中文摘要：

本文结合某抽水蓄能电站埋藏式月牙肋钢岔管的实际,采用三维有限元方法,研究不同围岩条件下钢岔管布置形式选择和围岩承载特性。计算结果表明：对于大HD值埋藏式钢岔管,围岩条件较差时对称布置明显优于非对称布置,但围岩条件较好时其优势不再明显,所以不应强调任何条件下都采用对称布置;另外,国内目前把钢岔管外围岩体承载比统一控制在30%以内,往往导致围岩条件较好时埋藏式钢岔管设计管壁厚度反而大于围岩条件相对较差时的设计厚度,这显然是不合理的,应根据不同的围岩条件对承载比进行相应控制,围岩条件较好时应放宽承载比为30%的限制。

英文摘要：

A 3-D FEM is adopted to study the layout and load-bearing characteristics of surrounding rock under different geological conditions and applied in a case study of embedded steel crescent-rib reinforced bifurcated pipe of a pumped storage power station. The analysis indicates that for the embedded steel bifurcated pipe with high HD, symmetrical layout is superior to asymmetric one under poor rock conditions while the superiority is insignificant under good rock conditions. Thus, symmetrical layout should not be recommended for good surrounding rock conditions. In addition, it is obviously unreasonable that in China the bearing ratio of surrounding rock is limited to 30%, which often makes the shell thickness of bifurcated pipes under better geological conditions even larger than that under poorer geological conditions. The bearing ratio threshold should be adjusted according to different surrounding rock conditions and suitably increased for good geological conditions.