Mechanical Properties of Reinforcement Cage Underreamed Anchor Bolts and Their Application in Soft Rock Slope Stabilization

The utilization of reinforcement cage underreamed anchor bolts is prevalent in the reinforcement of foundation pit engineering, but there are few studies on the reinforcement of soft rock slopes and the influence of its parameters on slope stability. This study combines laboratory tests to analyze the mechanical properties of reinforced and non-reinforced bolts with finite element analysis to model the anchorage support system in soft rock slopes. Key parameters affecting the stability of the slope, such as bolt diameter, expansion section diameter, and anchorage depth, were considered. The findings indicate that the inclusion of a reinforcement cage leads to a more rational distribution of mechanical properties, promoting even axial force distribution to the grouting medium. An increase in bolt diameter enhances slope stability, while the expansion section diameter has minimal impact when a strong bond exists between the grouting body and the rock mass. However, in the absence of such bonding, increasing the expansion section diameter significantly improves slope stability. Deeper anchorage also correlates with higher stability, though the rate of increase in safety factor slows as the anchorage depth approaches the critical slip plane. In conjunction with field application, the research outcomes can exert a certain directive impact on practical engineering and can be used as a reference for the design method of bolt support for soft rock slope