A slope is to be driven through moderately weathered sandstone which is dipping at 30° at the direction of the drive. Us

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A Slope Is To Be Driven Through Moderately Weathered Sandstone Which Is Dipping At 30 At The Direction Of The Drive Us 1 (77.11 KiB) Viewed 28 times

A slope is to be driven through moderately weathered sandstone which is dipping at 30° at the direction of the drive. Use index testing and RQD values from question 2 and question 1 respectively. The joints were rough and moderately weathered with a separation of < 0.1 mm, are spaced at 250 mm. The joints had hard filling with about in 4mm thickness. Discontinuities possess typically a length of 2 m. Slope was observed to shed water at inflow rate of 10 litre/m and ratio of joint water press and major principal stress (o) was 0.08. Determine the rock mass rating based on RMR method developed by Bieniawski (1989). Provide comment on the rock quality.