Hollow grouting rock bolt plays an indispensable role in various coal mine tunnel support. So, what is the bearing principle of hollow grouting rock bolt ?

In the layered rock layer, the rock bolt hangs the lower unstable rock layer on the upper stable rock layer, and the pulling force of the rock bolt comes from the suspended rock layer. In a thin rock layer without a stable rock layer, after rock bolts are installed with ease, the clamping force of the rock bolt will increase the friction force between the layers. This friction force can prevent the rock from continuing to slide along the layer and pass several thin rock layers. The bolt is locked into a thicker rock layer. The maximum bending stress and strain in this thick rock beam are inversely proportional to the square of the beam thickness. The thicker the integrated rock beam, the smaller the maximum bending stress and strain. At the same time, the strength of the hollow grouting rock bolt itself also increases the overall shear resistance of the beam.

Combined arch principle of hollow grouting rock bolt: When prestressed rock bolt is installed in the rupture area of surrounding rock of arched roadway, compressive stress in the form of a circular cone will be formed at both ends of the rod body. If the bolt groups are arranged along the roof, the compressive stress cones formed by each bolt will overlap and form a pressure-bearing arch to prevent the diffusion of the fracture zone. This arch can bear the radial load applied by the broken rock at the upper part. The prestressing force along the axial direction of the rock bolt produces hoop stress in the composite arch, which obviously improves the stress state of the pressure-bearing arch and changes the surrounding rock state from uniaxial and biaxial to triaxial compression. In this way, a uniformly compressed continuous bearing area is formed in the surrounding rock, thereby greatly improving the bearing capacity of the composite arch.

The above is the load bearing principle of hollow grouting rock bolt. If you have any requirements for supporting products, please contact us!

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