Obstacles can play a prominent role in evacuations from spaces like classrooms. This study investigates the impact of two types of human-obstacle interactions on evacuations, including passing-over-obstacles and pushing-obstacles. A modified cellular automata model was adopted which considers the influence of exits and aisles, local density, and personality traits. Calibrated with a real-world evacuation video, this model enabled the simulation of passing-over-obstacle behavior. Parametric analyses were then conducted testing various geometrical layouts and behavioral features in the context of both traditional classrooms and active learning classrooms. Results showed that (1) human-obstacle interaction has a substantial impact on evacuation when exit capacity is less restrictive; (2) the passing-over-obstacle behavior can be advantageous for evacuation efficiency, opposite to the pushing-obstacle behavior; (3) interplay between the two types of interactions is conspicuous when the frequency of pushing-obstacle behavior is high; (4) appropriate geometrical design could make the evacuation process more robust to disadvantageous effects of the pushing-obstacle behavior; (5) proper evacuation management can make the best of pedestrians' advantageous passing-over-obstacle behavior. Accordingly, we propose several strategies for evacuation management practices. This includes setting aisles beside walls, encouraging appropriate passing-over-obstacle behavior in the front of or near the walls in traditional classrooms, discouraging pushing-obstacle behavior and leaving enough space near the exit regions in active learning classrooms.