摘要
各向异性是珊瑚砂的固有属性。对饱和南沙珊瑚砂开展了一系列不排水单向剪切试验,探究了固结应力方向角α_(0)和单向加载方向角α_(m)对饱和珊瑚砂不排水反应的影响。α_(0)和α_(m)对饱和珊瑚砂的不排水反应均有显著影响,且α_(0)与α_(m)的耦合作用对其不排水反应的影响更为复杂。对所有试验的应力条件,饱和珊瑚砂的超静孔压ue均呈现出先增大后减小的趋势。α_(0)不同时饱和珊瑚砂的相变强度S_(PT)、有效内摩擦角Φ_(PT)与α_(m)的关系存在显著差异。发现饱和珊瑚砂的相变强度S_(PT)与无量纲参数β存在事实上的线相关性,其中,β是以α_(0),α_(m)为变量的余弦函数。随着广义剪应力q_(g)的增大,饱和珊瑚砂呈现出明显的应变硬化现象。
Anisotropy is the inherent property of coral sand.A series of undrained monotonic shear tests are carried out on the saturated Nansha coral sand by using the GDS hollow cylinder torsional shear apparatus.The effects of consolidation stress direction angleα0 and monotonic loading direction angleαm on the undrained response of saturated coral sand are investigated.The test results show thatα0 andαm have significant influences on the undrained response of saturated coral sand.The undrained response characteristics of coral sand will become more complex under the coupling effects ofα0 andαm.For all the test conditions considered,the excess pore water pressure ue of saturated coral sand presents contraction first and then dilatancy trend.The change of the shear resistance(SPT)and its effective angle(PTf¢)mobilized at the phase transformation state along withαm are significantly different for variousα0.There is a unique linear correlation between SPT and the dimensionless parameterβ,which is a cosine function withα0 andαm as variables.With the increase of the generalized shear stress qg,obvious strain hardening phenomenon can be observed for the samples.
作者
马维嘉
秦悠
王常德
陈国兴
MA Wei-jia;QIN You;WANG Chang-de;CHEN Guo-xing(Institute of Geotechnical Engineering,Nanjing Tech University,Nanjing 210009,China;Civil Engineering and Earthquake Disaster Prevention Center of Jiangsu Province,Nanjing 210009,China)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2022年第3期576-583,F0003,F0002,共10页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金项目(51678299)
国家重点研发计划项目(2018YFC1504301)。
关键词
饱和珊瑚砂
各向异性
固结应力方向角
单向加载方向角
相变强度
saturated coral sand
anisotropy
consolidation direction angle
monotonic direction angle
shear resistance at phase transformation point
