In consideration of difference in micro-structure of rocks

the paper presents random non-homogeneous solid-head coupled model and FEM concerned

and then in consideration of the random non-homogernity of thermal dilation and conduction coefficients

plane stain model

For example of granite

assumed thermal dilatability and thermal conduction with uniform distributing

Gauss distributing

Weibull distributing

based on a lot of numerical experiments

study on the hot cracking threshold of rock

conclusions of random distributing function and parameter and time influence to thermal cracking law and temperature threshold is presented.