Journal of the Southern African Institute of Mining and Metallurgy
On-line version ISSN 2411-9717
GHOLINEJAD, M. and ARSHADNEJAD, Sh.. An experimental approach to determine the hole-pressure under expansion load. J. S. Afr. Inst. Min. Metall. [online]. 2012, vol.112, n.7, pp. 631-635. ISSN 2411-9717.
Applying non-explosive expansion material (NEEM) is one of the safest methods for rock fracturing, especially in a hard rock quarry. An experimental study was conducted to determine the pressure exerted by NEEM in a hole, which is necessary for analysing rock fracturing, particularly in a numerical modelling. Stress distribution was developed in a thick-wall cylinder in order to measure the tangential strain on the external boundary. In the experiments, nine pipes of different materials and varying diameters were selected and then loaded internally with a general type of NEEM. Through electrical strain gauges, the tangential strains were recorded on the external boundary of the pipes. The results obtained from these tests and existing data from previous researchers were utilized for the statistical analysis. A new experimentally-derived formula is proposed for determining the pressure exerted by NEEM by multiple parameter regression with a high correlation coefficient. The proposed model has a nonlinear form with three independent parameters i.e. the hole diameter, the time, and the modulus of elasticity of the material.
Keywords : experimental test; non-explosive expansion material; thick-wall cylinder..