Monitoring of Soil-steel Structures During Construction

Abstract

A unique feature of soil-steel structures, unlike classical bridges, for example vaulted ones, is the very large effect of backfill and road superstructure on the bearing capacity of the bridge. In the model of a buried structures made of corrugated steel plates, two structural subsystems are distinguished: a flexible arch shell and a soil backfill with road superstructure. The interaction between these subsystems is modelled as a contact layer, i.e. forces with a normal and tangent direction to the surface of the steel shell. It is a static condition for the compatibility of mutual interactions between soil and coating. Between the sub-systems, slip is allowed, i.e. the difference of displacements. The paper presents the structure safety assessment algorithm based on the shell deformation determined on the basis of deflection measurement and change of curvature in the shell crown point. The construction phase of the structure is analysed and a also the symmetrical deformation is assumed during the backfill material placement. Usually, during the bridge construction the forces in the steel shell are several times greater than those arising from operational loads. For this reason, the results of analyses given in the paper are also important as the basis for calculation and behaviour of the soil during live loads.