抽水蓄能电站压力钢管与围岩缝隙对压力钢管受力及围岩分担率的影响分析

Analysis of the Influence of the Gap between Penstock and Surrounding Rock on the Stress of the Penstock and the Sharing Ratio of Internal Pressure in Bedrock of Pumped Storage Power Station

抽水蓄能电站水头高,容量大,输水系统高压管道的HD值高,多采用钢板衬砌。结合已建抽水蓄能电站引水压力管道的监测资料,通过数值计算,对不同缝隙值的敏感性进行研究分析。结果表明,在内水压力作用下,缝隙值对钢衬的变形和应力影响十分显著,其大小显著影响着内水压力的传递,影响围岩与钢衬联合承载。在工程实践中,通过提高钢管外围回填混凝土质量、采用微膨胀混凝土、提高回填和接触灌浆的质量、控制钢管安装时温度等,减少钢管与回填混凝土和回填混凝土与围岩间的累积缝隙,确保钢板衬砌受力安全。

The steel plate lining is mostly used in the pumped storage power station with high head,large capacity and high HD.Combined the constructed monitoring data of penstock in pumped storage power station,numerical analysis of the sensitivity of the different gap value were carried out.The results showed that under the internal water pressure,the impacts of gap value which had significant influence on the internal water pressure transfer and joint bearing of surrounding rock and penstock on the deformation and stress of penstock were very significant,In engineering practice,according to improving the quality of backfill concrete,adopting micro-expansion concrete,improving the quality of backfill concrete and contact grouting,controlling the temperature of penstock,reducing the cumulative gap between penstock and backfill concrete with backfill concrete and surrounding rock,so as to ensure the stress safety of penstock.