三氯化铁对砂土微生物矿化的强化作用试验研究  

Experimental study on enhancing effect of FeCl_(3)on microbial mineralization of sandy soils

作　　者：卫仁杰 唐彤芝[2] 彭劼[1] 李亮亮[1] 商志阳 蒋钊 WEI Renjie;TANG Tongzhi;PENG Jie;LI Liangliang;SHANG Zhiyang;JIANG Zhao(Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing 210098,China;Geotechnical Engineering Department,Nanjing Hydraulic Research Institute,Nanjing 210024,China)

机构地区：[1]河海大学岩土力学与土堤坝工程教育部重点实验室,江苏南京210098 [2]南京水利科学研究院岩土工程研究所,江苏南京210024

出　　处：《岩土工程学报》2025年第5期948-957,共10页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(51578214);江苏省交通运输厅科技成果转化项目(2021QD07)。

摘　　要：微生物诱导碳酸钙沉积(MICP)是一种十分有前景的土体改良技术,然而基于MICP处理土体方法的缺点是只有通过多次胶结液处理才能达到预期的改善效果。为提升微生物矿化处理土体的效率,在胶结液中加入少量(1~30 mmol/L)三氯化铁,开展溶液试验和砂柱试验,通过碳酸钙生成情况、无侧限抗压强度和渗透系数评估其强化效果。研究结果表明:①三氯化铁能改变溶液试验中MICP碳酸钙的形态和大小。②胶结液中加入三氯化铁,在灌注5次的情况下可使砂柱无侧限抗压强度最高可达1617.9 kPa,较常规MICP处理砂柱提升10.4倍,渗透系数较未处理砂降低两个数量级。③三氯化铁没有增加砂土中MICP碳酸钙数量,但是改变了碳酸钙在砂土中的分布模式,从而提高砂土的强度,协同MICP降低砂土渗透系数。The microbially induced calcium carbonate precipitation(MICP)is a promising technique for soil improvement.However,the disadvantage of the MICP-based method for soil treatment is that the intended effect of improvement can only be achieved by multiple treatments of the cementing solution.To enhance the efficiency of soil treatment by microbial mineralization,the solution tests and sand column tests are carried out by adding 1~30 mmol/L of FeCl_(3)in the cementing solution.The strengthening effect is evaluated by the calcium carbonate generation,unconfined compressive strength and coefficient of permeability.The results show that:(1)FeCl_(3)can change the morphology and size of the calcium carbonate produced by the MICP in the solution tests.(2)The addition of FeCl_(3)to the cementing solution can lead to a maximum unconfined compression strength of up to 1617.9 kPa in sand columns under five injections,which is 10.4 times higher than that of the conventional MICP-treated sand columns,and the coefficient of permeability is reduced by two orders of magnitude compared with that of the untreated sands.(3)FeCl_(3)does not increase the amount of the MICP calcium carbonate in sandy soils,but modifies the distribution pattern of the calcium carbonate in the pores of the sandy soils,thus increasing the strength of sandy soils and lowering the coefficient of permeability of sandy soils in co-operation with the MICP.

关 键 词：微生物矿化 三氯化铁 碳酸钙 无侧限抗压强度 渗透系数 

分 类 号：TU41[建筑科学—岩土工程]