Mechanism Research On Blasting Damage And Fracture Of Bedded Composite Rock And Its Engineering Application

The blasting damage and fracture process of rock is complicated dynamic evolvement process. Owing to inborn high temperature and high pressure gas after blasting and complexity of dynamic principal relationship and interact ional complexity between dynamite and rock and non-equal character and anisotropies of rock, the rock blasting mechanism research is quite complex. The damage and fracture of blasting on rock include two phases of blasting stress wave and denotation vapor. Based on the existing research results and up to the minute theory of rock damage and fracture mechanics, the blasting damage and fracture mechanism of rock and bedded composite rock is studied. Mainly results as follow:(1) Based on fracture mechanics and damage mechanics theory, the mechanism of rock damage and fracture has been analyzed and the rock damage and fracture rules have been put forwarded. Based on damage and destroy theory of bedded composite rock, damage principal equation and damage and fracture rules of bedded composite rock have been founded. (2) Based on the existing damage model of rock blasting and the theory of rock damage and fracture, a new damage model for rock blasting has been founded.(3) The blasting stress wave reflects and transmission rules of blasting stress wave have been found. Based on rules and damage principal equation of rock, damage principal equation of bedded composite rock has been built. The conclusions of rock damage produced by blasting stress wave and denotation vapor have been educed.(4) By use of dynamic strain testing, the ultrasonic wave, bedded composite rock damage and fracture mechanisms and the fragmentation process during blasting have been experimentally studied. Blasting stress wave of bedded composite rock spread rules and rock damage situations are studied. The inflection of manner and structure of detonation of pre-splitting and step blasting on blasting effect have been studied. (5) Based on the structure of DYNA-2D program in which rock and bedded composite rock blasting damage principal model was embedded, number simulation of the rock blasting process is realized, which proves built model accurate and reasonable 。 (6) The research results were used in cutting slope blasting excavating engineering, which makes blasting design project optimize and improve economy, social and safe benefits.