牛栏江红石岩堰塞湖整治工程施工期出、入库洪水量平衡分析

Abstract

为给2016年汛期堰塞体整治、溢洪洞、发电厂房和库区复建交通隧道等项目施工的防洪度汛工作提供决策依据，最大限度减轻施工期间的洪灾风险，根据堰塞湖坝址各设计标准的入库洪水过程、原红石岩电站引水隧洞和溢洪洞联合泄流曲线及堰塞湖库容曲线，分析了当堰塞湖发生200、100、50、30、20、10、5年一遇洪水时，堰塞湖的洪水下泄和库水位变化情况，并选取了2015年汛期发生的三场洪水进行水量平衡分析。分析表明：2015年堰塞湖出、入库水量平衡性较好，实际下泄流量与泄流曲线及天生桥站的水位、流量关系符合性较好，洪水下泄通畅，安全可控。原红石岩电站引水隧洞和右岸溢洪洞(上半洞)能够合并下泄200a一遇以下标准的洪水，坝前水位低于堰塞体泄流槽底部高程。 Analysis is done on the discharge of flood and variation of water level in the reservoir at the barrier lake in case of 5-year, 10-year, 20-year, 30-year, 50-year, 100-year and 200-year flood according to reservoir inflow flood process under various design standards at the dam site of the barrier lake, the discharge curve of combination of diversion tunnel and spillway tunnel of the former Hongshiyan HPP, and the ca-pacity curve of the barrier lake reservoir, in order to provide decision basis for flood control in barrier regulation, construction of spillway tunnels, power plants and reconstruction of traffic tunnels in the re-servoir area in the flood season in 2016, and to minimize the flood risk during construction. And three flood events occurring during the flood season in 2015 are selected for water balance analysis. The anal-ysis shows that the reservoir outflow and inflow at the barrier lake in 2015 are well balanced, the actual discharge flow and discharge curve are well consistent with the water level and flow at Tianshengqiao HPP, and the flood is discharged without blockage and is controlled safely. The diversion tunnel from the former Hongshiyan HPP and the spillway tunnel (upper part) on the right bank can jointly discharge flood below standard of the 200-year flood. The water level before the dam is lower than the elevation of the bottom of the sluice channel of the barrier.