微生物加固混合砂的单轴压缩试验

Uniaxial Compression of Microbe Reinforced Mixed Sand

为了有效利用MICP(微生物诱导碳酸钙沉淀)技术加固岛礁地基土,本试验以珊瑚砂和滨海粉细砂混合形成的砂柱为研究对象,依据微生物培养所需的pH值、温度、胶结液浓度等条件来处理混合砂试样,同时研究了不同粉细砂掺量对试样抗压强度及局部不均匀性的影响.试验结果表明,MICP技术适用于处理混合砂试样,粉细砂的掺量较高时会降低试样的抗压强度,而掺量过低时又会使试件产生脆性破坏,因此综合考虑,质量掺量控制在16%~20%之间时能够有效提高试样的无侧限抗压强度,从而使试件的整体胶结性能较好.

In order to strengthen the island foundation soil with microbially induced carbonate precipitation(MICP)technology,in our report,the sand column formed by mixing coral sand and coastal silty fine sand was used as the research object,the mixed sand specimen were prepared based on the microbial culture conditions,such as pH,temperature,and the concentration of cementing fluid handling;the effects of the different silty fine sand content on the compressive strength and local inhomogeneity of the samples were compared. The results showed that MICP technology is suitable for the treatment of mixed sand samples;the higher the fine sand content,the lower the compressive strength of the sample,however,too low dosage cause brittle failure of the specimen,which suggested that the unconfined compressive strength of the sample can be effectively improved and the overall cementing property of the sample will be good when the mixing content is between 16% and 20%.