Jordan Journal of Civil Engineering

Paper Detail

Experimental study on the effect of implementation and progressive failure of pre-lining method for tunnel in soft and broken surrounding rock

Volume 15, No. 4, 2021
Received: 2021/04/10, Accepted:

Authors:

Jin-xiu YUAN; Dao-yuan WANG;

Abstract:

By conducting a large-scale three-dimensional model test in an outdoor experimental tank, this paper aims to reveal the effect of the pre-lining method during the full-section excavation and the mechanism of the progressive failure and instability. Firstly, the test purpose, test site, similar materials, test process and measuring systems are described in detail. Then, the effect of the pre-lining method is obtained through the comparative analysis of the internal displacement, surrounding rock pressure and pre-deformation of advanced core soil. Finally, the mechanisms of progressive failure and instability are explored by studying the instability process and the deformation evolution under different loadings. The results show that the convergences of vault and sidewall are decreased by 25% and 80%, the pre-convergence rate is reduced by 20 %~30 % and the longitudinal influence range of advanced core soil is decreased by nearly 60% under normal load conditions. The instability process of the tunnel is peeling-slip-collapse of rock mass and the collapse is finally formed with 2 m depth of sidewall, 1.4 m depth of vault and 1.2 m depth of excavating face. The limit displacement value of railway double-track tunnel under the geological condition of completely weathered V-grade granite is given.

Keywords:

Tunnel engineering, Weak and broken surrounding rock, Pre-lining method, Effect of implementation, Progressive failure, Model test