What is rock anchor support? Rock anchor support is a support technology that uses anchoring devices to reinforce rock masses. It is primarily used in underground projects (such as roadways, tunnels, and foundation pits) to control surrounding rock deformation and prevent rock separation. Its core functions, effects, and applications are as follows:

   I. Support Principle (Based on Mechanical Mechanisms)

   1. Suspension Effect: Anchor bolts suspend weak rock strata (such as the immediate roof) to the upper, stable rock strata (old roof), inhibiting rock separation.

   2. Composite Beam Effect: The preload of anchor bolts "stitches" the layered rock mass into a monolithic beam, increasing flexural stiffness and reducing interlayer movement.

   3. Compression Arch Effect: The prestress of multiple anchor bolts creates a continuous compression zone (load-bearing ring) in the surrounding rock, subjecting the rock mass to a triaxial stress state and improving overall stability.

   4. Reinforcement Effect: The triaxial stress state of the rock mass surrounding the roadway is restored, mitigating strength deterioration and inhibiting crack propagation.

  II. Functions of Rock Strata Anchor Bolt Support

   1. Stabilizes fractured rock mass: Prevents collapse in sandy, sand-interbedded, or fractured strata. It is particularly suitable for geological conditions prone to borehole collapse.

   2. Resists external loads: Withstands ground pressure, rock mass deadweight, and dynamic construction loads, maintaining the structural integrity of the roadway or tunnel.

   3. Adapts to complex environments: Suitable for use in harsh conditions such as water inrush and fracture zones, using specialized techniques (such as post-enlarged anchor bolts) to enhance anchoring strength.

   III. Core Functions

   1. Controls rock movement: Increases interlayer friction through preload, reducing delamination and roof subsidence.

   2. Enhances the self-bearing capacity of the surrounding rock: Forms a "secondary critical bearing layer," optimizes deep stress distribution, and reduces the need for external support.

   3. Limits structural deformation: Steel belts/beams, combined with anchor bolts, resist horizontal and bending deformation.

   IV. Main Applications

   1. Mining: Supports tunnel roofs, side walls, and working faces to prevent roof collapse and spalling.

   2. Tunnels and underground chambers: Reinforces broken roofs, particularly suitable for large-span tunnels or intersections (e.g., anchor cable truss support).

   3. Slope and foundation pit engineering: Stabilizes slope rock masses and supports deep foundation pit sidewalls (e.g., soil anchor bolts).

   4. Special geological treatments: Use grouting anchor bolts to enhance bond strength in weak surrounding rock (e.g., silt layers).