MICP技术加固岩石节理的力学机理试验研究∗

Experimental Study on Mechanical Mechanism of Rock Joints Strength- ened by MICP Technology

摘要:

微生物诱导碳酸盐沉淀(MICP)是近年国内外兴起的一种微生物岩土技术，即利用微生物新陈代谢的矿化作用诱导产生碳酸盐沉淀，在土体抗液化、堤坝加固等领域得到广泛实验和应用，相较传统边坡加固手段，其绿色环保的特点更符合可持续发展理念。为探究 MICP 技术在完全分离的岩石节理试件中的胶结效果，通过一种可采用流体分阶段胶结岩石节理面的实验装置，实现 MICP 胶结液对岩石节理试件的胶结，在不同法向应力下探究其抗剪强度。结果表明：(1)MICP 技术对岩石节理具有一定胶结作用；(2)随剪切位移的增加，MICP 胶结实验组与无充填对照组的剪切强度维持一致，即二者抗剪残余应力基本相等；(3)胶结养护 7 d 的抗剪强度可达无充填对照组的 85%。

Abstract:

Microbial induced carbonate precipitation(MICP)is a new microbial geotechnical technology that has been developed at home and abroad in recent years. MICP，which causes carbonate precipitation through mineralization of microbial metabolism，has been widely used in soil anti-liquefaction and dam reinforcement. Compared with traditional slope reinforcement methods，microbial reinforcement is more environmentally friendly and in line with the concept of sustainable development. In order to explore the cementing effect of MICP technology in completely separated rock joint specimens， an experimental device that can use fluid to cement rock joints in stages is adopted to realize the cementing effect of MICP cementing fluid on joint specimens. The shear strength of joints was investigated under different normal stresses，and the results show that：(1)The MICP technology had a certain cementing effect on rock joints；(2)With the increase of shear displacement，the shear strength of the MICP cementing group and the control group without filling remained consistent，that is，the residual shear stress of the two groups was basically equal；(3)The shear strength of cementing curing for 7 days can reach 85% of the control group without filling.