Study On Influence Of Train Vibration On Tunnel Tructure And The Airport Runway Lying Above

Along with economic development and the growing demand of infrastructure, thenew and expanded traffic civil large engineering projects are increasing. At the sametime, engineering construction meet more and more problem. It is a complicatedengineering problem, that there is railway tunnel through below the expansion airport inexisting. There is a mesh of circumstance that two constructions influence each other, inthe expansion of Chongqing Jiangbei Airport and the construction of Jiangbei airporttunnel of Chongqing inter-city railway. And the geological condition is complex: thereare two big gulfs in the original terrain and there will form a high fill subgrade after theconstruction of airport runway. So there are problems how to develop the constructionscheme early in the project and whether the two engineering still have influences oneach other after the project.As a part of engineering research project "The key techniques research on nearconstruction of high fill subgrade airport runway and the tunnel below". In this paper,the main research is the vibration characteristics of the tunnel and the influence of therunway in the train loads. Main job in the research:①Summarized the related problems on the tunnel under the runway at home andabroad, the research status of tunnel train vibration and the development status ofsimulation of train vibration load.②Discussed the underground structure static-dynamic analysis method used in thispaper. Described the forming process of the concept, the simulation process of staticexcavation, the form and solve process of balance equation and the treatment ofdynamic artificial boundary related to this analysis method in detail.③Summarized the theory and method of determining the train loads. Discussed themethod of simulate the train model and the vibration loads, the inverse analysis andcalculation theory of the train loads and the processing method of field measurementdata in this inverse analysis method. On the basis of that identified the final train load inthis paper.④Have made the dynamic calculation finite element model of tunnel, analyzed theinfluence of the train loads on the tunnel structure in high fill. Research shows that: inthe same form of the structure, the increase of buried depth, the principal stresscorresponding increase and the vertical displacement gradually decreased; the influence on lining structure of single hole double tunnel is smaller under the train loads thansingle hole tunnel; the influence of the train vibration load on the arch tunnel up isrelatively large.⑤Searched the train vibration load on top of the airport runway operation effect.Research shows that: the influence of train vibration on the airport runway is small andwill not affect the normal operation of the runway.This paper according to the results, recommend the buried depth of tunnel appropriatefor20m to25m or so and using a the single hole double section form.