白鹤滩泄洪洞横向三支臂弧门设计关键技术

Key Design Technology of Horizontal Three-arm Radial Gate for Spillway Tunnel of Baihetan Hydropower Station

针对白鹤滩水电站巨型、大宽高比泄洪洞弧门结构,提出了国内首个横向三支臂潜孔弧门型式,采用考虑三支臂布置位置、主梁与支臂单位刚度比等关键设计参数的多因素分析,并结合多载荷工况下的有限元数值验证,确定了悬臂长度和单位刚度比,进而优化了横向三支臂弧门的受力分布,有力保障了巨型泄量下土建结构的承载安全。结果表明:基于多因素参数敏感性分析的横向三支臂悬臂长度和单位刚度比确定准则,白鹤滩最优悬臂长度为2.5 m、最优单位刚度比为10.7。且优化后的弧门结构主要计算应力不超过145 MPa,最大计算合位移小于15 mm,均满足强度和刚度要求。研究建立的横向三支臂弧形闸门关键技术,能够为超宽高比孔口、超大泄量的泄洪洞安全运行提供技术保障。

Aiming at the spillway tunnel radial gate structure of Baihetan Hydropower Station with large width and height ratio,this paper uses the first horizontal three-arm hidden radial gate type in China.The multi-factor analysis of key design parameters,such as the placement of the three arms,the unit stiffness ratio of the main beam to the arm,and the finite element numerical calculation verification under multiple load conditions are adopted.The optimal arm length and unit stiffness ratio of the radial gate of Baihetan spillway tunnel are determined.Furthermore,the force distribution of the horizontal three-arm radial gate is optimized,which effectively guarantees the bearing safety of the civil structure under the huge discharge.The results show that the optimal arm length and unit stiffness ratio in Baihetan are 2.5 m and 10.7 based on the criteria for determining the length and unit stiffness ratio of the three lateral arms on the basis of the sensitivity analysis of multifactor parameters.The main calculated stress of the optimized radial gate structure is less than 145 MPa,and the maximum calculated combined displacement is less than 15 mm,both of which meet the requirements of strength and stiffness.The key technology of horizontal threearm radial gate is researched and established,which can provide technical support for the safe operation of spillway tunnel with super widthto-height ratio orifice and super large discharge volume.