**3. Numerical Simulations**

In this section, we present numerical simulations under various two-bump configurations including two bumps (positive forcing) or two holes (negative forcing). Our main focus is on trapped solitary waves between two bumps or two holes and their stability as they evolve in time. In particular, the bottom configuration is confined as two identical or symmetric positive bumps or negative holes. First, stationary trapped solitary waves are found as varying the distance between two bumps and the bump size. Then, we investigate the impact of various bump scenarios on their numerical stability.
