微生物-膨润土联合矿化防渗模型试验研究  

Experimental study on sand anti-seepage by microorganism-bentonite combined mineralization

作　　者：张宇 何想 路桦铭 马国梁 刘汉龙[1] 肖杨[1] ZHANG Yu;HE Xiang;LU Hua-ming;MA Guo-liang;LIU Han-long;XIAO Yang(School of Civil Engineering,Chongqing University,Chongqing 400045,China;School of Civil and Environmental Engineering,Nanyang Technological University,Singapore 639798,Singapore;Power China Guiyang Engineering Corporation Limited,Guiyang,Guizhou 550081,China)

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]南洋理工大学土木与环境工程学院,新加坡639789 [3]中国电建集团贵阳勘测设计研究院有限公司,贵州贵阳550081

出　　处：《岩土力学》2023年第8期2337-2349,共13页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.41831282,No.51922024,No.52078085);重庆英才计划优秀科学家项目(No.cstc2021ycjh-bgzxm0051)。

摘　　要：砂土地基发生渗漏时容易引发地基塌陷和工程结构破坏等工程安全问题。利用微生物-膨润土联合矿化的方法开展了大尺寸砂柱的防渗模型试验,研究了砂土的颗粒粒径、浆液的液固比与注浆次数等因素对砂柱的渗透特性、内部侵蚀特性及膨润土与碳酸钙沉淀分布的影响,分析了处理后试样的封堵稳定性和微观结构,进一步评估了微生物-膨润土联合矿化方法的处理效果。结果表明,通过微生物-膨润土联合矿化方法可以有效地提高砂土的防渗效果与封堵稳定性。经过1~3次注浆后,试样的渗透系数最大可以降低4个数量级,并且渗透过程中的侵蚀速率也得到了成倍的降低,最低达到了0.51 g/(s·m^(2))。针对膨润土与碳酸钙沉淀在砂土封堵中起到的作用,分析了微生物-膨润土联合矿化方法的防渗机制。该研究成果证实了微生物-膨润土联合矿化方法应用于砂土防渗工程的可行性,为微生物注浆技术解决砂土地基渗漏问题提供了重要参考。The seepage of sandy foundation would lead to the collapse of foundation and the destruction of engineering structure.A series of large-scale sand column seepage model experiments war carried out by microorganism-bentonite combined mineralization method.The discussion in-depth was conducted for the effects of sand particle size,slurry liquid-solid ratio and treatment cycles on the permeability,internal erosion characteristic and bentonite and calcium carbonate precipitation distribution of sand.Moreover,the stability of sealing and the microstructure were thoroughly investigated and the treatment effect of microorganism-bentonite combined mineralization method was evaluated.It was found that this method could improve the seepage prevention effect and the stability of sealing of sand,and the permeability coefficient of samples could be reduced by up to 4 orders of magnitude.In addition,the erosion rate during the permeation process was also reduced by several times and reached as low as 0.51 g/(s·m^(2)).Based on the effect of bentonite and calcium carbonate precipitation on sand sealing,the anti-seepage mechanism of microorganism-bentonite combined mineralization method was analyzed.The results show that the microorganism-bentonite combined mineralization method is feasible and efficient in the seepage control of sand,which will provide an important reference for the application of microbial mineralization technology to engineering anti-seepage problems.

关 键 词：微生物诱导碳酸钙沉淀 膨润土 渗透系数 颗粒粒径 浆液液固比 

分 类 号：TU457[建筑科学—岩土工程]