Abstract In the present scenario, with much focus on sustainable development worldwide, Microbially Induced Calcite Precipitation (MICP) is a promising biological soil improvement technology. However, only very limited research is reported on the effectiveness of this technique in marine clays. This paper presents the salient features of an experimental study conducted on two typical marine clays stabilised by MICP. Effectiveness of the technique was evaluated through a series of one-dimensional consolidation tests, unconfined compression tests, and index property determinations. It is found that biostimulation approach is not effective in marine clay; bio-augmentation is needed for soil improvement. Bio-augmentation results in the reduction of liquid limit and plasticity index to about 29% and 47%, respectively for the marine clays. A comparable improvement in volume change behaviour is also observed. There is a marked increase in undrained shear strength, upto about 148%, of MICP treated marine clays at toughness limit water content. Curing is also found to have a significant role in soil improvement. The observed transition in the nature of the tested marine clays from that of fat clay to elastic silt suggests the potential of the proposed approach. An empirical equation is also proposed to predict compression index of MICP treated marine clays.

中文翻译：

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MICP处理海相粘土的工程行为

摘要 在当前全球范围内都非常重视可持续发展的情况下，微生物诱导方解石沉淀（MICP）是一种很有前途的生物土壤改良技术。然而，只有非常有限的研究报告了这种技术在海洋粘土中的有效性。本文介绍了对 MICP 稳定的两种典型海洋粘土进行的实验研究的显着特征。该技术的有效性通过一系列一维固结试验、无侧限压缩试验和指数特性测定进行评估。发现生物刺激方法对海洋粘土无效；土壤改良需要生物强化。生物强化导致海相粘土的液限和塑性指数分别降低至约 29% 和 47%。还观察到体积变化行为的可比改进。在韧性极限含水量下，MICP 处理的海洋粘土的不排水剪切强度显着增加，高达约 148%。还发现固化在土壤改良中具有重要作用。观察到的测试海洋粘土性质从脂肪粘土到弹性淤泥的转变表明了所提出的方法的潜力。还提出了一个经验方程来预测 MICP 处理的海相粘土的压缩指数。观察到的测试海洋粘土性质从脂肪粘土到弹性淤泥的转变表明了所提出的方法的潜力。还提出了一个经验方程来预测 MICP 处理的海相粘土的压缩指数。观察到的测试海洋粘土性质从脂肪粘土到弹性淤泥的转变表明了所提出的方法的潜力。还提出了一个经验方程来预测 MICP 处理的海相粘土的压缩指数。