Research On Anti-breaking Structural Design Of The Highway Tunnel Across Active Fault Zones

The problem of faults are often encountered during the highway projects, the existing norms are based on the principle of avoidance provisions of nothing more than a general fracture of engineering activities and engineering to determine live two aspects such as fault avoidance; but as China's western development the implementation of the strategy, land resources development density, intensity and depth of the increasing number of projects, especially the process of tunnel construction will inevitably encounter the problem of active faults.Whether stick-slip fault or a sudden slow creep, would generate deformed fault, and the deformation of the space are three-dimensional deformation, both Tension, shear and twisting nature of the difference between the two is the size of the volume of fault creep.Accompanied by stick-slip earthquake fault movement, the larger fault deformation, Shear failure is often occurred because of the tunnel structure or deformation is too large, the impact of normal use. And fault creep movement is not accompanied by the slow movement of the earthquake occurred, the general in order to express the year slippage; Although fault creep dislocation in the volume of relatively small, but the tunnel project a relatively long useful life, in the life of the accumulated fault dislocation volume can not be ignored, we must consider the structure of the tunnel effect of shear failure. If this issue by relying on Galongla-tunnel project through the main fault slip rate of about 5mm per year, a hundred years the average dislocation of about 0.5m, so much the volume of the dislocation structure in the tunnel if the design does not attach importance to and taken into account, there will be serious threat to the safety of the tunnel structure.In this paper, the Ministry of Communications Science and Technology Project"the research of key technologies of Zhamu to Medog highway of the Bomi region in Tibet"through the anti-breaking measures study of the highway tunnel across active fault zones, Firstly, put forward "over-excavation", "articulated design" and "isolation of energy dissipation design" three design concepts, Secondly, with an emphasis on " articulated design " design philosophy and method of calculation have been studied, respectively, proposed the use of stratigraphic structure method and load structure method to determine the structure of lining segment length and inter-segment flexible connection method of calculating shear rigidity, and finally the use of three-dimensional finite difference numerical model testing on the " articulated design " anti-broken effects of measures to verify.In this paper, the innovation and work as follows:(1) Put forward design three design concepts for anti-breaking measures of the highway tunnel across active fault zones, namely "over-excavation design", " articulated design " and "isolation of energy dissipation design";(2) Put forward the methods caculating the lining segment length and the Shear rigidity of flexible inter-segment connections of "articulated design", with the load structure method.(3) Put forward the methods calculating the lining segment length and the length of flexible inter-segment connection of "articulated design", with the stratigraphic structure method.