Study On Blasting Seismic Response Of Cable-stayed Bridge And The Effect Of Pile-soil

The dynamical response of structures under the blasting seismic wave is a very complicated question. It's not only relate to the blasting strength, distant form the blasting center, but also associate to the communication media, the self-dynamic characteristics of structures. Because of the factors upon, it's difficult to simulate by numerical methods, At present, observer through the experiment is the most useful way to study it. The studies on this question are very finite, so the recearch is very rough whatever from the depth or span. But by the widely used of blasting in the transportation construction, the depth research on the dynamical response of the bridges under the blasting seismic wave is more and more necessary.In this paper, put the cable-stayed bridge as the research object, carry out a research aim on the blasting seismic response of cable-stayed bridge. Take into account the close relationship among the pile,soil and bridge structure, establish three different models, combine with dynamic analysis method, respectively use the response spectrum and time history analysis methods to study on the blasting seismic response of cable-stayed bridge, then summary and analysis the failure modes of the cable-stayed bridge under earthquake, give out the way to control the disaster, the main content is listed below:1. Abbreviate describe the elementary knowledge about the blasting seismic wave and its formation, kinds, basic characteristic, the regularity of the spread, as well as the factors of influence. Then introduced the basic theory of structural dynamic response, given the basic formulas and calculation methods of single degree of freedom system and multi-degree of freedom, analyse the structural response of blasting vibration method, and focuses on the response spectrum and time history analysis of the basic theory.2. The the research status of soil-piles-structure interaction and he current common method of pile-soil modeling is introduced, after it the theory on the basis of these modeling approaches is practiced.3. Establish three different models by the software which named midas, perform the self-oscillation characteristic analysis of cable-stayed bridge in three different models. Point out the effect by the pile-soil interaction can not be ignored. 4. Cooperate with the Response spectrum analysis method and the mode superposition method which named CQC, discuss the differences and similarities on the displacement and the internal force under the 4 kinds of blasting vibration response spectrum, then compare with the model with out the pile, find out the rule of the pile-soil interaction.5. Do the time history analysis by the time history curves, compare and conclusion between the results of response spectrum analysis and time history analysis.6. Summary and analysis the failure modes of the cable-stayed bridge under earthquake, the ways and means of how to control the disaster of blasting vibration are brought.