基于间隙变化的镇安抽水蓄能电站压力钢管联合承载机理研究

Study on Joint Bearing Mechanism of Penstock in Zhen′an Pumped Storage Power Station Based on Clearance Change

结合陕西镇安抽水蓄能电站,通过结构力学解析方法与数值仿真模拟方法,对不同初始间隙值以及承受不同内水压力的“钢衬-混凝土-围岩”组合结构进行联合承载机理研究。结果表明:间隙值对钢衬环向应力以及内水压力的传递有着显著的影响,将间隙值控制在0.5~1.0 mm范围内可更高效地将内水压力传递至围岩;对于围岩分担率,规范解析法的计算结果小于数值仿真法的,两者相差10%~13%,侧面呈现出混凝土衬砌的作用。在工程实践中,可通过减小联合体之间的间隙,提高回填混凝土的质量,充分利用三者的联合承载机制,减小钢衬环向应力,从而提高围岩分担率。

Combined with the Zhen′an Pumped Storage Power Station in Shaanxi Province,the joint bearing mechanism of“steel lining-concrete-surrounding rock”composite structure with different initial clearance values and different internal water pressure is studied by structural mechanics analysis method and numerical simulation method.The results are as follows.The clearance value has a significant effect on the transmission of circumferential stress of steel lining and internal water pressure of the steel lining.Controlling the clearance value between 0.5 mm and 1.0 mm can transmit the internal water pressure to the surrounding rock more efficiently.As for the the share rate of surrounding rock,the calculation result of the standard analytical method is less than that of numerical simulation method,and the difference between the two is 10%to 13%,showing the effect of concrete lining.In engineering practice,the quality of backfill concrete can be improved by reducing the gap between the consortia,and the joint bearing mechanism of the three can be fully utilized to reduce the circumferential stress of the steel lining,thus improving the sharing rate of surrounding rock.