Time Dependent Displacements in Tunnel Excavation

Aim of this research activity is the identification and quantification of time dependent displacements during tunnel excavation. Displacements during tunnel excavation have two components: advance dependent displacements and time dependent displacements. Time dependent displacements are also advance dependent and controlled by several factors such as geological structure, characteristics of rock mass etc. In this study the factors effecting amount, rate and stabilization period of the time dependent displacements and their relations will be investigated using displacement measurements, geological-geotechnical and construction data from various projects. Long term triaxial creep tests and direct shear tests will be performed on representative samples to interprete time dependent behavior of certain rock mass conditions. Discontinum methods for jointed rock conditions and continum methods for highly jointed or weathered rock mass conditions will be carried out to quantify the factors influencing time dependent displacements.