南海北部陆坡软黏土全流动强度试验研究  

Full-flow strength tests on the soft clay in the northern slope of the South China Sea

作　　者：年廷凯[1,2,3] 范宁 焦厚滨[1] 贾永刚 NIAN Ting-kai;FAN Ning;JIAO Hou-bin;JIA Yong-gang(State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian 116024, China;State Key Laboratory for Gcomechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou 221008, China;Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering Ocean University of China, Qingdao 266100, China)

机构地区：[1]大连理工大学海岸和近海工程国家重点实验室,辽宁大连116024 [2]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221008 [3]中国海洋大学山东省海洋环境地质工程重点实验室,山东青岛266100

出　　处：《岩土工程学报》2018年第4期602-611,共10页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(41427803,51579032);深部岩土力学与地下工程国家重点实验室基金项目(SKLGDUEK1307);山东省海洋环境地质工程重点实验室基金项目(MEGE1603)

摘　　要：鉴于海底软黏土强度测试困难和精度不足的现状,研发了一种适用于低强度、高含水率土体强度测试的新型全流动贯入仪,并进行了有效性校验。在此基础上,针对南海北部陆坡区典型软黏土,开展了多组原状试样的全流动强度试验,分析了试验中初始阻力系数N与重塑阻力系数Nrem的取值范围,给出了软黏土扰动前后不排水剪切强度沿深度的分布特征及变化趋势,并结合微观孔隙面积比和宏观构造灵敏度,探究了研究区土体的强结构特征。最后,基于重塑不排水剪切强度与含水率/液限间的关联性分析,提出了适用于研究区土体的不排水剪切强度归一化模型,为南海北部陆坡区海底能源开发、海洋工程基础设计与地质灾害预测提供参考。In view of the difficulty in testing the strength of submarine soft clay and the lack of test accuracy, a new type of full-flow penetrometer is developed for testing the strength of soils with the high water content and low strength, and its test validity is verified. On this basis, a series of full-flow strength tests on the undisturbed samples, some typical soft clay from the northern slope of the South China Sea, are carried out. The range of values of the initial resistance coefficient N and the remolded resistance coefficient N_（rem） in the tests are analyzed, and the distribution characteristics and trends of the undrained shear strength of soft clay in the study area along the seabed depth direction are presented.Then the structural characteristics of soils are discussed combined with the macro structure sensitivity measured by the full-flow strength tests and the micro pore area ratio measured by the scanning electron microscope tests. Finally, a normalized undrained shear strength model suitable for soils in the study area is proposed based on the relationship between the remolded shear strength and water content/liquid limit. This research will provide a reference for the development of seafloor energy resources, the ocean engineering foundation design and the prediction of geological hazards in the northern slope areas of the South China Sea.

关 键 词：南海北部陆坡 全流动强度试验 不排水剪切强度 土体结构性 归一化强度模型 

分 类 号：TU432[建筑科学—岩土工程]