微生物诱导碳酸钙沉淀技术改良黄土湿陷性研究

硅酸盐通报 ›› 2022, Vol. 41 ›› Issue (3): 969-975.

微生物诱导碳酸钙沉淀技术改良黄土湿陷性研究

孔德成¹, 孙治国², 贾方方¹

1.北京交通职业技术学院路桥系,北京 102200;
2.防灾科技学院中国地震局建筑物破坏机理与防御重点实验室,廊坊 065201

收稿日期:2021-11-04 修回日期:2021-12-07 出版日期:2022-03-15 发布日期:2022-04-08
作者简介:孔德成(1983—),男,讲师。主要从事工程技术方面的研究。E-mail:kongdc83@21cn.com
基金资助:
河北省高等学校科学技术研究项目(ZD2017306)

Microbial Induced Calcium Carbonate Precipitation Technique for Improving Collapsibility of Loess

KONG Decheng¹, SUN Zhiguo², JIA Fangfang¹

1. Road and Bridge, Beijing Jiaotong Vocational Technical College, Beijing 102200, China;
2. Key Laboratory of Building Collapse Mechanism and Disaster Prevention, China Earthquake Administration, Institute of Disaster Prevention, Langfang 065201, China

Received:2021-11-04 Revised:2021-12-07 Online:2022-03-15 Published:2022-04-08

摘要/Abstract

摘要： 为有效降低黄土地区遇水产生的湿陷性,以兰州黄土为研究对象,利用微生物诱导碳酸钙沉淀(MICP)技术对黄土湿陷性进行研究。首先对MICP处理前后黄土的无侧限抗压强度及湿陷系数进行评价,然后利用CT扫描技术分析MICP改良后的黄土微观特征,进一步探究MICP改良机理。试验结果表明:经MICP处理后的黄土试样无侧限抗压强度显著提高,最高可达150 kPa,黄土湿陷性有效降低;随着胶结液浓度不断增加,碳酸钙生成量持续增加,但在胶结液浓度大于1.25 mol/L时,碳酸钙生成量呈下降趋势;改良后黄土试样的孔隙率、孔隙等效直径等指标均降低。

关键词: 微生物诱导, 碳酸钙沉淀, 黄土, 无侧限抗压强度, 湿陷性, CT扫描, 孔隙特征

Abstract: In order to effectively reduce the collapsibility of loess areas in contact with water, a study was conducted on the collapsibility of loess using microbial induced calcium carbonate precipitation (MICP) in Lanzhou loess. The unconfined compressive strength and coefficient of collapsibility of the loess before and after MICP treatment were evaluated. The microscopic characteristics of loess modified by MICP were analysed by CT scanning technology,and the improvement mechanism of MICP was further explored. The test results show that the unconfined compressive strength of the loess specimens modified by MICP increases significantly, up to 150 kPa, and the collapsibility of the loess is effectively reduced; the amount of calcium carbonate production continues to increase with the increasing concentration of the cementing fluid, but decreases when the concentration of the cementing fluid is greater than 1.25 mol/L; the porosity and pore equivalent diameter of the modified loess specimens are decreased. The porosity and pore equivalent diameter of the modified loess specimens are all reduced.

Key words: microbial induced, calcium carbonate precipitation, loess, unconfined compressive strength, collapsibility, CT scan, pore characteristic

中图分类号:

TU444

孔德成, 孙治国, 贾方方. 微生物诱导碳酸钙沉淀技术改良黄土湿陷性研究[J]. 硅酸盐通报, 2022, 41(3): 969-975.

KONG Decheng, SUN Zhiguo, JIA Fangfang. Microbial Induced Calcium Carbonate Precipitation Technique for Improving Collapsibility of Loess[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2022, 41(3): 969-975.

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