Model experiments for examining heaving phenomenon in tunnels

In recent years, heaving has occurred in pavement slabs in some expressway tunnels, adversely affecting road comfort and tunnel stability. When the heaving displacement is limited, the repair is limited to the overlay slabs. However, in the sections where the displacements are significant, the tunnel invert needs to be reconstructed and this brings many additional problems; for example, in reconstruction, traffic needs to be restricted which brings inconvenience to the public. In this study, model experiments as well as numerical analysis using the finite differential method (Code FLAC) were carried out to establish a rational measure facing to the heaving phenomenon. Based on the results of model experiments and numerical analysis, the validity of reproducibility of the model experiments has been examined, some characteristics of heaving phenomenon have been grasped, factors for estimating the heaving phenomenon in different loading patterns have been established. All these factors have important implications for future construction practice.