Investigation of Deformations in Flexible Soil-Steel Arch Bridge Based on Strain Gauges’ Measurements

Abstract

In this paper the effects of live loads will be analysed. The loads are movable, but have characteristic of static passes. The results of strain measurements with relatively dense layout located around the periphery of the corrugated steel structure are used to calculate its deformations. Due to this, the solution includes the interaction of all elements of the structure i.e.: corrugated steel sheets, backfill material, road superstructure (real rules of interaction) between these elements. Thus, there is faithfully (exactly) mapping the geometry and physical characteristics of the structure, equipment and the loads in structure 3D layout. Convenience of the algorithm is that the function of displacement is determined with use of a scheme of the peripheral strip of the shell in the form of a beam element with the cross-section of the steel shell in the 2D model (without the other, the aforementioned elements of the object).

In previous studies of soil-steel bridges, the difference of the courses of the displacement functions during the primary and secondary passages was observed. A characteristic feature of these test results (strains) and calculated geometrical effects (displacement) is the formation of a hysteresis loop. As proposed in this paper the two-part terms of solutions, can be seen that the deformation of the structure comes from two equivalent bending and compression components of the corrugated steel shell. On this basis the behaviour of the contact layer between the backfill and the steel shell in such a hysteresis loop is assessed.

In this paper using dense strain gauges’ layout any direction of the structure displacement can be calculated based on the changes of the strains in the analysed circumferential strip (part) of the structure. To implement such calculation is sufficient to use the simplest FE models. The effectiveness of the algorithm was verified by comparing displacements obtained from different measurement technics i.e.: induction (sensors) and geodetic (3d laser scanning).