The currently available blast vibration attenuation equations (AEs) usually only accurate for one-location database. The site specific parameters usually changes when the geological condition and blasting pattern changes. This paper is aimed to study the influence of geological condition and blasting pattern upon the AE's parameters K and β. In order to achieve the research purpose, 8 blasting experiments were carried out. On each blasting experiment, a blast vibration device was set up on a rock surface and hooked up with a 120 m long coaxial cable consisting of a series of 8 geophones. The series of 8 geophones was positioned with respect to the geological condition and blasting pattern. The blasting revealed that the peak particle velocity (PPV) values were in the range of 0.0007 mm/s to 1.6175 mm/s. The frequencies corresponding to the PPV values varied from 4 Hz to 56 Hz, with dominant frequency in the range of 5 Hz to 10 Hz. The experiment suggest that the blast vibration which propagates deviating off the dip direction of the discontinuity plane at angle of less than 30° would be more affected by bench blasting direction as well as initiation sequence direction than the geological discontinuity characteristics. It was also confirmed that the K parameter was confirmed to be related to monitoring location toward bench blasting direction and diameter of blast-hole. Meanwhile, the β parameter was obviously more related to monitoring location toward initiation sequence direction and bench blasting direction rather than the transmitting medium condition.
Due to the fact that many mining operations become close to the community area, monitoring and controlled blasting in open pit mines have become paramount. It is therefore important to note that, the accuracy of AE in predicting the blast vibration is indeed a must, and there have been many AEs proposed by Duval-Fogelson (1962) [1]; Ambraseys-Hendron (1968) [2]; Langefors-Kihlstrom (1963) [3]; Gupta et al. (1988) [4]; Roy (1991) [5]; Bilgin et al. (1998) [6]; Hakan-Konuk (2008) [7] (see Table 1), etc.
The experimental study was carried out at the limestone quarry of PT. Indocement Tunggal Prakarsa (PTITP) located in Citeureup-Bogor, about 36 km South-East Jakarta, Indonesia and within the region of latitude –6°29'30'' to –6°31' and longitude 106°55' to 106°56'30'' (Figure 1). The quarry is composed of a series of limestone which has the highest elevation at 500 m above sea level and has many escarpments with dip around 60° to 70°. The thickness of bedding plane varies from 1.5 m to 7 m. Side hill quarrying method was applied in this limestone quarry. The lithology of PTITP consists of limestone, sandstone and claystone. Based on the rock properties test which were conducted in the Laboratory of Geomechanics and Mining Equipment of ITB, the UCS value, Young's Modulus, Poisson's ratio and Ultrasonic Velocity of limestone were in the range of 16.98 MPa to 45.5 MPa, 3.8 GPa to 10.1 GPa, 0.19 to 0.28 and 3033 m/sec to 4287 mm/sec, respectively.