The use of Flexible Tubular Elements of the Overhaul and Tunnels Reconstruction

The normal operation of the tunnels may not always be secured by renovations in current content. In some cases the factors affecting the condition of the tunnel construction (engineering-geological conditions, seismic effects, material and design of the lining, deviations in the construction process of the project, untimely repairs, etc.) can cause loss of stability and bearing capacity, increase deformation and lead to the need for premature overhaul, and in some cases even the reconstruction of the whole tunnel structure. The associated non-linear problems are related with geomechanical behavior of the rock mass, changes in the geometry of cavities and in some cases with developing surface contacts due to large strains.Many deep underground facilities were built in China, many of them went beyond the norms of the standard specifications of construction, in terms of the work execution scale and complexity. Places with high rocks pressure and the place of rocks faults occurrence, as a result of seismic activity, cause serious problems.The emergence of such defects requires immediate clarification of their causes and taking necessary action to eliminate them. As a rule, they cannot be eliminated by the track in the process of this repair, and require specialized construction organization for the production of major repairs or reconstruction of the tunnel structure.Tunnels must be designed to withstand static and dynamic loads. On the other hand, urban tunnels, which are located close to the surface of the earth in urban areas, may affect the behavior of existing structures such as buildings, roads and Railways. A specific feature of works on capital repair and reconstruction of tunnels is extremely tight up front and in most cases the inevitability of their conduct in terms of traffic and trains.