ABSTRACT
In the case of structures, which are inherently simple and geometrically symmetrical, invoking the principle of symmetry of the structure and symmetry and skew-symmetry of the applied loading can help achieve significant economies in the computational efforts required in their analyses. Any asymmetric loading can also be split up into its symmetric and skew-symmetric components so that, for each component, only half the structure need be analysed. Stress-resultants so obtained for the component loadings can then be algebraically combined to arrive at the values for the required asymmetric loading. In relation to cut-and-cover metro structures, such an approach can be particularly useful in the hand analysis of box structures, such as those forming the access corridors (i.e. Entrances) from the surface above to the main station structure below and the running tunnels. However, for the application of this approach, understanding of the methods of translational and cantilever moment distributions is essential. These methods are briefly discussed in the following section.
