Date of Graduation
The concept of using explosives to demolish buildings and structures revolutionized the methods to eliminate the unsafe and unwanted structures efficiently and with minimum danger. The idea of demolishing buildings was introduced by CDI (Controlled Demolition Inc., Phoenix, Maryland) during the late 1960s, and the technique has become very popular ever since with numerous blasting agencies and construction companies opting to use explosives over conventional methods of demolition. Though the technique has been used for about a couple of decades, there has not been a unified theory developed to determine the quantity and type of explosive needed to demolish a structure without overusing the explosive. The method is still used based mostly on practical experience and some empirical relationships particular to a certain type of explosive. Thus, there is a need to come up with a method to clearly understand if the explosive charge would develop sufficient stresses in the system to dismantle it prior to attempting the real demolition of the structure. This study focus on determining the stresses developed in a concrete column subjected to an internal explosive pressure. The plain concrete was used for static analysis, and both the plain concrete and the reinforced concrete were used for dynamic analysis. Finite element analysis code ANSYS 5.0 is used to evaluate the stress and strain distributions in the system. For dynamic analysis, the ANSYS program uses the Newmark time integration method to solve the equation of motion. Failure criteria are then employed to determine the failure of the system for the theory development to provide the better blasting design for the demolition.
Ro, Yong-Suk, "Stress distribution and failure mechanism of reinforced concrete column subjected to internal explosive charge." (1995). Graduate Theses, Dissertations, and Problem Reports. 9652.