| The pre-stressed tunnel lining with unbounded circular anchored tendons is atiptop structure applying in pressure tunnel. Especially,it’s suitable for large insidehydraulic, poor surrounding rock tunnel engineering and because of the high pressurewater infiltrating surrounding rock leads to the slope instability of the tunnelengineering. Unbonded ring anchor form can reduce the loss of the the path stress inanchor rope, as a result, it can effectively reduce the thickness of concrete lining, thenumber of anchor rope and the anchor slot. In this way, it lowers the cost, and it has avery good application prospect in our country. However, because of this structure is anew type of structure, the applying of the structure has made little access, and itexposes many problems in use process, then it’s urgent to optimize this structure. Asfor these problems and the structural properties of the pre-stressed tunnel lining withunbounded circular anchored tendons in hydraulic high pressure tunnel, this paper putforward a structure optimization program about setting the strand on the outer surfaceof the lining and anchorage slot on the bottom of the lining, and analysis the basis andthe feasibility of the optimization. Based on above, analysis the pre-stress state beforeand after optimization using the finite element method. The results show that theoptimization program been put forward can reduce the amount of excavation of therock and the pouring of the concrete of the lining significantly, it can reduce theamount of the unbonded strand significantly. The circumference stress distributesmore uniform, and the range of the low stress reduces significantly at the same time ofthe pre-stress remain unchanged. It makes the backfill concrete of the anchorage slotmore compacting and enhances the reliability of the anchorage protection duringsetting the anchorage slot in the bottom of the lining.Through calculating the lining model with different lining thickness, diversenumber of anchor rope and different anchor groove spacing, this paper analyses theprestressing for the the key position of the inside lining, and finds the functionrelation between lining thickness, anchor rope number, anchor groove spacing andinner stress, axial stress, then it can provide the basis for the following theoreticalresearch. |
