In recent times Jamaica has experienced an increase in infrastructure and
mineral resource (bauxite) developments. As a result, quarrying activities
have also increased to supply the needed construction material. Blasting
has been the main technique for loosening insitu rock before transporting
to construction site. Consequently there is a growing concern of the
effects of blasting activities on the environment. These effects are
normally nuisances to the neighbouring residence as they come in the form
of: dust, toxic gases, noise, fly rocks and ground vibration. Of the set of
nuisances the one that is of most concern is ground vibrations which can
cause damage to structures. In most cases worldwide, after blasting
activities there are the usual complaints about damage to residence, which
is also a focus of the thesis.
There have been researches on the subject of ground vibrations to help
refute some of these complaints. The works of Lewis Oriard and Charles
Dowding are the foundation on which standards and regulations are built as
guides to assist blasters in the prevention of creating unnecessary
nuisances. Most countries have developed their own regulations with respect
to blasting and parameters are set according to the geological conditions.
This is of importance as the rock structures determine the transmission of
the peak particle velocity. However, most countries in the west adopt
standards similar to ones put forward by the United States Bureau of Mines
or The Office of Surface Mining. It is my opinion that a whole scale
adoption should not take place, as the criteria used may not be suitable
for other countries' geological conditions.
For this thesis the aim was to identify a vibration level that will not
cause damage to structures close to a quarry. Based on the literature
review it was revealed that there are a number of parameters that needed to
be considered. These ranges: construction material, age of structures,
distance from structures, geology of the location, type and quantities of
explosives and the blast design. There was also the review of standards to
building threshold with respect to the level of ground vibration.
The case study with its main focus on vibration levels at structures in
close proximity to the Bengal quarry revealed that a tolerable level can be
determined which will not result in any form of damage to the structures.
However, having established a PPV limit using the USBM and OSM standards
that appears reasonable there is the need ...
