Original scientific paper
ALLOWED QUANTITY OF EXPLOSIVE CHARGE DEPENDING ON RELATIVE SEISMIC SENSITIVITY OF ROCK MASS
Josip Mesec
Abstract
During the last decade and more, seismic observations during blasting were carried out, particularly when blasting, near sensitive, i.e. endangered structures have been executed. Permitted oscillation speeds of ground and rock mass particles for certain structures are not standardized by Croatian regulations; therefore, international standards DIN, USBM, etc., are used in practice.
This paper analyses research conducted during testing, special, shallow or massive blasting in sediment rock deposits, mainly limestone and dolomite, whenever such blasting featured the determination of oscillation speed dependence on reduced explosive quantities. Such dependences, along with the use of DIN 4150 standard and results of engineering and geological research, led to determined allowed explosive quantity according to ignition degree for any given distance of endangered object from the blast fi eld and to corresponding relative seismic sensitivity of rock in question. Also determined is the dependence of relative damping of seismic oscillations on the geological strength index.
The results found in this paper have a particular bearing when used with planning open pits where the cliff rock mass is gained by blasting, and with planning basic blast parameters for special, i.e. sensitive blasting in urban areas.
Keywords
blasting; blast vibrations; allowed quantity of explosive charge
Hrčak ID:
7402
URI
Publication date:
4.12.2005.
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