Phone call from a blast:
Hello Thomas I'm Giacomo and on 21 January, a large rockfall occurred about 3000 cubic meters and impact a farm nearst of Bolzano in South Tirol -IT.
On the cliffs in high above the farm was (in precarious balance) a large pillar of about 500-600 cubic meters.
On January 22, we carried out flight with helicopter to verify the situation with the geologists of the Geological Survey of Bolzano and we approved the demolition plan.
In terms of urgency we have obtained licenses for explosives in a single day.
The dimension of pillar was:height of about 14m; width 10.5m and thickness 3.5 m; the base of the pillar was compromised and therefore it was decided to break up it to avoid the fall of large volumes .
The day 23 was prepared the site at the top of pillar with scalig operation and at the same time the climbing company has started to develop holes for blasting. Since the instable volume was big we decide for small diameter holes (51mm) made with portable drilling machine and depth of 4 m .
The day 24 was performed the first blast which was conducted with a strong overdose of the explosive in order to compensate for the small drilling that in some points appeared deficient for obvious safety problems (to limit the vibrations). Around the zone was made a security fence guarded by about 50 volunteer firefighters groups of Termeno (BZ) of about 400 m from the blasting point; at he end of slope we have realize a rockfall earth dam for protection of a pylon of high voltage ( interrupted at the time of the blasting ) and the farm .
The demolition was then completed on January 27; after the first blasting we could get with more security at the bottom of pillar for load the last part of blast and explosion.
This is all...in next days will send to you some video of events
Thank you Giacomo
By - By Thomas
Giacomo (www.geologico.it)
Large scale video
Detail scale video
http://www.stol.it/Media/Videos/Intern/Tramin-Erste-Sprengungen-an-der-Grauner-Wand
Thomas