Measures could be adopted in the design are introduced in this article by calculating and analyzing the ellipse flat arch bridge from two engineering examples and comparing the differences between two hinged arch and hingeless arch in different rise-span ratio.

In order to analyze and compute a kind of special bridge structure-the two-hinged flat arch bridge with scarce 1/12 rise-to-span ratio,the space Perspex model for the global structure was established based on the similarity theory of the model test.

According to the principles of multi-point supporting strengthening flat arch bridge,based on the fabrication of two model arches and test of the model arches before and after strengthening,strain,deflection,crack control,failure mode,maximum bearing capacity and stress of supporting longitudinal bar before and after flat arch multi-point supporting strengthening were compared and analysed.

In this paper,some equal descriptions are obtained by the relative flatness concept for some special situations-under the conditions of A-flat, A-principally flat and condition (P A).

The Design of Soft X ray Broadband and Flat Multilayer;

For any integer r,where r>1,a sufficient condition for the finite R-determinacy(r-1)-flat function germs of two variables is given.

By using the natural isomorphisms of functors,we obtain some characterizations for a flat S-act.