微生物拌和固化海相粉土的抗压强度试验研究  

Experimental study on compressive strength of solidified marinesilty soil mixed with microorganism

作　　者：付佳佳[1,2] 姜朋明 纵岗[1] 丁金画[1] FU Jiajia;JIANG Pengming;ZONG Gang;DING Jinhua(Yancheng Vocational Institute of Industry Technology,Yancheng 224005,China;School of Transportation Engineering,Nanjing Tech University,Nanjing 210009,China;School of Civil Engineering and Architecture,Jiangsu University of Science and Technology,Zhenjiang 212003,China)

机构地区：[1]盐城工业职业技术学院,江苏盐城224005 [2]南京工业大学交通运输工程学院,江苏南京210009 [3]江苏科技大学土木工程与建筑学院,江苏镇江212003

出　　处：《人民长江》2021年第1期167-172,189,共7页Yangtze River

基　　金：国家自然科学基金项目(51979128);江苏省高校自然科学研究面上项目(20KJB56003);江苏省高校优秀科技创新团队项目(2017);盐城工业职业技术学院自然科学课题(ygy1808)。

摘　　要：微生物诱导碳酸钙沉积(MICP)技术的研究主要针对粒径较大的砂土,对于使用MICP技术加固粉土的研究还有待进一步深入。通过无侧限抗压强度试验研究MICP拌和加固江苏省沿海吹填粉土的强度变化规律。在拌和过程中考虑了菌液和加固液的配比、加固液浓度的变化以及不同钙源对粉土固化效果的影响,然后与相同级配条件下的未加固试样进行对比。结果表明:(1)采用拌和法可以较简便、较均匀地加固粉土试样,随着拌和法固化效果的提升,试样逐渐表现出较为明显的脆性破坏现象。(2)加固液浓度为1.5 mol/L时,固化粉土试样的无侧限抗压强度能达到未加固试样的1.5倍。(3)两种钙源条件下固化粉土试样的无侧限抗压强度变化规律相近,但以Ca(CH3COOH)2作为钙源进行固化的试样的无侧限抗压强度均低于以CaCl2作为钙源的试样。(4)采用CaCl2作为钙源,拌和过程中在菌液与加固液的体积比为3/7,加固液浓度为1.5 mol/L的工况条件下,粉土试样的固化效果达到最佳。Research on microbial induced carbonate precipitation(MICP)is mainly aimed at sandy soil with large particle size,and MICP-treated silt needs further study.Therefore,a series of unconfined compressive strength tests were conducted to study strength change laws of marine silt treated by MICP.Ratios of bacterial solution and reinforcement solution,reinforcement solution concentration and different calcium sources were considered in the process of reinforcement and then were compared with unreinforced samples.The result showed that:(1) Mixing method could be used to strengthen the silty soil easily and evenly.With the improvement of treated effect,the samples gradually showed obvious brittleness.(2) The reinforcement solution concentration had the most significant effect on the unconfined compressive strength of the treated silty soil samples,and when it came to 1.5 mol/L,the unconfined compressive strength of the solidified soil samples could reach 1.5 times that of the unconsolidated samples.(3) The unconfined compressive strength of the samples treated by two calcium sources were similar but the values were different.(4) When the calcium source was CaCl2,and the volume ratio between bacterial solution and reinforcement solution in the mixing process was 3/7,and the concentration of reinforcement solution was 1.5 mol/L,the treatment effect of silty soil samples reached the best.

关 键 词：微生物诱导碳酸钙沉积 海相粉土 拌和法 无侧限抗压强度试验 

分 类 号：TU433[建筑科学—岩土工程]