Study On The Explosive Demolition And Numerical Simulation Of The Urban Viaduct

In recent years, with the method of explosive demolition has been successful applied in the demolition projects of urban viaduct, explosive demolition has become the preferred method for the demolition of urban viaduct for its security, economic, efficient and other advantages.However, the accident of explosive demolition happens from time to time due to the relevant theoretical research of explosive demolition lags behind, so it is urgent to study the related theory of explosive demolition of urban viaduct so as to meet the needs of engineering practice.Based on the previous studies on the relevant theories of explosive demolition, the using of numerical simulation research for explosive demolition of urban viaduct is discussed in this paper.First of all, the material model,the failure of the material,the contact pattern and the important parameters in solving the question and so on were studied when using the finite element software ANSYS/LS-DYNA to establish a separate model of common nodes.Secondly there has been established a separate model of common nodes of the pier of a certain urban viaduct,and then studied the pier’s collapsing process under different blasting height and analysed the causes from the unit stress, the study found that when the load at the top of the incision was certain, it was more prone to instability when the explosive height of the structure was greater;it also found that under the premise of instability or collapsing of pier, different explosive heights had different trajectories, and with the increase of explosive height of pier the collapsed movement of pier generally became more complex.Finally established the finite element models of simple- supported beam bridge and continuous beam bridge, and studied the falling process of superstructure under different explosive intervals between the front rows and back rows of piers, the study found that the value of the explosive intervals had a direct impact on the falling process and accumulation form and so on of the superstructure, so there should draw high attention to it.Through the above studies,it shows that separate model of common nodes can be used in the selection and majorization of explosive parameters and so on when there is a design ofstructure’s explosive demolition,this will play a role of breakthrough on the traditional explosive demolition engineerings which under imperfect theory of explosive demolition and excessive rely on experiences, and it will promote the improvements of the theories of explosive demolition to a certain extent.