Numerical Modeling of a Blast-Induced Landslide

摘要

A 2D dynamic finite element analysis (FEA) was carried out to simulate the stress wave propagation and accumulated strains of a blasting-induced landslide in sensitive clay that took place near the city of Namsos, Norway in 2009. The blasting triggered a large unintended transient motion of the rock mass with unfavorable weak planes and fault zones. The transient penetration of the rock mass into the clay triggered the devastating slide. A linear elastic model was used for the undrained response of soil. The interaction between soil and the blasted rock was modeled by means of an interface. The blast load was defined as a triangular velocity - time function with a peak value of 10 m/s. In accordance with the field observations after the slide, the predicted deformation of the rock face out into the sensitive clay was around one meter. The results showed a clear trend of the blast impact that diminished with distance. Stability checks using the volume of remolded clay determined from the dynamic analysis revealed that the factor of safety of the slope was reduced to less than unity following the blast.