The coupling mechanism between temperature fields and stress fields is briefly analyzed, and a
quantitative method for calculating the coupling parameterPTCis introduced in detail based on the thermo-
elasticity effect and the thermal diffusion equation. The proposed quantitative parameter is used to evaluate
the thermo-elasticity coupling effect. The thermo-elasticity coupling effect of several kinds of common rocks
are calculated, with a result showing that usually the value ofPTCis of the order of 10-3. In the mean
time, a preliminary discussion on the practicability and significance of the dimensionless parameterPTCin
engineering application is made.