TITLE:
Effects of Rock Mass Conditions and Blasting Standard on Fragmentation Size at Limestone Quarries
AUTHORS:
Takashi Sasaoka, Yoshiaki Takahashi, Wahyudi Sugeng, Akihiro Hamanaka, Hideki Shimada, Kikuo Matsui, Shiro Kubota
KEYWORDS:
Fragmentation, Borehole Camera, Mechanical Properties of Rock Mass, Crack Density, Blasting Standard
JOURNAL NAME:
Open Journal of Geology,
Vol.5 No.5,
May
18,
2015
ABSTRACT: The size distribution of
fragmented rocks depends on not only the blasting standard but also the
mechanical properties, joint system and crack density of rock mass. As,
especially, the cracks in the rock mass are heavily developed at the limestone
quarries in Japan, the joints and/or cracks in the rock mass have big impacts
on the blasting effects such as the size of fragmented rocks. Therefore, if the
joint system and/or crack density in the rock mass can be known and evaluated
in quantity, the blasting operation can be done more effectively, efficiency
and safety. However, the guideline for designing the appropriate blasting
standard based on the rock mass condition such as mechanical properties, joint
system and/or distribution of cracks, discontinuities, from the scientific
point of view, has not been developed yet. Therefore, a series of blasting
tests had been conducted in different mines and faces, geological conditions
and blasting standards in order to know the impacts of each factor on the
blasting effects. This paper summarizes the results of blasting tests and
describes the impacts of rock mass conditions and blasting standard on the size
of fragmented rocks.