Study on the Style Design and Anchoring Mechanism of Enlarged Head Anchors

To resolve insufficient traditional bolt supports due to the complexity of geological conditions, optimal design an expanded head was investigated by using theoretical calculations and experiments. The results show that drawing capacity is affected bearing front rear ends, side capacity, friction resistance. For a circular anchor bolt, stepped semi-ellipsoidal with increase in section’s radius, lateral resistance inner section gradually shared force end section; effect enhanced; pulling performance enhanced. Therefore, at maximum, followed minimum. can provide greater end-bearing force. Compared cylindrical enlarged anchors, circular, stepped, semi-elliptic anchors have smaller but larger section, reduction less than rear-end capacity; thus, has lowest back radius more influence on ability anchor. longer anchorage distribution range compression zone formed soil body tension rear. length conducive improving reinforcement bolt. this parameter plays important role redistribution ultimate pull-out table-shaped tensile highest, comes third, exhibiting force; constitutes best style design.