Abstract
This work dealt with an essential problem of fragmentation of rocks with expansive cement. The redistribution and magnitude of stresses and displacement generated around holes were done by using Ansys Inc. Code which is based on finite element code. Blocks of rock with one hole, two holes, and nine holes drilled in square mesh and staggered mesh have been considered. Numerical results reveal that many factors can influence the mechanism of fragmentation of a rock by using expansive cement: hole diameter, hole spacing, panel mesh, expansive pressure applied, and the elastic properties of the massif. Stresses and displacements generated globally decrease when spacing holes increase. Normal stresses allow a better stress interaction between holes in the case of square mesh disposition. Staggered mesh disposition generates higher stresses than the square mesh disposition. But the square mesh disposition can be useful for controlled fragmentation in order to obtain block of rock with square geometry. For each expansive cement and rock, there exist suitable range of diameter and spacing hole which can generate high stresses for breaking the rock.
Highlights
Explosives play a leading role in modern industries. ey are used for the extraction of metals; industrial minerals; mineral exploration works; or the construction of roads, railways, or hydroelectric plants. e excavation and fragmentation with explosives is an integral part of the technology mostly used by man to excavate the rock for multiple uses
“Expansive cements are inorganic binders that generate expansive stresses in the hardened paste in the course of hydration, counteracting the tensile stresses generated by chemical shrinkage and drying shrinkage.” [1]. is method consists of introducing expansive cement into previously drilled holes, and the expansive stresses created by the cement will have the function of initiating cracks and spreading them over the entire massif
We numerically investigated the redistribution of stresses and displacement around holes drilled in a square mesh and a staggered mesh
Summary
Explosives play a leading role in modern industries. ey are used for the extraction of metals; industrial minerals; mineral exploration works; or the construction of roads, railways, or hydroelectric plants. e excavation and fragmentation with explosives is an integral part of the technology mostly used by man to excavate the rock for multiple uses. Many models have been established to analytically and numerically simulate the cracks, stress, and strain around the hole. In 2004, Efremidis et al [9] used a simplified gradient elasticity theory to analytically simulate the behavior of the hollow cylinder loaded by internal and external pressure. Based on the theory of classic elastic linear behavior of rock, the analytical numerical solutions and of stresses redistribution were proposed by many researchers. In 2009, Arshadnejad et al used phase 2 code based on finite elements to study numerically the redistribution of stresses between two circular holes [13].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
