Introduction. The question of the practical method of calculating the temporary moving load from vehicles on arched bridge structures with an increased size of the opening made of metal corrugated structures (MCS) under the road embankment (small and medium bridges, overpasses) is considered. Based on the results of calculation and theoretical studies, proposals were made regarding the determination of the temporary moving load, distributed (through the soil of the embankment) only on part of the span, to the equivalent (according to the criterion of the maximum bending moment in arch structures), distributed along the entire span, to simplify the analytical calculations of such structures.
Problems. The current regulatory document on the design of road constructions from MCS contains data on analytical calculations of such round constructions with an opening size of only up to 6 m [1]. With this size of the structure under the embankment above it with a height of more than 1 m, the temporary load, for example according to the NK-100 or NK-80 scheme, is spread over the entire length of the span, as is accepted in the calculations of ordinary culverts under the road embankment.
With an increased span of the structure (10-20 m or more), the temporary load according to the specified schemes can be distributed only on part of the span. Therefore, there is a need to supplement the current normative document in terms of analytical calculations, in particular, temporary load.
Purpose and task. To carry out research and develop proposals for a possible scheme for determining the equivalent temporary moving load for arched structures from MCS with an increased span is the main goal and task of this work.
Research methods and results. Calculation-theoretical analysis of the formation and nature of the effect of a temporary load from a vehicle on an arched structure made of MCS at different positions of this load relative to the center of the span, based on the results of which proposals were made for a possible scheme for determining the equivalent load by using the corresponding influence lines determined for this purpose.
Conclusions. Proposals have been developed for a possible scheme for determining the equivalent (according to the criterion of maximum bending moment in arched structures) temporary moving load for arched structures made of metallic corrugated structures by reducing the actual shape of the load (on part of the arched span) to one distributed over the entire span in order to simplify the analytical calculations of such structures.
