摘要
以南海某岛礁的钙质砂为基础材料,采用微生物诱导碳酸钙沉积(简称MICP)技术加固,并对加固试样进行长期循环加载三轴试验,研究了MICP胶结钙质砂在不同循环荷载作用下的变形特性及营养盐浓度对于MICP胶结钙质砂变形特性的影响。试验结果表明:MICP胶结钙质砂抵抗变形的能力有效提升,且营养盐浓度的提升能在一定范围内提高MICP胶结钙质砂抵抗变形的能力;MICP胶结钙质砂轴向累积应变与循环振次基本呈双曲线关系,加载前期轴向累积应变迅速增长,随着加载的进行,轴向累积应变增长速率逐渐减缓,试样轴向累积应变最终趋于平稳;基于动力试验结果引入参数循环应力比,根据轴向累积应变双曲模型,建立了MICP胶结钙质砂长期循环加载永久变形预测式,对循环荷载下MICP胶结钙质砂的长期变形预测有积极意义。
The Microbially-induced calcite precipitation(MICP)method was used to test the calcareous sand collected from an island of South China Sea.A series of long-term dynamic triaxial tests of cemented samples were carried out to investigate the evolution of accumulated axial strain under different cyclic loading and nutrient concentrations.The experiments results indicated that the capability of the resisting deformation of MICP cemented calcareous sand are improved,and the increase of nutrients can improve the ability of MCP cemented calcareous sand to resist deformation.The accumulated axial strain of MICP cemented calcareous sand showed a hyperbolic relationship with the cyclic vibration number.The accumulated axial strain increased rapidly at the early stage of loading.With the loading progresses,the growth rate of the accumulated axial strain gradually slowed down and the accumulated axial strain eventually tended to be stable.On this basis,the cyclic stress ratio was introduced to establish the permanent deformation prediction formula of MICP cemented coral sand under cyclic loading,which was of positive effects on predicting the long-tern deformation of MICP cemented coral sand under cyclic loading.
作者
张磊
杨俊杰
王子玉
ZHANG Lei;YANG Junjie;WANG Ziyu(College of Environmental Science and Engineering,Ocean University of China,Qingdao 266100,China;The Key Laboratory of Marine Environment and Ecology of Ministry of Education,Ocean University of China,Qingdao 266100,China;School of Ecological Environment,Hainan Tropical Ocean University,Sanya 572022,China)
出处
《海洋湖沼通报》
CSCD
北大核心
2023年第6期19-26,共8页
Transactions of Oceanology and Limnology
基金
国家自然科学基金项目(NO.41602322,NO.51779235,NO.52078474)
海南省重点研发项目(NO.ZDYF2017100)。
关键词
钙质砂
微生物固化
循环荷载
永久变形
calcareous sand
microbially-induced calcite precipitation
cyclic loading
permanent deformation
