巴贡水电工程导流洞出口混凝土叠梁下闸施工

General review on concrete stop log installation of gate for outlet of diversion tunnel of Bakun Hydropower Station

马来西亚巴贡水电工程1号导流洞出口在混凝土叠梁下闸过程中,叠梁门槽及其两侧泥沙淤积严重,淤积最大速度达到0.5 m/h。在真空吸沙器无法完全排除泥沙且没有对导流洞出口作流态和泥沙淤积模型试验的不利情况下,通过现场观察、排沙效果评估、利用水力学知识分析和推断,对水流流态和泥沙淤积情况逐步的做出了正确判断。据此,及时调整了混凝土叠梁下闸方案,采用钢支撑将第一根叠梁垫出泥沙淤积高程,并采用了浇筑水下混凝土和灌浆处理,最终保证了下闸后,防渗处理成功。

During the concrete stop log installation of the outlet gate for the No. 1 diversion tunnel of Bakun Hydropower Station in Malaysia, The gate slots and both the side of them are heavily sedimented with the max. sedimentation rate of 0.5 m/h. Under such an unfavourable condition that the desedimentation can not be carried out with any kind of vacuum sediment cleaners and no any model tests are made for the sedimentation, a correct judgement on the flow pattern and the sedimentation is made with the analysis and deduction of hydraulics step by step through the site observation and the evaluation on the sediment discharging effect concerned. On the basis of this, the scheme of the installation of the concrete stop log is modified in time with the method of uplifting the first stop log above the sediment level with underlaying it with steel supporting and then placing underwater concrete and grouting; with which the anti-seepage treatment is finally ensured to be successful after the stop-logging.