一、工程概况葛洲坝水利枢纽上游横向围堰系二期临时性工程,其作用是除保护二期工程施工外,还担负着壅高上游水位,保证一期已完建的二江电厂发电、三江船闸通航的任务。该围堰将要在40米水头下运用长达5年以上,实际上是一座土石坝(其平面布置和结构断面参见《水力发电》1981年第4期第6、10页附图),因此必须确保堰体安全,防渗可靠。 I. Project Overview The second phase of temporary cofferdam project in the upper reaches of Gezhouba Hydro Project is to provide power to the two rivers and hydropower plants that have completed the first phase of the project except for the protection of the second phase of construction. Ship navigation mission. The cofferdam will be used for 40 years under the head of water for more than five years and is actually an earth-rock dam (its layout and structure section see “Hydroelectric power” No. 4, 1981, pages 6 and 10), so it must Weir to ensure safety, seepage and reliable.