Considering the layered characteristics of mining floor

the floor strata are equivalent to layered semi-infinite plane. A stress calculation model of multilayer floor strata is proposed based on the transfer matrix method. The corresponding calculating program is written by Matlab to calculate the stresses of multilayer mining floor strata. And the plastic zone of mining floor is determined by the Mohr-Coulomb yield criterion. The proposed model take into account the rock lithology and its composite structure of floor strata

so the calculation result of failure depth is more closer to the actual situation than the traditional method. Then different calculating models are established to study the influence of rock properties of the floor strata on the stress distribution and failure characteristics of mining floor. The results show that the hard rock has the reducing and dispersing effect on the abutment pressure. The reducing effect can cause lower stress in the deep floor strata

and inhibit the failure of mining floor. The dispersing effect can expand the influence scope of stress in underlying strata

and widen the failure scope of underlying strata. In soft rock with low load-bearing capacity

will aggravate floor stress concentration

so as to increase the scope and the depth of failure zone in the floor strata.