Abstract:

Soft rock engineering involves many important engineering fields such as mining, hydraulic engineering, transport and national defense. With the increase of mining depth and the development of tunnel engineering, a large number of tunnels and roadways need to pass through soft rock formations, in which the problems such as high geostress and broken and weak surrounding rocks are prominent. Large deformation disasters of soft rocks pose serious threats to engineering safety and cause enormeous economic losses. In this paper, the research progress on soft rock support in China is first reviewed, and the research status of technology for soft rock control for large deformation hazards is summarized in the following aspects. (1) Passive support methods represented by improved rigid support, retractable support and compound lining. (2) Reinforced active support technology using high-strength bolts and cables. (3) Soft rock modification technology dominated by grouting modification. (4) Soft rock reinforcement with pressure relief as the core idea. (5) Compound support methods. Furthermore, the development of different supporting technologies and methods are elaborated, and the applicable conditions, advantages and disadvantages of different supporting methods are analyzed. It is usually difficult to meet the demand of large deformation control of soft rock relying on a single support method. Therefore, it is urgent to solve the problems of the prevention and control of large deformation disaster of soft rock to realize the efficient collaborative control among different supporting measures and achieve the real-time accurate monitoring of deformation and stress fields. Finally, based on the above research results, the development tendency of support technology for soft rock with large deformation hazards is prospected and the countermeasures are proposed.

Key words: large deformation of soft rock, support, technical status, research progress, surrounding rock control