Abstract
A comparative analysis of backfill materials used to fill the space between tunnel lining and surrounding rock is considered. One of the most pressing issues in the construction of underground structures is ensuring safe working conditions through the effective use of support materials. Various types of mixtures were studied and compared, with calculations performed using standard software tools (including the use of the accelerating additive KRDf- 2). A step-by-step comparison algorithm was developed, and an economic analysis was carried out. Material costs for filling the gap between the tunnel lining and the rock mass during underground tunnel construction were taken into account. Samples obtained from a new composition of the support mixture are also presented.