为探究小断面TBM隧洞锚杆支护在地层围岩中的受力特性及支护参数的合理性，依托安徽桐城抽水蓄能电站自流排水洞工程，分别采用岩体力学法和数值模拟法计算得到隧洞Ⅲ类围岩工况下的锚杆内力和围岩位移，并在洞内TBM掘进段紧随TBM选取3个监测断面，分别采用锚杆应力计和多点位移计监测得到实际工况下的锚杆内力和围岩位移。对3种方法得到的结果进行对比分析后得出： 1）数值模拟法和岩土力学法计算得到的轴力值变化趋势相近，均在锚杆中间部位出现轴力最大值，与中性点理论相符，最大轴力值为4.78 kN； 2）3种方法得到的围岩位移值变化趋势相似，均在隧洞围岩表面出现位移最大值，在岩层内部围岩位移最小，最大位移为2.03 mm。进一步，与已有关于较大断面隧洞结构受力研究成果对比发现： 小断面TBM隧洞的锚杆轴力及围岩变形均较小，锚杆支护作用未得到充分利用，据此提出了延迟、减少或取消小断面TBM隧洞锚杆支护的优化建议。

To explore the stress characteristics of the anchor bolt support in small-section TBM tunnels and assess the rationality of the support parameters, a case study is conducted on the Tongcheng pumped storage power station′s self-flow drainage tunnel project in Anhui province, China. The rock mass mechanics method and numerical simulation method are used to calculate the anchor internal force and surrounding rock displacement under the Grade Ⅲ surrounding rock conditions. Three monitoring sections are selected immediately following the TBM in the TBM excavation section of the tunnel, and the anchor stress meter and multi-point displacement meter are used to monitor the anchor internal force and surrounding rock displacement under actual working conditions. After comparative analysis of the results obtained by the three methods, conclusions are drawn as follows: (1) The changing trends of the axial force calculated by the numerical simulation method and the geotechnical method are similar. The maximum axial force value appears in the middle of the anchor bolt, which is consistent with the neutral point theory. The maximum axial force is 4.78 kN. (2) The changing trends of the surrounding rock displacement obtained by the three methods are similar, with the maximum displacement appearing on the surface of the tunnel surrounding rock, and the smallest displacement of the surrounding rock inside the rock layer, with the maximum displacement being 2.03 mm. Furthermore, compared with the existing research results on the structural stress of larger cross-section tunnels, it is shown that compared with larger cross-section tunnels, the anchor bolt axial force and surrounding rock deformation of small-section TBM tunnels are smaller, and the anchor support function has not been fully utilized. Based on this, optimization suggestions are put forward to delay, reduce or cancel the anchor support of small-section TBM tunnels.