Anchorage mechanical characteristics of newly designed rebar bolt and optimization of its support scheme

In Shendong coalfield, large cross-section underground gateways are often excavated for large machine transportation. It causes large deformation of the surrounding rock and the phenomenon of rib spalling. In this study, taking Xiaobaodang coal mine as the engineering background, a newly designed rebar bolt for large deformational roadway support was introduced to control large deformation. Results that the peak anchoring force of the new bolt increased by 20-30%, the total energy absorption of the system is increased by 35-50%, the post-peak displacement increases by 4.5mm comparing with traditional left-spiral non-longitudinal rebar bolt. The support schemes were analyzed by using FLAC3D, the newly bolting effect was better than the original scheme when the new rebar bolt was used in full-length anchorage and the increased bolting interval. This study provides a referencr for the similar roadway support.