Numerical Simulation Analysis Of The Continuous Collapse Of Building Under Blast Loads

Numerical simulation has always been a significant method to analyze and reproduce the continuous collapse of buildings under blast loads. However, numerical simulation has been applying a static method to form an idealized blast incision and paying attention to the collapse of buildings only after the formation of blast incision. Whereas the real life situation is more complicated. This paper attempts to analyze the formation of incision under blast loading with a combination of actual constructive practice and further study the continuous collapse of the building that has formed the blast incision. The main contents of this paper are:1. Modeling the reinforced concrete structure with total nodes separate mode in ABAQUS and confirming the applicability of total nodes separate mode after comparing different models.2. Comparing the two methods of loading the blast loads with CONWEP and JWL and confirming the equivalent conversion formula to emulsion explosive when apply CONWEP in contact explosions emulsion explosive.3. Pointing out that the focus of numerical simulation of blasting demolition should be moved forward to the process of the formation of blast incision, in which way the spread and the attenuation of explosive stress wave within a frame structure can be reproduced; analyzing the actual incision of reinforced concrete column under blast loads; and comparing the state of blast incisions of three different actual constructive practice with standard explosive, increased explosive and decreased explosive respectively.4.. Comparing the damage distribution of reinforced concrete columns, under top & bottom decked charge structures and bottom decked charge structures,confirm that top & bottom decked charge structures can fully damaged columns,weaken the structural rigidity,conducive to the collapse of the structure.5.. Discovering the phenomenon of “closure of blast incision” in the analysis of continuous collapse of the building with the explosive loaded at the bottom of the supporting structure; and drawing to the conclusion that this phenomenon may lead to tilting without collapsing in blast demolition.