Prediction of ground load by performing back analysis using composite support model in concrete lining design

A ground load prediction method is suggested herein based on the deterioration of the primary support during its durable life. This study includes two contents; firstly, the real behavior of primary support was evaluated and secondly, it was used to propose back analysis procedure based on measurement data. To predict the ground load acting on the primary support, it is important to estimate the real behavior of shotcrete and steel sets by performing experiments. Thus, large-scale experiments were performed on archshaped specimens, combining the application of axial forces and bending moments. The results show that shotcrete can resist only axial forces but steel sets can withstand both axial and flexural loads. Based on these results, back analysis was performed to predict ground load, using the measurement data from a domestic construction site. Compared to other widely used methods, the proposed method predicts 21% to 51% smaller ground load values in different zones. Because the proposed method predicted different ground loads in the same ground conditions, it was deduced that these ground load values were more realistic than the previously predicted results.