Abstract:

It is of great importance for studying anchoring effect when considering distribution and variation of anchor stress based on creep effect of rock mass; however, there are not many articles to deal with this aspect in recent years. In this paper, we begin with the load-bearing characteristics of anchorage micro-unit, research on variation of anchor stress under the condition of rock mass creeping, then give some conclusions as follows. Force variation of anchor which is embedded in the creeping rock mass has much relationship with stress state and displacement of surrounding rock mass. When anchorage micro-unit is in tensile state; the axial force of anchor is increasing as time goes on. On the contrary, when anchorage micro-unit is in compressive state, the axial force of anchor is decreasing. In terms of stress distribution of anchorage in visco-elastoplastic rock mass, it is concluded to be in accordance with each other between the location of peak stress of anchor and the plastic zone of surrounding rock mass. The conclusion is further verified to be correct by analytical method of engineering. In addition, it is analyzed that the anchor stress is increasing with creeping of surrounding rock mass in underground engineering.

Key words: creep, anchor, distribution of stresses, plastic zone, underground engineering