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Railway tunnel for the permanent building , in order to ensure the tunnel to meet the needs of long-term operation , the tunnel should do the lining , and , in the lining in the form of selection should consider the economic rationality . Monolayer lining the 1970s developed a new kind of tunnel support system , and compared with the composite lining , the most significant feature is canceled in the supporting layer waterproof board , full transfer shear between layers , its mechanical dynamic one . Currently, many countries , such as Norway, Germany , Finland , France , South Africa , Brazil , Japan , China and other countries using the single-layer lining do tunnel permanent support , can be seen , the single-layer lining both at home and abroad has been a wide range of applications , but needs further study the structural stress mechanism , waterproof lining surface flatness . The papers to the the mountain tunnel the monolayer lining construction process in field measurement -based study from the aspects of measurement theory , measurement planning and measurement information processing and its feedback . According to the site for a variety of measurement information , focusing clearance convergence displacement information , contact pressure , the concrete strain information for statistical analysis , combined with the finite element method in accordance with a variety of experience and the ultimate strain Standards , comprehensive feedback grasp mountain tunnel monolayer lining whole section NATM surrounding rock - Bracing System deformation and force changes in the law , determine reasonable support parameters and supporting opportunity to study the stability of the surrounding rock - Bracing System ensure construction safety based on the pursuit of engineering economy . The study showed that: the same degree of loading conditions , the internal forces generated by the single-layer lining than the composite lining to be small , it may be appropriate thinning the lining thickness , as well as reducing the amount of excavation and lining of masonry conservation investment ; canceled waterproof the board, instead of water resistance good waterproof concrete sprayed layer , easy to operate construction to ensure water quality, conducive to shorten the construction period . So , in-depth study of the single-layer lining not only has a high theoretical value , and create huge economic benefits in engineering practice .
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