Parametric study of soil abrasivity for predicting wear issue in TBM tunneling projects

The lack of reliable methods for evaluation of soil abrasivity and revealing the effects of different parameters on wear rate are nowadays considered as a deficiency in geotechnical investigation during feasibility study, design and construction phases of tunneling projects with the use of tunneling boring machine (TBM). The subject is recently attracts a broad international attention and focus. The background of existing standard test methods are reviewed and wear types occurrences in TBM tunneling are discussed in this paper. A new soil abrasion testing system is developed which is called Soil Abrasion Testing Chamber (SATC) and the results of soil abrasion tests are compared with results of the commonly used tests such as: Cerchar, LCPC and SAT tests. Some of the most influencing factors including presence of water, bentonite slurry, soil particle size, quartz content, water pressure and confining chamber pressure are considered for the use of the new devise. The test results indicate that the soil abrasivity tends to increase with the increasing of soil particle size, bentonite slurry, soil pressure and quartz content. The effect of water on abrasivity varies for different types of soil. The soil abrasivity decreases with the increase of water pressure. The internal friction does not seem to have any influence on the wear rates measured with the new proposed apparatus. (C) 2015 Elsevier Ltd. All rights reserved