Damping ratio is a very important parameter for building structures in the analysis of dynamic response. Story-adding RC structure of light-weight steel is composed by two different material stories. If all the modal damping ratios are defined as the same, as to the dynamic analysis for that structure, the results of analysis will be inappropriate. This paper made some response spectrum analysis on a six-story story-adding RC structure of light-weight steel by finite element analysis software Midas Gen through defining the Rayleigh damping. In the meanwhile, compared the results based on different Rayleigh damping parameters with the results by using the method of strain energy proportional, and got the rule of the definition of Rayleigh damping.

The value of sensitive factors in structural reliability analysis greatly affects reliability calculation results. These factors must be accurately determined and studied to improve the accuracy of calculated results. Based on the analysis of existing sensitivity calculation methods, a new practical sensitive factor analysis method was put forward to analyzing sensitive factors in structural strength reliability calculations. The dimensionless sensitive indexes of structural reliability were defined in the new method to compare the influence degree of random parameters to reliability. And the method was applied to analyze sensitivity under the two conditions of the structural resistance decreasing and not changing with time. Random variables, defined by their probability distribution and corresponding distribution parameters, were used to describe uncertainties in the reliability calculation. Different forced state RC columns were taken as examples to analyze the structural sensitivity, and sensitive factors affecting the columns’ structural reliability were obtained. The results show that the reliability of time-varying structure has descended to some extent compared with that without time-varying structure, and the effect from the random parameters to reliability index. The example and theory demonstrate the feasibility and rationality of the new method. This article has certain reference value to the structural design, construction and detection.

Based on the analysis for damages of masonry structure from Wenchuan earthquake, the seismic behavior of multi-story masonry school building is analyzed, and the seismic behavior with load-bearing structural system of longitudinal wall is mainly discussed. Based on the analysis and study, several problems which need more attention to the seismic appraisal and reinforcing design are pointed out, and finally the differences and correlation of seismic appraisal, as well as seismic design are discussed.