Abstract:

In order to study the influence of geological factors on TBM tunneling efficiency, five factors, i.e. uniaxial compressive strength, rock abrastivity, rock mass integrity coefficient, angle between structure strike and tunneling direction, and groundwater seepage, are selected as evaluation indices; the TBM tunneling efficiency is divided into five grades; and thereby the matter element model for geological influencing factors on TBM tunneling efficiency is established based on extenics theory. And then the importance order of evaluation indices is made by analytic hierarchy process (AHP)； and the weights of indices are determined. Finally, the relation degree calculation between matter element to be evaluated of CCS hydropower station headrace tunnel in Ecuador and TBM tunneling efficiency grade is carried out, of which the results are compared with actual tunneling parameters and conditions; and the results coincide with the engineering practice. The study results show that the extenics theory can evaluate TBM tunneling efficiency grade well and the AHP is rational for indices′ weights evaluation. The related research content and methods can provide reference for TBM equipment selection, construction schedule management and cost budgeting of the similar projects in the future.

Key words: tunnel, TBM, tunneling efficiency, extenics theory, analytic hierarchy process (AHP), relation degree