Abstract: The deformation and failure laws of expressway subgrade and pavement influenced by coal mining subsidence have been researched by the similar model experiment.The results showed that，the deformation of subgrade along with ground is continuous，gradually and regularly changed，and the developed cracks inside the subgrade will approach or even be compacted gradually with the working face advance; Before the failure of pavement occurs，the gap has been formed between pavement and subgrade and vertical cracks have been developed inside the pavement.In conclusion，subsidence of the pavement is not consistent with that of the subgrade and ground.It is put forward that roadbase fracture is the sign that the expressway is destroyed.The mechanical formulas as the fracture failure criterions of expressway have been derived for interpreting the deformation and failure mechanism of expressway influenced by coal mining subsidence by using linear elastic fracture mechanics.

Key words: Expressway, Coal mining subsidence, Similar model experiment, Fracture, Criterion, Failure mechanism