微生物诱导碳酸钙沉淀技术固化海相淤泥试验  

Experimental study on reinforcement of marine silt by microbial induced calcium carbonate precipitation technology

作　　者：柳嘉豪 林文彬 卓祖磊 吴杉颖 高玉朋 张佳源 罗承浩 LIU Jiahao;LIN Wenbin;ZHUO Zulei;WU Shanying;GAO Yupeng;ZHANG Jiayuan;LUO Chenghao(Fujian Provincial Key Laboratory of Advanced Technology and Informatization in Civil Engineering,Fujian University of Technology,Fuzhou 350118,China;Institute of Earth Sciences and Engineering,Fujian University of Technology,Fuzhou 350118,China;Xiamen Institute of Marine Seismology,China Earthquake Administration,Xiamen 361013,China;Fujian Yonking Construction Geotechnical Co.,Ltd.,Longyan 364000,China)

机构地区：[1]福建省土木工程新技术与信息化重点实验室,福建福州350118 [2]福建理工大学地球科学与工程研究所,福建福州350118 [3]中国地震局厦门海洋地震研究所,福建厦门361013 [4]福建永强岩土股份有限公司,福建龙岩364000

出　　处：《福建理工大学学报》2025年第1期33-39,共7页JOURNAL OF FUJILAN UNIVERSITY OF TECHNOLOGY

基　　金：福建省科技计划项目(2023Y3008);大学生创新创业训练计划项目(S202410388061,S202410388066)。

摘　　要：探究了菌液浓度(OD 600)、胶结液浓度和龄期等因素对微生物诱导碳酸钙沉淀(MICP)技术固化海相淤泥的物理力学性能的影响,并通过X射线衍射(XRD)和扫描电镜(SEM)试验,探究加固后试样微观形态特征及其固化机理。结果表明,MICP固化后,试样的无侧限抗压强度(UCS)、内摩擦角和黏聚力随着菌液浓度的增加而增加,而液塑限逐渐减小。在低菌液浓度条件下,MICP固化后淤泥试样的UCS、内摩擦角和黏聚力都随着胶结液浓度的增加而增加,而液塑限逐渐减小;在高菌液浓度条件下,随着胶结液浓度的增加,MICP固化后淤泥试样的UCS、内摩擦角和黏聚力先增加后减小,而液塑限先减小后增加。MICP固化淤泥的物理力学性能在7 d内随着龄期的增加而增强,7 d后基本不再增加。因此,当OD 600为4、胶结液浓度为2 mol/L时,淤泥固化效果最佳,7 d后试样UCS可达104.96 kPa,内摩擦角可达27.2°,黏聚力可达9.4 kPa,同时液塑限也有着一定程度的减小。微观试验结果显示,MICP产生的六面体形态的方解石将其周围的片状淤泥土颗粒黏结为团聚体,从而起到固化土体的作用。In this study,the effects of bacterial liquid concentration(OD 600),cementing liquid concentration,age and other factors on the physical and mechanical properties of marine silt reinforced by microbial induced calcium carbonate precipitation(MICP)technology were investigated,and the micro-morphological characteristics and the reinforcement mechanism of the consolidated specimens were probed by X-ray diffraction(XRD)and scanning electron microscopy(SEM).Test results show that after MICP curing,the unconfined compressive strength(UCS),internal friction angle and cohesion of the specimens increased with the rising of the bacterial liquid concentration,while the liquid-plastic limit gradually decreased.Under the condition of low bacterial solution concentration,the UCS,internal friction angle and cohesion of the reinforced specimens increased with the rising of cement concentration,while the liquid-plastic limit gradually decreased.However,at high bacterial solution concentrations,as cement concentration increased,the UCS,internal friction angle and cohesion of the reinforced specimens initially increased and then decreased,while the liquid-plastic limit firstly decreased and then increased.The physical and mechanical properties of the reinforced specimens enhanced with the increase of curing age within 7 days and then basically no more changes would occur.The optimal solidification effect of silt was achieved with an OD 600 of 4 and a bonding fluid concentration of 2 mol/L,resulting in a UCS of 104.96 kPa,an internal friction angle of 27.2°,and a cohesion of 9.4 kPa after 7 days,along with a significant reduction in the liquid limit.The microscopic test results reveal that the hexahedral calcite produced by MICP process can bind the surrounding flaky silt particles into aggregates,thus helping to solidify the soil.

关 键 词：微生物诱导碳酸钙沉淀 碳酸钙 固化 淤泥 微观机理 无侧限抗压强度 

分 类 号：TU442[建筑科学—岩土工程]