摘要
利用微生物温控加固技术对南海某岛钙质砂进行了MICP加固砂柱试验,并通过循环三轴试验开展了MICP加固钙质砂的动强度特性试验研究,探讨了不同MICP加固程度、相对密实度以及有效围压对钙质砂动强度与液化特性的影响。研究发现,经过MICP加固后松散钙质砂的动力液化特性由"流滑"逐渐演变为"循环活动性";相较于未加固中密砂试样,MICP加固中密钙质砂试样表现出更加明显的"循环活动性"特点。MICP加固钙质砂的动强度随着MICP加固程度、相对密实度以及有效围压的提高表现出不同程度的提高。针对MICP加固钙质砂提出了优化动强度经验公式,建立了MICP加固钙质砂的统一动强度准则。该研究成果将为MICP加固技术在南海岛礁建设发展和应用中提供重要的理论基础。
A series of undrained cyclic triaxial tests are carried out for calcareous sand treated by temperature-controlled MICP(microbially induced calcium carbonate precipitation) technology, and the dynamic strength characteristics of MICP-treated calcareous sand are thoroughly investigated. The in-depth discussion is conducted for the effects of biocementation level, relative density and effective confining pressure on dynamic strength and liquefaction characteristics. The dynamic and liquefaction characteristics of loose calcareous sand gradually change from flow slide to cyclic mobility after MICP treatment. Compared with the untreated medium dense calcareous sand, the MICP-treated medium dense calcareous sand shows more obvious characteristics of cyclic mobility. An increase in biocementation level, relative density and effective confining pressure leads to an increase in the dynamic strength of MICP-treated calcareous sand in different extents. Based on the optimized empirical formula of dynamic strength for MICP-treated calcareous sand, a uniform dynamic strength criterion is further established for MICP-treated calcareous sand. The unified dynamic strength criterion in this study will provide an important theoretical basis for the development and application of MICP treatment technology in the construction of islands and reefs in South China Sea.
作者
肖鹏
刘汉龙
张宇
蒋翔
李驰
楚剑
肖杨
XIAO Peng;LIU Han-long;ZHANG Yu;JIANG Xiang;LI Chi;CHU Jian;XIAO Yang(School of Civil Engineering,Chongqing University,Chongqing 400045,China;Key Laboratory of New Technology for Construction of Cities in Mountain Area,Chongqing University,Chongqing 400045,China;Chongqing Railway Investment Group Co.,Ltd.,Chongqing 400023,China;Department of Civil Engineering,Inner Mongolia University of Technology,Hohhot 010051,China;School of Civil and Environmental Engineering,Nanyang Technological University,Singapore 639798,Singapore)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2021年第3期511-519,共9页
Chinese Journal of Geotechnical Engineering
基金
中央高校基本科研业务费资助项目(2019CDQYTM031)
国家自然科学基金项目(41831282,51922024,52078085,51709139)
重庆市自然科学基金项目(cstc2019jcyjjq X0014)。
关键词
微生物温控加固技术
钙质砂
循环三轴试验
动强度特性
统一动强度准则
temperature-controlled MICP treatment technology
calcareous sand
cyclic triaxial test
dynamic characteristic
unified dynamic strength criterion
