NUMERICAL & EXPERIMENTAL ANALYSIS OF GROUT-REINFORCED TUNNEL

초록

A three-dimensional anisotropic yield function model is proposed to analyze the elasto-plastic behavior of the grout-reinforced tunnel where grouting columns are assumed to be periodically injected into the in-situ soil to increase the safety factor of the tunnel. For this, previous work on the anisotropic yield function having unidirectional reinforcement is extended to take into account of the volume effect of the reinforcements and three different models are introduced to estimate the composite material properties of the grout-reinforced soil. A composite yield function together with a plastic multiplier having directional anisotropy is next defined by way of the residual stresses which come from the stress differences between constituent materials. Accuracy and efficiency of the proposed model are verified by the comparison of the numerical prediction with the experimental data on small scale grout-reinforced tunnel. The predicted results are shown to be in good agreement with the experimental data available and future work is briefly outlined.