Creep characteristics of soft rock and modelling of creep in tunnel : determination of creep characteristics of soft rock and development of non-linear creep analysis code for squeezing tunnel problem

• Main Author: Yu, Chi-Wen
• Published: University of Bradford 1998
• Subjects: 624.1
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.586717

Squeezing or time-dependent creep deformation of rock has been encountered frequently in tunnels. It is particularly common in tunnels excavated in very soft rock or heavily fractured rock under significant in-situ stresses. In Taiwan, due to the inferior geological setting and the young sedimentary rock formations, squeezing in tunnels was found to be a very common problem from the recent case histories of some large span road tunnels. This research reviewed the existing rock creep models, and an adequate creep model for representing the creep behaviour of soft rock or a weak rock mass in general was selected based on testing data of some soft rock cores. A numerical code was developed and validated by using tunnel physical model test. Actual tunnel case histories were also used to develop the creep analysis method for practical engineering purpose.