|
|
|
| UNDRAINED SHEAR STRENGTH BEHAVIOR OF OCEAN SILT UNDER LOW STRESS CONDITIONS AND ITS APPLICATION TO ANALYZING SUBMARINE SHALLOW LANDSLIDES |
| WANG Hu1,2,LIU Hongjun1,2,ZHANG Minsheng1,2 |
(1. Key Laboratory of Marine Environment and Ecology,Ministry of Education,Ocean University of China,Qingdao,
Shandong 266100,China;2. College of Environmental Science and Engineering,Ocean University of China,Qingdao,
Shandong 266100,China) |
|
|
|
|
Abstract A series of the vane shear tests and the triaxial tests investigating the undrained shear strength of typical ocean silt under low stress conditions were carried out to understand the submarine geological hazards such as shallow landslide. It was found that the degree of consolidation affected the vane shear strength of silt and the vane shear strength decreased as the excess pore pressure increased. The triaxial undrained shear strength of silt is affected by the over consolidation ratio and the confining stress level but not by the shear strain rate. All samples reached the critical state in the triaxial tests and the shear strength at the critical state increased with the increase of the over consolidation ratio and the confining pressure. The vane shear strength and the triaxial undrained shear strength at critical state were normalized using the mean effective stress and the good consistency was found between them. The critical strength line of marine silt under low stress condition was obtained,which explained the reactivation of the submarine landslide by the storm wave in the Yellow River delta.
|
|
Received: 02 July 2013
|
|
|
|
| [1] 钱寿易,杜金声,楼志刚,等. 海洋土力学现状及发展[J]. 力学进展,1980,10(4):1–14.(QIAN Shouyi,DU Jinsheng,LOU Zhigang,et al. The status and development of ocean soil mechanics[J]. Advances in Mechanics,1980,10(4):1–14.(in Chinese))
[2] 肖军华,刘建坤,彭丽云,等. 黄河冲积粉土的密实度及含水率对力学性质影响[J]. 岩土力学,2008,29(2):409–414.(XIAO Junhua,LIU Jiankun,PENG Liyun,et al. Effects of compactness and water Yellow River alluvial silt content on its mechanical behaviors[J]. Rock and Soil Mechanics,2008,29(2):409–414.(in Chinese))
[3] 刘红军,吕文芳,杨俊杰,等. 黄河三角洲粉质土初始干密度和黏粒含量对稳态强度的影响研究[J]. 岩土工程学报,2009,31(8):1 287–1 291.(LIU Hongjun,LU Wenfang,YANG Junjie,et al. Influence of initial dry density and clay content on steady state strength of silty soil in Yellow River delta[J]. Chinese Journal of Geotechnical Engineering,2009,31(8):1 287–1 291.(in Chinese))
[4] YANG S L,ROLF S,LARS G. Undrained behaviour of silt under static and cyclic loading[J]. Journal of Ocean University of Qingdao,2002,1(2):176–182.
[5] 杨迎晓,朱向荣,金兴平,等. 钱塘江冲海积粉土剪胀性三轴试验研究[J]. 岩土力学,2010,31(增2):48–52.(YANG Yingxiao,ZHU Xiangrong,JIN Xingping,et al. Triaxial testing study of dilatant characteristics of Qiantangjiang alluvial silts[J]. Rock and Soil Mechanics,2010,31(Supp. 2):48–52.(in Chinese))
[6] 郭 莹,王跃新. 原状与重塑粉土固结不排水剪切特性的对比实验研究[J]. 水利学报,2011,42(1):68–75.(GUO Ying,WANG Yuexin. Comparative test study on consolidation undrained shear characteristics of undisturbed and remolding silt[J]. Journal of Hydraulic Engineering,2011,42(1):68–75.(in Chinese))
[7] FLEMIN L N,DUNCAN J M. Stress-deformation characteristics of an Alaskan silt[J]. Journal of Geotechnical Engineering,1990,116(3):377–393.
[8] WANG S,LUNA R. Monotonic behavior of Mississippi river valley silt in triaxial compression[J]. Journal of Geotechnical and Geoenvironmental Engineering,2012,138(4):516–525.
[9] USMANI A,RAMANA G,SHARMA K. Experimental evaluation of shear-strength behavior of Delhi silt under static loading conditions[J]. Journal of Materials in Civil Engineering,2011,23(5):533–541.
[10] NOCILLA A,COOP M R,COLLESELLI F. The mechanics of an Italian silt:an example of ‘transitional’ behaviour[J]. Geotechnique,2006,56(4):261–271.
[11] PRIOR D B,SUHAYDA J N,LU N J,et al. Storm wave reactivation of a submarine landslide[J]. Nature,1989,341(47/50):47–50.
[12] XU G H,SUN Y F,WANG X,et al. Wave-induced shallow slides and their features on the subaqueous Yellow River delta[J]. Canadian Geotechnical Journal,2009,46(12):1 406–1 417.
[13] 李洪增. 电测式十字板剪切试验的研究与应用[J]. 岩石力学与工程学报,2004,23(增1):4 446–4 449.(LI Hongzeng. Study and application of electrical-logging vane shear test[J]. Chinese Journal of Rock Mechanics and Engineering,2004,23(Supp.1):4 446–4 449.(in Chinese))
[14] 闫澍旺,封晓伟,侯晋芳,等. 用十字板强度推算软黏土抗剪强度指标的方法及应用[J]. 岩土工程学报,2009,31(12):1 805–1 810. (YAN Shuwang,FENG Xiaowei,HOU Jinfang,et al. Deduction and application of strength parameters of soft clay by use of vane strength[J]. Chinese Journal of Geotechnical Engineering,2009,31(12):1 805–1 810.( in Chinese))
[15] LEFEBVRE G,LADD C C,PARE J J. Comparison of field vane and laboratory undrained shear strength in soft sensitive clays[C]// Vane Shear Strength Testing in Soils:Field and Laboratory Studies. Philadelphia:American Society for Testing and Materials,1988:233–246.
[16] LIU R,YAN S W,ZHANG L F. Vane shear strength based stability analysis of slopes in unconsolidated soft clay[J]. Transactions of Tianjin University,2004,10(3):195–200.
[17] 李广信. 基坑中土的应力路径与强度指标以及关于水的一些问题[J]. 岩石力学与工程学报,2012,31(11):2 269–2 275.(LI Guangxin. Stress path and strength parameters of soil in foundation pits and some problems about water[J]. Chinese Journal of Rock Mechanics and Engineering,2012,31(11):2 269–2 275.(in Chinese))
[18] ROSCOE K H,SCHOFIELD A N,THURAIRAJAH A. Yielding of clay in states wetter than critical[J]. Geotechnique,1963,13(3):211–240.
[19] MARVIN R. PYLES M. Vane shear data on undrained residual strength[J]. Journal of Geotechnical Engineering,1984,110(4):543–547.
[20] CASTRO G,SEED R B,KELLER T Q,et al. Steady state strength analysis of Lower san fernando dam slid[J]. Geotechnical Engineering,1992,118(3):406–427
[21] 刘红军,王 虎,张民生,等. 波浪作用下黄河三角洲粉质土海床动力响应分析[J]. 岩土力学,2013,34(7):2 065–2 071.(LIU Hongjun,WANG Hu,ZHANG Minsheng,et al. Analysis of wave-induced dynamic response of salty seabed in the Yellow River Delta[J]. Rock and Soil Mechanics,2013,34(7):2 065–2 071.(in Chinese))
[22] 吕文芳. 黄河口粉质土稳态性状与强度特征研究[硕士学位论文][D]. 青岛:中国海洋大学,2009.(LU Wenfang. Steady-state behavior and strength properties of salty soil in Yellow River delta[M. S. Thesis][D]. Qingdao:Ocean University of China,2009.(in Chinese))
[23] 强 跃,赵明阶,林军志,等. 静止土压力系数探究[J]. 岩土力学,2013,34(3):727–730.(QIANG Yue,ZHAO Mingjie,LIN Junzhi,et al. Research on coefficient of earth pressure at rest[J]. Rock and Soil Mechanics,2013,34(3):727–730.(in Chinese)) |
|
|
|