Masahisa SUZUKI

A study on strength of a cable crane steel tower

Eiji IWASAKI，Masatsugu NAGAI

A cable crane steel tower is a temporary structure used for construction. Since removal is required after bridge completion, as for a temporary structure, neither a design nor a safe management may be carried out enough. It is necessary for the plan of temporary structure, which needs to examine sufficient safety, and to be able to use it repeatedly.
The type using the diagonal member (cable), which can resist loads, such as a wind and an earthquake, and can stop displacement. However,I think that the effect as diagonal member is small. In analysis, conditions of load states and diagonal member, modeling of support, and modeling of horizontal member are studied.

The following results are obtained:
・Cross-sectional forces differ in near support, and a difference between pinupd and tixed support.
・The difference between truss model and equiralent beam model to horizontal member is small.Therefore truss model can replace to equiralent beam model.
・There is little influence by the diagonal member until stress is less than yield stress.
・The horizontal displacement at tower increases duastically over yield stress. And, as for the case without diagonal member, rigidity suddenly deteriorates.
・When there are diagonal member, a fall of rigidity can be relaxed and horizontal displacement can be made small.