Equivalent Static Analysis Considering the Accidental Case During the Launching of Precast Bridge Segments

Akash Parashar and Hariom Khungar

The designer’s general approach is to design structure for the load which was applied statically on the structure and ignored the dynamic effects of it. Various analysis and design software used, also perform the static analysis and to incorporate the dynamic effects impact factors were multiplied. These impact factors vary on many parameters and if it is generalized to a fixed number for all the possible case, then this would not seem to be a good approximation. The aim was to check whether a multiplicative constant could be arrived at, which could have multiplied to the results of static analysis to get the dynamic effects. Cable-stayed bridge in its various construction stages was modelled and applied with a step function to simulate a condition of accidental removal of the segment during launching. Ratio of the reaction and moments for the dynamic load and static load was found out respectively and aimed to verify that “AI” [1] factor for dynamic effect due to accidental release or sudden application of an otherwise static load to the dead load should be taken as 100 % of the load is correct or not.

Volume 11 | 06-Special Issue

Pages: 218-223