Laboratory test method to determine modulus of elasticity of rocks
Answers
The laboratory tests have been used most frequently to determine Modulus of Elasticity of rocks. The intact core rock samples representing the region were tested to determine their Young's modulus in the laboratory using three different means. Compressometer, linear variable differential transformer (LVDT) and strain gauges type of instruments were used in this study. The axial compressive strain values of rock sample with compressometer apparatus were calculated by reading on the digital dial gauge indicator. On the other hand, to measure the axial strain of LVDT and strain gauge, there needs to be some experimental tools as LVDT, 120 ohm resistive unit strain gauges, the connection terminals,100 kN capacity load cell Testbox1001 8-channel data acquisition device (to turn the signals into meaningful results), and the software. Although, strain values obtained with compressometer and LVDT are not same as with strain gauge value, but it is observed that the elasticity modulus of the three methods were close to each other. These three methods can be used to find Young's modulus of rocks, but there are important details that need to be considered. All the methods are compared with each other and the actual behavior of the rock mass is predicted successfully.