Rock stethoscope to control mining accidents
A stethoscope-like instrument will soon be deployed in mines for predicting movement of rocks during excavation and minimise the risk of mining accidents.
Developed by IIT Kharagpur researchers, the “Instrumented Rock Bolt” can forecast vital information of rock movement before any unwanted accident occurs.
Field trials at Asansol coal mines of West Bengal have yielded positive results after which experiments would soon be done in the copper mines of Madhya Pradesh. “The instrument will collect data on the health of the rock just like a stethoscope. It will then be analysed using geocomputing technology. People who are excavating for mining or making a tunnel for a hydropower project will then know which rock is risky and to what extent,” Prof Debasis Deb of the department of mining engineering at IIT Kharagpur said.
A part of this project is funded by the Central Mine Planning and Design Institute (CMPDI), a subsidiary of Coal India Limited. IIT-Kgp and CMPDI have already filed a joint patent for the instrument. “We are getting good response but the technology needs further validation before it is released in the market for commercial use. We hope that the entire system will be ready in the next two years,” the scientist said.
IIT-Kgp researchers are also collaborating with fellows from the MIT who are currently employing the same methods for shale gas exploration. Underground mining is amongst the most dangerous professions as collapses often lead to casualties.
“Unlike metal, rock has a very complex structure with a lot of joints and fractures. To address these geomechanics and rock mechanics impediments we are using highly sophisticated numerical techniques in the computer software models,” Deb said.
The geonumerics lab at the IIT employs cutting-edge, highly sophisticated methods to simulate the actual conditions of excavation in a computing environment to arrive at the optimal solutions for the underground mine or tunnel.
According to researchers, a good blast can be carried out with high level of accuracy by simulating it using a computer model with Smoothed Particle Hydrodynamics (SPH) before the actual event occurs, thus saving cost and manpower.
The “extended Finite Element Method” model, on the other hand, will be able to suggest design, dimensions of excavations and support requirement of the proposed tunnel in highly joined rock mass with a high degree of accuracy.
Prof Deb and his team are also developing a model for detecting rock structure failures well before they actually happen in mines and tunnels and slopes using XFEM-based Digital Image Correlation (DIC) method.
“We want to achieve 100 per cent accuracy in our prediction model so that mining industry becomes a safe place to work in,” he said.