The Key Construction Technology Study On The Super-Small Clear Space And Super-Big Section Subway Station In The Layered Rock

With the social economic developed and the level of modern construction technology enhanced, the urban underground station construction technology is also constantly updating and progressing. Limited by the certain areas of specific geological and environmental, the construction of larger section and smaller the spacing is necessary to meet the functional requirements. So more and more larger section and closer tunnels appear, the record is also constantly refreshed. Then the study for small spacing tunnel large section need to be more widely and in depth, so as to ensure the tunnel technology has made rapid progress.Tunnel project is different from other civil engineering works. The unpredictability and complexity will be larger, and will face more construction risks. The possible losses may be greater, and therefore provide a safe construction environment is particularly important, which requires a more in-depth investigation in the early design and construction, and there should be more extensive research.Considering the differences of the tunnel design and construction of the difficulty with the existing tunnels, while the importance of the city’s subway stations.This paper summarizes the basis of the previous, made a comprehensive study of the deformation and failure mechanism of tunnel Stratified conditions, the middle rock pillars and unilateral drop bottom construction methods, as well as the power law key processes and parameters optimization studies, conducted a study on the impact of large wind Road. Combined with Lijia station of Chongqing6th line, targeted the Lijia station construction technical difficulties and emphasis, through theoretical analysis and numerical calculation and field measurement method, mainly studied from the following aspects:(1)、For the station in which the region’s in peculiar geological environment, studied on the horizontally layered, medium to thick layers like the surrounding rock the destruction characteristics and mechanical mechanism and analyzed the main factors.(2) Combined with the Lijia station site construction, established a method of a large section tunnel called the middle rock pillars and unilateral drop bottom construction method, and determined the feasibility,also researched in rock pillars of width, height parameters.(3) Compared the layered rock mass and continuous media under conditions of Neighborhood Tunnel force characteristics, and gave a clear distance and stagger distance of the design parameters.