三峡左岸电站厂房施工设计概述

三峡左岸电站厂房属坝后引水式厂房。机组为立轴混流式，单机容量700MW，总装机容量9800MW。电站厂房共设14台机组、3个安装场，总长643.7m，底宽68m，最大高度93.8m，机组中心距38.3m，主厂房上下游平台高程82m；上游副厂房宽17m，高40m，总长619.8m；尾水平台宽19.5m，尾水渠宽580－310m，渠底高程29.9-50m。高程67m以下为大体积结构，高程67m以上为钢筋混凝土薄壁结构。三峡左岸电站厂房规模宏大，施工工序繁杂，要求的施工工期紧张，切实做好施工设计，是保障其有序施工和按期投产的先决条件。

Construction Design of Three Gorges Left Powerhouse

The Three Gorges left powerhouse located at the left dam toe is of a diversion type, has a total installed capacity of 9 800 MW and 14 vertical shaft turbines of 700 MW each. The powerhouse has a total length of 643. 7 m, a bottom width of 68 m and a maximum height of 93. 8 m, with 3 erection bays. The central space is 38. 3 m between turbines, and the elevation of the up-and downstream platforms for the main powerhouse is 82 m; the upstream auxiliary powerhouse has a width of 17 m and height of 40 m, with a total length of 619. 8 m; the tailwater platform has a width of 19. 5 m, and the tailrace canal has a width of 580-310 m and bottom elevation of 29. 9-50 m. The powerhouse is composed of massive structures below elevation 67 m and thin reinforced concrete structures above elevation 67 m. The construction sequences for the powerhouse are very complicated as a result of its huge size and tight time requirements. A good construction design, therefore, could be the prerequisite to ensure an orderly construction and operation on schedule.