Research On The Interaction Between Surrounding Rock And Support Of Insightful Ribwork Arch Tunnels

Insightful ribwork arch Tunnels (In this paper is Longpu tunnel) originates in our country tunnel history. The total length is 80 meters, that is shallow buried and half-open and half-hidden structure tunnel is an optimum pattern. Because of half-open and half-hidden particularity structure tunnel. Its tunnel excavation is carries on the half-hidden tunnel on the shallow surface layer. Its tunnel adjacent formation distortion and the destruction mainly concentrate in the tunnel face and above the rock mass. In this tunnel construction process, Both consider the tunnel adjacent formation's stability and note the tunnel in the mountain massif whole stability. This paper unifies Longpu tunnel of Anhui province, uses research tool which the geological condition research and the numerical simulation analysis unifies, it has carried on the new structure of Insightful ribwork arch Tunnels which research on rock mass structural feature, the distortion destruction pattern, the distortion monitor analysis and the crustal stress release's rate.①According to side slope distortion sign, And unifies the slope monitoring data to know, Side slope distortion reason mainly for terrain landform, rock mass structure, rainfall, tunnel excavation footage, construction demolition and so on five aspects.②According to the scene geology investigation and study analysis we obtains tunnel's distortion pattern mainly to have two kinds, falls the distortion along the level landslide.③Through parameter inversion, In the nature Condition the stability coefficient is 1.15, Under factor influences as demolition, rainfall the stability coefficient is 1.04, that is at the limiting equilibrium condition. In earthquake condition the stability coefficient is 0.99, it extremely possibly produce whole instability.④Through distortion monitor analysis, Longpu Tunnel is shallow buried tunnel underunsymmetrical pressure. The slope distorts besides excavates the discharge to cause part ofdisplacements, also has the itself rock mass structural plane control influence. Its distortion's rule isextends from outside to inside. Looked from the monitor data, The tunnel slope body displacement mainly controls the development by the control structural plane. Pipe shed support depth is 15 meters, but slope distortion depth is 9 meters, Also shows pipe shed depth is enough. pipe shed support play the control reinforcement role to the slope body overall stability.⑤The scene geological investigation and the monitor drill hole data indicated, that have a group grow control structural plane Favors the slope in the tunnel. in tunnel excavation process, Confirmed displacement's sudden change is because the control structural plane opens creates, Through excavates footage and the displacement percentage relations, we estimate the displacement value which its control structural plane opens.⑥According to the hypothesis of highway tunnel design standard, I use Classical Coulomb Earth pressure formula Inferential this new structure of insightful ribwork arch Tunnels of lining support Computational method.⑦Through numerical simulation, we have obtain rule, Looking from the surrounding rock aspect, after tunnel excavation, Nearby its first control weak structural plane presents the tensile stress in the tunnel adjacent formation to be centralized. But presents the compressed stress in the skewback position to be centralized. In support structure, Is approaching the first control weak structural plane nearby structure inside, Presents the compressed stress to be centralized. But is approaching the first control weak structural plane the structure flank, presents the tensile stress to be centralized . Through build a objective function again. The test point displacement result of numerical simulation and the revision actual test point displacement result have carried on the contrast. Determined the best rate of crustal stress relieving of Longpu tunnel is between 60%~70%.⑧According to close this real rate of crustal stress relieving, analysis the distortion shape and mechanics characteristic of the surrounding rock-supporting structure.