Evaluation Of Blasting Vibration Based On Disintegration Rate In PT Dahana At Ck Kjb Job Site, Lanuk Long Village, Sambaliung District, Berau, East Kalimantan Province

Abstract

This research was conducted in Nyapa West P2 PIT in PT Dahana CK GOC
Job Site, Berau, East Kalimantan. One of the excavation activities in the area of
research is the stripping of the overburden. This activity was preceded by dispersing
process using drilling and blasting method. One of the effect of the blasting activity
is the ground vibration.
Under the standard vibration levels refer to the criteria of SNI 7571: 2010
classified as class 2, with the blasting vibration frequency is in the range between
5.2 Hz to 12 Hz, then the Threshold Limit Value (TLV) of 5 mm/s. With the PPV
value of 5.26 mm/s - 14.87 mm/s at a distance of 200 m - 300 m declared unsafe to
the building nearby. While the value of PPV of 0.46 mm / s - 1.12 with a distance of
400 m - 750 m declared safe to the building nearby.
Calculation of PPV value approaching the actual PPV value using the
USBM equation, so it can be used to predict the future ground vibrations. The
results of the PPV according to the USBM equation that has a large enough range
of values is 4.90 mm/s using USBM equation and 0.46 mm/s for the actual data, it
caused by several factors that lead to that labour, ground vibration measurement
error and the distance measurement error.
Equation formula of the Peak Particle Velocity (PPV) relations with the Scale
Distance (SD) obtained from the ground vibration analysis measurement data is
PPV = 1331.9 (SD)-1.972 with R2 = 0.4931 and R = -0.702. R = -0.702 expressed
correlation of the equation that are negative and strong.
Ground vibration measurement results using Blastware application established the
constant disintegration value with the conviction level of 50 % that is disintegration
coefficient is -1.941 and rock factor 2.200,4, while the 90% confidence level that the
disintegration coefficient is -1.941 and rock factor 5.018, 4.
The tie-up plan evaluation with controlling the vibration level is at the
optimum level. Because of the tie-up resulted only few holes exploded
simultaneously.
Optimization of explosives according to a threshold limit value that has been
determined with the value of 3 mm/s, using the VS, SD, and PPV graph from the
Blastware application. With a distance of 300 m for explosives / delay that used 100
kg, while at a distance of 200 m used 44.44 Kg.