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江河大水滔滔,从堤上开明口放水抗旱是一件最危险的事情,一出问题,国家和人民就会受到不可计算的损失,因此开明口首先一条是如何控制水量,如何确保安全。1.位置选择:明口的位置应选在堤外有沙洲堤内地面高程与明口口底高程大致相平和堤身土质较好的地方。因为在进口处有沙洲,便于打防护桩,在江河水猛涨时容易堵塞,堤内地面高程与口底高程相平可以不致形成陡坡或跌水而造成放水流速过大,冲刷过水断面。若堤身土质较好(如粘土)则不易塌坡,可
The rivers are overflowing with flood water. It is one of the most dangerous things to drain water from dikes and to prevent drought. If a problem occurs, the country and people will suffer irreparable losses. Therefore, the first one is how to control the amount of water and how to ensure safety. 1. Location choice: Mingkou location should be selected outside the embankment in the embankment within the ground elevation and the mouth of the mouth at the end of roughly the same elevation and the embankment soil better place. Because there is a sandbar at the entrance, it is easy to play protective piles. When the water in the river is soaring, it is easy to be blocked. The ground elevation in the embankment and the elevation in the mouth floor can not cause steep slopes or falls, resulting in excessive flow velocity and excessive water cross-section. If the embankment soil is better (such as clay) is not easy to collapse, can