| Tunnel engineering gets great development in the world, especialy in China. At the same time, more and more lining diseases have great impact on normal operation of the tunnel. Reinforcement corrosion is one of the main disease causes in reinforced concrete structures. If steel bar in lining occurs corrosion prematurely, the maintenance will not only cost plenty of manpower and material, but also affect the normal running of the tunnel. It may shorten the service life, and even bring the security problems for the running vehicles in tunnel. It has great significance for the health evaluation in tunnel to carry out the research on the influence of lining structure stability with concrete deterioration in different corrosion conditions. This paper stduies the reinforcement corrosion of lining with various means. Theoretical analysis, physical experiment and numerical simulation are included. Reinforcement corrosion can be converted to the degradation of mechanical properties of corresponding concrete. The influence rules of stress and displacement in lining structure are researched under the action of reinforcement corrosion. The influence degree of each factors on structure and the judgment of stability is concluded. The main research results are acquired as follows:(1)Through the experiment, the average depth of steel bar corrosion yearly in HCl solution, Na Cl solution and water is obtained.(2) Reinforcement corrosion of vault and straight wall increases the deformation of lining structure, but has little effect on the maximum stress. The stress of the elements of concrete deterioration decreases and their surrounding stress increases with spandrel and foot of the wall corrosion. The inside stress of lining changes obviously. The maximum stress and displacement of the structure enlarge gradually and the value of safety factor reduces gradually as corrosion aggravates.(3) For each position under the action of range corrosion, the increasing in axial direction has more influence on the stress of lining than circumferential direction. The displacement of surroungding rock remains unchanged basically and the stress is small change when each position occurs corrosion. The mild corrosion of lining has little effect on the stability of surroungding rock.(4) Foot of the wall is dangerous position that easily appeared problems after the lining occurs reinforcement corrosion, spandrel secondly and then straight wall. Corrosion degree is the most disadvantage in the three factors for the stability of lining structure.(5) Reinforcement corrosion rate can be obtained according to corrosion depth, corrosion degree, corrosion range of the main position on tunnel lining and tensile strength of concrete can be calculated. Then it can make the evaluation to the stability of tunnel structure in engineering. |
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