微生物固土胶结液的尿素和氯化钙优化配比试验  

Experimental study on the optimization ratio of urea and calcium chloride in microbial soil consolidation and cementing liquid

作　　者：王浩[1,2] 赖国正 夏传安 蔡晖 吴志刚 WANG Hao;LAI Guozheng;XIA Chuan’an;CAI Hui;WU Zhigang(Zijin School of Geology and Mining,Fuzhou University,Fuzhou,Fujian 350108,China;Key Laboratory of Geological Hazards in Fujian Province,Fuzhou,Fujian 350002,China;Fujian Expressway Maintenance Engineering Co.,Ltd.,Fuzhou,Fujian 350005,China)

机构地区：[1]福州大学紫金地质与矿业学院,福建福州350108 [2]福建省地质灾害重点实验室,福建福州350002 [3]福建省高速公路养护工程有限公司,福建福州350005

出　　处：《福州大学学报（自然科学版）》2024年第6期748-754,共7页Journal of Fuzhou University(Natural Science Edition)

基　　金：国家自然科学基金资助项目(41972268,U2005205);福建省科技厅产学研创新资助项目(2022Y4002);福建省交通运输科技资助项目(202202)。

摘　　要：采用微生物诱导碳酸钙沉淀(MICP)技术,开展不同胶结液配比方案的粘性土固化试验.测试MICP固化土样的物理性质、力学强度和矿化反应后的碳酸钙含量,研究胶结液中不同尿素和氯化钙体积配比对土体试样加固效果的影响.结果表明,MICP加固后的各试样与天然含水率重塑土样相比,其含水率和孔隙率均减小,干密度与碳酸钙含量增加,颗粒表面积聚大量CaCO_(3)晶体,抗剪强度与抗压强度均有不同程度的提高.当尿素和氯化钙的体积配比为1∶1时,微生物矿化形成的碳酸钙含量最高;当尿素和氯化钙的体积配比为2∶1时,微生物矿化试样的强度更高.分析认为微生物固土的效果不仅与矿化后的碳酸钙含量有关,也与矿化结晶体的微观结构及其在土体孔隙中的充填特性密切相关.Solidification tests was conducted on cohesive soil with different binder ratios by using microbially induced carbonate precipitation(MICP)technique.Physical properties,mechanical strength,calcium carbonate content after mineralization reaction were tested on MICP solidified soil.The aim was to investigate the effect of different urea and calcium chloride volume ratios in the binder on the reinforcement effect of soil samples.The experimental results show that compared with the remolded soil samples with natural moisture content,the moisture content and porosity of each sample reinforced by MICP decrease,while the dry density and calcium carbonate content increase.The shear strength and compressive strength are also improved to varying degrees.When the ratio of urea to calcium chloride is 1∶1,the content of calcium carbonate formed by microbial mineralization is the highest.When the ratio of urea to calcium chloride is 2∶1,the strength of microbial mineralization samples is higher.Analysis suggests that the effect of microbial soil stabilization is not only related to the content of calcium carbonate after mineralization,but also closely related to the microstructure of mineralized crystals and their filling characteristics in soil pores.

关 键 词：粘性土 微生物诱导碳酸钙沉淀技术 胶结液配比 固化试验 力学强度 

分 类 号：TU42[建筑科学—岩土工程]