Abstract:Based on Mohr-Coulomb failure criterion and wave theory,the failure mechanism of rock and soil masses under earthquake loading has been theoretically analyzed,with the calculation process assuming the maximum value of seismic stress and the most unfavorable orientation.It has been found that cohesive force and normal stress are linearly related to vibration velocity when the burial depth is within a certain range.When the burial depth is constant,vibration velocity increases as cohesive force,c,decreases,so with increasing vibration velocity,stresses in the rock mass would transform from the compressive state to the tensile state and continue to increase.When the vibration velocity is constant,the deeper the burial depth of the rock mass,the smaller is the cohesive force;and the shallower the burial depth,the greater is the tensile stress.When the burial depth increases to a certain value,the rock mass begins to vibrate within the elastic limit and no failure can occur.This research can be applied to the assessment of rock mass stability and the forecasting of geological hazards,as rock masses under different burial depths always have different stress states.More specifically,rock masses buried shallowly store only a small amount of strain energy,limiting their destructive potential.Increasing the burial depth correspondingly increases the strain energy;as a result,the rock masses are closer to reaching their limit state and can more easily fail.The evolution of geological bodies shares a similar rule;namely,when a geological body reaches its limit state,a slight perturbation can trigger a geological hazard,whereas if the geological body has not yet approached its limit state,only a sufficiently strong disturbance will induce the geological hazard.
