Seismic response of multi-storey reinforced concrete walls subjected to eastern North America high frequency ground motions

A research program has been undertaken to better characterizing the contribution of higher modes of vibration on the bending moment and shear force demand on cantilevered reinforced concrete shear walls. Emphasis is put on constructions located in eastern North America. Ground motions in this region have higher dominant frequency, which leads to relatively more significant higher mode response. An example of higher mode contribution is given for two sites in Canada exhibiting different seismic settings. A shake table test program is currently being prepared to examine the influence of damping and shear and flexural stiffness degradation on higher more response. The design of the test specimens and the results from prediction analyses are discussed. A preliminary test program conducted to validate assumptions in the use of reduced-scale wall test models is also presented

On the effects of uniform temperature variations on stay cables

The present paper is concerned with the analysis of thermal effects on both static and dynamic mechanical behaviors of inclined elastic stay cables used in cable-stayed structures. Based on the elastic catenary cable theory, a nonlinear analytical approach is proposed in order to calculate variations of stay cables’ tensions under uniform temperature changes. Making use of simplifying assumptions, the influence of temperature variations on the free undamped vibration of stay cables is also investigated. The validity and the effectiveness of the proposed approach are demonstrated by comparing model results with monitoring data measured on stay cables of the Rades-La Goulette cable-stayed bridge in Tunisia