ABSTRACT

Rippability is related to ease of breaking or ripping of a rock, that are easy to rip, hard to rip and even extremely hard to rip and need for blasting. Excavation work is one of the most common on mining. Before commencing excavation, decisions have to be made on the excavation method to be applied. Material factors affecting rippability are rock type, strength, abrasiveness, degree of weatherinig, rock structure, material density, rock fabric, seismic velocity , topography, bedding plane and boundary of weathered rock.

The study was conducted by taking some sandstones, it is the most dominant stone on pit Pinang and pit North. After getting the value of compressive strength test, the calculated values to seismic wave velocity, the writer gives ratings based on rippability of each pit. The value of compressive strength test on pit Pinang is 79,12 MPa and seismic wave velocity is 2548 m/s, and the value of compressive strength test on pit North is 53,07 MPa and seismic wave velocity is 2329 m/s. Given the results, the rippability assessment of both pit are hard to rip and need for blasting.

Given the results, the rippability assessment by Atkinson Method, Bailey, and Church are hard to rip and need for blasting of both pit Pinang and pit North. Whilst, the mining area were near by citizens’ house, and it is hard to accomplise for blasting near the area, then writer gave a ripper recommendation on pit Pinang by using D11R, and on pit North by using D10R

Keywords:Rippability, Compressive strength test, Seismic wave velocity