雅鲁藏布江街需水电站施工截流模型试验研究

雅鲁藏布江街需水电站施工截流为典型的大比降山区河道截流,天然河道状态下截流难度极大。本工程截流主要利用下游电站水库回水效应创造的截流条件。模型试验研究分析了下游库水位变化对截流难度的影响;验证了单导流洞和双导流洞过流条件下的截流水力学指标;提出了在导流洞进口岩坎设置缺口的截流优化措施并分析了缺口参数与分流效应的关系。试验对比了不同工况下的截流龙口水力学指标,优选了安全可靠的截流方案,为工程截流施工组织提供了重要指导作用。

Model experimental study on closure for construction of Jiexu Hydropower Station on Yarlung Zangbo River

The closure for the construction of Jiexu Hydropower Station on Yarlu Zangbo River is a typical closure of river channel in mountainous region with large gradient， which is quite difficult to be done under the natural state of river channel. For this closure， the closuring condition is mainly created with the effect from the backwater from the reservoir of the downstream hydropower station. The effect from the change of the water level of the downstream reservoir on the difficulty of the closure is analyzed in the model experimental study， and then the hydraulic indexes for the closures under the flow-conditions of both the single diversion tunnel and the double diversion tunnel are verified， while the optimization measure for the closure that arranging a gap at the rock bank for the intake of the diversion tunnel is proposed and the relationship between the parameters of the gap and the diversion effect is analyzed as well. By the experiment， the hydraulic indexes of the closure gap under various working conditions are compared， thus a safe and reliable closuring scheme is optimized， which plays an important role for guiding the construction organization of the closure construction.