The squeezing problem is one of the most tuff problems that appear during the construction of highway and railway tunnels. In the engineering practice
the squeezing problem is mainly caused by the creep of rock mass due to the shearing failure. Some squeezing problem is created by the swelling due to the reaction between the clay minerals of rock and the water present in the rock mass. Therefore
the squeezing problem can be classified into three categories: stress induced
swelling induced and structure induced. According to the research findings made by others
the tunnel strain of 3% can be adopted as a qualitative classification criterion to judge whether there is a severe squeezing problem. For the stress induced squeezing problem
the deformation prediction equation put forward by Hoek can estimate the deformation magnitude of a tunnel fairly well; so these equations are of practical significance. However
for different engineering conditions
the estimate method for in-situ stresses or the secondary stresses has to be adjusted for special purpose. The deformation prediction of swelling and structure induced squeezing problem