2005. (YI Hua-qiang. Experimental study on the structure stability in soil-geotextile filtration[D]. Beijing: Tsinghua Univeresity, 2005. (in Chinese)) [8] 童朝霞. 土工织物-非连续级配土反滤系统的淤堵特性研究[D]. 北京: 清华大学, 2002. (TONG Zhao-xia. Study on clogging properties of geotextile-discontinuous graded soil filtration system[D]. Beijing: Tsinghua Univeresity, 2002. (in Chinese)) [9] 魏取福. 非织造土工布反滤性能的研究[J]. 安徽机电学院学报, 2002(3): 52-54. (WEI Qu-fu.Study on filtration properties of nonwovenv geotextile[J]. Journal of Anhui Institute of Mechanical and Electrical Engineering, 2002(3): 52-54. (in Chinese)) [10] 王 钊, 陆士强. 土工织物滤层淤堵标准的探讨[J]. 水力发电学报, 1991(3): 55-63. (WANG Zhao, LU Shi-qiang. Discussion on clogging standard of geotextile filtration[J]. Journal of Hydroelectric Engineering, 1991(3): 55-63. (in Chinese))