Research On Blasting Demolition Of Reinforced Concrete High-rise Structure

With increasing of various forms of tall building in towns, demolition environment increasingly complex, which means collapsed space is less. Meanwhile, the theory of blasting demolition is far behind the engineering experience. So in order to better guide the engineering practice, in-depth study of theory and numerical simulation of blasting demolition of buildings is urgent need.Based on the analysis and discussion of blasting demolition theory, author establishes the common node separate model by using ANSYS/LS-DYNA software. Three blasting demolition of tall buildings are analyzed in the numerical simulation. And by comparing with the engineering practice, author comes to the conclusion that the numerical simulation method is feasible.When using directional blasting demolition of the building, different structural forms and different treatments of transfer hinge point forward method on rear column are analyzed for their impact of sat value, concluded that:(1)under the same aspect ratio, different structure forms of buildings causes the different effects of collapse and sat value. When selecting the parameters of the blasting cut, engineers need to consider the effects of structure for collapse effect.(2) after taking forward the hinge point of building, the different treatment of rear column take different effects on sat value:sat value is decreasing with the decreasing of the tensile strength of the back column F, and by improving the back column cutoff point’s location can eliminate sat value.In addition, by using simulation of different blasting delay and different blasting sequence on each incision of pure shear wall folding blasting demolition, author gets the conclusion that if priming time between each incision and detonating sequence could be planned reasonably, the collapse areas would be well controlled. And bidirectional folding blasting demolition method should not be used at the bottom of the detonation.