Abstract It is critical to control the pre-convergence of the advance core at the working face in order to control soft rock deformation. The lateral continuous pre-lining shell finished by the mechanical pre-cutting technique can protect the advance core soil and thus control pre-convergence. The interaction between the pre-lining support and the rock mass is complex due to the time-space effect at the tunnel face. Based on the convergence-confinement mechanism, the theoretical solution for the interaction between the pre-lining and the rock mass was derived, and the law of the applicable depth of the pre-lining varying with concrete strength, rock mass parameters and pre-lining parameters was studied. The results indicate: 1) the higher the compressive strength of the pre-lining concrete,the larger the applicable depth for pre-lining support, thus it is a linear relationship between the concrete compressive strength and the applicable depth; 2) with an increase of the stress release coefficient, the applicable depth of the pre-lining increases as under the same concrete compressive strength; 3) the pre-lining thickness has a significant effect on the applicable depth of the pre-lining, and the bigger the pre-lining thickness, the larger the applicable depth of the pre-lining; and 4) the applicable depth of the pre-lining increases if the tunnel diameter is reduced
Abstract：
It is critical to control the pre-convergence of the advance core at the working face in order to control soft rock deformation. The lateral continuous pre-lining shell finished by the mechanical pre-cutting technique can protect the advance core soil and thus control pre-convergence. The interaction between the pre-lining support and the rock mass is complex due to the time-space effect at the tunnel face. Based on the convergence-confinement mechanism, the theoretical solution for the interaction between the pre-lining and the rock mass was derived, and the law of the applicable depth of the pre-lining varying with concrete strength, rock mass parameters and pre-lining parameters was studied. The results indicate: 1) the higher the compressive strength of the pre-lining concrete,the larger the applicable depth for pre-lining support, thus it is a linear relationship between the concrete compressive strength and the applicable depth; 2) with an increase of the stress release coefficient, the applicable depth of the pre-lining increases as under the same concrete compressive strength; 3) the pre-lining thickness has a significant effect on the applicable depth of the pre-lining, and the bigger the pre-lining thickness, the larger the applicable depth of the pre-lining; and 4) the applicable depth of the pre-lining increases if the tunnel diameter is reduced
2017, Vol. 54 