The Research About The Mechanical Behavior Of Large Section And Small Interval Tunnel

In order to meet the growing demands of economic development andtransportation as well as to solve the outstanding issues of minimum s not flexibleexhibition line、large area、high because of the minimum spacing requirements inseparated tunnel, the construction number of three-lane or more-lanes large sectionand small neighborhood highway tunnel is growing. However, the low flat ratestructure of the large section tunnels with small spacing tunnel lead to constructionhard in two holes，there are many critical issues to be addressed in both the design andconstruction. In this paper, it study the mechanical behavior of a large neighborhoodtunnel，and discusses the reasonable value of minimum small spacing and middlepillar reinforcement type in two-way eight-lane tunnel.It summarize the basic characteristics of a large section with neighborhoodtunnel from large sections、small spacing and low flat rate; it explore the differencesbetween large section tunnels and two-lane small spacing neighborhood tunnel fromthe rock stability and tunnels Lining through numerical analysis.Based on rock pressure theory, it summed up the formula of vertical rockpressure and lateral pressuresmall in buried tunnel，and summarize rock pressure inshallow neighborhood tunnel when the cross hole is not excavated, but alsosummarize the formula of vertical rock pressure and lateral pressuresmall when thecross hole is excavated in shallow neighborhood tunnel.It discusses the value criterion of neighborhood tunnel minimum spacing. Basedon four-lane large section and small spacing as the background, the minimum spacingis optimized in the four-lane midas neighborhood the tunnel by the application ofnumerical calculation,and obtainl the minimum reasonable value spacing under thefour-lane neighborhood tunne in grade Ⅴ, Ⅳ, Ⅲ grade rock.According to the existing engineering practice and experience，it explore themiddle pillar reinforcement methods in large section with small space tunnel.Focuseon the middle pillar reinforcement type of grouting and prestressed anchor, andobtaine the middle pillar reinforcement program in a good quality and poor qualityrock conditions.Based on White Mountain tunnel as engineering examples, and conduct thedesign of tunnel lining and the middle pillar reinforcement pattern. Finally, it conduct the design of tunnel lining and middle pillar reinforcement type in the WhiteMountain.