Study on Similar Materials for Weakly Cemented Medium and Indoor Excavation Test

Area of Science:

• Geotechnical Engineering
• Mining Engineering
• Material Science

Background:

• Shallow buried strata movement in western China mining areas causes disasters, threatening operational safety.
• Creep failure of weakly cemented soft rock under low stress is a critical issue for secure mining.
• Weakly cemented mudstone exhibits unique particle contact and mechanical responses distinct from typical soft rocks.

Purpose of the Study:

• To develop qualified weakly cemented medium similar materials for long-term creep tests.
• To accurately simulate the mechanical behavior of weakly cemented formations in western mining areas.
• To investigate the influence of material composition on creep characteristics.

Main Methods:

• Orthogonal proportioning tests were used to develop the similar material.
• The material's mechanical properties (compressive strength σc, elastic modulus E, and creep rate γ) were analyzed.
• A similar indoor model test simulated a mining roadway, employing speckle analysis for examination.

Main Results:

• The developed similar material exhibits low strength and prominent creep characteristics, effectively simulating weakly cemented rocks.
• Rosin-alcohol solution concentration significantly impacts key mechanical parameters (σc, E, γ).
• Increasing iron powder (I) and barite powder (B) content progressively reduces creep characteristics.

Conclusions:

• The new similar material accurately replicates the properties of weakly cemented rocks found in western China mining areas.
• The material's composition can be adjusted to control its mechanical and creep behaviors.
• The material is suitable for similar model tests, providing reliable data for improving mining safety.