The Numerical Simulation Analytical On The Construction Method For The Neighborhood Highway Tunnel With Large Span

The neighborhood highway tunnel with is a tunnel structure which interposes between the separable tunnels and multi-arch tunnels. Such tunnel structures are less complicated than multi-arch tunnel technology, easier to be dealt with water-proof technology and limit the construction expenses as well. Owning to two-hole spacing is smaller and the interaction between two tunnels is fairly serious. Thus, there are still several key problems needed to be solved during the design and construction procedure. Taking the practical engineering as example, this thesis is devoted to mechanics theoretical and the calculation methods of the elastic-plastic theory of the neighborhood highway tunnel with large span. The numerical simulation analytical on the construction method for the neighborhood highway tunnel with large span is analyzed as well. This is achieved to supply basis and supervise for design and construction of the neighborhood highway tunnel with large span.The main contents are follows:1. Based on comparing the various constitutive model of the geotechnical, the expression of matrix for the finite element method for elastic-plastic incremental constitutive is deduced by combining the intensity characteristics and constitutive relation of geotechnical materials.2.The basic characteristics of tunnels with large span and small spacing is obtained by analyzing the causes of the. In accordance with the practical engineering, compared the basic construction methods and auxiliary construction method of tunnels with large span and small spacing.3.Relying on engineering practice, the plane elastic-plastic finite element model of Yan Gang tunnel is established by using elastic-plastic theory and the basic principles of finite element method. Simulating the mechanical behavior of CRD method and the construction to double sidewall drift method for the neighborhood highway tunnel with large span by using finite element method. Drawing related conclusions by analysis of the situation of two methods every step of the excavation process of the stress, displacement and internal force. Through detailed analysis, each step in the excavation of the stress, displacement and internal force conditions is obtained. Providing a theoretical basis for design and construction of the neighborhood highway tunnel with large span.