The writers have analyzed completely the strength and stability calculation methods of eccentric compression bars with dual-angle steel combined section which are often used in boiler structural design, deduced the expressive formula calculating the allowable load designed value of bars with the dual-angle steel combined section.

To analyze the tower top longitudinal anti-push rigidity and allowable displacement of a suspension bridge while its superstructure was being constructed, the finite element spatial models of 3 kinds of different elements for the bridge tower are established, using the general finite element program ANSYS.

Through discussing on allowable micro-displacement of fixed supports, this paper probes into the possibility of lowering construction cost and reducing construction difficulty by means of downsizing fixed supports and according to the concrete conditions of the engineering in actual engineering design.

The application of the standard under some special conditions is discussed in the aspects of operational mode and the allowable value calculation,and suggestions to test operators on practical usage of .

With the rapid development of economic construction in China, super long tunnels are becoming more and more, up to now there is no specification about the allowable value of lateral breakthrough error for super long tunnel from 20 to 50 kilometers.