WEATHERING OF SOME SELECTED ROCK TYPES AND THEIR STRENGTH DEGRADATION OBTAINED FROM SCHMIDT HAMMER

PROCEEDINGS PIT IAGI RIAU 2006
The 35^th IAGI Annual Convention and Exhibition
Pekanbaru – Riau, 21 – 22 November 2006

WEATHERING OF SOME SELECTED ROCK TYPES AND THEIR STRENGTH DEGRADATION OBTAINED FROM SCHMIDT HAMMER

Imam A. Sadisun ¹, Andri S. Subandrio ¹, Asep Nurjamil ¹, Prihananto Setiadji ²

¹ Research Division on Applied Geology , Faculty of Earth Science and Mineral Technology,
Bandung Institute of Technology, Bandung.

² Department of Mineral Technology , Faculty of Engineering, Cendrawasih University, Papua

ABSTRACT

Weathering generally develops in irregular depth and intensity controlled by some very complex factors, whether from internal or external factors of the rock, such as climatic condition, topography/morphology, groundwater, and organism activity. Differences in result of weathering are almost gradual and often reflected by regular patterns in weathering profile. Due to similarity of weathering products, it is possible to establish a classification scheme and systematic description of weathered rock.

In this study, an effort was made to know some sequences of changes in different degree of weathering of selected rock types, which are andesite, diorite, limestone, claystone and tuff. In addition, the influence of weathering in weakening of the rocks was assessed based on the data obtained from a Schmidt hammer test. Site-specific classification schemes have been developed for each rock type. The correlations between weathering grade (WG) and Schmidt hammer value (SHV) have been derived. It is very clear that weathering will lead to a significant reduction in rock strength.

Keywords: rock, weathering, weathering grade, strength, Schmidt hammer