If the structure reliability of the existing arch-bridges is analyzed and its current and future reliability level on bearing capacity is presented, it will profit the highway development and administration department in making an economic and reasonable decision on the maintenance of the arch-bridges.

Theoretical analyses of the strength of overlying voids of geomembrane, used as anti seepage materials covered by soil in the embankment dam, are carried out based on membrane theory and arch action of soil.

Which is based on arching action and catenary action in RC continuous beam and slab members,illustrates that RC frame beam has higher flexural and shear capacities than those that are predicted according to normal design, and demonstrates that RC frame beam has the inherent ability to overload,and form a new effective path to transmit loads to put the purpose to resist collapse into effect.