Influence of ground anchors corrosion and uncertainty strength parameters: A case study slope failure in northern Taiwan

A significant fatal scale dip slope failure incident occurred at The Freeway No.3, located in Northern Taiwan, on April 25, 2010. From the post-failure investigations, it is found that the deteriorating anchor systems and uncertainties in strength parameters as the most likely the primary reasons for this slope failure. This study main conducted a numerical modeling work using Universal Distinct Element Code (UDEC), a two-dimensional numerical program based on the distinct element method for discontinuum modeling. First, the numerical modeling was generated to check the original design of this dip slope failure. Then a series of parametric studies were introduced to investigate the influences of the triggering design factors that affected this slope-failure event. The ground anchor failure order in this slope is also assessed by bracketing approach and strength-reduction method using a new term called “Adjusted Factor”. Furthermore, this study will focus on an anchors’ failure order from the perspective of the random field to assess whether the anchors’ failure mechanism considering the random field will match or be closely similar to the anchor failure order in the field.