Numerical Simulation On Blasting Demolition Of Frame Structure With The Separate Model

At present, blasting demolition is one of the main methods used for demolishing buildings. Due to the increasingly complex environment of blasting, experiment-based design of blasting cannot fulfill the need of currently development. Thus, improvement on theoretical study for blasting demolition of buildings is imperative.The demolishing of an11-story reinforced concrete frame structure building which adopts the total nodes separate finite element is analyzed by the ANSYS/LS-DYNA software. First, numerical model is found to agree with the practical situation after the comparison of the pediment and recoil distance from numerical simulation with those from the in-situ measurements. Second, analysis on the exploration of stress-time curves of steel and concrete element has discovered that the total nodes separate model can reflect the differences mechanical properties differences between these two materials. Third, research on the relationship among the pediment distance, degree of fragmentation from the rock pile after the buildings collapsed and blasting cut height has been conducted by changing the height of building blasting cut base on the original model.In addition, modeling of the demolition for a14-story reinforced concrete frame structure with the same numerical simulation method has also been conducted. Four different conditions of blasting cut each segment delay interval are simulated. It is found that the delay interval affects the pediment and recoil distance through the analysis on the scope and height of the rock pile.The results show that the separate model based-numerical simulation method is credible, results from the numerical simulation can be used as the scientific basis for programming pre-established of blasting demolition. The result base on the height of building blasting cut and delay interval has guiding significance for practical engineering.