Study on Physical Model Experiment of Dam's Seepage Stability base on Coastal Sand

Qingcaosha Reservoir, based on coastal sand of Changxing Island at the Yangtze Estuary, is the largest plain and coastal reservoir storing fresh water at home and abroad, with the full length of 48 km. The dam foundation is mainly filled with arenaceous soil and powdery sand, which owns large permeability and poor seepage stability; the body of dam is built by the new way for filling the sand, blowing the sand and casting the sand bags, which also owns poor seepage stability. Focusing on the three body forms of filling the sand, laying the tubular bags with sand and casting the sand-bags and two typical forms of section, the article has completed the indoor large-scale hydraulic model experiment of sand tank. By the experiment, the researchers have found the characters of contacting seepage between soil and bag, between bags and bags and between sand and bags, also determined the permeability coefficient and integrated permeability coefficient of different embankment materials, and the quantity of the single-wide flow, then acquired the index of seeping characters among dam body's materials, and finally discussed the seepage stability of the dam body and the rationality of controlling seepage.