A new tunnelling method, which utilizes shotcrete and rockbolts as main supporting member of tunnel, has been recently introduced into Korea. The new tunnelling method requires proper understanding of the ground response during tunnel excavation. It can be achieved from theoretical analyses, laboratory experiments, and the field measurements.
This thesis presents a two-dimensional finite element analysis method devised for theoretical evaluation of tunnel behavior. Elasto-plasticity theory was adopted for the material properties with different yield criteria in the program.
To delineate the effects of various factors influencing tunnel behavior, a simple model was chosen, and a series of parametric studies was performed. The parameters studies include the major soil properties parameters and the tunnel geometry features. To research the actual tunnel behavior, an actual construction section from the Seoul Subway Lines 3 and 4 was analyzed using the program, and the results were compared with those field measurements during construction.
The results from the parametric studies have confirmed various trends and observations reported previously, and the predictions from the actual tunnel analyses have shown reasonable agreement with the field measurements.
