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To study the biaxial strength and failure characteristics of reinforced concrete in the state of biaxial tension-compression stresses and provide some suggestions for the practical engineering design, 3 one-third scale reinforced concrete (RC) plate specimens are tested. The results indicate that, in biaxial tension-compression stresses, reinforced concrete cracks in the direction normal to the principal tensile stress direction and presents the characteristics of shear failure modes. The test device could simulate the required stress condition. The compression strength of reinforced concrete is obviously lower than the uniaxial strength fc. The reduction factor k is about 0.55~0.75 which varies with different tension-compression force ratio. Concrete material takes part in the tension process of reinforced concrete and shares part of the tension, while the share ratio decreases as concrete cracks gradually.

A nonlinear analysis program based on fiber model was developed and used in analyzing the flexural behavior of steel reinforced concrete (SRC) columns under axial and bilateral loading. Concrete different confinement levels for different zones in a SRC column section, such as cover concrete zone, stirrup confined concrete zone and steel confined concrete zone, etc., can be considered. Some SRC tested specimens were simulated using the developed program. It was pointed out that the flexural capacity will be lower-estimated if the concrete confinement was neglected.

There are a large number of acceleration records obtained in the near fault strong motion of Wenchuan earthquake in 2008, which greatly enriched the database of strong motion. By the classification analysis to Sichuan records and comparison with the domestic and international earthquakes analysis, we draw the following conclusions: 1) whether parallel or perpendicular direction, the peaks of soil are greater than rock. With the fault distance increasing, the gap between the two gradually will minish.2) With the increase in the number of peaks obtained, the correlation coefficient of GPGA or LGPA is generally increasing.3) The mean of R is respectively 8.10(rock), 10.31(soil), 10.10(total) in the usual range.4). The average of λ is respectively 0.5862(rock), 0.5707(soil), 0.5722(total), they are between 1/2 and 2/3. The difference is not large.

This paper presents several methods usually used for measuring cable tension in cable-stayed bridges, especially frequency vibration method. Taken two different length stay-cables under given tension forces in a real cable-stayed bridge as an example, different modeling methods in finite element methods (FEM) were used to solve their natural vibration frequencies. The results by FEM were compared with those from other available theoretical predicting method. It was found that FEM based on tightening string model is more suitable for a long stay-cable. For a short stay-cable under given tension force, beam bending stiffness can be ignored in predicting its first five natural frequencies using a hinged beam model in FEM. While the predicted lower frequency using clamped beam FEM model is more accurate and reasonable.

Steel braces are widely used in seismic retrofit of buildings. However, their tendency of buckling under compression impairs their efficacy. In this paper, characteristics of a cross bracing with rigid intersection, including its bearing capacity, hysteretic property and fracture ductility are investigated. With the analysis results, performance-based design requirements of a steel cross bracing are proposed based on its width-thickness ratio and effective slenderness ratio.