CONTRIBUTION TO THE MODIFICATION OF INPUT DATA OF SUBGRADE STRUCTURE DIMENSIONING FOR NON-TRAFFIC LOAD ACCORDING TO THE ZSR METHODOLOGY

摘要

The Slovak Railways (ZSR) have been continuously upgrading their main tracks - parts of the Trans-European corridors. The upgraded tracks must comply with European standards: they must be safe and reliable. The present subgrade structure dimensioning and assessment methodology for non-traffic load (effects of climatic factors, mainly water and snow), as stated in TNZ 73 6312, does not reflect the current level of knowledge and must be updated. This paper brings some proposals for modification of input data of subgrade structure dimensioning for non-traffic load, in the form of a design map of average annual air temperatures in Slovakia. The original methodology was based on the design map of frost indexes. However, long-term monitoring of subgrade structure freezing confirmed the insufficiency of the original methodology as irrelevant for the subgrade structure design for non-traffic load. The map of average annual air temperatures substantially extends the original methodology.