Models for estimation of TBM performance in granitic and mica gneiss hard rocks in a hydropower tunnel

The risk of excavation operations due to high capital costs can be reduced by correct estimation of machine performance. Many models have been proposed to study this issue, but considering the nature of the problem, it is rather difficult to estimate tunnel boring machine performance by simple linear prediction models. The purpose of the present study is to construct linear and non-linear multivariate prediction models to estimate TBM performance as a function of rock mass properties in granitic and mica-gniess rocks. For this purpose, rock properties and machine data were obtained from a historical TBM tunneling project in Norway and then the database was established to develop performance prediction models utilizing the linear and the non-linear multiple regression methods. This study proposes more accurate and practical statistical models compared to the previous ones based on multivariate regression analyses to estimate the performance of hard rock TBMs.