STUDY ON STABILITY OF ROOF-TRUSS SYSTEM BY CATASTROPHE THEORY

The paper analyzes the stability of cracky roof system by catastrophe theory.Its destabilizing model belongs to the cusp catastrophe model of catastrophe theory.The critical condition for roof falling is educed by bifurcation set equation of this model.With reference to the figures of bifurcation set eauation,the paper analyzes the impact on roof stability imposed by the change of system parameters and observes that the rheological property of rock mass in the roof and the accumulation volume of local fragmentation are the main factors causing the roof falling.As shown in Fig.2 below,if the compensation of the truss is enough,the route of control point which is determined by the system parameters can not reach the right ramification of bifurcation set and critical conditions of roof falling can not be satisfied,the roof is therefore stable.