Numerical analyses of the influences of rock properties and joints on rock fragmentation in shaft sinking by drilling method.

The mechanical rock-crushing efficiency is directly influenced by rock properties and joint structure. Tipped-hob is widely used in the construction of shafts. By analyzing the motion of tipped-hob and the mechanical properties of granite and sandstone, numerical rock samples with different mechanical properties were built to investigate the influences of rock properties and joint structure on rock-crushing efficiency using a single ring of tipped cutter.

Erosion degradation analysis of rice husk ash-rubber-fiber concrete under hygrothermal environment.

To study the resistance of rice husk ash-rubber-fiber reinforced concrete (RRFC) to dry-wet cycle/chloride erosion under a hygrothermal environment, the optimal combination was selected by an orthogonal test. The peak strain, residual strain, and fatigue damage strength of the optimal group of RRFC samples under cyclic loading and unloading after dry-wet cycle/chloride erosion under different environments and temperatures were compared and analyzed. After that, microscopic analysis and anti-erosion mechanism analysis were carried out.