Geometri Peledakan Dan Pengaruh Getarannya Terhadap Stabilitas Lereng Bendungan Bener, Kabupaten Purworejo

Abstract

Blast geometry is an important factor in blasting activities so that special studies are needed related to the appropriate blast geometry, especially the preparation of Spillway building area on the construction of the Bener Dam. Approach methods used to analyze slope geometry include Anderson's theory, R. L. Ash., and ICI-Explosive. As for the analysis of slope stability, observations were carried out using vibration meter applications and soil material data obtained from laboratory tests. Based on calculations, changes were made in several aspects, namely, burden 2.3 m, space 2.7 m, height level 5.4 m, sub drilling 0.6 m, powder coloumb 2.84 m, stemming 3.16 m. The proposed geometry resulted in a powder factor of 0.29 kg/m3 with an average fragmentation of 30.5 cm. From the results of observations in the field it is also known that there is a change in vibrational level from IV MMI to III - I MMI with a decreased noise and damage.Exception value that initially amounted to 0.66 m / s2 to 0.01 – 0.44 m / s2. The results of the slope stability analysis due to vibrations from blasting stated all slopes were above the safe number (>2.0), so all slopes were declared safe. The ruins that have occurred because there are remnants of chunks due to uneven fragmentation from previous blasts that are large so as to cause a slide on the slopes.