Concerning the potential roof collapse in tunnels or cavities, it is indeed a rather complicated issue, due to the random variability of mechanical properties of the rock as well as other affecting factors, such as the presence of cracks and fractures in the rock masses. Indraratna et al. [5] put forward a joint material mode characterizing the mechanical characteristics of the discontinuous rock masses instead of equivalent continuum-based method considered to be unsuitable, and soil-infilled joint model was then employed to investigate the rock wedge in the crown of cavities. Afterwards, with the prevalence of Hoek–Brown criterion, Fraldi and Guarracino [6], [7] and [8] proposed a curved failure mechanism on the roof of deep tunnels and derived upper bound solutions of collapsing region in the realm of plasticity theory together with variational principle. Notice however the findings of practical roof failure suffer from the issue that the collapsing block appears three-dimensional (3D) characteristics rather than simple two-dimensional (2D) collapse mode. To overcome the shortcoming of existing plane failure mechanism, Yang and Huang [9] constructed a 3D rotational failure mechanism aiming at the relatively accurate description of actual roof failure and the improvement of existing findings. Thereafter, considering the non-ignorable influence of ground water imposed on the impending collapse, Huang and Yang [10] incorporated the pore pressure into upper bound theorem, being regarded as external forces, and some discussions were made to estimate the region of failure in tunnel roofs. Similarly, Yang and Qin et al. [11] and [12] evaluated the effect of seepage forces in the process of analyzing roof stability with 2D and 3D collapse mechanisms respectively and the findings obtained are in sound agreement with the existing results.