ABSTRACT
This paper addresses the importance of accurate geometry modelling of a complex sprayed concrete lined (SCL) tunnel junction to predict an optimised tunnel lining behaviour. The geometry modelling aspects include the accurate geometrical representation of the linings and the finite element (FE) mesh sizes at the area of interest. Modelling at least one of the linings (i.e., primary or secondary linings) is often performed using zero-physical-thickness plate structural elements in the FE model and the other lining using volume elements. However, this geometrical simplification will make the tunnel diameter bigger in the FE model compared to the actual design geometry. Another key aspect of geometry modelling is element size and distribution, especially across the lining thickness, affecting the accuracy of volume elements’ stress outputs. This paper presents the early investigations undertaken to study the above modelling aspects in preparation for undertaking the soil-structure interaction analyses for designing complex tunnel junctions.
