Based on the effective width of strip footing and the plastic limit analysis theory,a variable static stress field and a lower bound solution of strip footing under combined loading were presented.

Based on the Meyerhof′s effective width of strip footing and the plastic limit analysis theory,an upper-bound solution of strip footing under vertical,horizontal and moment loads due to combined loading is presented by constructing variable permissive moving field.

Theoretical models of equivalent bending strength of ternary boride cermet cladding material when the clad is under press condition are built based on the position of the maximum extension stress and that of the maximum press stress respectively.

The concept of the equivalent flexural rigidity of Functionally Gradient Materials (FGM)beams was presented for the first in this paper, and its formula was derived.

The equivalent longitudinal bending rigidity of a shield tunnel is discussed in this paper,as traditional equivalent longitudinal rigidity continuity model doesn t consider the longitudinal joints which can influence the equivalent longitudinal bending rigidity,al- so it doesn t consider mode of lining ring erection which can influence the equivalent longi- tudinal bending rigidity.