Abstract: With the continuous advancement of urbanization construction, the hazard of road collapse in urban areas is becoming increasingly prominent, but the inherent mechanisms and evolutionary patterns are not yet clear. Taking the road collapse induced by underground engineering construction as an example, with a focus on the significant deformation and strain-softening characteristics during the collapse process, a numerical analysis method based on the Material Point Method (MPM) and the Drucker-Prager elastoplastic model was established. This method investigated the influence of different excavation conditions and stratum parameters on the deformation and failure modes of road collapse, as well as the underlying mechanisms. The results indicate that: (1) the proposed material point method numerical framework can effectively replicate the entire process of large deformation induced by shielded tunneling construction, providing an effective means for predicting hazards of similar nature; (2) the thickness of the overlying soil layer affects the shape and evolution of the shear band, thereby influencing the collapse characteristics-specifically, a thicker overlying soil layer results in a smaller degree of soil collapse, and when the subsidence on both sides is greater, the middle subsidence is smaller; (3) a smaller friction angle of the soil makes it easier for shielded tunneling construction disturbances to induce collapse, whereas in sites with greater soil cohesion, the degree of collapse induced by shielded tunneling construction disturbances is smaller.

Key words: Road Collapse, Material Point Method, Underground Engineering, Shear Zone, Soil Arch Effect