Compressibility characteristics of bio-cemented calcareous sand treated through the bio-stimulation approach  

作　　者：Yijie Wang Ningjun Jiang Alexandra Clarà Saracho Ogul Doygun Yanjun Du Xiaole Han 

机构地区：[1]Institute of Geotechnical Engineering,Southeast University,Nanjing,China [2]Department of Civil and Environmental Engineering,University of Hawaii at Manoa,Honolulu,USA [3]Department of Engineering,Cambridge University,Cambridge,UK [4]Geosyntec Consultants,Inc.,Huntington Beach,USA

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2023年第2期510-522,共13页岩石力学与岩土工程学报（英文版）

基　　金：This study was financially supported by the Natural Science Foundation of China(Grant No.42007246);the Fundamental Research Funds for the Central Universities(Grant No.2242022k30055);Indo-U.S.Science and Technology Forum(Grant No.IUSSTF/AUG/JC/047/2018).

摘　　要：Calcareous sand is widely present in coastal areas around the world and is usually considered as a weak and unstable material due to its high compressibility and low strength.Microbial-induced calcium carbonate precipitation(MICP)is a promising technique for soil improvement.However,the commonly adopted bio-augmented MICP approach is in general less compatible with the natural soil environment.Thus,this study focuses on the bio-stimulated MICP approach,which is likely to enhance the dominance of ureolytic bacteria for longer period and thus is deemed more efficient.The main objective of this paper is to investigate the compressibility of calcareous sand treated by bio-stimulated MICP approach.In the current study,a series of one-dimension compression tests was conducted on bio-cemented sand pre-pared via bio-stimulation with different initial relative densities(D r).Based on the obtained compression curves and particle size distribution(PSD)curves,the parameters including cementation content,the coefficient of compressibility(a v),PSD,relative breakage(B r),and relative agglomeration(A r)were discussed.The results showed that a v decreased with the increasing cementation content.The bio-cemented sand prepared with higher initial D r had smaller(approximately 20%e70%)a v values than that with lower initial D r.The specimen with higher initial D r and higher cementation content resulted in smaller B r but larger A r.Finally,a conceptual framework featuring multiple contact and damage modes was proposed.

关 键 词：Calcareous sand Bio-cementation Bio-stimulation COMPRESSIBILITY 

分 类 号：TU43[建筑科学—岩土工程]