三峡工程重大技术问题的研究

The Study of Key Technical Issues on the Three Gorges Project

三峡泥沙问题与黄河不同，三峡水库年平均径流量为4510亿m3，平均含沙量为1．2kg／m3，而黄河（三门峡水库）年输沙量为16亿t，平均含沙量37kg／m3，三峡水量为黄河三门峡的10倍，而年输沙量仅为1／3，三峡工程泥沙问题可以解决．二期围堰防渗采用混凝土防渗墙下接帷幕灌浆，墙上接防渗土工膜方案，上游围堰防渗体超过40m处加第二道防渗墙，下游围堰在相应部位加设一道高压旋喷桩柱连续墙．二期工程大坝和厂房混凝土施工方案采用大型塔带机为主，辅以高架门机和缆机．大坝泄洪采用深孔及表孔两套泄洪设施，为了尽量缩短溢流的前缘，采用了现在的深孔与表孔相间布置的型式．水轮发电机组参数为：水轮机额定转速75r／min，额定水头80．6m，额定出力710MW，最大出力852MW；发电机最大容量840MVA，功率因数0．9，永久船闸启闭机选用液压直推式启闭机，启闭力3500kN，开门时间3min．

The sediment problem of Yangtze River is quite differrent in nature from that of the Yellow River, The water discharge at TGP's dam site is large. reaching 451 billon m3 annually with average sediment rate only about 1. 2 kg/m3,whereas, the sediment discharge at Sanmenxia Projcet of Yellow River is 1. 6 billon tons with average sediment load of 37 kg/m3,The water discharge at TGP dam site is 10 times that at Sanmenxia project, but the annual sediment load is only one third of it, the sediment proboem of the TGP is resolvable. The impervious patten for the stage Ⅱ coferdam is the plastic concrete cut off wall connecting above it the geosynthetic cutoff wall and under is treated by curtain grouting double plastic concrete cut off wall is adopted in the upstream deep channel. Rotational shotcrete wall is added in the downstream deep channel. The construction alternatives mainly by tower belt, auxiliary by large cablecranes and gantry. The fIood discharging are used 22 surface sluice gates and 23 bottom outlets. The main parameters of power station and generation of the Three Gorges project are as follows. Turbines revoluiton speed of unit 75 r/min, rated water head 80. 6 m, rated capacity 710 MW, maximum capacity 852 MW. Generator capacity 840 MVA, power factor 0. 9. The headstock gearload of permanent shiplock is 3 500 kN, time of open gate is 3 min.