The average gestation period for rabbits is 31 days; however, it can vary from 29 to 35 days. Does should be pregnancy-checked 14 days after mating. If not pregnant, they can be re-bred immediately.
Buttresses and an arch of the Roselend Dam in France. A buttress dam or hollow dam is a dam with a solid, water-tight upstream side that is supported at intervals on the downstream side by a series of buttresses or supports.The dam wall may be straight or curved. Most buttress dams are made of reinforced concrete and are heavy, pushing the dam into the ground.ater pushes against the dam, but the buttresses are inflexible and prevent the dam from falling over. Buttress or hollow gravity dams were originally built to retain water for irrigation or mining in areas of scarce or expensive resources but cheap labour.
iv) Earthquake may cause the following types of failure to earthfill dams; 1 cracks may develop in the core wall, causing leakages and piping failure. 2. slow waves may set up due to shaking of reservoir bottom, and dam may fail due to overtopping. 3. settlement of dam which may reduce freeboard causing failure byovertopping