Simulation Of Collapse Process Of Blasting Demolition Of Towering Building And Tall Building

Controlled blasting technology has been applied widely in demolition of the towering buildings and tall buildings' in recent years. However, the conventional blasting design method which based on the experiential formulation can't meet the precision and safety need in practical projects.In accordance with steel reinforced concrete (RC) chimney's structural characteristic, a mechanic model to analyze stress distribution of the section of the RC chimney's blasting cut during the collapse process of the chimney is proposed in this thesis. With this model, the stress distribution and the breakage process on the section blasting cut could be determined if the obliquity of the inclining chimney is not very large, and so some guidance for the design of blasting cut could be provided.The RC chimney's folded falling process was simplified as the kinematic model of hinge jointed pole's movement in accordance with the folded blasting demolition of RC chimney and the program to solve the equations was complied to simulate the collapse process of the chimney. Theoretic analysis and numerical simulation show that the position of the top blasting cut and the delay time of priming are the most important factor that directly related to the whole project's success. Calculation result shows that only when l₁ /l₂ > 1, the delay time of priming meets the need of kinematics and the topsegment chimney don't recoil when the delay time of priming is not very long, the RC chimney will have good folded falling process. With the model and methods proposed a RC chimney's folded blasting project is studied in the thesis which belonged to the Yangluo fertilizer factory in Wuhan, and the calculation result is coincide well with the actual condition.A combined method of applying FEM and rigid multi-body dynamics simulation system to simulate blasting demolition of frame structure is put forward in the thesis. Firstly, the process of the loss of stability of frame structure is analyzed with FEM, secondly, the collapsed structure is simplified as a rigid multi-body dynamics model, and then model is solved by the rigid multi-body simulation software. So the process of the loss of stability, the collapse process and the collapse range, and this is helpful to improve the accuracy and reliability of the demolition design during demolition could all be determined with the method proposed. With the method proposed, a practical frame structure's demolition process was simulated and a good result is obtained.