微生物诱导碳酸盐沉淀改良残积土坡面水力学特性研究  

Study on hydraulic characteristics of microbial induced carbonate precipitation improved residual soil slope

作　　者：王延宁 李子仪 孟智祥 薛锦强 WANG Yanning;LI Ziyi;MENG Zhixiang;XUE Jinqiang(Department of Civil and Environmental Engineering,Shantou University,Shantou 515063,Guangdong China;Guangdong Engineering Research Center for Structural Safety and Monitoring,Shantou 515063,Guangdong China)

机构地区：[1]汕头大学土木与环境工程系,广东汕头515063 [2]广东省结构安全与监测工程技术研究中心,广东汕头515063

出　　处：《华中科技大学学报（自然科学版）》2023年第12期158-165,共8页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：深部岩土力学与地下工程国家重点实验室开放课题资助项目(SKLGDUEK2005);广东省科技计划资助项目(STKJ2021129);广东省自然科学基金资助项目(2022A1515011200)。

摘　　要：针对花岗岩残积土分布广泛,具有遇水软化、崩解的特性,易产生滑坡、泥石流等地质灾害的问题,提出了一种新的利用微生物诱导碳酸钙沉积技术进行坡面防护的方法.通过室内渗透试验和冲刷模型试验,对比分析了微生物诱导碳酸盐沉淀(MICP)加固花岗岩残积土的抗渗特性和抗冲刷特性.微生物诱导碳酸盐沉淀处理后的土样渗透性降低了90.8%,径流速率和侵蚀速率分别降低25.0%和96.1%.此外,通过扫描电镜(SEM)和X射线衍射(XRD)研究了加固的微观机理.结果表明:微生物诱导碳酸盐沉淀生成碳酸钙晶体对土壤颗粒进行胶结和孔隙填充,使土体表面板结,提高了土体的完整性和抗渗性,从而提升边坡的稳定性和抗冲刷性;同时,相较于传统喷射混凝土坡面防护具有绿色、可持续的优点,具有良好的应用前景.Granite residual soil is widely distributed in China and has strong behavior of softening and disintegrating in water,having a tendency to occur landslides,debris flow and other geological disasters.A new method of slope protection by microbial induced carbonate precipitation(MICP)deposition was provided.The anti-permeability and anti-erosion properties of MICP reinforced granite residual soil were compared and analyzed by direct shear test,permeability test and slope scouring model test.MICP treatment reduced soil permeability by 90.8%,runoff rate and erosion rate by 25.0%and 96.1%,respectively.Furthermore,scanning electron microscopy(SEM)and X-ray diffraction(XRD)were used to study the microstructure mechanism of the reinforcement.The results show that MICP generates calcium carbonate crystals to cement and fill the pores of soil particles,which makes the soil surface consolidated and improves the integrity and impermeability of soil,thus improving the stability and erosion resistance of slope.In addition,compared with the traditional shotcrete slope protection,this method has the advantages of environmentally friendly and sustainable,having a promising application prospect.

关 键 词：岩土工程 边坡工程 坡面防护 抗冲刷特性 微生物诱导碳酸盐沉淀 

分 类 号：TU472[建筑科学—结构工程] S157.1[建筑科学—土工工程]