Study on engineering properties of alteration zone in a tunnel project

Phenomenon of surrounding rock deformation and collapse, groundwater lowering, ground collapse and cracking appeared in a tunnel project. It is necessary to master engineering properties of compressive rupture zone for guarantying construction safety and ensuring the reliability of supporting structures. This paper, using geological survey and microanalysis methods, determines the mineral composition of all typical altered rocks in the alteration zone. Furthermore, an overall understanding of their physical and mechanical characteristics will be presented based on the results of physical and mechanical (triaxial and direct shear tests) experiments. Finally, this paper suggests engineering protective measures by summarizing the major determinant of engineering properties.