Energy-based forming and anchoring mechanism and criterion for zonal disintegration

The energy transmission and variation law during rock damage are studied. Consequently the energy-based criterion for rock damage is obtained. Based on analyzing the energy distribution law in rock mass, the geostress condition for Zonal Disintegration Phenomenon (ZDP) is studied. The criterion for ZDP in terms of strain energy is thus established. The forming mechanism for ZDP is revealed. Additionally the sensitive factors and the influences on ZDP are determined. An equivalent excavation model is proposed to investigate the releasable strain energy. Therefore, the energy-based criterion for anchoring ZDP is established with the Energy analysis of anchor bolt. Meanwhile, the number of bolts to control the ZDP formation is calculated in this paper. Finally, a model test is compared with the theoretical result and testifies the criterion.