According to your description, you should be a student. If cracks are found in the bed of the dormitory, you should inform the dormitory administrator and the class teacher in time. Because this is a big security risk, they should do so. Handle in time. Besides, you know that you are heavier, and this situation is not suitable for sharing the upper berth, which is more dangerous. So I suggest you change beds with the lower berth and live in the lower berth.