A distinguishing feature of tunnels in squeezing rocks is that a large
deformation of the surrounding rocks takes place slowly and gradually,
often called squeezing phenomenon. It is different from the rocksbursting
phenomenon during which the deformation of tunnels occurs
instantaneously when the resulting stresses exceed the strength of the
surrounding rocks. The squeezing phenomenon has received great
attention in the field of rock mechanics and tunnelling recently. The mechanism and various factors related to the large deformation
and failure of tunnels in squeezing rocks are discussed in this paper on the
basis of field investigations and laboratory model tests. The relationship
between the deformation of surrounding rocks and support of the tunnels
in squeezing rocks is presented in the form of numerical modelling.