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The Madeira Airport runway has recently been extended with a 1,000 m long structure over the Atlantic Ocean supported by concrete columns. To prevent aircraft from falling down special lateral reinforced concrete safety barriers were designed. In order to study the efficiency of these barriers in accident situations, small-scale models of the runway, safety barriers, and most frequent aircraft were tested at the Structures and Materials Resistance Laboratory of IST (Instituto Superior Tecnico), in collaboration with LNEC (the Portuguese National Laboratory of Civil Engineering), the Airbus Company, TAP (Air Portugal), and the Madeira airport authorities (ANAM). The paper presents this study, including an initial evaluation of a set of aircraft accident related statistics from the International Civil Aviation Organization (ICAO) databases, the results of the tests performed at the TAP simulator of Airbus A-320, and the preparation and main results of the experimental small-scale tests at IST. It was concluded that, under specific conditions, the designed safety barriers were efficient in preventing aircraft from falling during landing and takeoff accidents. CE Database subject headings: Safety; Barriers; Airport runways; Accidents; Model tests; Aircraft.

This paper deals with the oscillations of bridge stay cables that may be excited by wind or by traffic-induced periodic motions of the deck and/or towers. A theoretical model is developed for the study of nonlinear oscillations in inclined stay cables as a result of small anchorage motions. Laboratory tests are performed to check the validity of the model in some particular situations. Approximate analytic formulas and numerical solutions are obtained for the cable transverse displacements and the corresponding axial force oscillations. The behavior of inclined stay cables is interpreted by comparison with similar horizontal or vertical cables subjected to appropriate components of the excitation. It is shown that reasonably small anchorage amplitudes may lead to important cable oscillations when conditions are met for lower-order classical or parametric resonance of the cables.