Safe design of underground shaft lining to withstand repeated blasting impacts from a nearby opencast mine

摘要

A return airway shaft was being constructed under Adriyala Long-wall Project in Ramagundam Area-Ill of M/s Singareni Collieries Company Limited in Andhra Pradesh state of India. In its first phase of construction i.e. up to 325 m depth, CIMFR (Central Institute of Mining and Fuel Research) provided the technical guidance on shaft lining and re-enforcement design from safety standpoint. Below the depth of 325 m and up to 468 m, the efficacy of the shaft lining was further investigated keeping in view of the effect of repeated blasting at nearby opencast mine. The stress computed at the depth of 468 m was found to be well within the expected average of horizontal and vertical stresses acting at this depth.