RAIN INDUCED SLOPE FAILURE AND CORRECTIVE MEASURES IN AN OPENCAST COAL MINE IN CENTRAL INDIA - A CASE STUDY
This paper presents the investigation conducted in an opencast coal mine of Wardha Valley Coalfield in central India, where slope failure had occurred on the rise side slope. The failure involved soil and weak sandstone and partially disrupted the mining operations. The time between the first sign of tension crack and the actual failure was 39 days. The displacement velocity increased from 5cm/day to 30 cm/day during the last 8 days of failure. The cumulative rainfalls on the days of first sign of tension crack and the actual failure were recorded at 516 mm and 1076 mm respectively. The rock mass at this mine was predominantly weak with Bieniawski’s rock mass rating (RMR) varying between 25 and 40. Examination of failure zone revealed that ingress of rain water in soil benches and consequent build up of pore pressure triggered the failure. The cohesion of 20 - 45 KPa and an angle of internal friction of 21 - 24° for soil were obtained from the back analysis. The overall slope angles of 32 to 34° for soil strata and of 49° to 54° in rock strata were suggested. It was suggested that the workings be so oriented that they don’t strike parallel to the strike of the fault.
J.C.Jhanwar A.K.Chakraborty
Central institute of Mining and Fuel Research Regional Centre, 3rd Floor, MECL Complex, Seminary Hills, Nagpur - 440 006, India
国际会议
香港
英文
1-4
2009-05-19（万方平台首次上网日期，不代表论文的发表时间）