Jacking Construction Techniques And Stability Analysis Of A Box Culvert Under Railway Overpass

The structure form of frame box culvert has been increasingly adopted to improve the traffic capacity level crossing and the security of people and vehicles when going across the path as many roads and railways have been unable to meet the rapidly increasing flow of people and traffic with the progress of urbanization.However,as the railway cannot stop in the operations and the box culvert structure generally cannot be cast by the construction practices,so it need to adopt higher technical methods to meet the need.It is more strict to adopt the key technology because of the effect of geological conditions and the limit of railway running in jacking construction of box culvert.However,it will produce different effects for the box culvert and embankment when the loads of excavating and the train passing the railway applied to the box culvert in the process of jacking construction.In order to get a better control of key technology in jacking construction and adequate understand of the effect of box culvert and embankment in jacking,it has important practical significance for the stability study of key technology in jacking and the box culvert in place.This paper analyzed and studied the key construction process and the stability of box culvert and the embankment when jacking in place with the example of a culvert under railway overpass jacking project and the numerical simulation analysis software.(1)Summarized the main construction methods and sequence as well as the consideration in jacking construction of the under railway overpass.(2)Analyzed the excavation,the production of slide and back,the prefabricated of box culvert,the reinforcement of railway and the sequence of jacking construction in jacking construction and summarized the notice in the concrete construction of each step with the engineering example.(3)The project adopted four-hole box culvert separate frame and simulate the stability situation of railway embankment under train load after every culvert jacking in place by the finite element analysis.(4)Analyzed the deformation and internal forces after the four-hole box culvert in place by the numerical simulation and determined the stability of box culvert in place.(5)Determined the maximum deformation position of the embankment and the maximum internal force position of the box culvert structure under the train road by the analysis of numerical simulation consequence and provided a reference for maintenance of the railway line and box culvert in future operation.