Advantages of self-drilling anchor bolt in slope treatment of hazardous geology

With the rapid development of the social economy and infrastructure, it is urgent to solve geological disaster problems such as landslides and high and steep collapse slopes. Therefore, the research, development and application of slope protection and reinforcement treatment technology have certain social significance and economic value.

There are various forms of slope protection technology. Self-drilling hollow anchor bolt support can satisfy the designed anchoring force and has been widely used in various protection and reinforcement projects.

The Yangjiang nuclear power plant is located in Yangjiang city, Guangdong Province. The western slope beside its main factory is a rocky slope. Due to the impact of rain erosion and blasting construction, the slopes partially collapsed and fell off. To strengthen the stability of the slope, concrete repair and self-drilling anchor bolt are adopted in construction.
 

The mechanical principle of self-drilling hollow anchor bolt has three points:

1) Anchor bolt suspension: Anchor bolt passes through the weak and loose rock and soil to generate tension in the stable stratum. By overcoming the dead weight and sliding force of the sliding rock and soil to prevent the slope wall from sliding and collapse.
 

2) Extrusion reinforcement: The stress zone of adjacent bolts overlap to form a compression zone, enhancing the integrity and bearing capacity.
 

3) Composite beam (arch): After the anchor bolt is inserted into the stratum at a certain depth, the strata squeeze each other under anchoring force, which increases the friction and reduces the internal stress between layers. This is equivalent to changing the beam (arch) from simple stacking to combination. The flexural rigidity and strength of composite beam (arch) are improved, thus enhancing the stratum bearing capacity.
 

The practice of the slope protection and reinforcement in the main plant west side of Yangjiang nuclear power plant shows that the construction efficiency of self-drilling hollow anchor bolt is 30%+ higher than traditional grouting bolt. Self-drilling anchor bolt brings great convenience to the disastrous geological slope treatment, makes the protection and reinforcement of slope more advanced, applicable and economical, and it has an irreplaceable effect than other anchoring materials.

And the main basis for selecting protection and reinforcement measures in slope engineering are slope angle and height, geological conditions, hazard degree and on-site construction conditions. Reasonable technical solutions are the key to realize high-steep slope protection and reinforcement with high efficiency and safe construction.