Study On Mechanical Behavior Of The Medium Partition In Double-Arch Tunnel

Double-arched tunnel, Is to the rock between the two tunnels replaced byconcrete,Or adjacent the two tunnel walls into a whole form a structure of Doublearch wall Connected.With the advantages of whole lines smooth, efficient use ofspace, avoid a lot of digging fill, beneficial to shorten the time and so on,favorableapplication by engineering.Multi-arch tunnel span ratio is large, construction process is various, the multipledisturbance of surrounding rock, the middle wall bear pressure, tensile, bending,torsion, shear stress And the stability of middle wall concerns the multi-arch tunnelsecurity as a whole. Therefore, the In-depth analysis and simulation study of Influenceof middle wall stress factors and mechanical characteristics, it is of great significancefor the design of multi-arch tunnel and construction.This paper based on carpenter tunnel engineering, According to the actualexcavation process in numerical simulation by finite element software, forcomparative and analysis of monitoring results through the construction site,thenconduct three-dimensional finite element analysis for Multi-arch tunnel middle wallmechanics in construction process,in the situation of different pattern of the wall anddifferent construction methods.Main research contents including:(1) Comparison of the actual engineering field monitoring data and the resultsof numerical simulation,Set up three-dimensional finite element model based on carpenter tunnel projectsummary and the site formation situation of the tunnel, analyzed the model by takingthe same construction method as the actual excavation process.Contrast theconvergence deformation of the goals section and results for ground surfacesettlement with the monitoring data in actual site. analysis of the feasibility andcredibility of numerical analysis.(2) Research on the influence of the displacement and stress in the situation ofusing different construction methods of middle wall.Adopted two kinds of the three pilot tunnel method and whole section driftmethod in construction, research on the mechanical characteristics of curved wallstructure, compared the merits of the two methods of construction and applicable condition, as to provide theoretical basis for cross-section design of middle wall drift.（3）Research on the impact of displacement and stress on middle wall usingdifferent type of middle wall.Using two sections of straight middle wall and twist middle wall, compare themerits and cons of two kinds of section form and the suitable conditions, providestheory basis for the design of multi-arch tunnel middle wall cross-section.（4）Adjust the excavation method of wall of three pilot tunnel for furtheroptimization for twist middle wall stress.Through comparison of four kinds of model，slect the excavation method of threepilot tunnel. adopt backfill in a timely on one side of the wall, analysis of mechanicalbehavior of the wall, To further optimize the construction process.