Study On The Scheme Of Nanan District People’s Hospital Of Pedestrian Underpass Wear The Rail Viaduct

City Road, rail transportation, transportation hub station construction had speed up the process of urbanization, increased the city’s "person car conflict". To solve this contradiction, we must build a safe, convenient, economic stereo crossing facilities, and in harmony with the environment of the.Stereo crossing facilities including pedestrian overpass and pedestrian underpass which has the advantage be richly endowed by nature in the limited city land and with the surrounding landscapecoordination.In the pedestrian underpass planning and construction process, the conflict with the adjacent buildings will inevitably, in such a complex environment,how to make the effects that pedestrian underpass with adjacent buildings in the scope of required in engineering specifications,so as to ensure the safety of pedestrian underpass and adjacent building.In the pedestrian underpass construction process,the following aspects need to be considered: ① super dig and owe dig in the underpass excavation; ② the effect of stability on the adjacent buildings in the excavation;③ surface settlement problem.In C hongqing, with the rapid development of rail transportation, underground walkways wear track viaduct will be more and more. So, in the design of underground pedestrian passage, not only to consider the feasibility andsafety of underground pedestrian passage, but also consider the impact of the stability in the construction process of rail transit viaduct, but from the present research situation,underground walkways wear track viaduct process engineering relatively few, So the calculation theory in this area is still relatively lack, not mature enough. This paper takes the pedestrian passage of Nan’an District People’s Hospital of C hongqing City wear the rail transit viaduct of No. three line process as the research object,discussing the affect of the stability of viaduct for pedestrian passage in different horizontal distance, buried depth and with different excavation methods.This paper focuses on the effect of underground pedestrian passage in different horizontal distance, depth of wear track on viaduct bridge stability, combined with the practical engineering, analysis of two-dimensional numerical simulation by finite element method, and using the field monitoring measurement technology observation track elevated top pier column displacement as a check to two-dimensional finite element analysis results, and analyze the cause of the error.At the same time, select a reasonable level of distance and rational burying depth,using the drilling blasting method for 3D finite element numerical simulation of excavation, judging the influence of blasting excavation to the stability of rail transit viaduct through numericalanalysis results,so as to reduce project duration and cost.By means of the research on mechanics behavior of Nan’an District of Chongqing C ity People’s Hospital underpass beneath the rail transit line three, this paper gets the general rules of the effects of to the stability of the rail viaduct in the process of different levels distance, depth and different excavation methods of underground passage wear the viaduct in orbit:①The reasonable horizontal distance is 1.05 times or 2.13 times the span when the the underground passage is in 1 times the depth;The reasonable horizontal distance is 1.2 times or 1.9 times the span span when the the underground passage is in 1.5 times the depth;The reasonable horizontal distance is 1.77 times the span when the the underground passage is in 2 times the depth.② The reasonable depth is 0.6 times or 2.81 times the depth of the buried depth when the underground passage is in 1 times of span;The reasonable depth is 1.62 times or 5.84 times the depth of the buried depth when the underground passage is in 1.5 times of span;The reasonable depth is 26.85 times or 1.21 times the depth of the buried depth when the underground passage is in 2 times of span.③The use of pre splitting blasting excavation will not affect the safety and stability of the structure of railway pier when the underground passage is in 1 times of span and 2.5 times of depth.④ Gave a brief analysis of the cause of the error between the monitoring andmeasuring results and the finite element numerical simulation analysis results,at the same time also fully validated the reliability of finite element numerical simulation analysis.