关键词: 深埋隧洞;软岩;围岩-支护体系;承载机制;支护时机;支护强度;滇中引水工程;

Abstract: The deformation of deep-buried soft rock tunnel has large amplitude and long duration, which makes the surrounding rock support very difficult.How to formulate effective design countermeasures to control soft rock deformation is one of the important technical problems in the design and construction of deep-buried soft rock tunnels.There are three critical problems in the research of soft rock deformation control, i.e.the bearing mechanism of surrounding rock-support system of soft rock tunnel, the safety control indices and control standards of surrounding rock-support system, and the reasonable support timing and support rigidity of soft rock tunnel.Remarkable achievements have been made in the deformation control of deep-buried soft rock tunnel by theoretical analysis, field tests and numerical simulation over the past decades.By summarizing the research progress related to these three critical problems, the applied forms of surrounding rock load and bearing proportion between surrounding rock and support are discussed, and the safety control indices and standards for surrounding rock-support system are established.Based on the load-bearing law of the surrounding rock-support system and its safety control standards, the reasonable support timing and reasonable support strength of the surrounding rock of deep-buried soft rock tunnels are discussed.The related knowledge and conclusion have certain theoretical and engineering significance.

Key words: deep buried tunnel; soft rock; surrounding rock-support system; bearing mechanism; support timing; support strength; Central Yunnan Water Diversion Project;