Pore pressure effects on strength and elasticity of ornamental stones

Abstract

This experimental study determines the effects of pore pressure on the compressive strengths and elasticity of six ornamental stones. An approach to determine the pore pressure in low porosity rocks is presented. Rectangular rock specimens (50 × 50 × 100 mm 3 ) under dry and wet conditions were axially loaded under different rates from 0.001-10 MPa/s using a polyaxial load frame. The confining pressures ranged from 0 to 12 MPa. Wet granite, marl, marble, Phra Wihan sandstone, Phu Phan sandstone, and siltstone specimens have an average water content of 0.14%, 2.7%, 0.09%, 2.05%, 4.9%, and 1.5%, respectively. Compressive shear failure was observed in specimens under slow loading rate while extension failure was found in specimens under high loading rate. The strength values of the wet specimens were lower than those of the dry ones, particularly under the high confining pressure and loading rates.The strength values obtained from the dry testing were used to quantitatively calibrate the loading rate effect from the wet strengths, and hence the effect of pore pressure could be calculated. The pore pressures notably reduced the compressive strength and elastic modulus, and slightly increased Poisson's ratio of the rocks tested.

Nonlinear Mechanical Effect of Free Water on the Dynamic Compressive Strength and Fracture of High-Strength Concrete

“…Numerical implementation of this criterion in the discrete element method is based on determining the local stress tensor on the contact area of the linked pair of elements and calculating its invariants [62]. These invariants are calculated for the pair at each time step and then substituted into Equation (15) to check the bond break condition is met in the pair.…”

“…Water or an aqueous solution in the pore space has a significant effect on the mechanical properties of concrete. The pore fluid is reported to be responsible for numerous phenomena of premature fracture of various brittle materials (including concretes) under loads significantly lower than permissible for these materials in a dry state [ 6 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ].…”

Subsidence Mechanism and Stability Assessment Methods for Partial Extraction Mines for Sustainable Development of Mining Cities—A Review

“…Recent research also showed that the mechanical properties of rock material (e.g., rock strength, rock stiffness, the fracture toughness of rock, the elastic modulus of rock, etc.) may degrade due to water [110][111][112][113][114][115][116][117][118][119][120]. Poulsen et al [121] suggested that the strength reduction of saturated coal pillars can be estimated by the average strength reduction of all the lithological components of coal.…”