THE CHANGES OF MECHANICAL PROPERTIES IN THE PYROCLASTIC BRECCIA WEATHERING, A CASE STUDY OF SOIL PROFILE IN BANJARMANGU AREA

Abstract

The weathering of pyroclastic rocks in the Banjarmangu area, specifically on Mount Pawinihan, indicates a change in rock material into soil on the surface, thus causing changes in soil mechanics values in the area. This study aims to determine changes in soil mechanics values in the area. The research method uses the British Standard method for heterogeneous materials, then tests several soil and rock mechanics values as the weathering level changes. The results obtained show differences in soil and rock mechanics
values with the weathering level. The specific gravity value tends to decrease from weathering zone 2 to 3 then remains relatively the same until weathering zone 6, the water content tends to increase from weathering zone 2 to 6, the unit weight tends to decrease from weathering zone 3 to 4 then remains stagnant until weathering zone 6, the liquid and plastic limits increase from weathering zone 4 to 6, Cohesion tends to decrease from weathering zone 2 to 4 then remains relatively the same until weathering zone 6, the internal friction angle decreases from weathering zone 2 to 4 then remains relatively the same until weathering zone 6, then the clay content increases from weathering zone 4 to 5 then decreases until weathering zone 6.