Abstract: In order to reveal the influence of lateral pressure coefficients on floor burst induced by dynamic disturbance, dynamic response rules and burst process of floor in extra-thick coal seam induced by dynamic disturbance at different lateral pressure coefficients were studied by using the rock mechanics and FLAC2D finite difference numerical software. The results show that the ultimate stress equilibrium in floor can be disturbed by dynamic loads so that floor burst is induced. With the increase of the lateral pressure coefficients, critical horizontal stress and maximum stress difference of floor will increase linearly, maximum vertical displacement of floor will increase nonlinearly if  and then decrease slightly as  under dynamic loads. These indicate that instability difficult degree is not positively correlated with burst strength for floor completely. The floor burst process is: 1) horizontal stresses reaches critical value instantly, 2) plastic area extends, 3) elastic energy releases rapidly, 4) vertical displacement of floor increase suddenly, 5) the floor burst occurs. The conclusions will provide reference for the study on mechanism of floor burst and its prevention in the same conditions.

Key words: floor burst, lateral pressure coefficients, dynamic disturbance, numerical simulation