A Study on Rock Mass Classifications and Tunnel Support Systems in Unconsolidated Sedimentary Rock

摘要

This paper presents new valuable field data and a comprehensive approach to the determination of the rock mass classification and tunnel support systems for tunnels in unconsolidated sedimentary rocks as a special soil condition. The main objective of this study is to investigate and present the characteristics of the unconsolidated sedimentary rock by using the point load tests and slake durability tests. In addition, the appropriate rock mass classification and tunnel support system for the unconsolidated sedimentary rock tunnel are proposed, based on the results of experimental tests. The proposed rock mass classification and tunnel support system are validated through comparison against results from measuring the convergence of a tunnel under the construction. The proposed tunnel support system is appropriate for the unconsolidated sedimentary rocks, since the convergence factors, such as the maximum displacement and velocity of displacement, satisfy the criteria.