ABSTRACT
The soil-steel bridges are more and more popular in many parts of the world as an efficient alternative to typical steel and concrete bridges. The design codes and methods include, among others, the requirements on the minimum soil cover height of soil-steel bridges and culverts. This aspect plays an important role in the case of impact of static and dynamic loads. However, bridge regulations are not fully detailed on the design of such bridges situated in seismic areas; in most cases, they include only general suggestions. Instead, it is important to know how the soil-steel bridges behave under seismic excitation taking into account various soil cover height. Usually, an increase in the soil cover in these type of bridges causes the decrease of internal forces in the steel shell structure under the static and dynamic loads (passing vehicles). The paper presents the results of the numerical study of the soil-steel bridge under seismic excitation. The soil-steel bridge with span more than of 17 m was analysed. In this study, three heights of soil cover (1.8 m, 3.0 m and 5.0 m) are analysed. The DIANA FEA program was used in the seismic analysis taking into account the El Centro (1940) record. Moreover, to reflect the soil-structure interaction, the interface function (Coulomb friction) was applied. Displacements, stresses, axial forces, bending moments, velocities and accelerations of the soil-steel bridge are analysed in detail in the nonlinear range of response. This study involves a computational numerical model that can be used in engineering practice, especially when designing such bridges located in seismic and paraseismic areas.
