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.
Dam Safety-Glossary of Terms. ABUTMENT-The part of a valley side (wall) against which a dam is constructed. An artificial abutment is sometimes constructed as a concrete gravity section, to take the thrust of an arch dam where there is no suitable natural abutment.REST WIDTH-The width or thickness of a dam at the level of the crest of the dam. In general, the term thickness is used for gravity and arch dams and width is used for other dams. CRIB DAM-A gravity dam built up of boxes, cribs, crossed timbers, or gabions and filled with earth or rock.