Exploration and Mining
Yaghoob Zarei; Ali Uromeihy; MohammadReza Nikoodel
Abstract
In this labratory study, the effect of joint density (number and spacing) on the pressure wave velocity was researched in pyroclastic rocks. After determining the physical properties, the P-wave velocities of intact rock samples were measrued. Then, an artificial joint perpendicular to the measuring ...
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In this labratory study, the effect of joint density (number and spacing) on the pressure wave velocity was researched in pyroclastic rocks. After determining the physical properties, the P-wave velocities of intact rock samples were measrued. Then, an artificial joint perpendicular to the measuring direction was created in each sample, and the wave velocity tests were repeated. These tests were continued up to 5 joints with two sets of 2 and 5 cm spacing. Consequently, the data were analyzed using the statistical methods. The results show that the P-wave velocity was decreased by increasing the number of joints in both spacing sets, and thus an inverse linear relationship was obtained. However, as the number of joints increases, the reduction rates of wave velocity were different at two spacing sets. More precisely, up to 3 joints, the reduction rate in the 5 cm spacing set was more than that in the other set. Nonetheles, after the third joint, the decreasing rate in the 2 cm spacing set became greater. Generally, the shorter spacing had a more reduction (attenuation) in the P-wave velocity. In this regard, at a total of 5 joints, the reduction rate of the P-wave velocity in 2 cm spacing set was more than that in the other set.
A Jamshidi; M.R Nikudel; M Khamehchiyan
Abstract
In cold regions, freeze-thaw cycles are one of the most important agents affecting on the mechanical properties of stones and consequently their durability. Uniaxial compressive strength, Brazilian tensile strength and P-Wave velocity are among important mechanical properties in assessing the durability ...
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In cold regions, freeze-thaw cycles are one of the most important agents affecting on the mechanical properties of stones and consequently their durability. Uniaxial compressive strength, Brazilian tensile strength and P-Wave velocity are among important mechanical properties in assessing the durability of the stones used in cold regions. As regards of determination these properties during the freeze-thaw cycles experiment is very time consuming and cumbersome, statistical relationships can be used to estimate the mechanical properties. In this study, a multivariate statistical model is presented for 15 samples of travertine, which can estimate uniaxial compressive strength, Brazilian tensile strength and P-Wave velocity in each cycle of the freeze-thaw experiment. In this model, mechanical properties after freeze-thaw cycles were considered to be the dependent variable that dependent on the variables of the initial mechanical properties, water absorption and the number of freeze-thaw cycle. The statistical tests results and also data from other researchers show that model presented is reasonably accurate in estimating uniaxial compressive strength, Brazilian tensile strength, P-Wave velocity and consequently their durability of the travertines in each cycle of the freeze-thaw experiment.
