连云港海相软土在孔隙水盐分溶脱环境下的固结特性

邓永锋; 岳喜兵; 张彤炜; 刘松玉; 杨忠超

doi:10.11779/CJGE201501004

连云港海相软土在孔隙水盐分溶脱环境下的固结特性 English Version

邓永锋^{1, 2},
岳喜兵^{1, 2},
张彤炜^{1, 2},
刘松玉^{1, 2},
杨忠超³

1. 东南大学交通学院岩土工程研究所,江苏南京 210096; 2. 江苏省城市地下工程与环境安全重点实验室,江苏南京 210096; 3. 重庆交通大学水利水运工程教育部重点实验室,重庆 400074

基金项目: 国家自然科学基金项目（51308576）; 中国博士后科学基金项目（2014M552324）; 重庆市博士后科研项目特别资助项目（Xm2014034）

详细信息

作者简介:
邓永锋 (1978- ),男,福建清流人,教授,博士生导师,主要从事软黏土工程特性与地基处理原理研究。E-mail: noden@seu.edu.cn。

中图分类号: TU411
计量
- 文章访问数: 471
- HTML全文浏览量: 2
- PDF下载量: 448
出版历程
- 收稿日期: 2014-02-13
- 发布日期: 2015-01-19

Consolidation behaviors of soft marine clay in Lianyungang under desalination environment of pore water

1. Institute of Geotechnical Engineering, Transportation College, Southeast University, Nanjing 210096, China; 2. Key Laboratory of Urban Underground Engineering and Environmental Safety of Jiangsu Province, Nanjing 210096, China; 3. Key Laboratory of Hydraulic and Waterway Engineering of the Ministry of Education, Chongqing Jiaotong University, Chongqing 400074, China

摘要

摘要: 随着江苏沿海开发战略的实施,作为第四纪海进海退成因的典型区域性软土,连云港海相土的工程特性也日益引起关注。海相软土沉积过程中孔隙水盐分较高,而随着地表或地下淡水的冲蚀,孔隙水盐分发生溶脱,土的物理力学特性发生会改变,但是目前研究较少。以连云港海相沉积软土为研究对象,首先依托离岸线不同距离的连临高速与临海高等级公路,进行了多个场地的原位测试试验（CPTu）和孔隙水化学成分分析,对比后发现,两处场地具有相类似的沉积历史,含水比w₀/w_L、颗粒粒组与矿物成分基本相同;而相同深度处,孔隙水盐分高的场地土体强度较高。为了进一步探明其机理,设计了换盐和固结装置,即采用蒸馏水和取样点原位地下水（盐水）在一定水力梯度下淋洗原状土,淋洗后进行固结试验。结果表明：盐水淋洗的试样LYGOed1的压缩指数C_c、回弹指数C_s和次固结系数C_α小于蒸馏水淋洗试样LYGOed2,而LYGOed1的压缩模量E_Oed、固结系数C_v与渗透系数k大于LYGOed2,说明了盐分溶脱环境下,土的压缩性增大,次固结变形增大,固结时间变长,渗透系数变小。研究成果不仅能加深对连云港海相软土的认识,也为近岸或近海岩土工程设计提供参考。
- 孔隙水盐分 /
- 溶脱环境 /
- 海相软土 /
- 固结特性 /
- 换盐与固结试验
Abstract: The marine soft clays, the quaternary sediments, are widely deposited in the sea transgression/regression environment in Lianyungang, Jiangsu Province, whose behaviors are focused recently with the implementation of the coastal development strategy. The salinity of pore water during deposition is relatively high, and with the erosion of the surface or underground freshwater, the desalination of pore water occurs, whilst its effect on soil behaviors of the natural soft clays is still unclear. The piezo-cone penetration tests (CPTu) and physical property experiments of the soft clays with salinity of pore water of 0.1% and 4.9% at two sites, e.g. Lianyungang-Linyi highway and Linhai highway, are conducted. The higher strength of the soils with more salinity at the same depth is observed, but they have the similar deposition environment, ratios of water content to liquid limit, particle-size distributions and mineral compositions. To further clarify the effect of pore water, the paralleled percolation and oedometer tests with the synthetic solution and deionized water are performed. The results show that the parameters of oedometer modulus E_Oed, consolidation coefficient C_v and hydraulic conductivity k with the synthetic solution are higher than those with deionized water, while the compression index C_c, swelling index C_s and secondary consolidation coefficient C_α are on the contrary. Those results will deepen the understanding of behaviors of Lianyungang marine clays and provide the reference for the offshore engineering.
- pore water salinity /
- desalination environment /
- soft clay /
- consolidation behavior /
- percolation and oedoemter test

HTML全文

参考文献(23)

[1]	任美锷. 江苏省海岸带与海涂资源综合考察报告[M]. 北京:海洋出版社, 1987: 517. (REN Mei-e. Investigation report of coastal zone and tideland resource in Jiangsu Province[M]. Beijing: Ocean Press, 1987: 517. (in Chinese))
[2]	魏汝龙. 我国沿海软黏土特性及其工程问题[J]. 水利水运科学研究, 1985(3): 109-121. (WEI Ru-long. The engineering behavior of coastal soft clay in China[J]. Journal of Nanjing Hydraulic Research Institute, 1985(3): 109-121. (in Chinese))
[3]	LIU S Y, CAI G J, TONG L Y, et al. Approach on the engineering properties of Lianyungang marine clay from piezocone penetration tests[J]. Marine Georesources and Geotechnology, 2008, 26(3): 189-210.
[4]	邓永锋, 吴燕开, 刘松玉, 等. 连云港浅层海相软土沉积环境及物理力学性质研究[J]. 工程地质学报, 2005, 13(1): 29-34. (DENG Yong-feng, WU Yan-kai, LIU Song-yu, et al. Sediment environment of shallow marine clays deposited in Lianyungang area and their physical and mechanical properties[J]. Engineering Geology, 2005, 13(1): 29-34. (in Chinese))
[5]	CHEN J, ANADARAJAH A. Influence of pore fluid composition on volume of sediments in kaolinite suspensions[J]. Clays and Clay Minerals, 1998, 46 (2): 145-152.
[6]	SRIDHARAN A, PRAKASH K. Influence of clay mineralogy and pore medium chemistry on clay sediment formation[J]. Canadian Geotechnical Journal, 1999, 36: 961-966.
[7]	KAYA A, ÖREN A H, YUKSELEN-AKSOY Y. Settling of kaolinite in different aqueous environment[J]. Marine Georesources and Geotechnology, 2006, 24(3): 203-218.
[8]	ABDULLAH W S, AL-ZOU'BI M S, ALSHIBLI K A. On the physicochemical aspects of compacted clay compressibility[J]. Canadian Geotechnical Journal, 1997, 34(4): 551-559.
[9]	KAYA A, FANG H Y. The effects of organic fluids on physicochemical parameters of fine-grained soils[J]. Canadian Geotechnical Journal, 2000, 37: 943-950.
[10]	SRIDHARAN A, EL-SHAFEI A, MIURA N. Mechanisms controlling the undrained strength behavior of remolded Ariake marine clays[J]. Marine Georesources and Geotechnology, 2002, 20: 21-50.
[11]	DI Maio C, SANTOLI L, SCHIAVONE P. Volume change behavior of clays: the influence of mineral composition, pore fluid composition and stress state[J]. Mechanics of Materials, 2004, 36: 435-451.
[12]	GAJO A, MAINES M. Mechanical effects of aqueous solutions of inorganic acids and bases on a natural active clay[J]. Géotechnique, 2007, 57(8): 687-699.
[13]	YUKSELEN-AKSOY Y, KAYA A, ÖREN A H. Seawater effect on consistency limits and compressibility characteristics of clays[J]. Engineering Geology, 2008, 102: 54-61.
[14]	ÖREN A H, KAYA A. Some engineering aspects of homoionized mixed clay minerals[J]. Environmental Monitoring and Assessment, 2003, 84: 85-98.
[15]	LUNNE T, ROBERTSON P K, POWELL J J M. Cone penetration testing in geotechnical practice[M]. London: Blankie Academic and Professional, 1997.
[16]	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, 2010. (in Chinese))
[17]	HONG Z, LIU S, NEGAMI T. Strength sensitivity of marine Ariake clays[J]. Marine Georesources and Geotechnology, 2005, 23(3): 221-233.
[18]	GENS A. Soil-environment interactions in geo-technicalengineering[J]. Géotechnique, 2010, 60(1): 3-74.
[19]	MITCHELL J K, SOGA K. Fundamentals of soil behavior[M]. New York: Wiley, 1976.
[20]	TAVENAS F, JEAN P, LEBLOND J, et al. The permeability of natural soft clays Part II: permeability characteristics[J]. Canadian Geotechnical Journal, 1983, 20(4): 645-660.
[21]	CARMAN P C. Flow of gases through porous media[M]. London: Butterworths Scientific Publications, 1956.
[22]	KOZENY J. Ueber kapillare leitung des wassers im boden[J]. Sitzungsberichte der Akademie der Wissenschaften inWien, 1927, 136(2): 271-306. (KOZENY J. About capillary pipe of the water in the soil[J]. Proceedings of the Academy of Sciences in Vienna, 1927, 136(2): 271-306. (in German))
[23]	DENG Y F, TANG A M, CUI Y J, et al. Study on the hydraulic conductivity of Boom clay[J]. CanadianGeotechnical Journal, 2011, 48: 1461-1470.