Many geotechnical problems

such as deep excavation of mine

underground storage of nuclear waste and pervasive application of energy piles

need to consider the effect of temperature on the mechanical properties of soft rock. In order to describe the mechanical properties of soft rock more comprehensively

based on the superloading and subloading concept and the concept of temperature-equivalent stress

a new elastoplastic constitutive model for soft rock

which is able to consider the effect of temperature

intermediate principal stress

structure and overconsolidation at the same time

is proposed in the tij stress space. All parameters of the new model have clear physical meaning. By comparing theoretical curves with the experimental results

the correctness of the proposed constitutive model is verified. Finally

by changing the model parameters

the performance of the new constitutive model is analyzed and discussed. Increasing the value of m which controls development of overconsolidation ratio or reducing the value of m*that controls structural state development will enhance the shear strength of soft rock. With the increase of temperature

the shear strength of soft rock declines. The higher the initial overconsolidation ratio is

the more apparent the dilatancy of soft rock becomes.But when initial structure is large

the volume strain of soft rock presents shear contraction in the final shear stage.