微生物加固渠基粉土的冻融特性及微细观机理研究  

Freeze-thaw performance and micro-mechanism of canal foundation silt treated by MICP

作　　者：朱锐 邢玮 郭万里 黄英豪[4] 周峰 王旭东 ZHU Rui;XING Wei;GUO Wanli;HUANG Yinghao;ZHOU Feng;WANG Xudong(College of Transportation Engineering,Nanjing Tech University,Nanjing 211816,China;Postdoctoral Station of Civil Engineering,Army Engineering University of PLA,Nanjing 210007,China;State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,Beijing 100038,China;Key Laboratory of Dam Reservoir Safety of the Ministry of Water Resources,Nanjing Hydraulic Research Institute,Nanjing 210029,China)

机构地区：[1]南京工业大学交通运输工程学院,江苏南京211816 [2]陆军工程大学土木工程博士后科研流动站,江苏南京210007 [3]中国水利水电科学研究院流域水循环模拟与调控国家重点实验室,北京100038 [4]南京水利科学研究院水利部水库大坝安全重点实验室,江苏南京210029

出　　处：《岩土工程学报》2025年第2期376-387,共12页Chinese Journal of Geotechnical Engineering

基　　金：新疆维吾尔自治区中央引导地方科技项目(ZYYD2024CG20);国家自然科学基金项目(52408372);中国博士后科学基金面上项目(2023M744276);江苏省自然科学基金项目(BK20220356);流域水循环模拟与调控国家重点实验室开放课题(IWHR-SKLF202319);水利部水库大坝安全重点实验室项目(YK324009)。

摘　　要：渠基土性能冻融劣化是中国季冻区渠道结构损坏的主要原因,渠基土加固是保障供水渠道安全运行的重要手段。结合微生物岩土加固技术,开展微生物加固渠基粉土系列宏微观室内试验,刻画不同胶结液浓度、养护龄期、冻融循环下加固渠基粉土的体变率、渗透系数、孔隙率等宏微观指标的发展规律及其定量联系。结果表明:在不同胶结液浓度、养护龄期下,微生物加固可使得渠基粉土的冻融体变量削减约70%,渗透系数至少降低一个数量级、抗压强度提升约220.17%,抗剪强度指标最高增长约65.50%;当胶结液浓度为1.00 mol/L,养护龄期为28 d时,冻融循环下渠基粉土的微生物加固效果最优。此外,微生物诱导生成的碳酸钙沉淀通过填充、胶结、包裹等系列方式重塑了渠基粉土的微细观结构,使其在冻融风化作用下仍然保持整体性和完整性,这是微生物加固渠基粉土在冻融环境下仍然展现出良好工程特性的主要原因。The freeze-thaw deterioration characteristics of foundation soil are the main cause for damages of canal slopes in seasonally frozen areas.The soil treatment is an important means to ensure the safe operation of canals.Based on the microbially induced calcium carbonate precipitation(MICP)technique,a series of laboratory tests on treated silt with different concentrations,curing ages and freeze-thaw cycles are conducted.The macro-and micro-indices of treated silt,such as volumetric rate,permeability coefficient and porosity,are described,and their quantitative relationships are established.The results show that under different concentrations and curing ages,the treatment can reduce the freeze-thaw deformation by 70%,decrease the permeability coefficient by at least one order of magnitude,increase the compressive strength by 220.17%,and improve the shear strength index by 65.50%.As the concentration is 1.00 mol/L and the curing age is 28 days,the treatment effects of silt under freeze-thaw cycles are the most significant.In addition,the calcium carbonate precipitation induced by the MICP reshapes the microstructure of silt through a series of processes such as filling,cementation and encapsulation,which ensures the integrity of silt subjected to freeze-thaw cycles.It is also the main reason for the good engineering properties of treated silt in freeze-thaw environments.

关 键 词：微生物诱导碳酸钙沉淀 粉土 渠道边坡 冻融循环 微观结构 

分 类 号：TU432[建筑科学—岩土工程]