Evaluation of soil abrasiveness in mechanized tunneling with special attitude to the Tabriz metro line1

Soil abrasivity and TBM component wear issues is one of the most important factor in success of this type of projects. Despite of rocks there are very few test methods to describe the abrasive characteristic of soils. It can be mentioned that impossibility of reliable estimation of soil abrasivity on mechanical tunneling is one of the engineering geology science gaps in tunneling and drilling industry. In this paper the influence of some important parameter on soil abrasivity (soil particle size, equivalent quartz content and water content) are studied by use of LCPC standard and the abrasiveness of Tabriz metro line 1 soil are estimated. The results indicate by increasing of soil particle size the abrasivity trend to be increased. The influence of water content on abrasivity was not the same in all of the samples. The presence of water in some samples cause to increase and in the other sample cause to decrease of abrasivity. With increasing the equivalent quartz content (EQC), the abrasivity of soil depends on grain size has trend to increase with power relation. Evaluation of Tabriz metro line 1 soil samples shown it is very abrasive and medium abrasive in dry and saturated condition respectively.