Based on the summary of the others researches,the applied calculation methods of the lateral stability of catenary single rib hingeless arch that carried the vertical loadings were analyzed.

A parameterized practical calculation method is proposed to investigate the lateral stability of a parabolic doublerib arch under nondirectional loads.

However,the weakness in lateral stability of arch ribs with.

Meanwhile,not only the webs are likely to have local buckling,but also the compressed flanges are likely to have lateral buckling in the region of negative bending moments.

Based on the theoretical analysis of steel-concrete composite box-beams’ lateral buckling,computational model on the stability of composite box-beams are proposed.

And this dissertation studies the stability of composite beam in the following aspects:1) Based on the theoretical analysis of steel-concrete composite box-beams\' lateral buckling, analytical model on the stability of composite box-beams is put forward, and the formula which is used to calculate critical bending moment in negative bending regions is deduced.

new structure of shaft lining with its cross section varying with the depth of shaft lining which was for the first time introduced in drilling deep shaft;calcula- tions to avoid axial instability of the shaft lining in erection when it is floating down.